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

const repoRoot = process.cwd();
const outDir = path.join(
  repoRoot,
  'output',
  'imagegen',
  'edutainment-road-town-map-concepts-20260523',
);
const styleReferencePath = path.join(
  repoRoot,
  'public',
  'child-motion-demo',
  'picture-book-grass-stage.png',
);
const layoutReferencePaths = [
  path.join(repoRoot, 'tmp', 'edutainment_video_frames', 'video1_t2_11950ms.png'),
  path.join(repoRoot, 'tmp', 'edutainment_video_frames', 'video1_t3_23400ms.png'),
];
const defaultTimeoutMs = 1000000;

const commonPrompt = [
  '横屏 16:9 电视端寓教于乐板块玩法入口概念图。',
  '新的结构要求：抛弃原本乐园地图、环形乐园、岛屿乐园和主题公园分区结构，改为参考 Toca Life World 地图的“马路串联小建筑群”结构。',
  '每一屏都是一个完整的主题小建筑群街区：画面中心必须有一条灰蓝色可通车马路横向贯穿，马路有双车道、白色虚线、斑马线、路口、转弯支路和小汽车。',
  '马路必须从画面左侧边缘进入、从画面右侧边缘离开，左右边缘都要明确暗示可以接到上一屏和下一屏，像横向滑动世界地图的一段。',
  '建筑群沿马路两侧聚集，不要平均散成乐园点位；每屏像一个小镇街区、一组主题建筑、一段可探索街道。',
  '采用轻微俯视的卡通等距地图视角，能看清建筑立面、屋顶、路网和车辆路径。',
  '整体保持 Genarrative 寓教于乐现有明亮卡通绘本插画风：柔和水彩笔触、纸张纹理、温暖草地、浅蓝天空、圆润儿童友好、干净低噪声。',
  '入口模块只用建筑外形和道具暗示，不写任何文字：识物可用水果店、动物卡片屋、观察橱窗；绘画可用彩笔工坊、画纸屋；动作可用小操场、跳圈馆；拼图可用积木拼图屋；声音节奏可用小剧场、音乐屋；自然探索可用树屋、温室、观测台。',
  '参考图只用于学习“中央马路 + 两侧主题小建筑群 + 横向连续世界”的结构，不要复制 Toca Life World 的 logo、角色、建筑外形、UI、按钮、文字、字幕、水印或品牌元素。',
  '不要出现中文、英文、数字、字母、按钮文案、UI 面板、教程说明、logo、水印、商业 IP、真实品牌、城堡、环球影城/迪士尼式乐园、环形乐园岛、漂浮岛、地球球体、过度奇幻设施、真实照片感、暗黑科技风。',
].join('');

