import { ref } from 'vue'
import { isTauri, getTauriStore } from '@/lib/tauri'
import { trackLoading } from '@/lib/loadingWindow'

const STORE_KEY_PREFIX = 'pipWindow.geometry.'

interface WindowGeometry {
  x: number
  y: number
  width: number
  height: number
}

const pipWindows = ref<Map<number, boolean>>(new Map())

async function loadGeometry(idx: number): Promise<WindowGeometry | null> {
  try {
    const store = await getTauriStore()
    return await store.get<WindowGeometry>(`${STORE_KEY_PREFIX}${idx}`) ?? null
  } catch {
    return null
  }
}

async function saveGeometry(idx: number, geo: WindowGeometry): Promise<void> {
  try {
    const store = await getTauriStore()
    await store.set(`${STORE_KEY_PREFIX}${idx}`, geo)
  } catch {}
}

export function usePipWindow() {
  async function openPip(terminalIndex: number): Promise<boolean> {
    if (!isTauri) return false

    const pipLabel = `pip-terminal-${terminalIndex}`

    try {
      const { WebviewWindow } = await import('@tauri-apps/api/webviewWindow')

      const existing = await WebviewWindow.getByLabel(pipLabel)
      if (existing) {
        await existing.setFocus()
        return true
      }

      const pipUrl = `/transcript-debug/${terminalIndex}?pip=1`

      // Restore last position/size or use defaults
      const saved = await loadGeometry(terminalIndex)
      const x = saved?.x ?? (window.screen.width - 400)
      const y = saved?.y ?? (60 + (terminalIndex - 1) * 40)
      const width = saved?.width ?? 380
      const height = saved?.height ?? 620

      // Track in the shared loading indicator (bottom-right spinner)
      const dismissLoading = await trackLoading(pipLabel)

      // Create real window hidden
      const pip = new WebviewWindow(pipLabel, {
        url: pipUrl,
        title: `T${terminalIndex} - Agent UI`,
        width,
        height,
        x,
        y,
        visible: false,
        alwaysOnTop: false,
        decorations: false,
        resizable: true,
        focus: true,
      })

      pipWindows.value.set(terminalIndex, true)

      // When real window is ready: show it, remove from loading tracker
      pip.once('tauri://webview-created', () => {
        setTimeout(async () => {
          try { await pip.show() } catch {}
          try { await pip.setFocus() } catch {}
          await dismissLoading()
        }, 200)
      })

      // Persist geometry on close
      pip.onCloseRequested(async () => {
        try {
          const pos = await pip.outerPosition()
          const size = await pip.outerSize()
          await saveGeometry(terminalIndex, {
            x: pos.x,
            y: pos.y,
            width: size.width,
            height: size.height,
          })
        } catch {}
        pipWindows.value.delete(terminalIndex)
      })

      return true
    } catch (e) {
      console.warn(`Failed to open PiP window for T${terminalIndex}:`, e)
      pipWindows.value.delete(terminalIndex)
      return false
    }
  }

  async function closePip(terminalIndex: number): Promise<void> {
    const pipLabel = `pip-terminal-${terminalIndex}`
    try {
      const { WebviewWindow } = await import('@tauri-apps/api/webviewWindow')
      const existing = await WebviewWindow.getByLabel(pipLabel)
      if (existing) await existing.close()
    } catch {}
    pipWindows.value.delete(terminalIndex)
  }

  function isPipOpen(terminalIndex: number): boolean {
    return pipWindows.value.get(terminalIndex) ?? false
  }

  return { openPip, closePip, isPipOpen, pipWindows }
}