import { Buffer } from 'node:buffer';
import { existsSync, mkdirSync, readFileSync, writeFileSync } from 'node:fs';
import path from 'node:path';
import { fileURLToPath } from 'node:url';

const scriptDir = path.dirname(fileURLToPath(import.meta.url));
const repoRoot = path.resolve(scriptDir, '..');
const defaultOutDir = path.join(repoRoot, 'public', 'match3d-style-references');
const defaultTimeoutMs = 180000;

const styleTemplates = [
  {
    id: 'flat-icon',
    title: '扁平图标',
    prompt:
      '扁平矢量游戏道具图标风格，干净色块，正面视角，深色清晰轮廓，移动端休闲游戏素材，可读性很强。',
  },
  {
    id: 'cel-cartoon',
    title: '赛璐璐卡通',
    prompt:
      '赛璐璐卡通游戏道具风格，明亮配色，清晰线稿，硬边阴影，边缘干净，像轻松休闲手游里的 2D 素材。',
  },
  {
    id: 'pixel-retro',
    title: '像素复古',
    prompt:
      '复古像素游戏道具素材风格，有限色板，清晰像素边缘，主体轮廓稳定，像 32-bit 休闲游戏图标。',
  },
  {
    id: 'watercolor',
    title: '手绘水彩',
    prompt:
      '手绘水彩游戏道具风格，柔和纸张纹理，透明叠色，边缘轻微晕染，但主体剪影仍然清楚。',
  },
  {
    id: 'sticker-outline',
    title: '贴纸描边',
    prompt:
      '贴纸描边游戏道具素材风格，粗白边，深色外轮廓，柔和投影，色彩活泼，适合休闲消除游戏。',
  },
  {
    id: 'painterly-icon',
    title: '厚涂图标',
    prompt:
      '厚涂游戏道具图标风格，细腻笔触，明确体积光影，中心构图，清晰剪影，适合高品质 2D 道具素材。',
  },
];

const args = new Map();
for (let index = 2; index < process.argv.length; index += 1) {
  const raw = process.argv[index];
  if (!raw.startsWith('--')) {
    continue;
  }
  const next = process.argv[index + 1];
  if (next && !next.startsWith('--')) {
    args.set(raw, next);
    index += 1;
  } else {
    args.set(raw, true);
  }
}

function readDotenv(fileName) {
  const filePath = path.join(repoRoot, fileName);
  if (!existsSync(filePath)) {
    return {};
  }

  const values = {};
  for (const line of readFileSync(filePath, 'utf8').split(/\r?\n/u)) {
    const trimmed = line.trim();
    if (!trimmed || trimmed.startsWith('#')) {
      continue;
    }

    const match = /^([A-Za-z_][A-Za-z0-9_]*)=(.*)$/u.exec(trimmed);
    if (!match) {
      continue;
    }

    let value = match[2].trim();
    if (
      (value.startsWith('"') && value.endsWith('"')) ||
      (value.startsWith("'") && value.endsWith("'"))
    ) {
      value = value.slice(1, -1);
    }
    values[match[1]] = value;
  }
  return values;
}

function resolveEnv() {
  const loaded = {
    ...readDotenv('.env.example'),
    ...readDotenv('.env.local'),
    ...readDotenv('.env.secrets.local'),
    ...process.env,
  };
  return {
    baseUrl: String(loaded.VECTOR_ENGINE_BASE_URL || '')
      .trim()
      .replace(/\/+$/u, ''),
    apiKey: String(loaded.VECTOR_ENGINE_API_KEY || '').trim(),
    timeoutMs: Number.parseInt(
      String(loaded.VECTOR_ENGINE_IMAGE_REQUEST_TIMEOUT_MS || defaultTimeoutMs),
      10,
    ),
  };
}

function buildVectorEngineImagesGenerationUrl(baseUrl) {
  return baseUrl.endsWith('/v1')
    ? `${baseUrl}/images/generations`
    : `${baseUrl}/v1/images/generations`;
}

function buildPrompt(template) {
  return [
    '请生成一张 1:1 方形抓大鹅入口 2D 素材风格参考图。',
    '画面是一组 5 个小型游戏道具样张，题材统一为水果、甜点、玩具和宝石的混合展示。',
    `整体风格：${template.prompt}`,
    '要求：每个道具都是独立 2D 素材示例，主体集中，轮廓清晰，适合被切成抓大鹅局内物品素材。',
    '构图：浅色干净背景，散点排列，留有呼吸感，不要九宫格边框，不要 UI 面板，不要按钮。',
    '避免：文字、水印、logo、教程标注、真实照片、复杂场景、人物、动物、3D 模型视口、明显透视地面、厚重阴影。',
  ].join('');
}

function collectStringsByKey(value, targetKey, output) {
  if (Array.isArray(value)) {
    value.forEach((entry) => collectStringsByKey(entry, targetKey, output));
    return;
  }
  if (!value || typeof value !== 'object') {
    return;
  }

