import path from 'node:path';
import fs from 'node:fs';
import express from 'express';
import cors from 'cors';
import multer from 'multer';
import {z} from 'zod';
import {
  DEFAULT_SETTINGS,
  MAX_RENDER_SECONDS,
  MAX_UPLOAD_BYTES,
  type HealthResponse,
  type VisualSettings,
} from '../shared/types.js';
import {
  createJob,
  getJob,
  JOBS_DIR,
  jobDirectory,
  listJobs,
  loadJobsFromDisk,
  publicJob,
  updateJob,
} from './jobs.js';
import {buildScrollKeys} from '../shared/scroll.js';
import {runPipeline} from './pipeline.js';
import {enqueueRender} from './queue.js';
import {findMuseScore, museScoreVersion} from './musescore.js';
import {IS_PRODUCTION, PORT, PUBLIC_BASE_URL} from './config.js';

loadJobsFromDisk();

const app = express();
app.use(cors());
app.use(express.json({limit: '2mb'}));

const upload = multer({
  storage: multer.memoryStorage(),
  limits: {fileSize: MAX_UPLOAD_BYTES, files: 2},
});

const colorSchema = z.string().regex(/^#[0-9a-fA-F]{3,8}$/, '颜色必须是 #RRGGBB');
const settingsSchema = z
  .object({
    width: z.number().int().min(320).max(3840),
    height: z.number().int().min(320).max(3840),
    fps: z.number().int().min(15).max(60),
    introSeconds: z.number().min(0).max(5),
    outroSeconds: z.number().min(0).max(15),
    scoreHeightRatio: z.number().min(0.18).max(0.82),
    scrollLead: z.number().min(0.1).max(0.7),
    paperColor: colorSchema,
    paperAlpha: z.number().min(0).max(1),
    scoreColor: colorSchema,
    background: colorSchema,
    staffColors: z.array(colorSchema).min(2).max(8),
    ballScale: z.number().min(0.4).max(3),
    ballLift: z.number().min(0).max(3),
    glow: z.number().min(0).max(3),
    showTitle: z.boolean(),
    showProgress: z.boolean(),
    titleFont: z.string().min(1).max(300),
    audioOffsetMs: z.number().min(-5000).max(5000),
    tiltX: z.number().min(-85).max(85),
    tiltY: z.number().min(-60).max(60),
    tiltZ: z.number().min(-60).max(60),
    perspective: z.number().min(400).max(6000),
    tiltZoom: z.number().min(0.5).max(3),
  })
  .partial();

function normalizeSettings(input: Partial<VisualSettings> | undefined): VisualSettings {
  return {...DEFAULT_SETTINGS, ...(input ?? {})};
}

/** Scroll keys depend on the viewport and strip height, so recompute them when those change. */
function scrollForSettings(
  data: {events: import('../shared/types.js').NoteEvent[]; meta: import('../shared/types.js').ScoreMeta},
  settings: VisualSettings,
) {
  const displayHeight = settings.height * settings.scoreHeightRatio;
  const displayScale = displayHeight / Math.max(1, data.meta.svgHeight);
  const viewWidthScore = settings.width / displayScale;
  const maxLeft = Math.max(0, data.meta.svgWidth - viewWidthScore);
  return buildScrollKeys(
    data.events,
    settings.scrollLead,
    viewWidthScore,
    maxLeft,
    data.meta.musicDuration,
  );
}

app.get('/api/health', (_req, res) => {
  const musescorePath = findMuseScore();
  const body: HealthResponse = {
    ok: true,
    musescore: {
      available: Boolean(musescorePath),
      path: musescorePath ?? undefined,
      version: museScoreVersion(),
    },
    chrome: {
      available: true,
      note: 'Remotion 首次渲染会使用或下载 Chrome Headless Shell。',
    },
    ffmpeg: {
      available: true,
      note: 'Remotion 渲染使用内置 FFmpeg。',
    },
    version: process.env.npm_package_version ?? '0.1.0',
  };
  res.json(body);
});

app.get('/api/jobs', (_req, res) => {
  res.json({jobs: listJobs().slice(0, 30).map((job) => publicJob(job))});
});

app.post('/api/jobs', upload.fields([{name: 'score', maxCount: 1}, {name: 'audio', maxCount: 1}]), (req, res) => {
  const files = req.files as Record<string, Express.Multer.File[]> | undefined;
  const score = files?.score?.[0];
  if (!score) {
    res.status(400).json({error: '请选择 MusicXML / MXL / MIDI 谱面文件。'});
    return;
  }
  if (score.size > MAX_UPLOAD_BYTES) {
    res.status(413).json({error: '文件超过 30MB 限制。'});
    return;
  }
  let settings: VisualSettings = DEFAULT_SETTINGS;
  const rawSettings = typeof req.body?.settings === 'string' ? req.body.settings : null;
  if (rawSettings) {
    try {
      const parsed = settingsSchema.parse(JSON.parse(rawSettings));
      settings = normalizeSettings(parsed);
    } catch (error) {
      res.status(400).json({error: `设置无效：${error instanceof Error ? error.message : String(error)}`});
      return;
    }
  }
  const metadata = {
    title: typeof req.body?.title === 'string' ? req.body.title : undefined,
    subtitle: typeof req.body?.subtitle === 'string' ? req.body.subtitle : undefined,
    composer: typeof req.body?.composer === 'string' ? req.body.composer : undefined,
  };
  const audio = files?.audio?.[0];
  const job = createJob({
    settings,
    inputName: score.originalname,
    inputFormat: path.extname(score.originalname).toLowerCase().replace('.', ''),
  });
  void runPipeline({
    jobId: job.id,
    file: {buffer: score.buffer, filename: score.originalname},
    audio: audio ? {buffer: audio.buffer, filename: audio.originalname} : undefined,
    settings,
    metadata,
  });
  res.status(202).json({id: job.id});
});

