feat: add file comparison, data splitting, and sensor modification functionality to SessionController

src/pygui/ISC/HomePage.qml

@@ -22,6 +22,7 @@ Rectangle {
     onSelectedTabIndexChanged: {
         if (selectedTabIndex === 2) {
             file_browser.refreshFiles();
+            streamController.unloadFile()
         }
     }
 
@@ -36,10 +37,12 @@ Rectangle {
         function onParsedDataReady(result) {
             if (result.success && result.csv_path) {
                 streamController.loadFile(result.csv_path)
+                if (root.selectedTabIndex === 0) {
                 root.selectedTabIndex = 2
                 }
             }
         }
+    }
     Connections {
         target: deviceController
         function onReadResult(result) {
@@ -74,6 +77,11 @@ Rectangle {
         }
     }
 
+    // ===== Split Dialog (Threshold Segmentation) =====
+    SplitDialog {
+        id: splitDialog
+    }
+
     // ===== Settings Popup =====
     Popup {
         id: settingsPopup
@@ -300,7 +308,7 @@ Rectangle {
                         StackLayout {
                             Layout.fillWidth: true
                             Layout.fillHeight: true
-                            currentIndex: root.selectedTabIndex
+                            currentIndex: root.selectedTabIndex === 0 ? 0 : 1
 
                             // ── Status tab: Hardware Actions ────────────────
                             ColumnLayout {
@@ -320,7 +328,7 @@ Rectangle {
                                     label: "DETECT WAFER"
                                     iconSource: "../icons/detect.svg"
                                     Layout.fillWidth: true
-                                    enabled: !deviceController.isDetecting
+                                    enabled: !deviceController.operationInProgress
                                     onClicked: root._doDetect()
                                 }
 
@@ -345,44 +353,6 @@ Rectangle {
                                 Item { Layout.fillHeight: true }
                             }
 
-                            // ── Data tab: Data Operations ───────────────────
-                            ColumnLayout {
-                                spacing: 6
-
-                                Label {
-                                    text: "DATA OPERATIONS"
-                                    color: Theme.sideMutedText
-                                    font.family: Theme.uiFontFamily
-                                    font.pixelSize: Theme.fontSm
-                                    topPadding: 6
-                                    font.letterSpacing: 1.5
-                                    font.bold: true
-                                }
-
-                                RailActionButton {
-                                    label: "OPEN IN EXCEL"
-                                    iconSource: "../icons/excel.svg"
-                                    Layout.fillWidth: true
-                                    onClicked: deviceController.openCsvFile()
-                                }
-
-                                RailActionButton {
-                                    label: "COMPARE CSV"
-                                    iconSource: "../icons/compare.svg"
-                                    Layout.fillWidth: true
-                                    onClicked: console.log("[P3.1] Compare dialog not yet built")
-                                }
-
-                                RailActionButton {
-                                    label: "SPLIT DATA"
-                                    iconSource: "../icons/split.svg"
-                                    Layout.fillWidth: true
-                                    onClicked: console.log("[P3.2] Split dialog not yet built")
-                                }
-
-                                Item { Layout.fillHeight: true }
-                            }
-
                             // ── Map tab: Source file browser ──────────────
                             SourcePanel {
                                 Layout.fillWidth: true
@@ -637,6 +607,7 @@ Rectangle {
                     active: StackLayout.index === root.selectedTabIndex
                 }
                 Loader {
+                    id: dataTabLoader
                     source: "Tabs/DataTab.qml"
                     active: StackLayout.index === root.selectedTabIndex
                 }

src/pygui/ISC/Tabs/DataTab.qml

@@ -2,183 +2,807 @@ import QtQuick
 import QtQuick.Controls
 import QtQuick.Layouts
 import ISC
+import ISC.Wafer
 
-// ===== Data Tab =====
+// ===== Data Tab (Compare Mode Only) =====
-// Displays parsed temperature data in a scrollable table.
+// Focuses exclusively on comparing two wafer runs side-by-side using DTW.
-// Column 0 = Row index, remaining columns = Sensor1, Sensor2, ...
+// Clicking Box 1 or Box 2 activates selection mode, and clicking a file in the
+// left rail's file browser populates that slot.
 Item {
     id: root
     anchors.fill: parent
 
-    readonly property int rowCount: deviceController.dataRowCount
+    // Properties for DTW Comparison
+    property int activeBox: 1 // 1 for Reference (Run A), 2 for Session (Run B), 0 for inactive
+    property string compareFileA: ""
+    property string compareFileB: ""
+    property real warpingDistance: -1
+    property real maxSensorDeviation: -1
+    property bool comparing: false
+    property var trendDataA: []
+    property var trendDataB: []
+    property string errorMessage: ""
 
-    // Re-layout columns whenever the model is reset
+    // Wafer overlap properties
+    property var compareSensorLayout: []
+    property var compareSensorDiff: []
+    property string compareWaferShape: "round"
+    property real compareWaferSize: 300.0
+
+    function diffBands(diffs) {
+        return diffs.map(d => d > 1.0 ? "high" : d < -1.0 ? "low" : "in_range")
+    }
+
+    function resetComparison() {
+        root.compareFileA = ""
+        root.compareFileB = ""
+        root.warpingDistance = -1
+        root.maxSensorDeviation = -1
+        root.comparing = false
+        root.trendDataA = []
+        root.trendDataB = []
+        root.compareSensorLayout = []
+        root.compareSensorDiff = []
+        root.errorMessage = ""
+        root.activeBox = 1
+    }
+
+    // Connections to handle clicked/selected files on left rail file browser
     Connections {
-        target: deviceController
+        target: streamController
-        function onParsedDataReady(result) {
+        function onLoadedFileChanged() {
+            if (streamController.loadedFile && root.activeBox > 0) {
+                if (root.activeBox === 1) {
+                    root.compareFileA = streamController.loadedFile
+                    root.activeBox = 2 // Auto-advance to box 2
+                } else if (root.activeBox === 2) {
+                    root.compareFileB = streamController.loadedFile
+                    root.activeBox = 0 // Finished selecting
+                }
+            }
+        }
+
+        function onComparisonResult(result) {
+            root.comparing = false
             if (result && result.success) {
-                dataTable.forceLayout();
+                root.warpingDistance = result.distance
+                root.maxSensorDeviation = result.max_sensor_deviation !== undefined ? result.max_sensor_deviation : -1
+                root.trendDataA = result.series_a || []
+                root.trendDataB = result.series_b || []
+                root.compareSensorLayout = result.sensor_layout || []
+                root.compareSensorDiff = result.sensor_diff || []
+                root.compareWaferShape = result.wafer_shape || "round"
+                root.compareWaferSize = result.wafer_size || 300.0
+                root.errorMessage = ""
+            } else {
+                root.warpingDistance = -1
+                root.maxSensorDeviation = -1
+                root.trendDataA = []
+                root.trendDataB = []
+                root.compareSensorLayout = []
+                root.compareSensorDiff = []
+                root.errorMessage = (result && result.error) ? result.error : "Comparison failed"
             }
         }
     }
 
