import { app, BrowserWindow, ipcMain, shell } from 'electron'
import http from 'node:http'
import https from 'node:https'
import path from 'node:path'
import fs from 'node:fs'
import fsp from 'node:fs/promises'
import { URL } from 'node:url'
import type { ChildProcess } from 'node:child_process'
import type { Manifest, PackDefinition, PackList } from '../shared/types.js'
import { normalizePackDefinition } from '../shared/store.js'
import { getAppDataDir, getMcCustomDir } from '../shared/paths.js'
import type { RpFetchedPack } from './types.js'
import { ensureYtDlpExe } from './ytdlp.js'
import { ensureFfmpegExe } from './ffmpeg.js'
import { downloadMusicTrack } from './music.js'
import { downloadImage, normalizeToCover, coverFileName } from './images.js'
import { buildResourcepackZip } from './pack.js'

interface RpInstallerState {
  manifestUrl: string
  baseUrl: string
  packs: Map<string, RpFetchedPack>
  selectedKey: string | null
  /** 현재 설치 진행 중인지 여부. 취소 신호로 사용. */
  cancelRequested: boolean
  /** 현재 실행 중인 외부 프로세스(yt-dlp/ffmpeg). 취소 시 kill 대상. */
  currentChild: ChildProcess | null
}

const DEFAULT_MANIFEST_URL = process.env.MANIFEST_URL ?? 'http://127.0.0.1:3000/manifest.json'

const state: RpInstallerState = {
  manifestUrl: DEFAULT_MANIFEST_URL,
  baseUrl: deriveBaseUrl(DEFAULT_MANIFEST_URL),
  packs: new Map(),
  selectedKey: null,
  cancelRequested: false,
  currentChild: null
}

let mainWindow: BrowserWindow | null = null

function deriveBaseUrl(manifestUrl: string): string {
  try {
    const parsed = new URL(manifestUrl)
    return `${parsed.protocol}//${parsed.host}`
  } catch {
    return ''
  }
}

function createMainWindow(): void {
  mainWindow = new BrowserWindow({
    width: 900,
    height: 680,
    webPreferences: {
      preload: path.join(__dirname, 'preload.js'),
      contextIsolation: true,
      nodeIntegration: false
    }
  })
  mainWindow.removeMenu()
  void mainWindow.loadFile(path.join(__dirname, '..', '..', 'installer-rp', 'index.html'))
}

function sendLog(line: string): void {
  if (!mainWindow || mainWindow.isDestroyed()) return
  const stamped = `[${new Date().toLocaleTimeString('ko-KR', { hour12: false })}] ${line}`
  mainWindow.webContents.send('log', stamped)
}

function fetchBuffer(url: string): Promise<Buffer> {
  return new Promise((resolve, reject) => {
    const target = new URL(url)
    const transport = target.protocol === 'https:' ? https : http
    const request = transport.get(target, { timeout: 30000 }, (response) => {
      if (response.statusCode === 301 || response.statusCode === 302) {
        const redirect = response.headers.location
        if (redirect) {
          response.resume()
          fetchBuffer(new URL(redirect, target).toString()).then(resolve, reject)
          return
        }
      }
      if ((response.statusCode ?? 0) >= 400) {
        response.resume()
        reject(new Error(`HTTP ${response.statusCode}`))
        return
      }
      const chunks: Buffer[] = []
      response.on('data', (chunk: Buffer) => chunks.push(chunk))
      response.on('end', () => resolve(Buffer.concat(chunks)))
    })
    request.on('error', reject)
    request.on('timeout', () => request.destroy(new Error('요청 시간 초과')))
  })
}

async function fetchJson<T>(url: string): Promise<T> {
  const buffer = await fetchBuffer(url)
  return JSON.parse(buffer.toString('utf8')) as T
}

