const {
  app,
  BrowserWindow,
  Menu,
  Notification,
  clipboard,
  dialog,
  ipcMain,
  nativeImage,
  session,
  shell,
  systemPreferences
} = require('electron')
const crypto = require('node:crypto')
const fs = require('node:fs')
const http = require('node:http')
const https = require('node:https')
const net = require('node:net')
const path = require('node:path')
const { fileURLToPath, pathToFileURL } = require('node:url')
const { spawn } = require('node:child_process')

const PORT_FLOOR = 9120
const PORT_CEILING = 9199
const DEV_SERVER = process.env.HERMES_DESKTOP_DEV_SERVER
const REPO_ROOT = path.resolve(__dirname, '../../..')
const DESKTOP_ROOT = path.resolve(__dirname, '..')
const IS_MAC = process.platform === 'darwin'
const APP_NAME = 'Hermes'
const TITLEBAR_HEIGHT = 34
const MACOS_TRAFFIC_LIGHTS_HEIGHT = 14
const WINDOW_BUTTON_POSITION = {
  x: 24,
  y: TITLEBAR_HEIGHT / 2 - MACOS_TRAFFIC_LIGHTS_HEIGHT / 2
}
const APP_ICON_PATH = path.join(DESKTOP_ROOT, 'public', 'apple-touch-icon.png')

app.setName(APP_NAME)

let mainWindow = null
let hermesProcess = null
let connectionPromise = null
const hermesLog = []

function rememberLog(chunk) {
  const text = String(chunk || '').trim()
  if (!text) return
  hermesLog.push(...text.split(/\r?\n/).map(line => `[hermes] ${line}`))
  if (hermesLog.length > 300) {
    hermesLog.splice(0, hermesLog.length - 300)
  }
}

function findPython() {
  const local = [path.join(REPO_ROOT, '.venv', 'bin', 'python'), path.join(REPO_ROOT, 'venv', 'bin', 'python')]
  return local.find(candidate => fs.existsSync(candidate)) || 'python3'
}

function isPortAvailable(port) {
  return new Promise(resolve => {
    const server = net.createServer()
    server.once('error', () => resolve(false))
    server.once('listening', () => {
      server.close(() => resolve(true))
    })
    server.listen(port, '127.0.0.1')
  })
}

async function pickPort() {
  for (let port = PORT_FLOOR; port <= PORT_CEILING; port += 1) {
    if (await isPortAvailable(port)) return port
  }
  throw new Error(`No free localhost port in ${PORT_FLOOR}-${PORT_CEILING}`)
}

function fetchJson(url, token, options = {}) {
  return new Promise((resolve, reject) => {
    const body = options.body === undefined ? undefined : Buffer.from(JSON.stringify(options.body))

    const req = http.request(
      url,
      {
        method: options.method || 'GET',
        headers: {
          'Content-Type': 'application/json',
          'X-Hermes-Session-Token': token,
          ...(body ? { 'Content-Length': String(body.length) } : {})
        }
      },
      res => {
        const chunks = []
        res.on('data', chunk => chunks.push(chunk))
        res.on('end', () => {
          const text = Buffer.concat(chunks).toString('utf8')
          if ((res.statusCode || 500) >= 400) {
            reject(new Error(`${res.statusCode}: ${text || res.statusMessage}`))
            return
          }
          try {
            resolve(text ? JSON.parse(text) : null)
          } catch (error) {
            reject(error)
          }
        })
      }
    )

    req.on('error', reject)
    if (body) req.write(body)
    req.end()
  })
}

function mimeTypeForPath(filePath) {
  const ext = path.extname(filePath || '').toLowerCase()
  if (ext === '.png') return 'image/png'
  if (ext === '.jpg' || ext === '.jpeg') return 'image/jpeg'
  if (ext === '.gif') return 'image/gif'
  if (ext === '.webp') return 'image/webp'
  if (ext === '.svg') return 'image/svg+xml'
  if (ext === '.bmp') return 'image/bmp'
  return 'application/octet-stream'
}

function extensionForMimeType(mimeType) {
  const type = String(mimeType || '')
    .split(';')[0]
    .trim()
    .toLowerCase()
  if (type === 'image/png') return '.png'
  if (type === 'image/jpeg') return '.jpg'
  if (type === 'image/gif') return '.gif'
  if (type === 'image/webp') return '.webp'
  if (type === 'image/bmp') return '.bmp'
  if (type === 'image/svg+xml') return '.svg'
  return ''
}

function filenameFromUrl(rawUrl, fallback = 'image') {
  try {
    const parsed = new URL(rawUrl)
    const base = path.basename(decodeURIComponent(parsed.pathname || ''))
    return base && base.includes('.') ? base : fallback
  } catch {
    return fallback
  }
}