-    // ===== Empty State =====
+    // ── Main Layout ───────────────────────────────────────────────
-    Column {
-        anchors.centerIn: parent
-        spacing: 16
-        visible: root.rowCount === 0
-
-        Label {
-            text: "No Data"
-            font.pixelSize: Theme.font2xl
-            font.bold: true
-            color: Theme.headingColor
-            anchors.horizontalCenter: parent.horizontalCenter
-        }
-
-        Label {
-            text: "Read and parse wafer data to see temperature readings here."
-            font.pixelSize: Theme.fontMd
-            color: Theme.bodyColor
-            anchors.horizontalCenter: parent.horizontalCenter
-            wrapMode: Text.WordWrap
-        }
-    }
-
-    // ===== Data Table =====
     ColumnLayout {
         anchors.fill: parent
         anchors.margins: Theme.panelPadding
         spacing: Theme.rightPaneGap
-        visible: root.rowCount > 0
 
-        // --- Header row ---
+        // ── Title / Header ─────────────────────────────────────────
         RowLayout {
             Layout.fillWidth: true
-            spacing: Theme.rightPaneGap
+            spacing: 8
 
             Label {
-                text: "Temperature Data"
+                text: "Run Comparison (DTW)"
                 font.pixelSize: Theme.fontXl
                 font.bold: true
                 color: Theme.headingColor
+                Layout.fillWidth: true
+                elide: Text.ElideRight
             }
 
-            Item {
+            // Reset button
-                Layout.fillWidth: true
+            Button {
+                id: resetBtn
+                flat: true
+                implicitWidth: 32
+                implicitHeight: 32
+                visible: root.compareFileA !== "" || root.compareFileB !== ""
+                onClicked: root.resetComparison()
+
+                background: Rectangle {
+                    radius: Theme.radiusSm
+                    color: resetBtn.hovered ? Qt.rgba(1, 1, 1, 0.08) : "transparent"
+                }
+
+                contentItem: Label {
+                    text: "\u21BA"
+                    font.pixelSize: Theme.fontLg
+                    color: Theme.bodyColor
+                    horizontalAlignment: Text.AlignHCenter
+                    verticalAlignment: Text.AlignVCenter
+                }
+
+                ToolTip.visible: resetBtn.hovered
+                ToolTip.text: "Reset comparison"
             }
 
             Label {
-                text: deviceController.dataRowCount + " rows × " + deviceController.dataColCount + " sensors"
+                text: "Dynamic Time Warping Profile Matching"
                 font.pixelSize: Theme.fontSm
                 color: Theme.bodyColor
             }
         }
 
-        // --- Toolbar ---
+        // ── Selection Boxes (Box 1 and Box 2) ──────────────────────
         RowLayout {
             Layout.fillWidth: true
-            spacing: 8
+            spacing: 16
 
-            Button {
+            // --- Box 1: Reference CSV (Run A) ---
-                text: "Open in Excel"
+            Rectangle {
-                icon.source: "icons/excel.svg"
+                id: box1
-                icon.color: Theme.headingColor
+                Layout.fillWidth: true
-                onClicked: deviceController.openCsvFile()
+                Layout.preferredHeight: 70
+                radius: Theme.radiusMd
+                color: Theme.cardBackground
+                border.width: root.activeBox === 1 ? 2 : 1
+                border.color: root.activeBox === 1 ? Theme.primaryAccent : Theme.cardBorder
+
+                Behavior on border.color { ColorAnimation { duration: Theme.durationFast } }
+
+                MouseArea {
+                    anchors.fill: parent
+                    cursorShape: Qt.PointingHandCursor
+                    onClicked: root.activeBox = 1
                 }
 
-            Button {
+                RowLayout {
-                text: "Compare"
+                    anchors.fill: parent
-                onClicked: compareDialog.open()
+                    anchors.margins: 14
+                    spacing: 10
+
+                    // Color indicator dot
+                    Rectangle {
+                        width: 10; height: 10; radius: 5
+                        color: Theme.primaryAccent
+                        Layout.alignment: Qt.AlignVCenter
                     }
 
