import QtQuick
import QtQuick.Controls
import QtQuick.Effects
import qs.Common
import qs.Services
import qs.Widgets

Rectangle {
  id: events

  property date selectedDate: new Date()
  property var selectedDateEvents: []
  property bool hasEvents: selectedDateEvents && selectedDateEvents.length > 0
  property bool shouldShow: CalendarService && CalendarService.khalAvailable

  function updateSelectedDateEvents() {
    if (CalendarService && CalendarService.khalAvailable) {
      let events = CalendarService.getEventsForDate(selectedDate)
      selectedDateEvents = events
    } else {
      selectedDateEvents = []
    }
  }

  onSelectedDateEventsChanged: {
    eventsList.model = selectedDateEvents
  }
  width: parent.width
  height: shouldShow ? (hasEvents ? Math.min(
                                      300,
                                      80 + selectedDateEvents.length * 60) : 120) : 0
  radius: Theme.cornerRadius
  color: Qt.rgba(Theme.surfaceVariant.r, Theme.surfaceVariant.g,
                 Theme.surfaceVariant.b, 0.12)
  border.color: Qt.rgba(Theme.outline.r, Theme.outline.g, Theme.outline.b, 0.08)
  border.width: 1
  visible: shouldShow
  layer.enabled: true
  Component.onCompleted: {
    updateSelectedDateEvents()
  }
  onSelectedDateChanged: {
    updateSelectedDateEvents()
  }

  Connections {
    function onEventsByDateChanged() {
      updateSelectedDateEvents()
    }

    function onKhalAvailableChanged() {
      updateSelectedDateEvents()
    }

    target: CalendarService
    enabled: CalendarService !== null
  }

  Row {
    id: headerRow

    anchors.top: parent.top
    anchors.left: parent.left
    anchors.right: parent.right
    anchors.margins: Theme.spacingL
    spacing: Theme.spacingS

    DankIcon {
      name: "event"
      size: Theme.iconSize - 2
      color: Theme.primary
      anchors.verticalCenter: parent.verticalCenter
    }

    StyledText {
      text: hasEvents ? (Qt.formatDate(
                           selectedDate,
                           "MMM d") + " • " + (selectedDateEvents.length
                                               === 1 ? "1 event" : selectedDateEvents.length
                                                       + " events")) : Qt.formatDate(
                          selectedDate, "MMM d")
      font.pixelSize: Theme.fontSizeMedium
      color: Theme.surfaceText
      font.weight: Font.Medium
      anchors.verticalCenter: parent.verticalCenter
    }
  }

  Column {
    anchors.centerIn: parent
    spacing: Theme.spacingXS
    visible: !hasEvents

    DankIcon {
      name: "event_busy"
      size: Theme.iconSize + 8
      color: Qt.rgba(Theme.surfaceText.r, Theme.surfaceText.g,
                     Theme.surfaceText.b, 0.3)
      anchors.horizontalCenter: parent.horizontalCenter
    }

    StyledText {
      text: "No events"
      font.pixelSize: Theme.fontSizeMedium
      color: Qt.rgba(Theme.surfaceText.r, Theme.surfaceText.g,
                     Theme.surfaceText.b, 0.5)
      font.weight: Font.Normal
      anchors.horizontalCenter: parent.horizontalCenter
    }
  }

  DankListView {
    id: eventsList

    anchors.top: headerRow.bottom
    anchors.left: parent.left
    anchors.right: parent.right
    anchors.bottom: parent.bottom
    anchors.margins: Theme.spacingL
    anchors.topMargin: Theme.spacingM
    visible: opacity > 0
    opacity: hasEvents ? 1 : 0
    clip: true
    spacing: Theme.spacingS
    boundsBehavior: Flickable.StopAtBounds

    // Qt 6.9+ scrolling: flickDeceleration/maximumFlickVelocity only affect touch now
    interactive: true
    flickDeceleration: 1500
    maximumFlickVelocity: 2000
    boundsMovement: Flickable.FollowBoundsBehavior
    pressDelay: 0
    flickableDirection: Flickable.VerticalFlick

    // Custom wheel handler for Qt 6.9+ responsive mouse wheel scrolling
    WheelHandler {
      acceptedDevices: PointerDevice.Mouse | PointerDevice.TouchPad
      property real momentum: 0
      onWheel: event => {
                 if (event.pixelDelta.y !== 0) {
                   // Touchpad with pixel delta
                   momentum = event.pixelDelta.y * 1.8
                 } else {
                   // Mouse wheel with angle delta
                   momentum = (event.angleDelta.y / 120) * (60 * 2.5) // ~2.5 items per wheel step
                 }

                 let newY = parent.contentY - momentum
                 newY = Math.max(0,
                                 Math.min(parent.contentHeight - parent.height,
                                          newY))
                 parent.contentY = newY
                 momentum *= 0.92 // Decay for smooth momentum
                 event.accepted = true
               }
    }

    ScrollBar.vertical: ScrollBar {
      policy: eventsList.contentHeight
              > eventsList.height ? ScrollBar.AsNeeded : ScrollBar.AlwaysOff
    }