async function resourceBufferFromUrl(rawUrl) {
  if (!rawUrl) throw new Error('Missing URL')
  if (rawUrl.startsWith('data:')) {
    const match = rawUrl.match(/^data:([^;,]+)?(;base64)?,(.*)$/s)
    if (!match) throw new Error('Invalid data URL')
    const mimeType = match[1] || 'application/octet-stream'
    const encoded = match[3] || ''
    const buffer = match[2] ? Buffer.from(encoded, 'base64') : Buffer.from(decodeURIComponent(encoded), 'utf8')
    return { buffer, mimeType }
  }
  if (rawUrl.startsWith('file:')) {
    const filePath = fileURLToPath(rawUrl)
    const buffer = await fs.promises.readFile(filePath)
    return { buffer, mimeType: mimeTypeForPath(filePath) }
  }

  const parsed = new URL(rawUrl)
  const client = parsed.protocol === 'https:' ? https : http
  return new Promise((resolve, reject) => {
    const req = client.get(parsed, res => {
      if ((res.statusCode || 500) >= 400) {
        reject(new Error(`Failed to fetch ${rawUrl}: ${res.statusCode}`))
        res.resume()
        return
      }
      const chunks = []
      res.on('data', chunk => chunks.push(chunk))
      res.on('end', () => {
        resolve({
          buffer: Buffer.concat(chunks),
          mimeType: res.headers['content-type'] || 'application/octet-stream'
        })
      })
    })
    req.on('error', reject)
  })
}

async function copyImageFromUrl(rawUrl) {
  const { buffer } = await resourceBufferFromUrl(rawUrl)
  const image = nativeImage.createFromBuffer(buffer)
  if (image.isEmpty()) throw new Error('Could not read image')
  clipboard.writeImage(image)
}

async function saveImageFromUrl(rawUrl) {
  const { buffer, mimeType } = await resourceBufferFromUrl(rawUrl)
  const fallbackName = filenameFromUrl(rawUrl, `image${extensionForMimeType(mimeType) || '.png'}`)
  const result = await dialog.showSaveDialog(mainWindow, {
    title: 'Save Image',
    defaultPath: fallbackName
  })
  if (result.canceled || !result.filePath) return false
  await fs.promises.writeFile(result.filePath, buffer)
  return true
}

async function waitForHermes(baseUrl, token) {
  const deadline = Date.now() + 45_000
  let lastError = null

  while (Date.now() < deadline) {
    try {
      await fetchJson(`${baseUrl}/api/status`, token)
      return
    } catch (error) {
      lastError = error
      await new Promise(resolve => setTimeout(resolve, 500))
    }
  }

  throw new Error(`Hermes dashboard did not become ready: ${lastError?.message || 'timeout'}`)
}

function getWindowButtonPosition() {
  if (!IS_MAC) return null
  return mainWindow?.getWindowButtonPosition?.() || WINDOW_BUTTON_POSITION
}

function getAppIconPath() {
  return fs.existsSync(APP_ICON_PATH) ? APP_ICON_PATH : undefined
}

function resolveHermesCwd() {
  const candidates = [process.env.HERMES_DESKTOP_CWD, process.env.INIT_CWD, process.cwd(), REPO_ROOT]
  for (const candidate of candidates) {
    if (!candidate) continue
    const resolved = path.resolve(String(candidate))
    try {
      if (fs.statSync(resolved).isDirectory()) return resolved
    } catch {
      // Try the next candidate.
    }
  }
  return REPO_ROOT
}

function buildApplicationMenu() {
  const template = []
  if (IS_MAC) {
    template.push({
      label: APP_NAME,
      submenu: [
        { role: 'about', label: `About ${APP_NAME}` },
        { type: 'separator' },
        { role: 'services' },
        { type: 'separator' },
        { role: 'hide' },
        { role: 'hideOthers' },
        { role: 'unhide' },
        { type: 'separator' },
        { role: 'quit' }
      ]
    })
  }

  template.push({
    label: 'File',
    submenu: [IS_MAC ? { role: 'close' } : { role: 'quit' }]
  })
  template.push({
    label: 'Edit',
    submenu: [
      { role: 'undo' },
      { role: 'redo' },
      { type: 'separator' },
      { role: 'cut' },
      { role: 'copy' },
      { role: 'paste' },
      { role: 'delete' },
      { role: 'selectAll' }
    ]
  })
  template.push({
    label: 'View',
    submenu: [
      { role: 'reload' },
      { role: 'forceReload' },
      { role: 'toggleDevTools' },
      { type: 'separator' },
      { role: 'resetZoom' },
      { role: 'zoomIn' },
      { role: 'zoomOut' },
      { type: 'separator' },
      { role: 'togglefullscreen' }
    ]
  })
  template.push({
    label: 'Window',
    submenu: IS_MAC
      ? [{ role: 'minimize' }, { role: 'zoom' }, { role: 'front' }]
      : [{ role: 'minimize' }, { role: 'close' }]
  })