// ── IPC: 1단계 manifest 로드 ─────────────────────────
ipcMain.handle('rp:packs:load', async (_event, manifestUrlInput?: string): Promise<RpFetchedPack[]> => {
  if (typeof manifestUrlInput === 'string' && manifestUrlInput.length > 0) {
    state.manifestUrl = manifestUrlInput
    state.baseUrl = deriveBaseUrl(manifestUrlInput)
  }
  sendLog(`manifest 다운로드: ${state.manifestUrl}`)
  const manifest = await fetchJson<Manifest>(state.manifestUrl)
  const results: RpFetchedPack[] = []
  for (const entry of manifest.packs ?? []) {
    if (typeof entry?.file !== 'string') continue
    const listUrl = `${state.baseUrl}/file/list/${encodeURIComponent(entry.file)}.json`
    const packUrl = `${state.baseUrl}/manifest/${encodeURIComponent(entry.file)}.json`
    try {
      // 목록(필수) + 팩 정의(mcVersion 용, 실패해도 폴백) 동시 로드.
      const [listRaw, packRaw] = await Promise.all([
        fetchJson<Partial<PackList>>(listUrl),
        fetchJson<Partial<PackDefinition>>(packUrl).catch((err) => {
          sendLog(`팩 정의 로드 실패 (${entry.file}): ${(err as Error).message} — mcVersion 폴백`)
          return null
        })
      ])
      const list: PackList = {
        musicPlaylistUrl: typeof listRaw.musicPlaylistUrl === 'string' ? listRaw.musicPlaylistUrl : '',
        imagePlaylistUrl: typeof listRaw.imagePlaylistUrl === 'string' ? listRaw.imagePlaylistUrl : '',
        music: Array.isArray(listRaw.music) ? listRaw.music : [],
        images: Array.isArray(listRaw.images) ? listRaw.images : []
      }
      const mcVersion = packRaw
        ? normalizePackDefinition(packRaw as Partial<PackDefinition>).mcVersion
        : ''
      results.push({ key: entry.file, name: entry.name || entry.file, mcVersion, list })
    } catch (error) {
      sendLog(`목록 로드 실패 (${entry.file}): ${(error as Error).message}`)
    }
  }
  state.packs.clear()
  for (const item of results) state.packs.set(item.key, item)
  sendLog(`로드된 음악퀴즈: ${results.length}개`)
  return results
})

ipcMain.handle('rp:packs:select', async (_event, packKey: string) => {
  if (!state.packs.has(packKey)) {
    throw new Error('선택한 음악퀴즈를 찾을 수 없습니다.')
  }
  state.selectedKey = packKey
  sendLog(`선택: ${packKey}`)
})

// ── IPC: 2단계 설치 ──────────────────────────────────
ipcMain.handle('rp:install:start', async (): Promise<{ resourcepackPath: string }> => {
  if (!state.selectedKey) throw new Error('음악퀴즈를 먼저 선택해주세요.')
  const pack = state.packs.get(state.selectedKey)
  if (!pack) throw new Error('선택된 음악퀴즈를 찾을 수 없습니다.')
  state.cancelRequested = false

  const tempRoot = path.join(getMcCustomDir(), '.temp')
  await fsp.mkdir(tempRoot, { recursive: true })

  try {
    // 2-1. yt-dlp / ffmpeg 준비 (%appdata%/.mc_custom/{yt-dlp,ffmpeg}.exe)
    sendLog('yt-dlp 준비 중…')
    const ytDlpBin = await ensureYtDlpExe(sendLog)
    sendLog(`yt-dlp 경로: ${ytDlpBin}`)
    throwIfCancelled()
    sendLog('ffmpeg 준비 중…')
    const ffmpegBin = await ensureFfmpegExe(sendLog)
    sendLog(`ffmpeg 경로: ${ffmpegBin}`)
    throwIfCancelled()

    // 2-2. 음악 다운로드 (1번부터 순차, ogg 변환)
    const musicDir = path.join(tempRoot, 'music')
    await fsp.mkdir(musicDir, { recursive: true })
    sendLog(`음악 다운로드 시작 (${pack.list.music.length}곡)`)
    for (let i = 0; i < pack.list.music.length; i++) {
      throwIfCancelled()
      const entry = pack.list.music[i]
      sendLog(`${i + 1}번 노래 다운로드 중…`)
      try {
        const outPath = await downloadMusicTrack({
          ytdlpExe: ytDlpBin,
          ffmpegExe: ffmpegBin,
          tempDir: musicDir,
          index: i + 1,
          url: entry.url,
          log: sendLog,
          onChild: (c) => { state.currentChild = c }
        })
        state.currentChild = null
        sendLog(`${i + 1}번 노래 완료: ${path.basename(outPath)}`)
      } catch (err) {
        state.currentChild = null
        // 취소된 경우는 throwIfCancelled 가 일관된 메시지로 다시 던지게 함.
        if (state.cancelRequested) throwIfCancelled()
        throw new Error(`${i + 1}번 노래 다운로드 실패: ${(err as Error).message}`)
      }
    }

