// scripts/keyframe.mjs — 场景 & 人物关键帧（provider: image）
//
// ✅ 通道可用（实测 gpt-image-2.5-sunburst 返回 b64_json）。
// 关键点：人物一致性 —— 每个含人物的镜头都必须复述 appearanceAnchor。

import { existsSync, mkdirSync, writeFileSync, readdirSync, statSync } from 'node:fs';
import { join } from 'node:path';
import {
  parseArgs, readJSON, writeJSON, paths, ensureWork, log, invoke, humanSize,
} from '../lib/index.mjs';
import { buildKeyframePrompt, aspectToSize, DEFAULT_ANCHOR } from '../lib/prompts.mjs';

/**
 * 生成关键帧。
 * @param {object} o
 * @param {object} o.storyboard  分镜（可选）
 * @param {string} [o.prompt]    裸 prompt（无分镜时）
 * @param {number} [o.shotId]    只生成某一镜
 * @param {number} [o.limit]     最多生成几镜
 * @param {string} [o.outDir]
 */
export async function generateKeyframes(o = {}) {
  const {
    storyboard,
    prompt,
    shotId,
    limit,
    outDir = paths.frames,
    aspect = storyboard?.aspect || '16:9',
    tier = 'standard',
    style = '',
    model,
    anchorOverride,
    dryRun = false,
  } = o;

  mkdirSync(outDir, { recursive: true });
  const anchor = anchorOverride || storyboard?.appearanceAnchor || DEFAULT_ANCHOR.song;
  const styleKw = style || storyboard?.styleKeywords || '';
  const size = aspectToSize(aspect, tier);

  let jobs;
  if (storyboard) {
    jobs = storyboard.shots.filter((s) => !shotId || s.id === Number(shotId));
    if (limit) jobs = jobs.slice(0, Number(limit));
  } else {
    if (!prompt) throw new Error('需要 --prompt 或 --from <storyboard.json>');
    jobs = [{ id: 0, imagePrompt: prompt, description: prompt, type: 'broll', hasCharacter: false }];
  }

  const results = [];
  for (const shot of jobs) {
    const fullPrompt = buildKeyframePrompt(shot, { appearanceAnchor: anchor, style: styleKw, aspect });
    const name = shot.id ? `shot-${String(shot.id).padStart(2, '0')}` : 'keyframe';
    const file = join(outDir, `${name}.png`);

    log.info(`[${name}] ${String(shot.description || '').slice(0, 60)}`);
    if (dryRun) {
      log.dim(`prompt: ${fullPrompt.slice(0, 160)}…`);
      results.push({ id: shot.id, file: null, status: 'pending', prompt: fullPrompt, size });
      continue;
    }

    try {
      const res = await invoke('image', { prompt: fullPrompt, size, n: 1, model });
      const buf = res.buffers[0];
      writeFileSync(file, buf);
      log.ok(`→ ${file}（${humanSize(buf.length)}，${size}）`);
      results.push({
        id: shot.id,
        file,
        bytes: buf.length,
        size,
        model: res.model,
        prompt: fullPrompt,
        status: 'ok',
      });
    } catch (e) {
      log.err(`[${name}] 生成失败：${e.message.split('\n')[0]}`);
      results.push({ id: shot.id, file: null, status: 'failed', error: e.message, prompt: fullPrompt });
      if (jobs.length === 1) throw e;
    }
  }

  const okCount = results.filter((r) => r.status === 'ok').length;
  const failCount = results.filter((r) => r.status === 'failed').length;
  writeJSON(join(outDir, 'keyframes.json'), {
    count: results.length,
    ok: okCount,
    failed: failCount,
    pending: results.filter((r) => r.status === 'pending').length,
    aspect,
    size,
    appearanceAnchor: anchor,
    styleKeywords: styleKw,
    frames: results,
    _meta: { createdBy: 'fmode-mv/keyframe', generatedAt: new Date().toISOString() },
  });

  return { results, okCount, failCount, outDir };
}

export async function main(argv = process.argv.slice(2)) {
  const { _, flags } = parseArgs(argv);

  if (flags.help || (!flags.from && !flags.prompt)) {
    console.log(`
fmode-mv keyframe — 场景 & 人物关键帧（image 通道，✅ 可用）

用法:
  fmode-mv keyframe --from work/storyboard.json            # 按分镜批量生成
  fmode-mv keyframe --from work/storyboard.json --shot 1   # 只生成第 1 镜
  fmode-mv keyframe --from work/storyboard.json --limit 4  # 只生成前 4 镜
  fmode-mv keyframe --prompt "傍晚城市天台，主角侧影，霓虹初上" --name rooftop

选项:
  --from <file>      分镜 JSON
  --shot <id>        只生成指定镜头
  --limit <n>        最多生成 n 镜
  --prompt "..."     裸 prompt（不依赖分镜）
  --out <dir>        输出目录（默认 work/frames）
  --aspect <r>       16:9 | 9:16 | 1:1（默认取分镜）
  --tier standard|large   尺寸档位（默认 standard）
  --style "..."      追加风格关键词（英文更稳）
  --anchor "..."     覆盖人物外观锚点（英文）
  --model <name>     覆盖图像模型（默认 gpt-image-2.5-sunburst）
  --dry-run          只打印将发送的 prompt，不实际生成（不产生费用）

产出:
  work/frames/shot-XX.png + work/frames/keyframes.json
`);
    return 0;
  }

  ensureWork();
  let storyboard = null;
  if (flags.from) {
    const from = String(flags.from);
    if (!existsSync(from)) throw new Error(`分镜文件不存在：${from}`);
    storyboard = readJSON(from);
    log.step(`生成关键帧：${storyboard.title || ''}（共 ${storyboard.shots.length} 镜）`);
  } else {
    log.step('生成关键帧（单张）');
  }

  const r = await generateKeyframes({
    storyboard,
    prompt: flags.prompt ? String(flags.prompt) : undefined,
    shotId: flags.shot ? Number(flags.shot) : undefined,
    limit: flags.limit ? Number(flags.limit) : undefined,
    outDir: typeof flags.out === 'string' ? flags.out : paths.frames,
    aspect: flags.aspect,
    tier: flags.tier || 'standard',
    style: flags.style,
    model: flags.model,
    anchorOverride: flags.anchor,
    dryRun: !!flags['dry-run'],
  });

  if (flags['dry-run']) {
    log.warn(`dry-run：${r.results.length} 个 prompt 已生成，未调用图像通道（无费用）`);
  } else {
    log.ok(`完成：成功 ${r.okCount} / 失败 ${r.failCount}`);
    const files = readdirSync(paths.frames).filter((f) => f.endsWith('.png'));
    let total = 0;
    for (const f of files) total += statSync(join(paths.frames, f)).size;
    log.key('目录', `${paths.frames}（${files.length} 张，共 ${humanSize(total)}）`);
  }
  return r.failCount > 0 && r.okCount === 0 ? 1 : 0;
}

if (import.meta.url === `file://${process.argv[1]}`) {
  main().then((c) => process.exit(Number(c) || 0)).catch((e) => {
    console.error(`✗ ${e.message}`);
    process.exit(1);
  });
}