-            Button {
+                    ColumnLayout {
-                text: "Split"
+                        Layout.fillWidth: true
-                onClicked: splitDialog.open()
+                        spacing: 2
+                        Label {
+                            text: "REFERENCE (RUN A)"
+                            font.pixelSize: Theme.fontXs
+                            font.bold: true
+                            font.letterSpacing: 1.0
+                            color: root.activeBox === 1 ? Theme.primaryAccent : Theme.sideMutedText
                         }
-
+                        Label {
-            Item {
+                            text: root.compareFileA !== ""
+                                ? root.compareFileA.split("/").pop()
+                                : (root.activeBox === 1 ? "← Select file from left panel..." : "Click to select")
+                            font.pixelSize: Theme.fontSm
+                            color: root.compareFileA !== "" ? Theme.headingColor : Theme.bodyColor
+                            opacity: root.compareFileA !== "" ? 1.0 : 0.6
+                            elide: Text.ElideMiddle
                             Layout.fillWidth: true
                         }
                     }
-        // --- Table container ---
+
+                    Button {
+                        text: "✕"
+                        visible: root.compareFileA !== ""
+                        flat: true
+                        implicitWidth: 24; implicitHeight: 24
+                        onClicked: {
+                            root.compareFileA = ""
+                            root.activeBox = 1
+                            root.warpingDistance = -1
+                            root.trendDataA = []
+                            root.trendDataB = []
+                            root.compareSensorLayout = []
+                            root.compareSensorDiff = []
+                        }
+                        background: Rectangle {
+                            radius: Theme.radiusSm
+                            color: parent.hovered ? Qt.rgba(1, 1, 1, 0.08) : "transparent"
+                        }
+                        contentItem: Label {
+                            text: "✕"
+                            color: Theme.bodyColor
+                            font.pixelSize: Theme.fontSm
+                            horizontalAlignment: Text.AlignHCenter
+                            verticalAlignment: Text.AlignVCenter
+                        }
+                    }
+                }
+            }
+
+            // --- Box 2: Session CSV (Run B) ---
+            Rectangle {
+                id: box2
+                Layout.fillWidth: true
+                Layout.preferredHeight: 70
+                radius: Theme.radiusMd
+                color: Theme.cardBackground
+                border.width: root.activeBox === 2 ? 2 : 1
+                border.color: root.activeBox === 2 ? Theme.themeSkill : Theme.cardBorder
+
+                Behavior on border.color { ColorAnimation { duration: Theme.durationFast } }
+
+                MouseArea {
+                    anchors.fill: parent
+                    cursorShape: Qt.PointingHandCursor
+                    onClicked: root.activeBox = 2
+                }
+
+                RowLayout {
+                    anchors.fill: parent
+                    anchors.margins: 14
+                    spacing: 10
+
+                    // Color indicator dot
+                    Rectangle {
+                        width: 10; height: 10; radius: 5
+                        color: Theme.themeSkill
+                        Layout.alignment: Qt.AlignVCenter
+                    }
+
+                    ColumnLayout {
+                        Layout.fillWidth: true
+                        spacing: 2
+                        Label {
+                            text: "SESSION (RUN B)"
+                            font.pixelSize: Theme.fontXs
+                            font.bold: true
+                            font.letterSpacing: 1.0
+                            color: root.activeBox === 2 ? Theme.themeSkill : Theme.sideMutedText
+                        }
+                        Label {
+                            text: root.compareFileB !== ""
+                                ? root.compareFileB.split("/").pop()
+                                : (root.activeBox === 2 ? "← Select file from left panel..." : "Click to select")
+                            font.pixelSize: Theme.fontSm
+                            color: root.compareFileB !== "" ? Theme.headingColor : Theme.bodyColor
+                            opacity: root.compareFileB !== "" ? 1.0 : 0.6
+                            elide: Text.ElideMiddle
+                            Layout.fillWidth: true
+                        }
+                    }
+
+                    Button {
+                        text: "✕"
+                        visible: root.compareFileB !== ""
+                        flat: true
+                        implicitWidth: 24; implicitHeight: 24
+                        onClicked: {
+                            root.compareFileB = ""
+                            root.activeBox = 2
+                            root.warpingDistance = -1
+                            root.trendDataA = []
+                            root.trendDataB = []
+                            root.compareSensorLayout = []
+                            root.compareSensorDiff = []
+                        }
+                        background: Rectangle {
+                            radius: Theme.radiusSm
+                            color: parent.hovered ? Qt.rgba(1, 1, 1, 0.08) : "transparent"
+                        }
+                        contentItem: Label {
+                            text: "✕"
+                            color: Theme.bodyColor
+                            font.pixelSize: Theme.fontSm
+                            horizontalAlignment: Text.AlignHCenter
+                            verticalAlignment: Text.AlignVCenter
+                        }
+                    }
+                }
+            }
+        }
+
+        // ── Compare Button ─────────────────────────────────────────
+        Button {
+            id: compareBtn
+            Layout.fillWidth: true
+            Layout.preferredHeight: 40
+            enabled: root.compareFileA !== "" && root.compareFileB !== "" && !root.comparing
+            onClicked: {
+                root.comparing = true
+                root.warpingDistance = -1
+                root.maxSensorDeviation = -1
+                root.trendDataA = []
+                root.trendDataB = []
+                root.errorMessage = ""
+                streamController.compareFiles(root.compareFileA, root.compareFileB)
+            }
+
+            background: Rectangle {
+                radius: Theme.radiusSm
+                color: compareBtn.enabled
+                    ? (compareBtn.hovered ? Qt.lighter(Theme.primaryAccent, 1.1) : Theme.primaryAccent)
+                    : Theme.buttonNeutralBackground
+                Behavior on color { ColorAnimation { duration: Theme.durationFast } }
+            }
+            contentItem: Row {
+                spacing: 8
+                anchors.centerIn: parent
+                Label {
+                    anchors.verticalCenter: parent.verticalCenter
+                    text: compareBtn.enabled
+                        ? (root.comparing ? "Comparing…" : "▶  RUN DTW COMPARISON")
+                        : "SELECT BOTH RUNS ABOVE"
+                    color: compareBtn.enabled ? Theme.tone100 : Theme.sideMutedText
+                    font.pixelSize: Theme.fontSm
+                    font.bold: true
+                    font.letterSpacing: 0.8
+                }
+                BusyIndicator {
+                    running: root.comparing
+                    visible: root.comparing
+                    width: 16; height: 16
+                    anchors.verticalCenter: parent.verticalCenter
+                }
+            }
+        }
+
+        // ── Error Banner ───────────────────────────────────────────
+        Rectangle {
+            Layout.fillWidth: true
+            Layout.preferredHeight: errorLabel.implicitHeight + 16
+            visible: root.errorMessage !== ""
+            color: Qt.rgba(0.93, 0.27, 0.27, 0.15)
+            border.color: "#ef4444"
+            border.width: 1
+            radius: Theme.radiusSm
+
+            Label {
+                id: errorLabel
+                anchors.fill: parent
+                anchors.margins: 8
+                text: "⚠  " + root.errorMessage
+                color: "#fca5a5"
+                font.pixelSize: Theme.fontSm
+                wrapMode: Text.WordWrap
+            }
+        }
+
+        // ── DTW Chart + Overlap Wafer Map Row ──────────────────────
+        RowLayout {
+            Layout.fillWidth: true
+            Layout.fillHeight: true
+            spacing: 16
+
+            // --- Left Column: Aligned Curves Chart ---
             Rectangle {
                 Layout.fillWidth: true
                 Layout.fillHeight: true
-            color: Theme.panelBackground
+                Layout.minimumWidth: 350
-            border.color: Theme.cardBorder
-            border.width: Theme.borderThin
-            radius: Theme.radiusSm
-            clip: true
-
-            ColumnLayout {
-                anchors.fill: parent
-                anchors.margins: 1
-                spacing: 0
-
-                // Column header strip
-                HorizontalHeaderView {
-                    id: headerView
-                    Layout.fillWidth: true
-                    syncView: dataTable
-                    clip: true
-
-                    delegate: Rectangle {
-                        implicitHeight: 28
                 color: Theme.cardBackground
                 border.color: Theme.cardBorder
                 border.width: 1
+                radius: Theme.radiusMd
 
-                        Text {
+                ColumnLayout {
-                            anchors.centerIn: parent
+                    anchors.fill: parent
-                            // 'display' is the Qt.DisplayRole value from headerData()
+                    anchors.margins: 16
-                            text: display !== undefined ? display : ""
+                    spacing: 10
-                            color: Theme.headingColor
+
-                            font.pixelSize: Theme.fontXs
+                    RowLayout {
+                        Layout.fillWidth: true
+                        Label {
+                            text: "Aligned Temperature Curves (DTW)"
+                            font.pixelSize: Theme.fontSm
                             font.bold: true
+                            color: Theme.headingColor
+                            Layout.fillWidth: true
                             elide: Text.ElideRight
                         }
+
+                        // Legend
+                        Row {
+                            spacing: 16
+                            visible: root.trendDataA.length > 1
+
+                            Row {
+                                spacing: 4
+                                Rectangle { width: 12; height: 3; radius: 1.5; color: Theme.primaryAccent; anchors.verticalCenter: parent.verticalCenter }
+                                Label { text: "Run A"; font.pixelSize: Theme.fontXs; color: Theme.bodyColor }
+                            }
+                            Row {
+                                spacing: 4
+                                Rectangle { width: 12; height: 3; radius: 1.5; color: Theme.themeSkill; anchors.verticalCenter: parent.verticalCenter }
+                                Label { text: "Run B"; font.pixelSize: Theme.fontXs; color: Theme.bodyColor }
+                            }
                         }
                     }
 
-                // Data rows
+                    Rectangle {
-                TableView {
-                    id: dataTable
                         Layout.fillWidth: true
                         Layout.fillHeight: true
-                    model: deviceController.dataModel
+                        color: Theme.fieldBackground
+                        border.color: Theme.cardBorder
+                        border.width: 1
+                        radius: Theme.radiusSm
                         clip: true
-                    reuseItems: true
 
-                    columnWidthProvider: function (col) {
+                        readonly property bool hasSeries: root.trendDataA.length > 1 && root.trendDataB.length > 1
-                        if (col === 0)
+
-                            return 52;   // row index column
+                        Canvas {
-                        const sensorCols = Math.max(1, dataTable.columns - 1);
+                            id: overlayCanvas
-                        const available = dataTable.width - 52;
+                            anchors.fill: parent
-                        return Math.max(52, Math.min(90, available / sensorCols));
+                            anchors.margins: 0
+                            visible: parent.hasSeries
+
+                            readonly property real padLeft: 50
+                            readonly property real padRight: 16
+                            readonly property real padTop: 16
+                            readonly property real padBottom: 28
+
+                            function drawGrid(ctx, minV, maxV, dataLen) {
+                                var plotW = width - padLeft - padRight
+                                var plotH = height - padTop - padBottom
+                                var range = (maxV - minV) || 1
+
+                                ctx.strokeStyle = Qt.rgba(1, 1, 1, 0.08)
+                                ctx.lineWidth = 1
+                                ctx.fillStyle = Qt.rgba(1, 1, 1, 0.35)
+                                ctx.font = "10px sans-serif"
+                                ctx.textAlign = "right"
+
+                                // Y-axis gridlines + labels
+                                var ySteps = 5
+                                for (var yi = 0; yi <= ySteps; yi++) {
+                                    var yFrac = yi / ySteps
+                                    var yPx = padTop + plotH * yFrac
+                                    var yVal = maxV - yFrac * range
+
+                                    ctx.beginPath()
+                                    ctx.moveTo(padLeft, yPx)
+                                    ctx.lineTo(padLeft + plotW, yPx)
+                                    ctx.stroke()
+
+                                    ctx.fillText(yVal.toFixed(1), padLeft - 6, yPx + 3)
                                 }
 
