import QtQuick
import QtQml.Models
import Quickshell
import Quickshell.Io

import "plugins/bar"
import "services"

ShellRoot {
  id: shell

  // Shared service instances. Plugins receive these via property injection
  // rather than re-importing them as singletons — relative-path imports do
  // not share singleton state, which silently leaves consumers with their
  // own empty copies.
  property PluginRegistry pluginRegistry: PluginRegistry { }
  property BarWidgetRegistry barWidgetRegistry: BarWidgetRegistry { }

  property string home: Quickshell.env("HOME")

  // The omarchy-shell host is the long-running entry point. Plugins live in
  // sibling directories under plugins/. Most child code (the bar, future
  // plugins) accept omarchyPath as a required property; resolve it once here
  // from the shellDir so we don't depend on OMARCHY_PATH being set in the env.
  function deriveOmarchyPath() {
    var env = Quickshell.env("OMARCHY_PATH")
    if (env) return env
    var dir = String(Quickshell.shellDir || "")
    if (dir.indexOf("/default/quickshell/omarchy-shell") !== -1)
      return dir.substring(0, dir.indexOf("/default/quickshell/omarchy-shell"))
    return home + "/.local/share/omarchy"
  }
  property string omarchyPath: deriveOmarchyPath()
  readonly property string firstPartyPluginsDir: omarchyPath + "/default/quickshell/omarchy-shell/plugins"

  Component.onCompleted: {
    console.log("omarchy-shell paths",
      "omarchyPath=" + shell.omarchyPath,
      "shellDir=" + Quickshell.shellDir,
      "firstPartyPluginsDir=" + shell.firstPartyPluginsDir)
    pluginRegistry.firstPartyDir = shell.firstPartyPluginsDir
    // PluginRegistry.ensureUserDir() runs in its own Component.onCompleted and
    // chains rescan() once the directory exists. We also kick a scan here in
    // case the user dir already existed at startup.
    pluginRegistry.rescan()
  }

  Bar {
    id: bar
    omarchyPath: shell.omarchyPath
    barWidgetRegistry: shell.barWidgetRegistry
  }

  // ---------------------------------------------------------- on-demand panels

  // openPanelIds is a plain object treated as a set. A plugin id maps to
  // `true` while the panel is summoned; deleting the key (well, building a new
  // object without it) hides it. Reassigning the whole object is required for
  // QML to notice the change.
  property var openPanelIds: ({})

  function isPanelOpen(id) { return openPanelIds[id] === true }

  // Pending payloads to deliver to a plugin's open() once its loader resolves.
  // Keyed by plugin id; the value is an array so two summon() calls before
  // the Loader resolves both reach the plugin in arrival order rather than
  // the second clobbering the first.
  property var pendingPayloads: ({})

  function summon(pluginId, payloadJson) {
    var id = String(pluginId || "")
    if (!id) return false
    var plugins = shell.pluginRegistry.installedPlugins
    if (!plugins[id]) {
      console.warn("summon: unknown plugin", id)
      return false
    }
    var next = ({})
    for (var k in openPanelIds) next[k] = openPanelIds[k]
    next[id] = true
    openPanelIds = next

    // Stash payload so the Loader.onLoaded handler can hand it to open().
    var pending = ({})
    for (var p in pendingPayloads) pending[p] = pendingPayloads[p].slice()
    var queue = pending[id] || []
    queue.push(payloadJson || "")
    pending[id] = queue
    pendingPayloads = pending

    // If the plugin is keepLoaded and already mounted, deliver immediately.
    deliverIfLoaded(id)
    return true
  }

  function hide(pluginId) {
    var id = String(pluginId || "")
    if (!id) return false
    invokeIfLoaded(id, "close", null)
    if (!openPanelIds[id]) return true
    var next = ({})
    for (var k in openPanelIds) if (k !== id) next[k] = openPanelIds[k]
    openPanelIds = next
    return true
  }

  function toggle(pluginId, payloadJson) {
    var id = String(pluginId || "")
    return openPanelIds[id] ? hide(id) : summon(id, payloadJson)
  }

