import QtQuick
import Quickshell
import Quickshell.Wayland
import qs.Commons

// Layer-shell popup attached to a bar widget icon, designed for
// click-driven AND keyboard-driven panels (e.g. SUPER+CTRL+W summon).
//
// Built on PanelWindow with WlrKeyboardFocus.Exclusive rather than
// PopupWindow (xdg-popup). Layer-shell surfaces declared Exclusive get
// keyboard focus from Hyprland *at map time*, which is the protocol-level
// equivalent of focus-on-launch for xdg-toplevels. xdg-popups don't get
// that — they only receive keys after a click/hover routes focus through
// their parent surface — so keyboard-summoned popups fell flat without it.
//
// API is a subset of Common.PopupCard: anchorItem, owner, bar, open,
// padding, margin, contentWidth/Height, default contentItem. Missing on
// purpose (for now): centerOnBar, triggerMode ("hover"), containsMouse.
// Hover-mode popups (system-stats, weather) and centered popups
// (calendar week-view) need extra plumbing before migrating; converting
// them is a follow-up.
//
// Positioning: full-screen layer-shell with the card placed inside at
// `cardOrigin`. We use the bar window's height/width for the perpendicular
// axis (away-from-bar) because mapToItem on the anchor returns
// bar-content-relative coords with internal layout offsets baked in
// (e.g. ~13px from the bar's vertical centering of its widget row). The
// parallel axis (along-the-bar) uses the anchor's content x/y since the
// bar spans full screen on that axis.
//
// Outside-click dismissal: an overlay MouseArea catches clicks, with the
// QsWindow.mask subtracting the bar strip so clicks on the bar still
// reach the bar widgets (activePopout coordinator hands off to another
// popup if the user clicks a different bar icon).
PanelWindow {
  id: root

  required property Item anchorItem
  required property QtObject bar
  property var owner: null
  property int margin: Style.gapsOut
  property int padding: Style.spacing.popupPadding
  property int contentWidth: 280
  property int contentHeight: 200
  property bool open: false
  property int gap: Style.gapsOut  // distance between bar edge and panel

  // Item that should take keyboard focus once the panel maps. Typically a
  // PanelKeyCatcher inside the panel content. Layer-shell grants focus to
  // the surface at map time, but Qt still needs an active-focus target
  // inside the surface for Keys.onPressed handlers to fire. Schedule the
  // focus through Qt.callLater so it runs after the surface is fully
  // mapped and child items have completed layout.
  property Item focusTarget: null

  default property alias contentItem: contentHolder.children

  readonly property var coordinatorKey: owner || root
  readonly property var anchorWindow: anchorItem ? anchorItem.QsWindow.window : null
  readonly property string barPos: bar ? bar.position : "top"

  function closePopout() {
    if (owner && "closePopout" in owner) owner.closePopout()
    else root.open = false
  }

  // --- screen + lifetime ---------------------------------------------------

  screen: anchorWindow ? anchorWindow.screen : null
  visible: open || card.opacity > 0
  color: "transparent"
  exclusionMode: ExclusionMode.Ignore

  WlrLayershell.namespace: "omarchy-keyboard-panel"
  WlrLayershell.layer: WlrLayer.Overlay
  // Keyboard focus follows `open` (NOT `visible`). The window remains
  // mapped during the fade-out so the opacity animation has something to
  // animate, but keyboard/click ownership must release the moment the
  // logical close fires — otherwise the user is locked out for 140ms.
  WlrLayershell.keyboardFocus: open ? WlrKeyboardFocus.Exclusive : WlrKeyboardFocus.None

  // Full-screen layer-shell. The visible card is positioned inside via
  // `cardOrigin`. The `mask` below makes the bar area click-through (so
  // the user can click another bar icon while the panel is open and the
  // activePopout coordinator swaps to that popup); everywhere else, the
  // overlay catches the click and dismisses via the MouseArea below.
  anchors {
    top: true
    bottom: true
    left: true
    right: true
  }