-                    rowHeightProvider: function () {
+                                // X-axis labels
-                        return 24;
+                                ctx.textAlign = "center"
+                                var xSteps = Math.min(5, dataLen - 1)
+                                for (var xi = 0; xi <= xSteps; xi++) {
+                                    var xFrac = xi / xSteps
+                                    var xPx = padLeft + plotW * xFrac
+                                    var xIdx = Math.round(xFrac * (dataLen - 1))
+                                    ctx.fillText(xIdx.toString(), xPx, height - 6)
                                 }
 
-                    delegate: Rectangle {
+                                // Y-axis title
-                        color: row % 2 === 0 ? Theme.panelBackground : Theme.cardBackground
+                                ctx.save()
+                                ctx.translate(12, padTop + plotH / 2)
+                                ctx.rotate(-Math.PI / 2)
+                                ctx.textAlign = "center"
+                                ctx.fillText("°C", 0, 0)
+                                ctx.restore()
 
-                        Text {
+                                // X-axis title
+                                ctx.textAlign = "center"
+                                ctx.fillText("Frame", padLeft + plotW / 2, height - 2)
+                            }
+
+                            function drawSeries(ctx, series, minV, range, color) {
+                                var plotW = width - padLeft - padRight
+                                var plotH = height - padTop - padBottom
+
+                                ctx.strokeStyle = color
+                                ctx.lineWidth = 2
+                                ctx.beginPath()
+                                for (var i = 0; i < series.length; i++) {
+                                    var x = padLeft + (i / (series.length - 1)) * plotW
+                                    var y = padTop + plotH - ((series[i] - minV) / range) * plotH
+                                    if (i === 0) ctx.moveTo(x, y)
+                                    else ctx.lineTo(x, y)
+                                }
+                                ctx.stroke()
+                            }
+
+                            onPaint: {
+                                var ctx = getContext("2d")
+                                ctx.reset()
+                                if (!parent.hasSeries) return
+                                var all = root.trendDataA.concat(root.trendDataB)
+                                var minV = Math.min.apply(null, all)
+                                var maxV = Math.max.apply(null, all)
+                                var padding = (maxV - minV) * 0.05
+                                minV -= padding
+                                maxV += padding
+                                var range = (maxV - minV) || 1
+
+                                drawGrid(ctx, minV, maxV, Math.max(root.trendDataA.length, root.trendDataB.length))
+                                drawSeries(ctx, root.trendDataA, minV, range, Theme.primaryAccent)
+                                drawSeries(ctx, root.trendDataB, minV, range, Theme.themeSkill)
+                            }
+
+                            Connections {
+                                target: root
+                                function onTrendDataAChanged() { overlayCanvas.requestPaint() }
+                                function onTrendDataBChanged() { overlayCanvas.requestPaint() }
+                            }
+                        }
+
+                        // Empty state
+                        ColumnLayout {
                             anchors.centerIn: parent
-                            text: display !== undefined ? display : ""
+                            visible: !parent.hasSeries
+                            spacing: 8
+
+                            Label {
+                                Layout.alignment: Qt.AlignHCenter
+                                text: root.comparing ? "" : "📊"
+                                font.pixelSize: 32
+                            }
+                            Label {
+                                Layout.alignment: Qt.AlignHCenter
+                                text: root.comparing ? "Running DTW comparison…" : "Select two files and run comparison"
+                                color: Theme.bodyColor
+                                font.pixelSize: Theme.fontSm
+                            }
+                            Label {
+                                Layout.alignment: Qt.AlignHCenter
+                                visible: !root.comparing
+                                text: "Click Box 1, then a file. Click Box 2, then a file."
+                                color: Theme.sideMutedText
+                                font.pixelSize: Theme.fontXs
+                            }
+                        }
+                    }
+                }
+            }
+
+            // --- Right Column: Wafer Map Overlap & Readouts ---
+            ColumnLayout {
+                Layout.fillWidth: false
+                Layout.preferredWidth: 280
+                Layout.minimumWidth: 280
+                Layout.maximumWidth: 280
+                Layout.fillHeight: true
+                spacing: 12
+
+                // ── DTW Readout Cards ─────────────────────────────────
+                Rectangle {
+                    Layout.fillWidth: true
+                    Layout.preferredHeight: dtwReadoutCol.implicitHeight + 24
+                    color: Theme.cardBackground
+                    border.color: Theme.cardBorder
+                    border.width: 1
+                    radius: Theme.radiusMd
+
+                    ColumnLayout {
+                        id: dtwReadoutCol
+                        anchors.fill: parent
+                        anchors.margins: 12
+                        spacing: 8
+
+                        Label {
+                            text: "COMPARISON RESULTS"
+                            font.pixelSize: Theme.fontXs
+                            font.bold: true
+                            font.letterSpacing: 1.2
+                            color: Theme.sideMutedText
+                            Layout.fillWidth: true
+                        }
+
+                        // DTW Distance
+                        Rectangle {
+                            Layout.fillWidth: true
+                            height: 52
+                            color: Theme.panelBackground
+                            border.color: Theme.cardBorder
+                            border.width: 1
+                            radius: Theme.radiusSm
+
+                            ColumnLayout {
+                                anchors.fill: parent
+                                anchors.margins: 8
+                                spacing: 2
+                                Label {
+                                    text: "DTW Alignment Distance"
+                                    font.pixelSize: Theme.fontXs
+                                    color: Theme.bodyColor
+                                }
+                                Label {
+                                    text: root.warpingDistance >= 0 ? root.warpingDistance.toFixed(2) : "--"
+                                    font.pixelSize: Theme.fontLg
+                                    font.bold: true
+                                    color: root.warpingDistance >= 0
+                                        ? (root.warpingDistance < 50 ? "#6ee7b7" : root.warpingDistance < 100 ? "#fde047" : "#ef4444")
+                                        : Theme.sideMutedText
+                                }
+                            }
+                        }
+
+                        // Max Sensor Deviation
+                        Rectangle {
+                            Layout.fillWidth: true
+                            height: 52
+                            color: Theme.panelBackground
+                            border.color: Theme.cardBorder
+                            border.width: 1
+                            radius: Theme.radiusSm
+
+                            ColumnLayout {
+                                anchors.fill: parent
+                                anchors.margins: 8
+                                spacing: 2
+                                Label {
+                                    text: "Max Sensor Deviation"
+                                    font.pixelSize: Theme.fontXs
+                                    color: Theme.bodyColor
+                                }
+                                Label {
+                                    text: root.maxSensorDeviation >= 0 ? root.maxSensorDeviation.toFixed(2) + "\u00B0C" : "--"
+                                    font.pixelSize: Theme.fontLg
+                                    font.bold: true
+                                    color: root.maxSensorDeviation >= 0
+                                        ? (root.maxSensorDeviation < 1.0 ? "#6ee7b7" : root.maxSensorDeviation < 3.0 ? "#fde047" : "#ef4444")
+                                        : Theme.sideMutedText
+                                }
+                            }
+                        }
+
+                        // Match Quality Badge
+                        Rectangle {
+                            Layout.fillWidth: true
+                            height: 28
+                            visible: root.warpingDistance >= 0
+                            radius: Theme.radiusSm
+                            color: root.warpingDistance < 50 ? Qt.rgba(0.43, 0.91, 0.72, 0.12)
+                                 : root.warpingDistance < 100 ? Qt.rgba(0.99, 0.88, 0.28, 0.12)
+                                 : Qt.rgba(0.94, 0.27, 0.27, 0.12)
+
+                            Label {
+                                anchors.centerIn: parent
+                                text: root.warpingDistance < 50 ? "✓ Excellent Match"
+                                    : root.warpingDistance < 100 ? "⚠ Moderate Deviation"
+                                    : "✗ Poor Match"
+                                font.pixelSize: Theme.fontXs
+                                font.bold: true
+                                color: root.warpingDistance < 50 ? "#6ee7b7"
+                                     : root.warpingDistance < 100 ? "#fde047"
+                                     : "#ef4444"
+                            }
+                        }
+                    }
+                }
+
+                // ── Wafer Overlap View ────────────────────────────────
+                Rectangle {
+                    Layout.fillWidth: true
+                    Layout.fillHeight: true
+                    color: Theme.cardBackground
+                    border.color: Theme.cardBorder
+                    border.width: 1
+                    radius: Theme.radiusMd
+
+                    ColumnLayout {
+                        anchors.fill: parent
+                        anchors.margins: 12
+                        spacing: 8
+
+                        RowLayout {
+                            Layout.fillWidth: true
+                            Label {
+                                text: "SENSOR DEVIATION MAP"
+                                font.pixelSize: Theme.fontXs
+                                font.bold: true
+                                font.letterSpacing: 1.2
+                                color: Theme.sideMutedText
+                                Layout.fillWidth: true
+                            }
+                            CheckBox {
+                                id: enableOverlapCheck
+                                checked: true
+                                implicitWidth: 18; implicitHeight: 18
+                                ToolTip.visible: hovered
+                                ToolTip.text: "Toggle overlap heatmap"
+                            }
+                        }
+
+                        Rectangle {
+                            Layout.fillWidth: true
+                            Layout.fillHeight: true
+                            color: Theme.fieldBackground
+                            border.color: Theme.cardBorder
+                            border.width: 1
+                            radius: Theme.radiusSm
+                            clip: true
+
+                            WaferMapItem {
+                                id: overlapMapItem
+                                anchors.fill: parent
+                                visible: root.compareSensorLayout.length > 0 && enableOverlapCheck.checked
+                                sensors: root.compareSensorLayout
+                                values: root.compareSensorDiff
+                                bands: root.diffBands(root.compareSensorDiff)
+                                shape: root.compareWaferShape
+                                size: root.compareWaferSize
+                                target: 0
+                                margin: 1.0
+                                blend: blendSlider.value / 100
+                                showLabels: true
+                                ringColor: Theme.waferRingColor
+                                axisColor: Theme.waferAxisColor
+                                lowColor: Theme.sensorLow
+                                inRangeColor: Theme.sensorInRange
+                                highColor: Theme.sensorHigh
+                                textColor: Theme.headingColor
+                            }
+
+                            ColumnLayout {
+                                anchors.centerIn: parent
+                                visible: root.compareSensorLayout.length === 0
+                                spacing: 4
+                                Label {
+                                    Layout.alignment: Qt.AlignHCenter
+                                    text: "🗺"
+                                    font.pixelSize: 24
+                                }
+                                Label {
+                                    Layout.alignment: Qt.AlignHCenter
+                                    text: "No sensor map available"
                                     color: Theme.bodyColor
                                     font.pixelSize: Theme.fontXs
-                            elide: Text.ElideRight
+                                }
                             }
                         }
 
