'use strict'

// .desktop shortcut generation. A shortcut launches the launcher itself with
// `--launch <id>`: the main process either starts the game in the running
// instance or boots headless (no window, tray only), starts the game and lets
// playtime tracking continue normally.

const fs = require('fs')
const path = require('path')
const { DIRS, resolvePortablePath, launcherIconDiskPath } = require('./paths')

const DATA_DIR = process.env.PLWL_BUILD_DIR ? path.join(process.env.PLWL_BUILD_DIR, 'files', 'data') : DIRS.DATA

// Where user-visible shortcuts live (XDG). Override with PLWL_SHORTCUTS_DIR
// so tests (and portable exotic setups) can redirect it.
function desktopDirs() {
  const home = process.env.HOME || '/'
  const dataHome = process.env.XDG_DATA_HOME || path.join(home, '.local', 'share')
  return {
    menu: process.env.PLWL_SHORTCUTS_DIR || path.join(dataHome, 'applications'),
    desktop: process.env.PLWL_SHORTCUTS_DIR || path.join(home, 'Desktop')
  }
}

// Launcher executable as the shortcut will see it, as an argv list: the
// packaged olcxja.plwl/olcxja.plwl binary, or `electron <project>` in dev.
function launcherArgv() {
  if (process.env.PLWL_LAUNCHER_CMD) return process.env.PLWL_LAUNCHER_CMD.split(' ').filter(Boolean)
  const m = __dirname.match(/^(.*)[/\\]app\.asar([/\\]|$)/)
  if (m) {
    const root = path.resolve(m[1], '..', '..')
    const bin = path.join(root, 'olcxja.plwl', 'olcxja.plwl')
    if (fs.existsSync(bin)) return [bin]
  }
  // dev fallback: run through electron from the project dir
  return ['electron', path.resolve(__dirname, '..')]
}

// Desktop Entry Exec field escaping (per the spec): % must be doubled,
// quotes and backslashes escaped, and tokens containing spaces wrapped in
// double quotes.
function execToken(token) {
  const escaped = token.replace(/%/g, '%%').replace(/\\/g, '\\\\').replace(/"/g, '\\"')
  return /[ $"'\\]/.test(token) ? `"${escaped}"` : escaped
}

function execLine(extraArgs) {
  return [...launcherArgv(), ...extraArgs.split(' ').filter(Boolean).map(execToken)].map(execToken).join(' ')
}

function sanitizeName(name) {
  return String(name || 'App').replace(/[\r\n]/g, ' ').trim() || 'App'
}

// Builds the .desktop file content for launching app `id`.
function buildDesktopEntry(game) {
  const name = sanitizeName(game.name)
  const iconDir = path.join(DATA_DIR, 'icons', game.id)
  let icon = ''
  try {
    const found = fs.readdirSync(iconDir).filter(f => f.startsWith('icon.')).sort().pop()
    if (found) icon = path.join(iconDir, found)
  } catch {}
  if (!icon) {
    // fall back to the launcher icon so the shortcut is never naked (the
    // on-disk copy: the desktop environment cannot read inside app.asar)
    icon = launcherIconDiskPath() || ''
  }
  const lines = [
    '[Desktop Entry]',
    'Type=Application',
    `Name=${name}`,
    'Comment=Launch via PLWL',
    `Exec=${execLine(`--launch ${game.id}`)}`,
    'Terminal=false',
    'Categories=Game;'
  ]
  if (icon) lines.push(`Icon=${icon}`)
  return lines.join('\n') + '\n'
}

// Where a given shortcut would be written (used by tests and by the UI hint).
function shortcutPaths(gameId) {
  const dirs = desktopDirs()
  return { menu: path.join(dirs.menu, `plwl-${gameId}.desktop`), desktop: path.join(dirs.desktop, `plwl-${gameId}.desktop`) }
}

// Writes the shortcut. Returns the paths it created.
function createShortcut(game) {
  const content = buildDesktopEntry(game)
  const dirs = desktopDirs()
  const written = []
  for (const [key, dir] of [['menu', dirs.menu], ['desktop', dirs.desktop]]) {
    try {
      fs.mkdirSync(dir, { recursive: true })
      const file = path.join(dir, `plwl-${game.id}.desktop`)
      fs.writeFileSync(file, content)
      if (key === 'menu') {
        // update desktop databases best-effort so the entry shows up at once
        try {
          require('child_process').execFileSync('update-desktop-database', [dir], { timeout: 10000 })
        } catch {}
      }
      written.push(file)
    } catch (err) {
      // a read-only Desktop must not fail the whole operation
      if (key === 'desktop') continue
      throw err
    }
  }
  return { ok: true, paths: written }
}

// Removes shortcuts for a game (also called when the game is removed).
function removeShortcut(gameId) {
  const dirs = desktopDirs()
  for (const file of [path.join(dirs.menu, `plwl-${gameId}.desktop`), path.join(dirs.desktop, `plwl-${gameId}.desktop`)]) {
    try {
      fs.rmSync(file, { force: true })
    } catch {}
  }
}

module.exports = { buildDesktopEntry, createShortcut, removeShortcut, shortcutPaths, launcherArgv }