import { app, BrowserWindow, dialog, ipcMain, shell } from 'electron'
import http from 'node:http'
import https from 'node:https'
import os from 'node:os'
import path from 'node:path'
import fs from 'node:fs'
import fsp from 'node:fs/promises'
import { spawn } from 'node:child_process'
import { URL } from 'node:url'
import natUpnp from 'nat-upnp'
// extract-zip은 CommonJS 기본 export.
const extractZip: (source: string, options: { dir: string }) => Promise<void> = require('extract-zip')
import type {
  ClientInstallPayload,
  FetchedPack,
  PortForwardResult,
  RamCheckResult,
  ServerInstallPayload
} from './types'
import type { Manifest, PackDefinition } from '../shared/types'
import { normalizePackDefinition } from '../shared/store'

interface InstallerState {
  manifestUrl: string
  baseUrl: string
  packs: Map<string, FetchedPack>
  selectedKey: string | null
  installPath: string | null
  configEditorServer: http.Server | null
  configEditorPort: number | null
}

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

const state: InstallerState = {
  manifestUrl: DEFAULT_MANIFEST_URL,
  baseUrl: deriveBaseUrl(DEFAULT_MANIFEST_URL),
  packs: new Map(),
  selectedKey: null,
  installPath: null,
  configEditorServer: null,
  configEditorPort: 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: 980,
    height: 720,
    webPreferences: {
      preload: path.join(__dirname, 'preload.js'),
      contextIsolation: true,
      nodeIntegration: false
    }
  })
  mainWindow.removeMenu()
  void mainWindow.loadFile(path.join(__dirname, '..', '..', 'installer', '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
}

async function downloadFile(url: string, target: string): Promise<void> {
  await fsp.mkdir(path.dirname(target), { recursive: true })
  const buffer = await fetchBuffer(url)
  await fsp.writeFile(target, buffer)
}

function containsHangul(text: string): boolean {
  return /[\u3131-\u318E\uAC00-\uD7A3\u1100-\u11FF]/.test(text)
}

ipcMain.handle('packs:load', async (_event, manifestUrlInput?: string): Promise<FetchedPack[]> => {
  if (typeof manifestUrlInput === 'string' && manifestUrlInput.length > 0) {
    state.manifestUrl = manifestUrlInput
    state.baseUrl = deriveBaseUrl(manifestUrlInput)
  }
  sendLog(`manifest 다운로드: ${state.manifestUrl}`)
  const manifest = await fetchJson<Manifest>(state.manifestUrl)
  const results: FetchedPack[] = []
  for (const entry of manifest.packs ?? []) {
    if (typeof entry?.file !== 'string') continue
    const packUrl = `${state.baseUrl}/manifest.json`.replace(/manifest\.json$/, `manifest/${entry.file}.json`)
    try {
      const raw = await fetchJson<Partial<PackDefinition>>(packUrl)
      const pack = normalizePackDefinition(raw)
      results.push({ key: entry.file, name: entry.name || pack.name, pack })
    } catch (error) {
      sendLog(`pack 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('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}`)
})

ipcMain.handle('dialog:pickFolder', async (): Promise<string | null> => {
  if (!mainWindow) return null
  const result = await dialog.showOpenDialog(mainWindow, {
    properties: ['openDirectory', 'createDirectory']
  })
  if (result.canceled || result.filePaths.length === 0) return null
  return result.filePaths[0]
})

ipcMain.handle('install:validatePath', async (_event, target: string) => {
  if (!target || target.trim().length === 0) {
    return { ok: false, message: '서버 설치 경로를 입력해 주세요.' }
  }
  if (containsHangul(target)) {
    return { ok: false, message: '경로에 한글이 포함되면 마인크래프트 서버가 정상 동작하지 않습니다.' }
  }
  const absolute = path.resolve(target)
  state.installPath = absolute
  return { ok: true, message: absolute }
})

ipcMain.handle('jdk:detect', async () => {
  const candidates: string[] = []
  if (process.env.JAVA_HOME) candidates.push(process.env.JAVA_HOME)
  if (process.env.JDK_HOME) candidates.push(process.env.JDK_HOME)
  candidates.push('C:\\Program Files\\Java')

  for (const candidate of candidates) {
    if (!candidate) continue
    try {
      const stat = await fsp.stat(candidate)
      if (stat.isFile()) {
        return { found: true, path: candidate }
      }
      if (stat.isDirectory()) {
        const javaExe = path.join(candidate, 'bin', process.platform === 'win32' ? 'java.exe' : 'java')
        if (fs.existsSync(javaExe)) {
          return { found: true, path: candidate }
        }
        const entries = await fsp.readdir(candidate)
        for (const entry of entries) {
          const child = path.join(candidate, entry)
          const childJava = path.join(child, 'bin', process.platform === 'win32' ? 'java.exe' : 'java')
          if (fs.existsSync(childJava)) {
            return { found: true, path: child }
          }
        }
      }
    } catch {
      continue
    }
  }
  return { found: false, path: '' }
})