-                    ScrollBar.horizontal: ScrollBar {
+                        // Blend slider
-                        policy: ScrollBar.AsNeeded
+                        RowLayout {
+                            Layout.fillWidth: true
+                            spacing: 6
+                            Label {
+                                text: "Blend"
+                                font.pixelSize: Theme.fontXs
+                                color: Theme.bodyColor
+                            }
+                            Slider {
+                                id: blendSlider
+                                Layout.fillWidth: true
+                                from: 0; to: 100; value: 50
+                                stepSize: 1
+                            }
+                            Label {
+                                text: Math.round(blendSlider.value) + "%"
+                                font.pixelSize: Theme.fontXs
+                                color: Theme.sideMutedText
+                                Layout.preferredWidth: 30
+                            }
+                        }
+
+                        // Color legend
+                        Row {
+                            Layout.fillWidth: true
+                            spacing: 8
+                            Row {
+                                spacing: 3
+                                Rectangle { width: 8; height: 8; radius: 4; color: Theme.sensorLow; anchors.verticalCenter: parent.verticalCenter }
+                                Label { text: "Cool"; font.pixelSize: 9; color: Theme.sideMutedText }
+                            }
+                            Row {
+                                spacing: 3
+                                Rectangle { width: 8; height: 8; radius: 4; color: Theme.sensorInRange; anchors.verticalCenter: parent.verticalCenter }
+                                Label { text: "Match"; font.pixelSize: 9; color: Theme.sideMutedText }
+                            }
+                            Row {
+                                spacing: 3
+                                Rectangle { width: 8; height: 8; radius: 4; color: Theme.sensorHigh; anchors.verticalCenter: parent.verticalCenter }
+                                Label { text: "Hot"; font.pixelSize: 9; color: Theme.sideMutedText }
+                            }
                         }
-                    ScrollBar.vertical: ScrollBar {
-                        policy: ScrollBar.AsNeeded
                     }
                 }
             }

src/pygui/ISC/Tabs/components/SourcePanel.qml

@@ -188,8 +188,15 @@ ColumnLayout {
                 return (modelData.baseName + modelData.waferType + modelData.date).toLowerCase().indexOf(q) >= 0;
             }
 
-            // Active only in review mode; no highlight during live streaming
+            // Active highlight logic: on Data tab, highlight compareFileA/B; otherwise highlight loadedFile (for Map tab).
-            readonly property bool isActive: streamController.mode === "review" && streamController.loadedFile !== "" && modelData.fileName === streamController.loadedFile
+            readonly property bool isActive:{
+                try {
+                    if (root.selectedTabIndex === 1 && dataTabLoader.item) {
+                        return modelData.fileName === dataTabLoader.item.compareFileA || modelData.fileName === dataTabLoader.item.compareFileB;
+                    }
+                } catch (e) {}
+                return streamController.mode === "review" && streamController.loadedFile !== "" && modelData.fileName === streamController.loadedFile;
+            }
             