  // Clickable region is the whole screen. Clicks in the bar strip are
  // forwarded to registered bar buttons so switching between panel icons
  // works in one click even when the overlay surface is above the bar.
  readonly property real _barStripSize: {
    if (!bar) return 0
    var actual = (root.barPos === "top" || root.barPos === "bottom") ? root.barH : root.barW
    return Math.max(bar.barSize, actual) + root.gap
  }
  mask: Region {
    width: root.screenW
    height: root.screenH
  }

  // Track every layout change between the bar's contentItem and the
  // anchor item. `transform` updates whenever any item in that chain
  // moves/resizes, which is what makes the position binding below
  // actually reactive — mapToItem on its own is a one-shot.
  TransformWatcher {
    id: anchorWatcher
    a: anchorWindow ? anchorWindow.contentItem : null
    b: anchorItem
  }

  // Anchor item's position within the bar's content surface. For a
  // full-width top bar, the content x maps directly to screen x; the y
  // returned here has the bar's internal padding baked in (e.g. ~13px
  // from vertical centering of the widget row), which is why `cardOrigin`
  // below uses `barH` for the perpendicular axis instead of this y.
  readonly property point anchorScreenPos: {
    anchorWatcher.transform  // reactive dependency
    if (!anchorItem || !anchorWindow) return Qt.point(0, 0)
    return anchorItem.mapToItem(anchorWindow.contentItem, 0, 0)
  }
  readonly property real anchorW: anchorItem ? anchorItem.width : 0
  readonly property real anchorH: anchorItem ? anchorItem.height : 0
  readonly property real screenW: screen ? screen.width : 0
  readonly property real screenH: screen ? screen.height : 0
  readonly property real availableCardWidth: screenW > 0
    ? Math.max(120, screenW - ((barPos === "left" || barPos === "right") ? barW + gap + margin : margin * 2))
    : 0
  readonly property real availableCardHeight: screenH > 0
    ? Math.max(120, screenH - ((barPos === "top" || barPos === "bottom") ? barH + gap + margin : margin * 2))
    : 0

  function fittedContentWidth(width, cap) {
    var desired = Math.max(1, Number(width) || 1)
    var maxWidth = root.availableCardWidth > 0 ? root.availableCardWidth : desired
    if (cap !== undefined && Number(cap) > 0) maxWidth = Math.min(maxWidth, Number(cap))
    return Math.round(Math.min(desired, maxWidth))
  }

  function fittedContentHeight(implicitHeight, cap) {
    var desired = Math.max(root.padding * 2, (Number(implicitHeight) || 0) + root.padding * 2)
    var maxHeight = root.availableCardHeight > 0 ? root.availableCardHeight : desired
    if (cap !== undefined && Number(cap) > 0) maxHeight = Math.min(maxHeight, Number(cap))
    return Math.round(Math.min(desired, maxHeight))
  }

  function cappedContentHeight(height) {
    var desired = Math.max(root.padding * 2, Number(height) || root.padding * 2)
    var maxHeight = root.availableCardHeight > 0 ? root.availableCardHeight : desired
    return Math.round(Math.min(desired, maxHeight))
  }

  // Desired top-left of the card in screen coordinates. For the
  // perpendicular axis (away-from-bar) we anchor to the bar window's edge
  // directly — not the anchor item's y/x — because mapToItem(barContent)
  // returns coordinates in the bar's content space, which can be offset
  // from the bar surface's screen-anchored corner by internal layout
  // (centering wrappers, padding). The bar's surface IS aligned to its
  // anchored screen edge, so using `barW`/`barH` gives the right edge
  // regardless of how the bar's internal widgets are positioned. For the
  // parallel axis (along the bar) the anchor item's reported position is
  // still consistent with the bar content origin, so it's accurate for
  // centering the card under the icon.
  readonly property real barW: anchorWindow ? anchorWindow.width : screenW
  readonly property real barH: anchorWindow ? anchorWindow.height : 0
  readonly property point cardOrigin: {
    if (!anchorItem || !bar) return Qt.point(margin, margin)
    var x = 0, y = 0
    if (barPos === "bottom") {
      x = anchorScreenPos.x + anchorW / 2 - contentWidth / 2
      y = screenH - barH - contentHeight - gap
    } else if (barPos === "left") {
      x = barW + gap
      y = anchorScreenPos.y + anchorH / 2 - contentHeight / 2
    } else if (barPos === "right") {
      x = screenW - barW - contentWidth - gap
      y = anchorScreenPos.y + anchorH / 2 - contentHeight / 2
    } else { // "top" (default)
      x = anchorScreenPos.x + anchorW / 2 - contentWidth / 2
      y = barH + gap
    }
    x = Math.max(margin, Math.min(x, screenW - contentWidth - margin))
    y = Math.max(margin, Math.min(y, screenH - contentHeight - margin))
    return Qt.point(Math.round(x), Math.round(y))
  }