/**
 * 입력값이 절대 URL이면 그대로, 상대값이면 manifest 도메인의 /file/<subDir>/<file> 로 해석.
 */
function resolveManifestRelative(input: string, subDir: string): string {
  if (!input) return ''
  if (/^https?:\/\//i.test(input)) return input
  const fileName = input.replace(/^\/+/, '')
  return `${state.baseUrl}/file/${subDir}/${fileName}`
}

async function downloadAndExtractZip(url: string, label: string, extractDir: string): Promise<void> {
  await fsp.mkdir(extractDir, { recursive: true })
  const tempDir = await fsp.mkdtemp(path.join(os.tmpdir(), 'mq-zip-'))
  const tempZip = path.join(tempDir, 'package.zip')
  try {
    sendLog(`${label} 다운로드: ${url}`)
    await downloadFile(url, tempZip)
    sendLog(`${label} 압축 해제: ${extractDir}`)
    await extractZip(tempZip, { dir: extractDir })
  } finally {
    await fsp.rm(tempDir, { recursive: true, force: true })
  }
}

async function downloadServerZip(pack: PackDefinition, targetDir: string): Promise<void> {
  if (!pack.serverPath) {
    sendLog('서버 파일(serverPath)이 비어 있어 서버 zip 다운로드를 건너뜁니다.')
    return
  }
  const url = resolveManifestRelative(pack.serverPath, 'servers')
  await downloadAndExtractZip(url, '서버 파일', targetDir)
}

async function downloadMapZip(pack: PackDefinition, customRoot: string): Promise<void> {
  if (!pack.mapPath) {
    sendLog('맵 파일(mapPath)이 비어 있어 맵 다운로드를 건너뜁니다.')
    return
  }
  const url = resolveManifestRelative(pack.mapPath, 'maps')
  const savesDir = path.join(customRoot, 'saves')
  await downloadAndExtractZip(url, '맵', savesDir)
}

ipcMain.handle('server:install', async (_event, payload: ServerInstallPayload) => {
  const pack = state.packs.get(payload.packKey)
  if (!pack) throw new Error('음악퀴즈를 찾을 수 없습니다.')
  if (containsHangul(payload.installPath)) {
    throw new Error('경로에 한글이 포함되면 안 됩니다.')
  }
  const installPath = path.resolve(payload.installPath)
  state.installPath = installPath
  await fsp.mkdir(installPath, { recursive: true })
  sendLog(`서버 설치 경로: ${installPath}`)

  await downloadServerZip(pack.pack, installPath)

  const eulaPath = path.join(installPath, 'eula.txt')
  if (fs.existsSync(eulaPath)) {
    await fsp.unlink(eulaPath)
    sendLog('기존 eula.txt 삭제, 사용자 동의를 다시 받습니다.')
  }
})

ipcMain.handle('server:acceptEula', async (_event, installPath: string) => {
  const target = path.join(installPath, 'eula.txt')
  await fsp.writeFile(target, `# Generated by music quiz installer\neula=true\n`, 'utf8')
  sendLog('EULA 동의 저장 완료.')
})

ipcMain.handle('server:checkRam', async (_event, packKey: string): Promise<RamCheckResult> => {
  const pack = state.packs.get(packKey)
  if (!pack) throw new Error('음악퀴즈를 찾을 수 없습니다.')
  const systemRamMb = Math.floor(os.totalmem() / (1024 * 1024))
  if (systemRamMb >= pack.pack.serverMaxRam) {
    return { systemRamMb, decision: 'maxOk', appliedRamMb: pack.pack.serverMaxRam }
  }
  if (systemRamMb >= pack.pack.serverMinRam) {
    return { systemRamMb, decision: 'minOk', appliedRamMb: pack.pack.serverMinRam }
  }
  return { systemRamMb, decision: 'tooLow', appliedRamMb: 0 }
})