             visible: matchesFilter
             height: matchesFilter ? implicitHeight : 0

src/pygui/ISC/Tabs/components/SplitDialog.qml

@@ -0,0 +1,315 @@
+import QtQuick
+import QtQuick.Layouts
+import QtQuick.Controls
+import QtQuick.Dialogs
+import ISC
+
+// ===== Split Dialog (Threshold Segmentation) =====
+// Modal popup for segmenting temperature profile into Ramp/Soak/Cool phases.
+// Backend: splitter.segment_profile() returns list of DataSegment objects.
+
+Popup {
+    id: root
+    modal: true
+    dim: true
+    closePolicy: Popup.CloseOnEscape | Popup.CloseOnPressOutside
+    width: Math.min(parent.width - 100, 800)
+    height: Math.min(parent.height - 100, 600)
+    anchors.centerIn: Overlay.overlay
+
+    property real threshold: 40.0
+    property bool segmenting: false
+    property var segments: []
+    property string currentFile: streamController.loadedFile || ""
+
+    background: Rectangle {
+        radius: Theme.radiusMd
+        color: Theme.cardBackground
+        border.color: Theme.cardBorder
+        border.width: 1
+    }
+
+    ColumnLayout {
+        anchors.fill: parent
+        anchors.margins: 20
+        spacing: 16
+
+        // ── Header ────────────────────────────────────────────────
+        RowLayout {
+            Layout.fillWidth: true
+            spacing: 10
+
+            Label {
+                text: "SPLIT DATA"
+                font.pixelSize: Theme.fontLg
+                font.bold: true
+                color: Theme.headingColor
+                Layout.fillWidth: true
+            }
+
+            Button {
+                text: "\u2715"
+                flat: true
+                Layout.preferredWidth: 32
+                Layout.preferredHeight: 32
+                onClicked: root.close()
+
+                background: Rectangle {
+                    radius: Theme.radiusXs
+                    color: parent.hovered ? Theme.buttonNeutralHover : "transparent"
+                }
+                contentItem: Label {
+                    text: parent.text
+                    color: Theme.bodyColor
+                    horizontalAlignment: Text.AlignHCenter
+                    verticalAlignment: Text.AlignVCenter
+                }
+            }
+        }
+
+        // ── Threshold Input ───────────────────────────────────────
+        RowLayout {
+            Layout.fillWidth: true
+            spacing: 16
+
+            ColumnLayout {
+                Layout.fillWidth: true
+                spacing: 4
+
+                Label {
+                    text: "THRESHOLD TEMPERATURE (°C)"
+                    color: Theme.sideMutedText
+                    font.pixelSize: Theme.fontSm
+                    font.bold: true
+                    font.letterSpacing: 1.0
+                }
+
+                RowLayout {
+                    Layout.fillWidth: true
+                    spacing: 8
+
+                    SpinBox {
+                        id: thresholdSpin
+                        from: 0
+                        to: 200
+                        value: root.threshold
+                        stepSize: 1
+                        editable: true
+                        Layout.fillWidth: true
+                        background: Rectangle {
+                            color: Theme.fieldBackground
+                            border.color: Theme.cardBorder
+                            border.width: 1
+                            radius: Theme.radiusSm
+                        }
+                    }
+
+                    Label {
+                        text: "°C"
+                        color: Theme.bodyColor
+                        font.pixelSize: Theme.fontMd
+                        verticalAlignment: Text.AlignVCenter
+                    }
+                }
+            }
+
+            ColumnLayout {
+                Layout.fillWidth: true
+                spacing: 4
+
+                Label {
+                    text: "SESSION CSV"
+                    color: Theme.sideMutedText
+                    font.pixelSize: Theme.fontSm
+                    font.bold: true
+                    font.letterSpacing: 1.0
+                }
+
+                Label {
+                    Layout.fillWidth: true
+                    text: root.currentFile !== ""
+                        ? root.currentFile.split("/").pop()
+                        : "No file loaded"
+                    color: root.currentFile !== "" ? Theme.bodyColor : Theme.sideMutedText
+                    font.pixelSize: Theme.fontSm
+                    elide: Text.ElideMiddle
+                }
+            }
+        }
+
+        // ── Split Button ──────────────────────────────────────────
+        RowLayout {
+            Layout.fillWidth: true
+            spacing: 10
+
+            Button {
+                id: splitBtn
+                text: "SPLIT"
+                Layout.fillWidth: true
+                enabled: !root.segmenting && root.currentFile !== ""
+                onClicked: {
+                    root.threshold = thresholdSpin.value;
+                    root.segmenting = true;
+                    streamController.splitData(root.currentFile, root.threshold);
+                }
+
+                background: Rectangle {
+                    radius: Theme.radiusSm
+                    color: splitBtn.enabled ? Theme.primaryAccent : Theme.buttonNeutralBackground
+                    border.color: splitBtn.enabled ? Theme.primaryAccent : "transparent"
+                    border.width: 1
+                }
+                contentItem: Row {
+                    spacing: 8
+                    anchors.centerIn: parent
+
+                    Label {
+                        text: splitBtn.enabled ? (root.segmenting ? "Segmenting..." : "SPLIT") : "LOAD DATA FIRST"
+                        color: splitBtn.enabled ? Theme.tone100 : Theme.sideMutedText
+                        font.pixelSize: Theme.fontSm
+                        font.bold: true
+                        font.letterSpacing: 1.0
+                    }
+
+                    BusyIndicator {
+                        running: root.segmenting
+                        visible: root.segmenting
+                        width: 16
+                        height: 16
+                    }
+                }
+            }
+        }
+
+        // ── Segments Table ────────────────────────────────────────
+        Rectangle {
+            Layout.fillWidth: true
+            Layout.fillHeight: true
+            radius: Theme.radiusSm
+            color: Theme.panelBackground
+            border.color: Theme.cardBorder
+            border.width: 1
+
+            ColumnLayout {
+                anchors.fill: parent
+                anchors.margins: 0
+                spacing: 0
+
+                // Table header
+                Rectangle {
+                    Layout.fillWidth: true
+                    Layout.preferredHeight: 36
+                    color: Theme.subtleSectionBackground
+                    border.color: Theme.cardBorder
+                    border.width: 1
+
+                    RowLayout {
+                        anchors.fill: parent
+                        anchors.margins: 12
+                        spacing: 8
+
+                        Label { text: "PHASE"; Layout.preferredWidth: 100; color: Theme.sideMutedText; font.bold: true; font.pixelSize: Theme.fontSm }
+                        Label { text: "START (s)"; Layout.preferredWidth: 120; color: Theme.sideMutedText; font.bold: true; font.pixelSize: Theme.fontSm }
+                        Label { text: "END (s)"; Layout.preferredWidth: 120; color: Theme.sideMutedText; font.bold: true; font.pixelSize: Theme.fontSm }
+                        Label { text: "AVG TEMP (°C)"; Layout.fillWidth: true; color: Theme.sideMutedText; font.bold: true; font.pixelSize: Theme.fontSm }
+                    }
+                }
+
+                // Table body (scrollable)
+                ScrollView {
+                    Layout.fillWidth: true
+                    Layout.fillHeight: true
+                    clip: true
+
+                    ColumnLayout {
+                        width: parent.width - 32
+                        spacing: 0
+
+                        Repeater {
+                            model: root.segments.length > 0 ? root.segments : []
+                            delegate: Rectangle {
+                                Layout.fillWidth: true
+                                Layout.preferredHeight: 40
+                                color: index % 2 === 0 ? Theme.cardBackground : "transparent"
+                                border.color: Theme.cardBorder
+
+                                RowLayout {
+                                    anchors.fill: parent
+                                    anchors.margins: 12
+                                    spacing: 8
+
+                                    Label {
+                                        text: modelData.label || ""
+                                        Layout.preferredWidth: 100
+                                        color: modelData.label === "Soak" ? Theme.statusSuccessColor :
+                                               modelData.label === "Ramp" ? Theme.statusWarningColor : Theme.bodyColor
+                                        font.bold: true
+                                        font.pixelSize: Theme.fontSm
+                                    }
+
+                                    Label {
+                                        text: (modelData.start_frame || 0).toString()
+                                        Layout.preferredWidth: 120
+                                        color: Theme.bodyColor
+                                        font.pixelSize: Theme.fontSm
+                                    }
+
+                                    Label {
+                                        text: (modelData.end_frame || 0).toString()
+                                        Layout.preferredWidth: 120
+                                        color: Theme.bodyColor
+                                        font.pixelSize: Theme.fontSm
+                                    }
+
+                                    Label {
+                                        text: (modelData.avg_temp || 0).toFixed(2) + " °C"
+                                        Layout.fillWidth: true
+                                        color: Theme.bodyColor
+                                        font.pixelSize: Theme.fontSm
+                                    }
+                                }
+                            }
+                        }
+
+                        // Empty state
+                        Label {
+                            visible: root.segments.length === 0
+                            text: root.currentFile !== "" ? "Click SPLIT to segment data" : "Load a CSV file first"
+                            color: Theme.sideMutedText
+                            font.pixelSize: Theme.fontSm
+                            Layout.fillWidth: true
+                            Layout.preferredHeight: 100
+                            horizontalAlignment: Text.AlignHCenter
+                            verticalAlignment: Text.AlignVCenter
+                        }
+                    }
+                }
+            }
+        }
+
+        // ── Summary line ──────────────────────────────────────────
+        Label {
+            visible: root.segments.length > 0
+            text: root.segments.length + " segment" + (root.segments.length === 1 ? "" : "s")
+                + " found above " + root.threshold.toFixed(0) + "°C threshold."
+            color: Theme.bodyColor
+            font.pixelSize: Theme.fontSm
+        }
+    }
+
+    // ── Backend Connection ────────────────────────────────────────
+    Connections {
+        target: streamController
+        function onSplitResult(result) {
+            root.segmenting = false;
+            if (result && result.success) {
+                root.segments = result.segments || [];
+                console.log("[SplitDialog] Segmented into", root.segments.length, "phases");
+            } else {
+                root.segments = [];
+                console.log("[SplitDialog] Split failed:", result.error || "unknown");
+            }
+        }
+    }
+
+}