const concepts = [
  {
    id: 'edutainment-road-town-01-cognition-main-street',
    title: '识物认知主街',
    prompt: [
      commonPrompt,
      '本屏主题：识物认知主街。',
      '马路从左到右横穿中轴，路两侧是一组水果小店、动物观察窗、图形积木屋、透明展示橱窗和小型公交站，像儿童认知街区。',
      '建筑数量 6 到 8 个，分成前景近路建筑和后景山坡建筑，街区整体紧凑，不能变成分散乐园点。',
      '左边缘的道路要露出半个弯道和继续驶入的小汽车，右边缘道路继续出画，暗示下一屏可以接到绘画工坊街。',
    ].join(''),
  },
  {
    id: 'edutainment-road-town-02-creative-workshop-street',
    title: '绘画创作工坊街',
    prompt: [
      commonPrompt,
      '本屏主题：绘画创作工坊街。',
      '中央马路横贯画面，马路两侧聚成彩笔工坊、画纸屋、颜料罐屋、绘本小剧场、手工材料店和圆顶小展馆。',
      '建筑轮廓要像一组主题小建筑群，屋顶可有画笔、颜料、纸张、拼贴形状等图形化暗示，但不要出现任何文字。',
      '左边道路接识物主街，右边道路接运动音乐街；用连续路面、车道线、小汽车和路灯强调可横向滑动探索。',
    ].join(''),
  },
  {
    id: 'edutainment-road-town-03-motion-music-block',
    title: '运动音乐街区',
    prompt: [
      commonPrompt,
      '本屏主题：运动音乐街区。',
      '中央马路是主要路径，两侧是一组动作热身馆、小操场、跳圈屋、音乐小剧场、鼓点屋、铃铛塔和户外小舞台。',
      '建筑群要围绕道路形成一个活泼街区，前景可以有迷你停车位、斑马线、小汽车、路牌形状图标，但不要文字。',
      '道路左侧出画连接绘画创作工坊街，右侧出画连接自然探索街；画面边缘不能封死。',
    ].join(''),
  },
  {
    id: 'edutainment-road-town-04-nature-lab-avenue',
    title: '自然探索实验大道',
    prompt: [
      commonPrompt,
      '本屏主题：自然探索实验大道。',
      '中央马路横向穿过一组自然探索小建筑群：温室、树屋、昆虫观察屋、云朵气象站、小望远镜塔、湖边小码头和拼图桥。',
      '建筑沿道路成街区分布，后景是柔和山坡和树林，前景保留路边草地、停车位和小汽车路径。',
      '左边道路接运动音乐街，右边道路继续进入森林或新的学习街区，明确体现一屏接一屏的世界地图结构。',
    ].join(''),
  },
];

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

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 inferExtensionFromBytes(bytes) {
  if (bytes.subarray(0, 8).equals(Buffer.from('\x89PNG\r\n\x1A\n', 'binary'))) {
    return 'png';
  }
  if (bytes.subarray(0, 3).equals(Buffer.from([0xff, 0xd8, 0xff]))) {
    return 'jpg';
  }
  if (
    bytes.subarray(0, 4).toString('ascii') === 'RIFF' &&
    bytes.subarray(8, 12).toString('ascii') === 'WEBP'
  ) {
    return 'webp';
  }
  return 'png';
}

function inferExtensionFromContentType(contentType) {
  const normalized = contentType.split(';')[0]?.trim().toLowerCase();
  if (normalized === 'image/png') {
    return 'png';
  }
  if (normalized === 'image/webp') {
    return 'webp';
  }
  if (normalized === 'image/jpeg') {
    return 'jpg';
  }
  return 'png';
}

function toDataUrl(filePath) {
  if (!existsSync(filePath)) {
    return null;
  }
  const bytes = readFileSync(filePath);
  const extension = inferExtensionFromBytes(bytes);
  const mime = extension === 'jpg' ? 'image/jpeg' : `image/${extension}`;
  return `data:${mime};base64,${bytes.toString('base64')}`;
}

function referenceDataUrls() {
  return [styleReferencePath, ...layoutReferencePaths]
    .map((filePath) => toDataUrl(filePath))
    .filter(Boolean);
}

function buildRequestBody(concept, size, references) {
  const body = {
    model: 'gpt-image-2-all',
    prompt: concept.prompt,
    n: 1,
    size,
  };
  if (references.length > 0) {
    body.image = references;
  }
  return body;
}

function buildDryRunRequestBody(concept, size, references) {
  return {
    model: 'gpt-image-2-all',
    prompt: concept.prompt,
    n: 1,
    size,
    imageReferenceCount: references.length,
  };
}

async function fetchJson(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 JSON.parse(text);
  } catch (error) {
    if (error?.name === 'AbortError') {
      throw new Error(`VectorEngine request timed out after ${timeoutMs}ms`);
    }
    throw error;
  } finally {
    clearTimeout(timer);
  }
}

async function downloadUrl(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 {
      bytes: Buffer.from(await response.arrayBuffer()),
      extension: inferExtensionFromContentType(
        response.headers.get('content-type') || '',
      ),
    };
  } catch (error) {
    if (error?.name === 'AbortError') {
      throw new Error(`Generated image download timed out after ${timeoutMs}ms`);
    }
    throw error;
  } finally {
    clearTimeout(timer);
  }
}