ipcMain.handle('server:configEditor', async (_event, installPath: string) => {
  if (state.configEditorServer) {
    state.configEditorServer.close()
    state.configEditorServer = null
  }
  const port = await pickPort()
  const server = http.createServer(async (req, res) => {
    try {
      await handleConfigEditorRequest(installPath, req, res)
    } catch (error) {
      res.statusCode = 500
      res.setHeader('content-type', 'text/plain; charset=utf-8')
      res.end(`서버 오류: ${(error as Error).message}`)
    }
  })
  await new Promise<void>((resolve) => server.listen(port, '127.0.0.1', resolve))
  state.configEditorServer = server
  state.configEditorPort = port
  const url = `http://127.0.0.1:${port}/`
  sendLog(`서버 설정 편집기 실행: ${url}`)
  await shell.openExternal(url)
  return { url }
})

async function pickPort(): Promise<number> {
  return new Promise((resolve, reject) => {
    const probe = http.createServer()
    probe.unref()
    probe.on('error', reject)
    probe.listen(0, '127.0.0.1', () => {
      const address = probe.address()
      probe.close(() => {
        if (address && typeof address === 'object') resolve(address.port)
        else reject(new Error('포트를 할당할 수 없습니다.'))
      })
    })
  })
}

const SERVER_CONFIG_FILES = ['server.properties', 'bukkit.yml', 'spigot.yml', 'paper-global.yml']

async function handleConfigEditorRequest(installPath: string, req: http.IncomingMessage, res: http.ServerResponse): Promise<void> {
  const url = new URL(req.url ?? '/', 'http://127.0.0.1')
  if (req.method === 'GET' && url.pathname === '/') {
    const fileSet = await collectConfigFiles(installPath)
    res.setHeader('content-type', 'text/html; charset=utf-8')
    res.end(renderConfigEditorPage(fileSet))
    return
  }
  if (req.method === 'GET' && url.pathname === '/file') {
    const target = url.searchParams.get('name')
    if (!target || !SERVER_CONFIG_FILES.includes(target)) {
      res.statusCode = 400
      res.end('알 수 없는 파일')
      return
    }
    const filePath = path.join(installPath, target)
    if (!fs.existsSync(filePath)) {
      res.setHeader('content-type', 'text/plain; charset=utf-8')
      res.end('')
      return
    }
    const content = await fsp.readFile(filePath, 'utf8')
    res.setHeader('content-type', 'text/plain; charset=utf-8')
    res.end(content)
    return
  }
  if (req.method === 'POST' && url.pathname === '/save') {
    const body = await readBody(req)
    const params = new URLSearchParams(body)
    const target = params.get('name') ?? ''
    const content = params.get('content') ?? ''
    if (!SERVER_CONFIG_FILES.includes(target)) {
      res.statusCode = 400
      res.end('알 수 없는 파일')
      return
    }
    const filePath = path.join(installPath, target)
    await fsp.writeFile(filePath, content, 'utf8')
    res.statusCode = 200
    res.setHeader('content-type', 'application/json')
    res.end(JSON.stringify({ ok: true }))
    return
  }
  res.statusCode = 404
  res.end('Not found')
}

async function collectConfigFiles(installPath: string): Promise<string[]> {
  const result: string[] = []
  for (const fileName of SERVER_CONFIG_FILES) {
    const filePath = path.join(installPath, fileName)
    if (fs.existsSync(filePath)) result.push(fileName)
  }
  return result
}

function renderConfigEditorPage(fileSet: string[]): string {
  const safeList = fileSet.length > 0 ? fileSet : SERVER_CONFIG_FILES.slice(0, 2)
  const optionMarkup = safeList
    .map((file, index) => `<option value="${file}" ${index === 0 ? 'selected' : ''}>${file}</option>`)
    .join('')
  return `<!doctype html>
<html lang="ko"><head><meta charset="utf-8"/><title>서버 설정 편집기</title>
<style>body{font-family:sans-serif;background:#0d1117;color:#e6edf3;padding:24px;}select,textarea,button{font:inherit;}textarea{width:100%;height:60vh;background:#161b22;color:#e6edf3;border:1px solid #30363d;padding:12px;border-radius:8px;}button{background:#2f81f7;color:#fff;border:none;padding:10px 16px;border-radius:8px;cursor:pointer;margin-top:12px;}small{color:#8b949e;}</style>
</head><body>
<h1>서버 설정 편집기</h1>
<p><small>아래 파일을 직접 편집한 후 "적용" 버튼으로 저장합니다. 설치기 화면에서 다음 단계로 진행하기 전 마음껏 편집할 수 있습니다.</small></p>
<label>대상 파일 <select id="file">${optionMarkup}</select></label>
<textarea id="content"></textarea>
<button id="save">적용</button>
<p id="status"><small></small></p>
<script>
const file=document.getElementById('file');
const content=document.getElementById('content');
const status=document.querySelector('#status small');
async function load(){const r=await fetch('/file?name='+encodeURIComponent(file.value));content.value=await r.text();}
file.addEventListener('change',load);
document.getElementById('save').addEventListener('click',async()=>{const body=new URLSearchParams();body.set('name',file.value);body.set('content',content.value);const r=await fetch('/save',{method:'POST',headers:{'content-type':'application/x-www-form-urlencoded'},body:body.toString()});status.textContent=r.ok?'저장 완료':'저장 실패';});
load();
</script></body></html>`
}