src/pygui/ISC/Tabs/components/qmldir

@@ -6,3 +6,4 @@ TransportBar 1.0 TransportBar.qml
 WaferMapView 1.0 WaferMapView.qml
 ReplaceSensorDialog 1.0 ReplaceSensorDialog.qml
 RailActionButton 1.0 RailActionButton.qml
+SplitDialog 1.0 SplitDialog.qml

src/pygui/__main__.py

@@ -1,4 +1,5 @@
 import logging
+import os
 import sys
 from pathlib import Path
 

src/pygui/backend/controllers/device_controller.py

@@ -3,8 +3,12 @@
 from __future__ import annotations
 
 import logging
+import os
+import subprocess
+import sys
 import threading
 from datetime import datetime
+from pathlib import Path
 from typing import Any, Optional
 
 from PySide6.QtCore import Property, QObject, Qt, Signal, Slot
@@ -68,7 +72,6 @@ class DeviceController(QObject):
         self._operation_in_progress = False
         self._activity_log: list[str] = []
         self._raw_bytes: Optional[bytes] = None
-        from pathlib import Path
         self._save_data_dir: str = getattr(settings, 'save_data_dir', "") or str(Path(self._data_dir) / "csv")
         self._last_wafer_info: dict[str, Any] = {}
         self._last_csv_path: str = ""
@@ -126,6 +129,34 @@ class DeviceController(QObject):
         self._append_log(f"Save data dir set to: {path}")
         self._save_status()
 
+    @Slot(str)
+    @slot_error_boundary
+    def openCsvFile(self, file_path: str) -> None:
+        """Open a CSV file in the system default spreadsheet application."""
+
+        if not file_path:
+            self._append_log("No file path provided to openCsvFile")
+            return
+
+        try:
+            path = Path(file_path)
+            if not path.exists():
+                self._append_log(f"File not found: {file_path}")
+                return
+
+            # Platform-appropriate file opener
+            if sys.platform == "darwin":
+                subprocess.Popen(["open", str(path)])
+            elif sys.platform == "linux":
+                subprocess.Popen(["xdg-open", str(path)])
+            else:  # Windows
+                os.startfile(str(path))
+
+            self._append_log(f"Opened file: {file_path}")
+        except Exception as exc:
+            log.warning("Failed to open file %s: %s", file_path, exc)
+            self._append_log(f"Error opening file: {exc}")
+
     @Property(str, notify=selectedPortChanged)
     def selectedPort(self) -> str:
         """Currently selected serial port shared across the UI."""
@@ -517,7 +548,6 @@ class DeviceController(QObject):
             return
 
         if not self._save_data_dir:
-            from pathlib import Path
             self._save_data_dir = str(Path(self._data_dir) / "csv")
             self._append_log(f"Auto-set save directory to: {self._save_data_dir}")
             self._save_status()

src/pygui/backend/controllers/session_controller.py

@@ -40,6 +40,8 @@ class SessionController(QObject):
     liveStatsChanged = Signal()  # emitted when receivedCount or errorCount change
     # trend: per-frame avg for live graph
     trendData = Signal(str)  # JSON array of floats
+    comparisonResult = Signal(object)  # dict with success, distance, warping_path, max_sensor_deviation, series_a, series_b
+    splitResult = Signal(object)  # dict with success, segments
     # private: marshal a worker-thread frame onto the main thread
     _liveFrame = Signal(object)    # Frame
     _liveError = Signal()          # worker-thread error ping
@@ -305,6 +307,169 @@ class SessionController(QObject):
         self.trendData.emit(json.dumps(self._stats_tracker.get_trend()))
         self.settingsChanged.emit()
 
