// Copyright (c) 未来飞马
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at https://mozilla.org/MPL/2.0/.
//
// Trademark Notice:
// The MPL-2.0 license grants copyright permissions for source code only.
// It does NOT grant any rights to use trademarks including "未来飞马",
// "Harness Loop", "RSI", and associated slogan "让AI进化提前发生，让AI落地快人一步".
// Any use of these trademarks requires separate written permission.
/**
 * 视频桥：抽帧（ffmpeg）+ 音频转写（复用兄弟技能 skill-listen）
 *
 * 产出：
 *   - frames[]      按时间轴均匀抽出的关键帧（落地到 --frames-out，交给 vision 做理解）
 *   - transcript    音轨转写文本（skill-listen / listen-runner.mjs，走 Fmode 网关，凭据仅服务端）
 *   - durationMs    时长（ffprobe；探测不到则 null）
 *
 * 缺 ffmpeg / ffprobe 或 skill-listen 时，返回 available:false + 明确安装提示，绝不伪造结果。
 * 绝不写任何 token / 凭据。
 */

import fs from 'node:fs';
import path from 'node:path';
import { spawnSync } from 'node:child_process';
import { parseArgs } from 'node:util';
import { ensureDir, resolveSiblingScript, truncate } from './lib.mjs';

const LISTEN_REL = path.join('skill-listen', 'scripts', 'listen-runner.mjs');

function hasBinary(name) {
  const probe = spawnSync(name, ['-version'], { encoding: 'utf8' });
  return probe.status === 0 || Boolean(probe.stdout);
}

export function resolveFfmpeg() {
  return process.env.CASE_FFMPEG || 'ffmpeg';
}

export function probeDurationMs(videoPath) {
  const probe = spawnSync(process.env.CASE_FFPROBE || 'ffprobe', [
    '-v', 'error',
    '-show_entries', 'format=duration',
    '-of', 'default=noprint_wrappers=1:nokey=1',
    videoPath,
  ], { encoding: 'utf8' });
  const seconds = Number.parseFloat(String(probe.stdout || '').trim());
  return Number.isFinite(seconds) && seconds > 0 ? Math.round(seconds * 1000) : null;
}

/**
 * 均匀抽帧。
 * @returns {{ok:boolean, frames:object[], error:string|null}}
 */
export function extractFrames(videoPath, framesOut, options = {}) {
  const count = Math.max(1, Math.min(24, Number(options.frameCount) || 6));
  ensureDir(framesOut);
  const durationMs = options.durationMs || probeDurationMs(videoPath);
  const ffmpeg = options.ffmpeg || resolveFfmpeg();

  const frames = [];
  if (durationMs && durationMs > 0) {
    // 均匀取 count 个时间点
    for (let i = 0; i < count; i++) {
      const tMs = Math.round((durationMs * (i + 0.5)) / count);
      const target = path.join(framesOut, `frame-${String(i + 1).padStart(3, '0')}.jpg`);
      const run = spawnSync(ffmpeg, [
        '-y', '-loglevel', 'error',
        '-ss', (tMs / 1000).toFixed(3),
        '-i', videoPath,
        '-frames:v', '1', '-q:v', '3',
        target,
      ], { encoding: 'utf8' });
      if (run.status === 0 && fs.existsSync(target)) {
        frames.push({ index: i + 1, atMs: tMs, localPath: target });
      }
    }
  } else {
    // 拿不到时长：按 fps 抽前 count 帧
    const run = spawnSync(ffmpeg, [
      '-y', '-loglevel', 'error',
      '-i', videoPath,
      '-frames:v', String(count), '-vf', 'fps=1', '-q:v', '3',
      path.join(framesOut, 'frame-%03d.jpg'),
    ], { encoding: 'utf8' });
    if (run.status === 0) {
      for (const name of fs.readdirSync(framesOut).sort().slice(0, count)) {
        frames.push({ index: frames.length + 1, atMs: null, localPath: path.join(framesOut, name) });
      }
    }
  }
  if (!frames.length) {
    return { ok: false, frames: [], error: 'FFMPEG_FRAME_EXTRACT_FAILED（检查 ffmpeg 是否可用及视频是否可解码）' };
  }
  return { ok: true, frames, error: null };
}

/** 抽出 16kHz 单声道 wav 音轨（转写前压体积，更稳）。 */
export function extractAudio(videoPath, audioOut, options = {}) {
  ensureDir(path.dirname(audioOut));
  const ffmpeg = options.ffmpeg || resolveFfmpeg();
  const run = spawnSync(ffmpeg, [
    '-y', '-loglevel', 'error',
    '-i', videoPath,
    '-vn', '-ar', '16000', '-ac', '1',
    '-f', 'wav', audioOut,
  ], { encoding: 'utf8' });
  if (run.status === 0 && fs.existsSync(audioOut) && fs.statSync(audioOut).size > 1024) {
    return { ok: true, audioPath: audioOut, error: null };
  }
  return { ok: false, audioPath: '', error: 'FFMPEG_AUDIO_EXTRACT_FAILED（视频可能没有音轨）' };
}