    // 2-3. 사진 다운로드 + painting variant 정규화
    const paintingDir = path.join(tempRoot, 'painting')
    await fsp.mkdir(paintingDir, { recursive: true })
    sendLog(`사진 다운로드 시작 (${pack.list.images.length}장)`)
    for (let i = 0; i < pack.list.images.length; i++) {
      throwIfCancelled()
      const entry = pack.list.images[i]
      sendLog(`${i + 1}번 사진 다운로드 중…`)
      let buf: Buffer
      try {
        buf = await downloadImage(entry.url)
      } catch (err) {
        throw new Error(`${i + 1}번 사진 다운로드 실패: ${(err as Error).message}`)
      }
      throwIfCancelled()
      const outPath = path.join(paintingDir, coverFileName(i + 1))
      try {
        await normalizeToCover(buf, outPath)
      } catch (err) {
        throw new Error(`${i + 1}번 사진 정규화 실패: ${(err as Error).message}`)
      }
      sendLog(`${i + 1}번 사진 완료: ${path.basename(outPath)}`)
    }

    // 2-4. 리소스팩 zip 빌드 (pack.mcmeta + sounds.json + 음악·이미지)
    throwIfCancelled()
    const resourcepackName = `${state.selectedKey}_musicquiz.zip`
    const resourcepackDir = path.join(getAppDataDir(), '.minecraft', 'resourcepacks')
    const resourcepackPath = path.join(resourcepackDir, resourcepackName)
    sendLog(`리소스팩 zip 빌드 중… (${resourcepackName})`)
    await buildResourcepackZip({
      musicDir,
      paintingDir,
      packName: pack.name,
      mcVersion: pack.mcVersion,
      workDir: tempRoot,
      outZipPath: resourcepackPath,
      log: sendLog
    })

    // 2-5. %appdata%/.minecraft/resourcepacks/ 에 배치 (위 빌드가 직접 outZipPath 에 저장)
    sendLog(`설치 완료: ${resourcepackPath}`)
    return { resourcepackPath }
  } finally {
    // 임시 파일 정리
    await fsp.rm(tempRoot, { recursive: true, force: true }).catch(() => {})
  }
})

ipcMain.handle('rp:install:cancel', async () => {
  state.cancelRequested = true
  sendLog('취소 요청됨. 진행 중 작업을 중단합니다…')
  if (state.currentChild && !state.currentChild.killed) {
    state.currentChild.kill()
  }
})

function throwIfCancelled(): void {
  if (state.cancelRequested) {
    throw new Error('사용자가 설치를 취소했습니다.')
  }
}

// ── IPC: 3단계 완료 ──────────────────────────────────
ipcMain.handle('rp:finish:openFolder', async () => {
  const dir = path.join(getAppDataDir(), '.minecraft', 'resourcepacks')
  if (!fs.existsSync(dir)) {
    await fsp.mkdir(dir, { recursive: true })
  }
  await shell.openPath(dir)
})

ipcMain.handle('rp:quit', async () => {
  app.quit()
})

// ── 앱 라이프사이클 ───────────────────────────────
app.whenReady().then(() => {
  createMainWindow()
  app.on('activate', () => {
    if (BrowserWindow.getAllWindows().length === 0) createMainWindow()
  })
})

app.on('window-all-closed', () => {
  // 강제 종료 시에도 임시 파일은 정리.
  fsp.rm(path.join(getMcCustomDir(), '.temp'), { recursive: true, force: true }).catch(() => {})
  if (process.platform !== 'darwin') app.quit()
})