  return Menu.buildFromTemplate(template)
}

function toggleDevTools(window) {
  if (!DEV_SERVER) return
  const { webContents } = window
  if (webContents.isDevToolsOpened()) {
    webContents.closeDevTools()
  } else {
    webContents.openDevTools({ mode: 'detach' })
  }
}

function installDevToolsShortcut(window) {
  if (!DEV_SERVER) return
  window.webContents.on('before-input-event', (event, input) => {
    const key = input.key.toLowerCase()
    const isInspectShortcut =
      input.key === 'F12' ||
      (IS_MAC && input.meta && input.alt && key === 'i') ||
      (!IS_MAC && input.control && input.shift && key === 'i')
    if (!isInspectShortcut) return
    event.preventDefault()
    toggleDevTools(window)
  })
}

function installContextMenu(window) {
  window.webContents.on('context-menu', (_event, params) => {
    const template = []
    const hasSelection = Boolean(params.selectionText?.trim())
    const hasImage = params.mediaType === 'image' && Boolean(params.srcURL)
    const hasLink = Boolean(params.linkURL)
    const isEditable = Boolean(params.isEditable)

    if (hasImage) {
      template.push(
        {
          label: 'Open Image',
          click: () => {
            if (params.srcURL && !params.srcURL.startsWith('data:')) {
              void shell.openExternal(params.srcURL)
            }
          },
          enabled: !params.srcURL.startsWith('data:')
        },
        {
          label: 'Copy Image',
          click: () => {
            void copyImageFromUrl(params.srcURL).catch(error => rememberLog(`Copy image failed: ${error.message}`))
          }
        },
        {
          label: 'Copy Image Address',
          click: () => clipboard.writeText(params.srcURL)
        },
        {
          label: 'Save Image As...',
          click: () => {
            void saveImageFromUrl(params.srcURL).catch(error => rememberLog(`Save image failed: ${error.message}`))
          }
        }
      )
    }

    if (hasLink) {
      if (template.length) template.push({ type: 'separator' })
      template.push(
        {
          label: 'Open Link',
          click: () => void shell.openExternal(params.linkURL)
        },
        {
          label: 'Copy Link',
          click: () => clipboard.writeText(params.linkURL)
        }
      )
    }

    if (hasSelection || isEditable) {
      if (template.length) template.push({ type: 'separator' })
      if (isEditable) {
        template.push(
          { role: 'cut', enabled: params.editFlags.canCut },
          { role: 'copy', enabled: params.editFlags.canCopy },
          { role: 'paste', enabled: params.editFlags.canPaste },
          { type: 'separator' },
          { role: 'selectAll', enabled: params.editFlags.canSelectAll }
        )
      } else {
        template.push({ role: 'copy', enabled: params.editFlags.canCopy })
      }
    }

    if (!template.length) {
      template.push({ role: 'selectAll' })
    }

    Menu.buildFromTemplate(template).popup({ window })
  })
}

function installMediaPermissions() {
  session.defaultSession.setPermissionRequestHandler((_webContents, permission, callback, details) => {
    if (permission === 'media' && details?.mediaTypes?.includes('audio')) {
      callback(true)

      return
    }

    callback(false)
  })
}

async function startHermes() {
  if (connectionPromise) return connectionPromise

  connectionPromise = (async () => {
    const port = await pickPort()
    const token = crypto.randomBytes(32).toString('base64url')
    const python = findPython()
    const args = [
      '-m',
      'hermes_cli.main',
      'dashboard',
      '--no-open',
      '--tui',
      '--host',
      '127.0.0.1',
      '--port',
      String(port)
    ]
    const hermesCwd = resolveHermesCwd()

    hermesProcess = spawn(python, args, {
      cwd: hermesCwd,
      env: {
        ...process.env,
        PYTHONPATH: [REPO_ROOT, process.env.PYTHONPATH].filter(Boolean).join(path.delimiter),
        HERMES_DASHBOARD_SESSION_TOKEN: token,
        HERMES_DASHBOARD_TUI: '1',
        HERMES_WEB_DIST: path.join(REPO_ROOT, 'apps', 'desktop', 'dist')
      },
      stdio: ['ignore', 'pipe', 'pipe']
    })

