import QtQuick
import QtQuick.Controls
import QtQuick.Layouts

// The transcript: cards for the messages, a card per tool call, folded
// thinking blocks and one-line notes. Follows the tail of the conversation
// until the user scrolls away from it.
Item {
    id: view
    property var model: null
    property bool running: false

    ListView {
        id: list
        anchors.fill: parent
        anchors.leftMargin: Theme.gapL
        anchors.rightMargin: Theme.gapL
        model: view.model
        clip: true
        spacing: Theme.gap
        topMargin: Theme.gapL
        bottomMargin: Theme.gapL
        cacheBuffer: 2000
        boundsBehavior: Flickable.StopAtBounds

        // The delegate picks the card by row kind; the components below read
        // the ListModel roles directly, which is why they are declared in the
        // delegate's scope.
        delegate: Loader {
            id: rowLoader
            width: list.width
            sourceComponent: model.kind === "tool" ? toolComp
                           : model.kind === "think" ? thinkComp
                           : model.kind === "note" ? noteComp : msgComp

            Component {
                id: msgComp
                MessageCard {
                    role: model.role
                    text: model.text
                    complete: model.complete
                    html: (model.role === "agent" || model.role === "error") &&
                          (model.complete || model.text.length > 12000) &&
                          model.text.length > 0
                          ? agent.renderMarkdown(model.text) : ""
                }
            }
            Component {
                id: thinkComp
                ThinkBlock {
                    text: model.text
                    complete: model.complete
                }
            }
            Component {
                id: toolComp
                ToolCard {
                    name: model.name
                    state: model.state
                    detail: model.detail
                    output: model.output
                    exitCode: model.exitCode
                    hasResult: model.complete
                }
            }
            Component {
                id: noteComp
                NoteLine {
                    text: model.text
                    level: model.state === "warn" || model.state === "error" ? model.state : "info"
                }
            }
        }

        onMovementEnded: view.stickBottom = atYEnd
        onCountChanged: if (view.stickBottom) Qt.callLater(list.positionViewAtEnd)
        onContentHeightChanged: if (view.stickBottom) Qt.callLater(list.positionViewAtEnd)
    }

    // Follow the tail unless the user asked otherwise.
    property bool stickBottom: true

    // Empty state: what this window is and what to do with it.
    ColumnLayout {
        anchors.centerIn: parent
        width: Math.min(parent.width - 80, 520)
        spacing: Theme.gap
        visible: view.model ? view.model.count === 0 : true

        Text {
            Layout.alignment: Qt.AlignHCenter
            text: "CST-agent"
            color: Theme.text
            font.pixelSize: 22
            font.bold: true
        }
        Text {
            Layout.alignment: Qt.AlignHCenter
            text: "The engine runs in this window — no server, no second process."
            color: Theme.textDim
            font.pixelSize: Theme.bodySize
            horizontalAlignment: Text.AlignHCenter
            wrapMode: Text.Wrap
            Layout.fillWidth: true
        }
        Text {
            Layout.alignment: Qt.AlignHCenter
            Layout.topMargin: Theme.gap
            text: "Ask for a change, a command to run, a file to explain.\n" +
                  "Every write, delete and command asks first: Deny / Once / Always.\n" +
                  "Enter sends, Shift+Enter adds a line, Esc stops a running turn."
            color: Theme.textFaint
            font.pixelSize: Theme.smallSize
            horizontalAlignment: Text.AlignHCenter
            wrapMode: Text.Wrap
            Layout.fillWidth: true
        }
    }

    // Jump back to the live end of the conversation.
    RoundButton {
        anchors.right: parent.right
        anchors.bottom: parent.bottom
        anchors.margins: Theme.padL
        width: Theme.jumpButton
        height: Theme.jumpButton
        visible: !view.stickBottom && list.contentHeight > list.height
        text: "↓"
        onClicked: {
            view.stickBottom = true
            list.positionViewAtEnd()
        }
    }
}