#!/usr/bin/env node
import { readFileSync, writeFileSync, mkdirSync, rmSync, existsSync, copyFileSync } from 'node:fs';
import { join } from 'node:path';
import { pathToFileURL } from 'node:url';
import { ROOT, HOST_PROJECT, frameworkUiDirOf } from './lib/paths.mjs';
import { loadSource } from './ui-migration/gameabc-source.mjs';
import { imageBuckets } from './ui-migration/buckets.mjs';
import { convertAll } from './ui-migration/convert.mjs';
import { splitSheet } from './ui-migration/frame-io.mjs';
import { frameNames } from './ui-migration/frames.mjs';

// 与 verify-frames.mjs 一致：相对 ROOT 推导，不硬编码绝对路径。
const DEFAULT_SOURCE = join(ROOT, '..', 'projects', 'Game_Surface_3');

/**
 * 全量转换：产出中间描述 + 切好的散图。
 * 幂等：每次先清空产出目录（spec §4.4），避免残留帧文件混进图集。
 * 清空对象包括中间描述目录，以及本次实际会写入的每个 atlas-{bucket} 目录
 * （按 bucket 惰性清空一次，防止在同一次运行中被同 bucket 的后续图片覆盖式清掉）。
 */
export function runConvert(opts = {}) {
  const projectDir = opts.projectDir ?? DEFAULT_SOURCE;
  const intermediateDir = opts.intermediateDir ?? join(ROOT, 'ui-migration', 'intermediate');
  const uiDir = opts.uiDir ?? frameworkUiDirOf(HOST_PROJECT);

  const source = loadSource(join(projectDir, 'output'));
  const bucketMap = imageBuckets(source);
  const { layers, manifest, warnings } = convertAll(source);

  // 1) 中间描述
  rmSync(intermediateDir, { recursive: true, force: true });
  mkdirSync(intermediateDir, { recursive: true });
  writeFileSync(join(intermediateDir, 'manifest.json'), `${JSON.stringify(manifest, null, 2)}\n`);
  writeFileSync(join(intermediateDir, 'warnings.json'), `${JSON.stringify(warnings, null, 2)}\n`);
  for (const doc of layers) {
    const entry = manifest.layers.find((l) => l.layerId === doc.layerId);
    writeFileSync(join(intermediateDir, entry.file), `${JSON.stringify(doc, null, 2)}\n`);
  }

  // 2) 散图：多帧图切分，单帧图直拷
  let frameCount = 0;
  const cleanedBuckets = new Set();
  for (const image of source.images.values()) {
    const bucket = bucketMap.get(image.id) ?? 'unassigned';
    const outDir = join(uiDir, `atlas-${bucket}`);
    if (!cleanedBuckets.has(bucket)) {
      rmSync(outDir, { recursive: true, force: true });
      mkdirSync(outDir, { recursive: true });
      cleanedBuckets.add(bucket);
    }

    const src = join(projectDir, 'assets', 'bmp', image.bmp);
    if (!existsSync(src)) {
      throw new Error(`图片文件不存在: ${src}（图 id=${image.id}）`);
    }
    if (image.frame_all <= 1) {
      copyFileSync(src, join(outDir, image.bmp));
      frameCount++;
      continue;
    }
    const names = frameNames(image);
    splitSheet(readFileSync(src), image).forEach((buf, i) => {
      writeFileSync(join(outDir, names[i]), buf);
      frameCount++;
    });
  }

  const unassigned = layers.filter((l) => l.bucket === 'unassigned').map((l) => l.name);
  return {
    layerCount: layers.length,
    nodeCount: layers.reduce((s, l) => s + l.nodes.length, 0),
    imageCount: source.images.size,
    frameCount,
    unassigned,
    warningCount: warnings.length,
  };
}

if (process.argv[1] && import.meta.url === pathToFileURL(process.argv[1]).href) {
  const r = runConvert();
  console.log(`界面 ${r.layerCount} 个 / 节点 ${r.nodeCount} 个`);
  console.log(`图片 ${r.imageCount} 张 → 散图 ${r.frameCount} 张`);
  if (r.unassigned.length) {
    console.warn(`\n⚠️ ${r.unassigned.length} 个层的 bucket 未定，资源已落入 atlas-unassigned，需人工归位：`);
    for (const n of r.unassigned) console.warn(`   ${n}`);
  }
  if (r.warningCount > 0) {
    console.warn(
      `\n⚠️ ${r.warningCount} 条已知的源数据遗留问题（FrameIndex 超出图帧数，已回退为帧 1），`
      + '详情见 ui-migration/intermediate/warnings.json',
    );
  }
}