  // --- popout coordination (same-bar single-popout model) -----------------

  // Coordinate on `open`, not `visible`. `visible` lags into the fade-out
  // animation, which made ownership transfer to a sibling popup race.
  onOpenChanged: {
    if (open && focusTarget) Qt.callLater(function() {
      if (root.open && root.focusTarget) root.focusTarget.forceActiveFocus()
    })
    if (!bar) return
    if (open) bar.requestPopout(coordinatorKey)
    else if (bar.activePopout === coordinatorKey) bar.releasePopout(coordinatorKey)
  }

  // --- outside-click dismissal --------------------------------------------

  // Catches clicks anywhere in the clickable region (i.e. everywhere on
  // screen except the bar strip, which is masked out). The card has its
  // own MouseArea below so clicks on it don't bubble up here. Disabled
  // during the fade-out so the dying overlay doesn't swallow clicks that
  // were meant for the apps behind it.
  MouseArea {
    id: dismissArea
    anchors.fill: parent
    enabled: root.open
    hoverEnabled: true
    property bool hoveringBar: false
    cursorShape: hoveringBar ? Qt.PointingHandCursor : Qt.ArrowCursor

    function inBarRegion(px, py) {
      if (root.barPos === "bottom") return py >= root.screenH - root._barStripSize
      if (root.barPos === "left") return px <= root._barStripSize
      if (root.barPos === "right") return px >= root.screenW - root._barStripSize
      return py <= root._barStripSize
    }

    function barPoint(px, py) {
      if (root.barPos === "bottom") return Qt.point(px, py - (root.screenH - root.barH))
      if (root.barPos === "right") return Qt.point(px - (root.screenW - root.barW), py)
      return Qt.point(px, py)
    }

    function pressTargetAt(px, py) {
      if (!root.anchorWindow || !root.anchorWindow.contentItem || !root.bar || !root.bar.clickTargets) return null
      var p = barPoint(px, py)
      var targets = root.bar.clickTargets
      for (var i = targets.length - 1; i >= 0; i--) {
        var target = targets[i]
        if (!target || !target.triggerPress || target.visible === false || target.opacity === 0 || !target.mapToItem) continue
        var pos = root.anchorWindow.itemPosition(target)
        if (p.x >= pos.x && p.x <= pos.x + target.width && p.y >= pos.y && p.y <= pos.y + target.height) return target
      }
      return null
    }

    function forwardBarClick(px, py, button) {
      var target = pressTargetAt(px, py)
      if (!target) return false
      target.triggerPress(button)
      return true
    }

    onPositionChanged: function(mouse) { hoveringBar = inBarRegion(mouse.x, mouse.y) }
    onExited: hoveringBar = false
    onClicked: function(mouse) {
      if (inBarRegion(mouse.x, mouse.y) && forwardBarClick(mouse.x, mouse.y, mouse.button)) return
      root.closePopout()
    }
  }

  // --- card ----------------------------------------------------------------

  Rectangle {
    id: card
    x: root.cardOrigin.x
    y: root.cardOrigin.y
    width: root.contentWidth
    height: root.contentHeight
    color: Color.popups.background
    border.color: Color.popups.border
    border.width: Math.max(1, Style.space(2))
    radius: Style.cornerRadius
    opacity: root.open ? 1.0 : 0
    Behavior on opacity {
      NumberAnimation { duration: 140; easing.type: Easing.OutCubic }
    }

    // Swallow clicks on the card so they don't bubble to the dismissal
    // MouseArea behind us.
    MouseArea { anchors.fill: parent }

    Item {
      id: contentHolder
      anchors.fill: parent
      anchors.margins: root.padding
    }
  }
}