function outputPathFor(concept, extension = 'png') {
  return path.join(outDir, `${concept.id}.${extension}`);
}

function findExistingOutputPath(concept) {
  for (const extension of ['png', 'jpg', 'jpeg', 'webp']) {
    const candidate = outputPathFor(concept, extension);
    if (existsSync(candidate)) {
      return candidate;
    }
  }
  return null;
}

async function generateOne(env, concept, size, references) {
  const payload = await fetchJson(
    generationUrl(env.baseUrl),
    {
      method: 'POST',
      headers: {
        Authorization: `Bearer ${env.apiKey}`,
        Accept: 'application/json',
        'Content-Type': 'application/json',
      },
      body: JSON.stringify(buildRequestBody(concept, size, references)),
    },
    env.timeoutMs,
  );

  const urls = [];
  const b64Images = [];
  collectStringsByKey(payload, 'url', urls);
  collectStringsByKey(payload, 'image', urls);
  collectStringsByKey(payload, 'image_url', urls);
  collectStringsByKey(payload, 'b64_json', b64Images);

  let image;
  const imageUrl = [...new Set(urls)].find((url) => /^https?:\/\//u.test(url));
  if (imageUrl) {
    image = await downloadUrl(imageUrl, env.timeoutMs);
  } else if (b64Images[0]) {
    const bytes = Buffer.from(b64Images[0], 'base64');
    image = {
      bytes,
      extension: inferExtensionFromBytes(bytes),
    };
  } else {
    throw new Error(`VectorEngine returned no image for ${concept.id}`);
  }

  mkdirSync(outDir, { recursive: true });
  const outputPath = outputPathFor(concept, image.extension);
  writeFileSync(outputPath, image.bytes);
  return outputPath;
}

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

const size = String(args.get('--size') || '3840x2160');
const dryRun = args.has('--dry-run') || !args.has('--live');
const selectedIds = String(args.get('--only') || '')
  .split(',')
  .map((value) => value.trim())
  .filter(Boolean);
const selectedConcepts = concepts.filter(
  (concept) => selectedIds.length === 0 || selectedIds.includes(concept.id),
);
const references = referenceDataUrls();

if (dryRun) {
  console.log(
    JSON.stringify(
      {
        mode: 'dry-run',
        outDir,
        size,
        styleReference: existsSync(styleReferencePath)
          ? styleReferencePath
          : null,
        layoutReferences: layoutReferencePaths.filter((filePath) =>
          existsSync(filePath),
        ),
        count: selectedConcepts.length,
        requests: selectedConcepts.map((concept) => ({
          id: concept.id,
          title: concept.title,
          body: buildDryRunRequestBody(concept, size, references),
        })),
      },
      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 files = [];
const generatedFileById = new Map();
for (const concept of selectedConcepts) {
  console.log(`Generating ${concept.id}...`);
  const file = await generateOne(env, concept, size, references);
  files.push(file);
  generatedFileById.set(concept.id, file);
}

const metadataFiles = concepts
  .map((concept) => {
    const file = generatedFileById.get(concept.id) ?? findExistingOutputPath(concept);
    if (!file) {
      return null;
    }
    return {
      id: concept.id,
      title: concept.title,
      file,
      prompt: concept.prompt,
    };
  })
  .filter(Boolean);

writeFileSync(
  path.join(outDir, 'generation-metadata.json'),
  JSON.stringify(
    {
      model: 'gpt-image-2-all',
      size,
      generatedAt: new Date().toISOString(),
      styleReference: existsSync(styleReferencePath) ? styleReferencePath : null,
      layoutReferences: layoutReferencePaths.filter((filePath) =>
        existsSync(filePath),
      ),
      generatedIds: selectedConcepts.map((concept) => concept.id),
      files: metadataFiles,
    },
    null,
    2,
  ),
);

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