+    @Slot()
+    @slot_error_boundary
+    def unloadFile(self) -> None:
+        """Clear the loaded file, resetting the player and frame states."""
+        self._player.load([])
+        self._model.reset()
+        self._stats_tracker.reset()
+        self._loaded_file = ""
+        self.loadedFileChanged.emit()
+        self.sensorsChanged.emit()
+        self.settingsChanged.emit()
+
+    # ---- comparison: DTW between two CSV files ----
+    @Slot(str, str)
+    @slot_error_boundary
+    def compareFiles(self, file_a: str, file_b: str) -> None:
+        """Run DTW comparison between two CSV files and emit result."""
+        from pygui.backend.comparison import compare_runs
+        from pygui.backend.data.data_records import is_official_csv, read_data_records, read_official_csv
+
+        try:
+            if is_official_csv(file_a):
+                _, recs_a = read_official_csv(file_a)
+            else:
+                recs_a = read_data_records(file_a)
+
+            if is_official_csv(file_b):
+                _, recs_b = read_official_csv(file_b)
+            else:
+                recs_b = read_data_records(file_b)
+            if not recs_a or not recs_b:
+                self.comparisonResult.emit({
+                    "success": False,
+                    "error": "No data in one or both files"
+                })
+                return
+
+            # Use first 100 frames of each for comparison (avoid O(n²) blowup)
+            max_frames = min(100, len(recs_a), len(recs_b))
+            series_a = [recs_a[i].values[0] if recs_a[i].values else 0.0
+                       for i in range(max_frames)]
+            series_b = [recs_b[i].values[0] if recs_b[i].values else 0.0
+                       for i in range(max_frames)]
+
+            result = compare_runs(series_a, series_b)
+
+            # Max sensor deviation: walk the DTW-aligned frame pairs and take
+            # the largest per-sensor abs difference across all sensors, not
+            # just the sensor[0] series used for alignment.
+            num_sensors = min(len(recs_a[0].values), len(recs_b[0].values)) if recs_a[0].values and recs_b[0].values else 0
+            max_sensor_deviation = 0.0
+            for i, j in zip(result["index_a"], result["index_b"]):
+                if i >= max_frames or j >= max_frames:
+                    continue
+                values_a = recs_a[i].values
+                values_b = recs_b[j].values
+                for s in range(min(num_sensors, len(values_a), len(values_b))):
+                    diff = abs(values_a[s] - values_b[s])
+                    if diff > max_sensor_deviation:
+                        max_sensor_deviation = diff
+
+            # Sensor layout + per-sensor diff for the wafer overlap view. Reuses the
+            # same sensor-parsing branch as loadFile() (file_a is assumed representative
+            # of both files' wafer type).
+            from pathlib import Path
+
+            from pygui.backend.data.data_records import is_official_csv, read_official_csv
+            from pygui.backend.wafer.wafer_layouts import resolve_shape_and_size
+            from pygui.backend.wafer.zwafer_parser import ZWaferParser
+
+            sensor_layout: list[dict] = []
+            sensor_diff: list[float] = []
+            wafer_shape = "round"
+            wafer_size = 300.0
+            try:
+                if is_official_csv(file_a):
+                    sensors, _ = read_official_csv(file_a)
+                    stem = Path(file_a).stem
+                    wafer_id = stem.split("-")[0] if "-" in stem else stem
+                else:
+                    parsed, _ = ZWaferParser().parse(file_a)
+                    sensors = parsed.sensors if parsed else []
+                    wafer_id = parsed.serial if (parsed and parsed.serial) else ""
+
+                if sensors:
+                    wafer_shape, wafer_size = resolve_shape_and_size(sensors, wafer_id)
+                    last_a = recs_a[max_frames - 1].values
+                    last_b = recs_b[max_frames - 1].values
+                    n = min(len(sensors), len(last_a), len(last_b))
+                    sensor_layout = [
+                        {
+                            "label": s.label,
+                            "x": s.x,
+                            "y": s.y,
+                            "side": getattr(s, "side", "right"),
+                            "offset_x": getattr(s, "offset_x", 0.0),
+                            "offset_y": getattr(s, "offset_y", 0.0),
+                        }
+                        for s in sensors[:n]
+                    ]
+                    sensor_diff = [round(last_b[i] - last_a[i], 3) for i in range(n)]
+            except Exception as layout_exc:
+                log.warning("Could not resolve sensor layout for overlap view: %s", layout_exc)
+
+            self.comparisonResult.emit({
+                "success": True,
+                "distance": result["distance"],
+                "warping_path": result["warping_path"][:50],  # limit path size
+                "max_sensor_deviation": max_sensor_deviation,
+                "series_a": series_a,
+                "series_b": series_b,
+                "sensor_layout": sensor_layout,
+                "sensor_diff": sensor_diff,
+                "wafer_shape": wafer_shape,
+                "wafer_size": wafer_size,
+            })
+        except Exception as exc:
+            log.warning("Comparison failed: %s", exc)
+            self.comparisonResult.emit({
+                "success": False,
+                "error": str(exc)
+            })
+
+    # ---- splitting: threshold-based segmentation ----
+    @Slot(str, float)
+    @slot_error_boundary
+    def splitData(self, file_path: str, threshold: float) -> None:
+        """Segment temperature profile into Ramp/Soak/Cool phases."""
+        from pygui.backend.data.data_records import is_official_csv, read_data_records, read_official_csv
+        from pygui.backend.splitter import segment_profile
+
+        try:
+            if is_official_csv(file_path):
+                _, records = read_official_csv(file_path)
+            else:
+                records = read_data_records(file_path)
+            if not records:
+                self.splitResult.emit({
+                    "success": False,
+                    "error": "No data in file"
+                })
+                return
+
+            # Extract average temperatures (use first sensor as proxy)
+            avg_temps = [rec.values[0] if rec.values else 0.0 for rec in records]
+            segments = segment_profile(avg_temps, threshold)
+
+            self.splitResult.emit({
+                "success": True,
+                "segments": [{
+                    "label": seg.label,
+                    "start_frame": seg.start_frame,
+                    "end_frame": seg.end_frame,
+                    "avg_temp": seg.avg_temp
+                } for seg in segments]
+            })
+        except Exception as exc:
+            log.warning("Split failed: %s", exc)
+            self.splitResult.emit({
+                "success": False,
+                "error": str(exc)
+            })
+
     @Slot()
     @slot_error_boundary
     def play(self) -> None:
@@ -597,3 +762,52 @@ class SessionController(QObject):
         self.trendData.emit(json.dumps(self._trend_buffer))
 
 
+        self.liveStatsChanged.emit()
+
+    # ---- recording ----
+    @Slot(str, str)
+    @slot_error_boundary
+    def startRecording(self, path: str, serial: str = "") -> None:
+        self._recorder.start(path, self._sensors, serial)
+        self.recordingChanged.emit()
+
+    @Slot()
+    @slot_error_boundary
+    def stopRecording(self) -> None:
+        if self._recorder.is_recording:
+            self._recorder.stop()
+            self.recordingChanged.emit()
+
+    @Slot(int, float)
+    @slot_error_boundary
+    def replaceSensor(self, index: int, value: float) -> None:
+        """Override sensor `index` to display `value` every frame."""
+        self._sensor_editor.set_replacement(index, value)
+        self._reprocess_current()
+
+    @Slot(int, float)
+    @slot_error_boundary
+    def offsetSensor(self, index: int, delta: float) -> None:
+        """Shift sensor `index` by `delta` every frame."""
+        self._sensor_editor.set_offset(index, delta)
+        self._reprocess_current()
+
+    @Slot(int)
+    @slot_error_boundary
+    def clearSensorEdit(self, index: int) -> None:
+        """Remove all overrides for sensor `index`."""
+        self._sensor_editor.clear(index)
+        self._reprocess_current()
+
+    @Slot()
+    @slot_error_boundary
+    def clearSensorEdits(self) -> None:
+        """Remove all sensor overrides."""
+        self._sensor_editor.clear()
+        self._reprocess_current()
+
+    def _flush_trend(self) -> None:
+        import json
+        self.trendData.emit(json.dumps(self._trend_buffer))
+
+

tests/test_session_controller.py

@@ -46,3 +46,34 @@ def test_pause_stop_timer(controller):
     controller.seek(2)
     controller.stop()
     assert controller.frameIndex == 0
+
+def test_compare_files_integration(controller):
+    # Mock the comparisonResult signal
+    mock_slot = MagicMock()
+    controller.comparisonResult.connect(mock_slot)
+
+    # Use sample_stream.csv for both arguments to test identical files compare
+    csv_path = "tests/fixtures/sample_stream.csv"
+    controller.compareFiles(csv_path, csv_path)
+
+    # Verify that the comparison signal is emitted with a success dict
+    assert mock_slot.call_count == 1
+    args = mock_slot.call_args[0][0]
+    assert args["success"] is True
+    assert "distance" in args
+    assert "series_a" in args
+    assert "series_b" in args
+
+def test_split_data_integration(controller):
+    # Mock the splitResult signal
+    mock_slot = MagicMock()
+    controller.splitResult.connect(mock_slot)
+
+    csv_path = "tests/fixtures/sample_stream.csv"
+    controller.splitData(csv_path, 149.0)
+
+    # Verify that the split signal is emitted
+    assert mock_slot.call_count == 1
+    args = mock_slot.call_args[0][0]
+    assert args["success"] is True
+    assert "segments" in args