  for (const [key, nested] of Object.entries(value)) {
    if (key === targetKey) {
      if (typeof nested === 'string' && nested.trim()) {
        output.push(nested.trim());
      }
      if (Array.isArray(nested)) {
        nested.forEach((entry) => {
          if (typeof entry === 'string' && entry.trim()) {
            output.push(entry.trim());
          }
        });
      }
    }
    collectStringsByKey(nested, targetKey, output);
  }
}

function extractImageUrls(payload) {
  const urls = [];
  collectStringsByKey(payload, 'url', urls);
  collectStringsByKey(payload, 'image', urls);
  collectStringsByKey(payload, 'image_url', urls);
  return [...new Set(urls)].filter((url) => /^https?:\/\//u.test(url));
}

function extractBase64Images(payload) {
  const values = [];
  collectStringsByKey(payload, 'b64_json', values);
  return values;
}

async function fetchWithTimeout(url, options, timeoutMs) {
  const abortController = new AbortController();
  const timer = setTimeout(() => abortController.abort(), timeoutMs);
  try {
    const response = await fetch(url, {
      ...options,
      signal: abortController.signal,
    });
    const text = await response.text();
    if (!response.ok) {
      throw new Error(`VectorEngine ${response.status}: ${text.slice(0, 600)}`);
    }
    return text;
  } catch (error) {
    if (error?.name === 'AbortError') {
      throw new Error(`VectorEngine request timed out after ${timeoutMs}ms`);
    }
    throw error;
  } finally {
    clearTimeout(timer);
  }
}

async function downloadImage(url, timeoutMs) {
  const abortController = new AbortController();
  const timer = setTimeout(() => abortController.abort(), timeoutMs);
  try {
    const response = await fetch(url, { signal: abortController.signal });
    if (!response.ok) {
      throw new Error(`download ${response.status}`);
    }
    return Buffer.from(await response.arrayBuffer());
  } catch (error) {
    if (error?.name === 'AbortError') {
      throw new Error(
        `Generated image download timed out after ${timeoutMs}ms`,
      );
    }
    throw error;
  } finally {
    clearTimeout(timer);
  }
}

async function generateOne(env, template, outDir, size) {
  const requestBody = {
    model: 'gpt-image-2-all',
    prompt: buildPrompt(template),
    n: 1,
    size,
  };
  const payloadText = await fetchWithTimeout(
    buildVectorEngineImagesGenerationUrl(env.baseUrl),
    {
      method: 'POST',
      headers: {
        Authorization: `Bearer ${env.apiKey}`,
        Accept: 'application/json',
        'Content-Type': 'application/json',
      },
      body: JSON.stringify(requestBody),
    },
    env.timeoutMs,
  );

  const payload = JSON.parse(payloadText);
  const urls = extractImageUrls(payload);
  const base64Images = extractBase64Images(payload);
  const imageBytes = urls[0]
    ? await downloadImage(urls[0], env.timeoutMs)
    : base64Images[0]
      ? Buffer.from(base64Images[0], 'base64')
      : null;

  if (!imageBytes) {
    throw new Error(`VectorEngine returned no image for ${template.id}`);
  }

  mkdirSync(outDir, { recursive: true });
  const outPath = path.join(outDir, `${template.id}.png`);
  writeFileSync(outPath, imageBytes);
  return {
    file: outPath,
    source: urls[0] ? 'url' : 'b64_json',
  };
}

const dryRun = args.has('--dry-run') || !args.has('--live');
const outDir = path.resolve(String(args.get('--out-dir') || defaultOutDir));
const size = String(args.get('--size') || '1024x1024');
const onlyIds = String(args.get('--only') || '')
  .split(',')
  .map((value) => value.trim())
  .filter(Boolean);
const templates = styleTemplates.filter(
  (template) => !onlyIds.length || onlyIds.includes(template.id),
);

if (dryRun) {
  console.log(
    JSON.stringify(
      {
        mode: 'dry-run',
        outDir,
        count: templates.length,
        requests: templates.map((template) => ({
          id: template.id,
          title: template.title,
          body: {
            model: 'gpt-image-2-all',
            prompt: buildPrompt(template),
            n: 1,
            size,
          },
        })),
      },
      null,
      2,
    ),
  );
  process.exit(0);
}

const env = resolveEnv();
if (!env.baseUrl || !env.apiKey) {
  console.error(
    JSON.stringify({
      ok: false,
      error: 'Missing VECTOR_ENGINE_BASE_URL or VECTOR_ENGINE_API_KEY',
      hasBaseUrl: Boolean(env.baseUrl),
      hasApiKey: Boolean(env.apiKey),
    }),
  );
  process.exit(1);
}

const generated = [];
for (const template of templates) {
  console.log(`Generating ${template.id}...`);
  generated.push({
    id: template.id,
    ...(await generateOne(env, template, outDir, size)),
  });
}

console.log(
  JSON.stringify(
    {
      ok: true,
      count: generated.length,
      files: generated,
    },
    null,
    2,
  ),
);