/** 调 skill-listen 转写音轨。缺技能时返回 available:false，不抛栈。 */
export async function transcribeAudio(audioPath, options = {}) {
  const listenPath = resolveSiblingScript('CASE_LISTEN_SCRIPT', LISTEN_REL);
  if (!listenPath) {
    return {
      available: false,
      text: '',
      segments: [],
      error: `未找到 skill-listen（期望 ${LISTEN_REL}）。请先安装：npx skill-listen@latest install`,
    };
  }
  try {
    const runner = await import(new URL(`file://${listenPath.split(path.sep).join('/')}`).href);
    const durationMs = probeDurationMs(audioPath);
    const out = await runner.transcribeFile({
      filePath: audioPath,
      language: options.language || 'autodialect',
      diarize: Boolean(options.diarize),
      speakers: options.speakers,
      durationMs: durationMs || undefined,
    });
    return {
      available: true,
      text: String(out.text || ''),
      segments: out.segments || [],
      error: null,
    };
  } catch (error) {
    return { available: true, text: '', segments: [], error: `TRANSCRIBE_FAILED: ${error.message}` };
  }
}

/**
 * 视频处理总入口：抽帧 → 抽音轨 → 转写。
 */
export async function processVideo(videoPath, options = {}) {
  const workDir = ensureDir(options.workDir || path.join(process.cwd(), 'case-get-outputs', 'video'));
  const durationMs = probeDurationMs(videoPath);
  const ffmpegOk = hasBinary(options.ffmpeg || resolveFfmpeg());

  const report = {
    video: path.resolve(videoPath),
    durationMs,
    frameCount: 0,
    frames: [],
    transcription: { available: false, text: '', segments: [], error: null },
    warnings: [],
  };

  if (!ffmpegOk) {
    report.warnings.push('未找到 ffmpeg：无法抽帧/抽音轨。请安装 ffmpeg 后重试。');
    return report;
  }

  const frameResult = extractFrames(videoPath, path.join(workDir, 'frames'), { frameCount: options.frameCount, durationMs });
  report.frames = frameResult.frames;
  report.frameCount = frameResult.frames.length;
  if (frameResult.error) report.warnings.push(frameResult.error);

  const audio = extractAudio(videoPath, path.join(workDir, 'audio.wav'));
  if (audio.ok) {
    report.transcription = await transcribeAudio(audio.audioPath, options);
    if (report.transcription.error) report.warnings.push(report.transcription.error);
  } else {
    report.transcription = { available: false, text: '', segments: [], error: audio.error };
    report.warnings.push(audio.error);
  }

  report.summary = truncate(report.transcription.text || '', 200);
  return report;
}

// ---------------------------------------------------------------------------
// CLI
// ---------------------------------------------------------------------------

async function main() {
  const { values, positionals } = parseArgs({
    options: {
      video: { type: 'string', multiple: true, default: [] },
      out: { type: 'string' },
      'work-dir': { type: 'string' },
      'frame-count': { type: 'string' },
      diarize: { type: 'boolean', default: false },
      speakers: { type: 'string' },
      language: { type: 'string' },
      help: { type: 'boolean', default: false },
    },
    allowPositionals: true,
  });

  if (values.help) {
    process.stdout.write([
      'skill-case-get / listen-bridge — 视频抽帧 + 音轨转写（复用 skill-listen）',
      '',
      '  node listen-bridge.mjs --video a.mp4 [--frame-count 6] [--diarize] [--out video.json]',
      '',
      '依赖：ffmpeg / ffprobe（抽帧、抽音轨）、skill-listen（转写）。缺任一都会在 warnings 里说明，不伪造结果。',
    ].join('\n'));
    return 0;
  }

  const inputs = [...values.video, ...positionals];
  if (!inputs.length) {
    process.stderr.write('至少需要一个 --video <file>\n');
    return 2;
  }

  const reports = [];
  for (const video of inputs) {
    reports.push(await processVideo(video, {
      workDir: values['work-dir'] || path.join(path.dirname(path.resolve(video)), 'case-get-video'),
      frameCount: Number(values['frame-count']) || 6,
      diarize: values.diarize,
      speakers: values.speakers ? Number(values.speakers) : undefined,
      language: values.language,
    }));
  }

  const payload = { ok: reports.every((r) => !r.warnings.length), count: reports.length, reports };
  const text = JSON.stringify(payload, null, 2);
  if (values.out) {
    fs.mkdirSync(path.dirname(path.resolve(values.out)), { recursive: true });
    fs.writeFileSync(path.resolve(values.out), `${text}\n`, 'utf8');
  } else {
    process.stdout.write(`${text}\n`);
  }
  return payload.ok ? 0 : 1;
}

const invokedDirectly = process.argv[1] && path.resolve(process.argv[1]).endsWith(path.join('scripts', 'listen-bridge.mjs'));
if (invokedDirectly) {
  main().then((code) => process.exit(code)).catch((error) => {
    process.stderr.write(`listen-bridge 失败：${error.message}\n`);
    process.exit(1);
  });
}