  // Map of pluginId -> Loader, populated by the Instantiator delegate below.
  property var panelLoaders: ({})

  function registerPanelLoader(pluginId, loader) {
    var next = ({})
    for (var k in panelLoaders) next[k] = panelLoaders[k]
    next[pluginId] = loader
    panelLoaders = next
    deliverIfLoaded(pluginId)
  }

  function unregisterPanelLoader(pluginId) {
    if (!panelLoaders[pluginId]) return
    var next = ({})
    for (var k in panelLoaders) if (k !== pluginId) next[k] = panelLoaders[k]
    panelLoaders = next
  }

  function deliverIfLoaded(pluginId) {
    var loader = panelLoaders[pluginId]
    if (!loader || !loader.item) return
    var queue = pendingPayloads[pluginId]
    if (!Array.isArray(queue) || queue.length === 0) return
    if (typeof loader.item.open === "function") {
      for (var i = 0; i < queue.length; i++) {
        try { loader.item.open(queue[i]) } catch (e) {
          console.warn("plugin " + pluginId + " open() threw:", e)
        }
      }
    }
    var next = ({})
    for (var k in pendingPayloads) if (k !== pluginId) next[k] = pendingPayloads[k].slice()
    pendingPayloads = next
  }

  function invokeIfLoaded(pluginId, method, arg) {
    var loader = panelLoaders[pluginId]
    if (!loader || !loader.item) return
    if (typeof loader.item[method] !== "function") return
    try { loader.item[method](arg) } catch (e) {
      console.warn("plugin " + pluginId + " " + method + "() threw:", e)
    }
  }

  // One Loader per discoverable panel/overlay/menu plugin. Active when the
  // host marks it open. The Loader holds onto the instance while active so the
  // plugin's FloatingWindow + state survive between summons within a session.
  property var panelEntries: []

  function computePanelEntries() {
    var out = []
    var plugins = shell.pluginRegistry.installedPlugins
    var panelKinds = ["panel", "overlay", "menu"]
    for (var id in plugins) {
      var m = plugins[id]
      if (!m || !Array.isArray(m.kinds)) continue
      var matched = false
      for (var i = 0; i < panelKinds.length; i++)
        if (m.kinds.indexOf(panelKinds[i]) !== -1) { matched = true; break }
      if (!matched) continue
      if (!shell.pluginRegistry.isEnabled(id)) continue
      var kind = m.kinds.indexOf("panel") !== -1 ? "panel"
        : (m.kinds.indexOf("overlay") !== -1 ? "overlay" : "menu")
      out.push({ id: id, manifest: m, kind: kind, keepLoaded: m.keepLoaded === true })
    }
    return out
  }

  Connections {
    target: shell.pluginRegistry
    function onPluginsChanged() { shell.panelEntries = shell.computePanelEntries() }
  }

  Instantiator {
    model: shell.panelEntries
    active: true

    delegate: QtObject {
      id: panelEntry
      required property var modelData
      readonly property string pluginId: modelData.id
      readonly property var manifest: modelData.manifest
      readonly property string entryKind: modelData.kind
      readonly property bool keepLoaded: modelData.keepLoaded === true
      readonly property string sourceUrl: shell.pluginRegistry.entryPointUrl(manifest, entryKind)

      property Loader panelLoader: Loader {
        source: panelEntry.sourceUrl
        active: panelEntry.sourceUrl !== "" && (panelEntry.keepLoaded || shell.openPanelIds[panelEntry.pluginId] === true)
        asynchronous: true
        onLoaded: {
          if (!item) return
          if ("omarchyPath" in item) item.omarchyPath = shell.omarchyPath
          if ("shell" in item) item.shell = shell
          if ("manifest" in item) item.manifest = panelEntry.manifest
          if ("barWidgetRegistry" in item) item.barWidgetRegistry = shell.barWidgetRegistry
          if ("pluginRegistry" in item) item.pluginRegistry = shell.pluginRegistry
          shell.registerPanelLoader(panelEntry.pluginId, this)
        }
        onStatusChanged: {
          if (status === Loader.Error) {
            console.warn("panel plugin " + panelEntry.pluginId + " failed:",
              sourceComponent ? sourceComponent.errorString() : "")
            shell.hide(panelEntry.pluginId)
          }
        }
        Component.onDestruction: shell.unregisterPanelLoader(panelEntry.pluginId)
      }
    }
  }