function readBody(req: http.IncomingMessage): Promise<string> {
  return new Promise((resolve, reject) => {
    const chunks: Buffer[] = []
    req.on('data', (chunk: Buffer) => chunks.push(chunk))
    req.on('end', () => resolve(Buffer.concat(chunks).toString('utf8')))
    req.on('error', reject)
  })
}

ipcMain.handle('server:portForward', async (_event, port: number): Promise<PortForwardResult> => {
  const targetPort = Number.isFinite(port) && port > 0 ? port : 25565
  const externalIp = await detectExternalIp()
  if (await testPortReachable(externalIp, targetPort)) {
    sendLog(`외부에서 ${externalIp}:${targetPort} 접근 확인됨. 포트포워딩 됨.`)
    return { status: 'preForwarded', externalIp, port: targetPort }
  }
  try {
    await openPortViaUpnp(targetPort)
    if (await testPortReachable(externalIp, targetPort)) {
      sendLog(`UPnP로 포트 ${targetPort} 자동 개방 완료.`)
      return { status: 'upnpOk', externalIp, port: targetPort }
    }
    sendLog('UPnP 개방은 시도했지만 외부 접근이 확인되지 않았습니다.')
    return { status: 'upnpFailed', externalIp, port: targetPort, message: '직접 포트포워딩을 해주세요.' }
  } catch (error) {
    sendLog(`UPnP 시도 실패: ${(error as Error).message}`)
    return { status: 'upnpFailed', externalIp, port: targetPort, message: '직접 포트포워딩을 해주세요.' }
  }
})

async function detectExternalIp(): Promise<string> {
  try {
    const buffer = await fetchBuffer('https://api.ipify.org')
    return buffer.toString('utf8').trim()
  } catch {
    return ''
  }
}

function testPortReachable(host: string, port: number): Promise<boolean> {
  if (!host) return Promise.resolve(false)
  return new Promise((resolve) => {
    import('node:net').then((net) => {
      const socket = net.createConnection({ host, port })
      socket.setTimeout(3000)
      socket.once('connect', () => {
        socket.end()
        resolve(true)
      })
      socket.once('error', () => resolve(false))
      socket.once('timeout', () => {
        socket.destroy()
        resolve(false)
      })
    }).catch(() => resolve(false))
  })
}

function openPortViaUpnp(port: number): Promise<void> {
  return new Promise((resolve, reject) => {
    const client = natUpnp.createClient()
    client.portMapping({ public: port, private: port, ttl: 0, description: 'MusicQuiz Server', protocol: 'tcp' }, (error) => {
      client.close()
      if (error) reject(error)
      else resolve()
    })
  })
}

ipcMain.handle('client:install', async (_event, payload: ClientInstallPayload) => {
  const pack = state.packs.get(payload.packKey)
  if (!pack) throw new Error('음악퀴즈를 찾을 수 없습니다.')
  const customRoot = path.join(getAppDataDir(), '.mc_custom')
  await fsp.mkdir(path.join(customRoot, 'mods'), { recursive: true })
  await fsp.mkdir(path.join(customRoot, 'resourcepacks'), { recursive: true })

  if (payload.installPlatform && pack.pack.platform.type !== 'vanilla' && pack.pack.platform.downloadUrl) {
    const platformUrl = resolveManifestRelative(pack.pack.platform.downloadUrl, 'platforms')
    const cacheDir = path.join(customRoot, 'platform-cache')
    await fsp.mkdir(cacheDir, { recursive: true })
    const installerPath = path.join(cacheDir, deriveFileName(platformUrl) || 'platform-installer.jar')
    sendLog(`플랫폼(${pack.pack.platform.type}) 다운로드: ${platformUrl}`)
    await downloadFile(platformUrl, installerPath)
    sendLog(`플랫폼 설치파일 저장: ${installerPath} (사용자가 직접 실행하거나 마인크래프트 런처에서 인식할 수 있습니다.)`)
  } else if (!payload.installPlatform) {
    sendLog('플랫폼 설치 건너뜀. 바닐라로 진행합니다.')
  }