    Behavior on opacity {
      NumberAnimation {
        duration: Theme.mediumDuration
        easing.type: Theme.emphasizedEasing
      }
    }

    delegate: Rectangle {
      width: eventsList.width
      height: eventContent.implicitHeight + Theme.spacingM
      radius: Theme.cornerRadius
      color: {
        if (modelData.url && eventMouseArea.containsMouse)
          return Qt.rgba(Theme.primary.r, Theme.primary.g,
                         Theme.primary.b, 0.12)
        else if (eventMouseArea.containsMouse)
          return Qt.rgba(Theme.primary.r, Theme.primary.g,
                         Theme.primary.b, 0.06)
        return Qt.rgba(Theme.surfaceVariant.r, Theme.surfaceVariant.g,
                       Theme.surfaceVariant.b, 0.06)
      }
      border.color: {
        if (modelData.url && eventMouseArea.containsMouse)
          return Qt.rgba(Theme.primary.r, Theme.primary.g, Theme.primary.b, 0.3)
        else if (eventMouseArea.containsMouse)
          return Qt.rgba(Theme.primary.r, Theme.primary.g,
                         Theme.primary.b, 0.15)
        return "transparent"
      }
      border.width: 1

      Rectangle {
        width: 4
        height: parent.height - 8
        anchors.left: parent.left
        anchors.leftMargin: 4
        anchors.verticalCenter: parent.verticalCenter
        radius: 2
        color: Theme.primary
        opacity: 0.8
      }

      Column {
        id: eventContent

        anchors.left: parent.left
        anchors.right: parent.right
        anchors.verticalCenter: parent.verticalCenter
        anchors.leftMargin: Theme.spacingL + 4
        anchors.rightMargin: Theme.spacingM
        spacing: 6

        StyledText {
          width: parent.width
          text: modelData.title
          font.pixelSize: Theme.fontSizeMedium
          color: Theme.surfaceText
          font.weight: Font.Medium
          elide: Text.ElideRight
          wrapMode: Text.Wrap
          maximumLineCount: 2
        }

        Item {
          width: parent.width
          height: Math.max(timeRow.height, locationRow.height)

          Row {
            id: timeRow

            spacing: 4
            anchors.left: parent.left
            anchors.verticalCenter: parent.verticalCenter

            DankIcon {
              name: "schedule"
              size: Theme.fontSizeSmall
              color: Qt.rgba(Theme.surfaceText.r, Theme.surfaceText.g,
                             Theme.surfaceText.b, 0.7)
              anchors.verticalCenter: parent.verticalCenter
            }

            StyledText {
              text: {
                if (modelData.allDay) {
                  return "All day"
                } else {
                  let timeFormat = SettingsData.use24HourClock ? "H:mm" : "h:mm AP"
                  let startTime = Qt.formatTime(modelData.start, timeFormat)
                  if (modelData.start.toDateString(
                        ) !== modelData.end.toDateString()
                      || modelData.start.getTime() !== modelData.end.getTime())
                    return startTime + " – " + Qt.formatTime(modelData.end,
                                                             timeFormat)

                  return startTime
                }
              }
              font.pixelSize: Theme.fontSizeSmall
              color: Qt.rgba(Theme.surfaceText.r, Theme.surfaceText.g,
                             Theme.surfaceText.b, 0.7)
              font.weight: Font.Normal
              anchors.verticalCenter: parent.verticalCenter
            }
          }

          Row {
            id: locationRow

            spacing: 4
            anchors.right: parent.right
            anchors.verticalCenter: parent.verticalCenter
            visible: modelData.location !== ""

            DankIcon {
              name: "location_on"
              size: Theme.fontSizeSmall
              color: Qt.rgba(Theme.surfaceText.r, Theme.surfaceText.g,
                             Theme.surfaceText.b, 0.7)
              anchors.verticalCenter: parent.verticalCenter
            }

            StyledText {
              text: modelData.location
              font.pixelSize: Theme.fontSizeSmall
              color: Qt.rgba(Theme.surfaceText.r, Theme.surfaceText.g,
                             Theme.surfaceText.b, 0.7)
              elide: Text.ElideRight
              anchors.verticalCenter: parent.verticalCenter
              maximumLineCount: 1
              width: Math.min(implicitWidth, 200)
            }
          }
        }
      }

      MouseArea {
        id: eventMouseArea

        anchors.fill: parent
        hoverEnabled: true
        cursorShape: modelData.url ? Qt.PointingHandCursor : Qt.ArrowCursor
        enabled: modelData.url !== ""
        onClicked: {
          if (modelData.url && modelData.url !== "") {
            if (Qt.openUrlExternally(modelData.url) === false)
              console.warn("Failed to open URL: " + modelData.url)
          }
        }
      }

      Behavior on color {
        ColorAnimation {
          duration: Theme.shortDuration
          easing.type: Theme.standardEasing
        }
      }

      Behavior on border.color {
        ColorAnimation {
          duration: Theme.shortDuration
          easing.type: Theme.standardEasing
        }
      }
    }
  }

  layer.effect: MultiEffect {
    shadowEnabled: true
    shadowHorizontalOffset: 0
    shadowVerticalOffset: 2
    shadowBlur: 0.25
    shadowColor: Qt.rgba(0, 0, 0, 0.1)
    shadowOpacity: 0.1
  }

  Behavior on height {
    NumberAnimation {
      duration: Theme.mediumDuration
      easing.type: Theme.emphasizedEasing
    }
  }
}