  // ---------------------------------------------------------- plugin loader

  // Mirror plugin registry state into BarWidgetRegistry whenever it changes.
  // Each enabled plugin with kind "bar-widget" gets a Component created from
  // its manifest entry point and registered under the id "plugin:<id>".
  Connections {
    target: shell.pluginRegistry
    function onPluginsChanged() { shell.syncPluginWidgets() }
  }

  property var pluginWidgetComponents: ({})

  function syncPluginWidgets() {
    var plugins = shell.pluginRegistry.installedPlugins
    var seen = ({})

    for (var pluginId in plugins) {
      var manifest = plugins[pluginId]
      if (!manifest || !manifest.kinds || manifest.kinds.indexOf("bar-widget") === -1) continue
      if (!shell.pluginRegistry.isEnabled(pluginId)) continue

      var registryKey = "plugin:" + manifest.id
      seen[registryKey] = true

      // Already loaded with matching source — leave it alone.
      var existing = pluginWidgetComponents[registryKey]
      var url = shell.pluginRegistry.entryPointUrl(manifest, "barWidget")
      if (!url) {
        console.warn("Plugin " + manifest.id + " has no barWidget entry point")
        continue
      }
      if (existing && existing.url === url && shell.barWidgetRegistry.has(registryKey)) continue

      var meta = manifest.barWidget || {}
      meta = {
        displayName: meta.displayName || manifest.name,
        description: meta.description || manifest.description,
        category: meta.category || "Plugin",
        allowMultiple: meta.allowMultiple === true,
        defaults: meta.defaults || {},
        schema: meta.schema || [],
        pluginId: manifest.id,
        source: "plugin"
      }

      loadPluginWidget(registryKey, url, meta)
    }

    // Drop registrations for plugins that are no longer present or enabled.
    var allIds = shell.barWidgetRegistry.availableIds()
    for (var i = 0; i < allIds.length; i++) {
      var id = allIds[i]
      if (id.indexOf("plugin:") !== 0) continue
      if (!seen[id]) {
        shell.barWidgetRegistry.unregister(id)
        var next = ({})
        for (var k in pluginWidgetComponents) if (k !== id) next[k] = pluginWidgetComponents[k]
        pluginWidgetComponents = next
      }
    }
  }

  function loadPluginWidget(registryKey, url, meta) {
    var comp = Qt.createComponent(url, Component.Asynchronous)
    function finalize() {
      if (comp.status === Component.Ready) {
        shell.barWidgetRegistry.register(registryKey, comp, meta)
        var next = ({})
        for (var k in pluginWidgetComponents) next[k] = pluginWidgetComponents[k]
        next[registryKey] = { url: url, component: comp }
        pluginWidgetComponents = next
      } else if (comp.status === Component.Error) {
        console.warn("Plugin widget " + registryKey + " failed: " + comp.errorString())
        shell.pluginRegistry.pluginLoadFailed(registryKey, comp.errorString())
      }
    }
    if (comp.status === Component.Loading) {
      comp.statusChanged.connect(finalize)
    } else {
      finalize()
    }
  }

  // ---------------------------------------------------------- shell IPC

  IpcHandler {
    target: "shell"

    function ping(): string {
      return "ok"
    }

    function rescanPlugins(): void {
      shell.pluginRegistry.rescan()
    }

    function setPluginEnabled(id: string, enabled: string): void {
      shell.pluginRegistry.setEnabled(id, enabled === "true")
    }

    function listPlugins(): string {
      var out = []
      var plugins = shell.pluginRegistry.installedPlugins
      for (var id in plugins) {
        out.push({
          id: id,
          name: plugins[id].name,
          kinds: plugins[id].kinds,
          enabled: shell.pluginRegistry.isEnabled(id),
          firstParty: !!plugins[id].__isFirstParty
        })
      }
      return JSON.stringify(out)
    }

    function summon(id: string, payloadJson: string): string {
      return shell.summon(id, payloadJson) ? "ok" : "unknown"
    }

    function hide(id: string): void {
      shell.hide(id)
    }

    function toggle(id: string, payloadJson: string): void {
      shell.toggle(id, payloadJson)
    }
  }
}