import QtQuick 2.12
import "../../Base"
import "../../utils.js" as Utils

HRectangle {
    property alias listView: eventList

    color: theme.chat.eventList.background

    HListView {
        id: eventList
        clip: true
        Component.onCompleted: shortcuts.flickTarget = eventList

        function canCombine(item, itemAfter) {
            if (! item || ! itemAfter) { return false }

            return Boolean(
                ! canTalkBreak(item, itemAfter) &&
                ! canDayBreak(item, itemAfter) &&
                item.sender_id === itemAfter.sender_id &&
                Utils.minutesBetween(item.date, itemAfter.date) <= 5
            )
        }

        function canTalkBreak(item, itemAfter) {
            if (! item || ! itemAfter) { return false }

            return Boolean(
                ! canDayBreak(item, itemAfter) &&
                Utils.minutesBetween(item.date, itemAfter.date) >= 20
            )
        }

        function canDayBreak(item, itemAfter) {
            if (! item || ! itemAfter || ! item.date || ! itemAfter.date) {
                return false
            }

            return Boolean(
                itemAfter.event_type == "RoomCreateEvent" ||
                item.date.getDate() != itemAfter.date.getDate()
            )
        }

        model: HListModel {
            keyField: "client_id"
            source:
                modelSources[["Event", chatPage.userId, chatPage.roomId]] || []
        }

        property bool ownEventsOnRight:
            width < theme.chat.eventList.ownEventsOnRightUnderWidth

        delegate: EventDelegate {}

        anchors.fill: parent
        anchors.leftMargin: theme.spacing
        anchors.rightMargin: theme.spacing

        topMargin: theme.spacing
        bottomMargin: theme.spacing
        verticalLayoutDirection: ListView.BottomToTop

        // Keep x scroll pages cached, to limit images having to be
        // reloaded from network.
        cacheBuffer: height * 4

        // Declaring this as "alias" provides the on... signal
        property real yPos: visibleArea.yPosition
        property bool canLoad: true
        onYPosChanged: if (canLoad && yPos < 0.1) Qt.callLater(loadPastEvents)

        function loadPastEvents() {
            // try/catch blocks to hide pyotherside error when the
            // component is destroyed but func is still running

            try {
                eventList.canLoad = false

                py.callClientCoro(
                    chatPage.userId, "load_past_events", [chatPage.roomId],
                    moreToLoad => {
                        try {
                            eventList.canLoad = moreToLoad
                        } catch (err) {
                            return
                        }
                    }
                )
            } catch (err) {
                return
            }
        }

        property string inviter: chatPage.roomInfo.inviter || ""
        // When an invited room becomes joined, we should now be able to fetch
        // past events.
        onInviterChanged: canLoad = true
    }

    HNoticePage {
        text: qsTr("No messages visible yet.")

        visible: eventList.model.count < 1
        anchors.fill: parent
    }
}