    hermesProcess.stdout.on('data', rememberLog)
    hermesProcess.stderr.on('data', rememberLog)
    hermesProcess.once('exit', (code, signal) => {
      rememberLog(`Hermes dashboard exited (${signal || code})`)
      hermesProcess = null
      connectionPromise = null
      mainWindow?.webContents.send('hermes:backend-exit', { code, signal })
    })

    const baseUrl = `http://127.0.0.1:${port}`
    await waitForHermes(baseUrl, token)

    return {
      baseUrl,
      token,
      wsUrl: `ws://127.0.0.1:${port}/api/ws?token=${encodeURIComponent(token)}`,
      logs: hermesLog.slice(-80),
      windowButtonPosition: getWindowButtonPosition()
    }
  })()

  return connectionPromise
}

function createWindow() {
  const icon = getAppIconPath()
  mainWindow = new BrowserWindow({
    width: 1220,
    height: 800,
    minWidth: 900,
    minHeight: 620,
    title: 'Hermes',
    titleBarStyle: IS_MAC ? 'hidden' : 'default',
    titleBarOverlay: IS_MAC ? { height: TITLEBAR_HEIGHT } : undefined,
    trafficLightPosition: IS_MAC ? WINDOW_BUTTON_POSITION : undefined,
    vibrancy: IS_MAC ? 'sidebar' : undefined,
    icon,
    backgroundColor: '#f7f7f7',
    webPreferences: {
      preload: path.join(__dirname, 'preload.cjs'),
      contextIsolation: true,
      nodeIntegration: false,
      devTools: Boolean(DEV_SERVER)
    }
  })

  if (IS_MAC) {
    mainWindow.setWindowButtonPosition?.(WINDOW_BUTTON_POSITION)
    if (icon) {
      app.dock?.setIcon(icon)
    }
  }

  installDevToolsShortcut(mainWindow)
  installContextMenu(mainWindow)

  if (DEV_SERVER) {
    mainWindow.loadURL(DEV_SERVER)
  } else {
    mainWindow.loadURL(pathToFileURL(path.join(__dirname, '..', 'dist', 'index.html')).toString())
  }
}

ipcMain.handle('hermes:connection', async () => startHermes())

ipcMain.handle('hermes:requestMicrophoneAccess', async () => {
  if (!IS_MAC || typeof systemPreferences.askForMediaAccess !== 'function') {
    return true
  }

  return systemPreferences.askForMediaAccess('microphone')
})

ipcMain.handle('hermes:api', async (_event, request) => {
  const connection = await startHermes()
  return fetchJson(`${connection.baseUrl}${request.path}`, connection.token, {
    method: request.method,
    body: request.body
  })
})

ipcMain.handle('hermes:notify', (_event, payload) => {
  if (!Notification.isSupported()) return false
  new Notification({
    title: payload?.title || 'Hermes',
    body: payload?.body || '',
    silent: Boolean(payload?.silent)
  }).show()
  return true
})

ipcMain.handle('hermes:readFileDataUrl', async (_event, filePath) => {
  const resolved = path.resolve(String(filePath || ''))
  const data = await fs.promises.readFile(resolved)
  return `data:${mimeTypeForPath(resolved)};base64,${data.toString('base64')}`
})

ipcMain.handle('hermes:selectPaths', async (_event, options = {}) => {
  const properties = ['openFile']
  if (options?.directories) properties.push('openDirectory')
  if (options?.multiple !== false) properties.push('multiSelections')

  const result = await dialog.showOpenDialog(mainWindow, {
    title: options?.title || 'Add context',
    defaultPath: options?.defaultPath ? path.resolve(String(options.defaultPath)) : undefined,
    properties,
    filters: Array.isArray(options?.filters) ? options.filters : undefined
  })

  if (result.canceled) return []
  return result.filePaths
})

ipcMain.handle('hermes:writeClipboard', (_event, text) => {
  clipboard.writeText(String(text || ''))
  return true
})

ipcMain.handle('hermes:saveImageFromUrl', (_event, url) => saveImageFromUrl(String(url || '')))

ipcMain.handle('hermes:openExternal', (_event, url) => shell.openExternal(url))

app.whenReady().then(() => {
  Menu.setApplicationMenu(buildApplicationMenu())
  installMediaPermissions()
  createWindow()
  startHermes().catch(error => rememberLog(error.stack || error.message))

  app.on('activate', () => {
    if (BrowserWindow.getAllWindows().length === 0) createWindow()
  })
})

app.on('before-quit', () => {
  if (hermesProcess && !hermesProcess.killed) {
    hermesProcess.kill('SIGTERM')
  }
})

app.on('window-all-closed', () => {
  if (process.platform !== 'darwin') app.quit()
})