app.get('/api/jobs/:id', (req, res) => {
  const job = getJob(req.params.id);
  if (!job) {
    res.status(404).json({error: '任务不存在。'});
    return;
  }
  res.json(publicJob(job));
});

app.patch('/api/jobs/:id/settings', (req, res) => {
  const job = getJob(req.params.id);
  if (!job) {
    res.status(404).json({error: '任务不存在。'});
    return;
  }
  if (!job.data) {
    res.status(409).json({error: '任务还没有生成预览数据。'});
    return;
  }
  if (job.status === 'rendering') {
    res.status(409).json({error: '正在渲染，暂时不能修改参数。'});
    return;
  }

  let parsedSettings: Partial<VisualSettings>;
  try {
    parsedSettings = settingsSchema.parse(req.body?.settings ?? {});
  } catch (error) {
    res.status(400).json({error: `设置无效：${error instanceof Error ? error.message : String(error)}`});
    return;
  }

  const settings = normalizeSettings({
    ...job.data.settings,
    ...job.settings,
    ...parsedSettings,
  });

  const meta = {...job.data.meta};
  const metadata = req.body?.metadata as
    | {title?: unknown; subtitle?: unknown; composer?: unknown}
    | undefined;
  if (typeof metadata?.title === 'string' && metadata.title.trim()) meta.title = metadata.title.trim();
  if (typeof metadata?.subtitle === 'string' && metadata.subtitle.trim()) {
    meta.subtitle = metadata.subtitle.trim();
  }
  if (typeof metadata?.composer === 'string' && metadata.composer.trim()) {
    meta.composer = metadata.composer.trim();
  }

  const data = {
    ...job.data,
    meta,
    settings,
    scroll: scrollForSettings(job.data, settings),
  };

  fs.writeFileSync(path.join(jobDirectory(job.id), 'score.json'), JSON.stringify(data, null, 2), 'utf8');
  const updated = updateJob(job.id, {
    settings,
    data,
    ...(job.status === 'done'
      ? {
          status: 'ready' as const,
          stage: 'done' as const,
          progress: 100,
          message: '参数已更新，可以重新导出。',
          videoFile: undefined,
        }
      : {}),
  });
  res.json(updated ? publicJob(updated) : {error: '任务不存在。'});
});

app.post('/api/jobs/:id/render', (req, res) => {
  const job = getJob(req.params.id);
  if (!job) {
    res.status(404).json({error: '任务不存在。'});
    return;
  }
  if (!job.data) {
    res.status(409).json({error: '任务还没有生成预览数据。'});
    return;
  }
  if (job.data.meta.audioDuration > MAX_RENDER_SECONDS || job.data.meta.musicDuration > MAX_RENDER_SECONDS) {
    res.status(400).json({
      error: `这段音乐超过 ${Math.round(MAX_RENDER_SECONDS / 60)} 分钟，请先截取片段再渲染。`,
    });
    return;
  }
  if (job.status === 'rendering') {
    res.json({ok: true, alreadyRunning: true});
    return;
  }
  updateJob(job.id, {message: '已加入渲染队列…'});
  enqueueRender(job.id);
  res.json({ok: true});
});

app.get('/api/jobs/:id/video', (req, res) => {
  const job = getJob(req.params.id);
  if (!job || !job.videoFile) {
    res.status(404).json({error: '视频还没有生成。'});
    return;
  }
  const file = path.join(JOBS_DIR, job.id, job.videoFile);
  if (!fs.existsSync(file)) {
    res.status(404).json({error: '视频文件不存在。'});
    return;
  }
  const safeName = (job.data?.meta.title || 'music-visualizer').replace(/[\\/:*?"<>|]/g, '_').slice(0, 80);
  res.download(file, `${safeName}.mp4`);
});

app.use('/jobs', express.static(JOBS_DIR, {maxAge: '1h'}));
app.use('/demo', express.static(path.resolve('public/demo'), {maxAge: '1h'}));

if (IS_PRODUCTION) {
  const clientDir = path.resolve('dist/client');
  app.use(express.static(clientDir));
  app.get('*', (_req, res) => {
    res.sendFile(path.join(clientDir, 'index.html'));
  });
}

app.use((error: unknown, _req: express.Request, res: express.Response, _next: express.NextFunction) => {
  if (error instanceof multer.MulterError) {
    res.status(error.code === 'LIMIT_FILE_SIZE' ? 413 : 400).json({error: error.message});
    return;
  }
  console.error(error);
  res.status(500).json({error: error instanceof Error ? error.message : '服务器错误。'});
});

app.listen(PORT, () => {
  console.log(`Music Visualizer API: http://127.0.0.1:${PORT}`);
  console.log(`Public base URL for render: ${PUBLIC_BASE_URL}`);
  console.log(`MuseScore: ${findMuseScore() ?? 'not found'}`);
  if (!IS_PRODUCTION) console.log('Client dev server: http://127.0.0.1:5173');
});