  for (const mod of pack.pack.mods) {
    if (!mod.downloadUrl) continue
    const target = path.join(customRoot, 'mods', deriveFileName(mod.downloadUrl) || `${mod.name}.jar`)
    sendLog(`모드 다운로드: ${mod.name}`)
    await downloadFile(mod.downloadUrl, target)
  }
  for (const resourcePack of pack.pack.resourcepacks) {
    if (!resourcePack.downloadUrl) continue
    const target = path.join(customRoot, 'resourcepacks', deriveFileName(resourcePack.downloadUrl) || `${resourcePack.name}.zip`)
    sendLog(`리소스팩 다운로드: ${resourcePack.name}`)
    await downloadFile(resourcePack.downloadUrl, target)
  }

  await downloadMapZip(pack.pack, customRoot)

  await updateLauncherProfile(pack.pack, customRoot)
})

function deriveFileName(url: string): string {
  try {
    const parsed = new URL(url)
    const last = parsed.pathname.split('/').filter(Boolean).pop() ?? ''
    return decodeURIComponent(last)
  } catch {
    return ''
  }
}

function getAppDataDir(): string {
  if (process.platform === 'win32' && process.env.APPDATA) return process.env.APPDATA
  return app.getPath('appData')
}

async function updateLauncherProfile(pack: PackDefinition, gameDir: string): Promise<void> {
  const launcherPath = path.join(getAppDataDir(), '.minecraft', 'launcher_profiles.json')
  if (!fs.existsSync(launcherPath)) {
    sendLog(`launcher_profiles.json을 찾을 수 없습니다: ${launcherPath}`)
    return
  }
  const raw = await fsp.readFile(launcherPath, 'utf8')
  const json = JSON.parse(raw) as { profiles?: Record<string, Record<string, unknown>> }
  json.profiles = json.profiles ?? {}
  const profileKey = pack.name
  const javaArgs = `-Xmx${pack.serverMaxRam}M -Xms${pack.serverMinRam}M`
  const lastVersionId = pack.platform.type === 'vanilla'
    ? pack.mcVersion
    : `${pack.mcVersion}-${pack.platform.type}`
  json.profiles[profileKey] = {
    ...(json.profiles[profileKey] ?? {}),
    name: profileKey,
    type: 'custom',
    gameDir,
    lastVersionId,
    javaArgs
  }
  await fsp.writeFile(launcherPath, `${JSON.stringify(json, null, 2)}\n`, 'utf8')
  sendLog(`launcher_profiles.json 갱신: 프로필 "${profileKey}", gameDir=${gameDir}`)
}

ipcMain.handle('finish:openServerFolder', async () => {
  if (!state.installPath) return
  await shell.openPath(state.installPath)
})

ipcMain.handle('finish:desktopShortcut', async () => {
  if (process.platform !== 'win32' || !state.installPath) return
  const desktopDir = app.getPath('desktop')
  const shortcutPath = path.join(desktopDir, 'MusicQuiz Server.lnk')
  const runBat = path.join(state.installPath, 'run.bat')
  const ok = require('electron').shell.writeShortcutLink(shortcutPath, 'create', {
    target: runBat,
    cwd: state.installPath,
    description: '음악퀴즈 서버 실행'
  })
  sendLog(ok ? `바로가기 생성: ${shortcutPath}` : '바로가기 생성 실패')
})

ipcMain.handle('finish:startServer', async () => {
  if (!state.installPath) return
  const runBat = path.join(state.installPath, 'run.bat')
  if (!fs.existsSync(runBat)) {
    sendLog(`run.bat을 찾을 수 없습니다: ${runBat}`)
    return
  }
  spawn('cmd.exe', ['/c', 'start', '', runBat], { cwd: state.installPath, detached: true, stdio: 'ignore' }).unref()
  sendLog('서버 실행 요청 완료.')
})

ipcMain.handle('finish:startLauncher', async () => {
  const candidates = [
    path.join(process.env['ProgramFiles(x86)'] ?? 'C:\\Program Files (x86)', 'Minecraft Launcher', 'MinecraftLauncher.exe'),
    path.join(process.env['ProgramFiles'] ?? 'C:\\Program Files', 'Minecraft Launcher', 'MinecraftLauncher.exe')
  ]
  const target = candidates.find((candidate) => fs.existsSync(candidate))
  if (!target) {
    sendLog('Minecraft Launcher를 찾을 수 없습니다. 직접 실행해 주세요.')
    return
  }
  spawn(target, [], { detached: true, stdio: 'ignore' }).unref()
  sendLog('마인크래프트 런처 실행 요청 완료.')
})

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

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