#!/usr/bin/env node
import { createHash, randomUUID } from 'node:crypto';
import { mkdir, writeFile } from 'node:fs/promises';
import { dirname, extname, join, resolve } from 'node:path';
import { homedir } from 'node:os';

const DEFAULT_COUNT = 8;
const MAX_COUNT = 20;
const DEFAULT_TIMEOUT_MS = 18_000;
const MAX_DOWNLOAD_BYTES = 15 * 1024 * 1024;
const USER_AGENT = 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/123 Safari/537.36 ZhinianAssistant/0.1';

function parseArgs(argv) {
  const args = {
    query: '',
    count: DEFAULT_COUNT,
    download: 0,
    outDir: join(homedir(), '.openclaw', 'media', 'image-search'),
    output: '',
    safe: 'moderate',
    language: 'zh-CN',
  };

  const positional = [];
  for (let index = 0; index < argv.length; index += 1) {
    const arg = argv[index];
    if (arg === '--count' || arg === '-n') {
      args.count = Number.parseInt(argv[++index] || '', 10);
    } else if (arg === '--download' || arg === '-d') {
      const next = argv[index + 1];
      if (next && !next.startsWith('-')) {
        args.download = Number.parseInt(next, 10);
        index += 1;
      } else {
        args.download = Math.min(args.count, 3);
      }
    } else if (arg === '--out-dir') {
      args.outDir = argv[++index] || args.outDir;
    } else if (arg === '--output' || arg === '-o') {
      args.output = argv[++index] || '';
    } else if (arg === '--safe') {
      args.safe = argv[++index] || args.safe;
    } else if (arg === '--language' || arg === '--lang') {
      args.language = argv[++index] || args.language;
    } else if (arg === '--help' || arg === '-h') {
      printHelp();
      process.exit(0);
    } else {
      positional.push(arg);
    }
  }

  args.query = positional.join(' ').trim();
  args.count = Number.isFinite(args.count) ? Math.max(1, Math.min(MAX_COUNT, args.count)) : DEFAULT_COUNT;
  args.download = Number.isFinite(args.download) ? Math.max(0, Math.min(args.count, args.download)) : 0;
  return args;
}

function printHelp() {
  process.stdout.write(`Usage:
  node search-images.mjs "<query>" [--count 8] [--download 3] [--out-dir <dir>] [--output <file>]

Options:
  --count, -n      Number of image candidates to return, 1-${MAX_COUNT}.
  --download, -d   Download the first N image candidates to local files.
  --out-dir        Directory for downloaded images. Defaults to ~/.openclaw/media/image-search.
  --output, -o     Write JSON result to a file in addition to stdout.
  --safe           Safe search level passed to the image search page. Default: moderate.
  --language       Accept-Language value. Default: zh-CN.
`);
}

function decodeHtml(value) {
  return String(value || '')
    .replace(/&quot;/g, '"')
    .replace(/&#34;/g, '"')
    .replace(/&amp;/g, '&')
    .replace(/&#39;/g, "'")
    .replace(/&lt;/g, '<')
    .replace(/&gt;/g, '>');
}

function stripBingHighlights(value) {
  return decodeHtml(value)
    .replace(/\uE000|\uE001|\uE002|\uE003/g, '')
    .replace(/\s+/g, ' ')
    .trim();
}

function siteNameFromUrl(url) {
  try {
    return new URL(url).hostname.replace(/^www\./, '');
  } catch {
    return '';
  }
}

function extFromMime(contentType) {
  const normalized = String(contentType || '').split(';')[0].trim().toLowerCase();
  if (normalized === 'image/jpeg' || normalized === 'image/jpg') return '.jpg';
  if (normalized === 'image/png') return '.png';
  if (normalized === 'image/webp') return '.webp';
  if (normalized === 'image/gif') return '.gif';
  if (normalized === 'image/avif') return '.avif';
  return '';
}

function extFromUrl(url) {
  try {
    const ext = extname(new URL(url).pathname).toLowerCase();
    if (['.jpg', '.jpeg', '.png', '.webp', '.gif', '.avif'].includes(ext)) return ext === '.jpeg' ? '.jpg' : ext;
  } catch {
    return '';
  }
  return '';
}

function stableId(value) {
  return createHash('sha1').update(value).digest('hex').slice(0, 12);
}

function buildBingImagesUrl(params) {
  const url = new URL('https://www.bing.com/images/search');
  url.searchParams.set('q', params.query);
  url.searchParams.set('form', 'HDRSC2');
  url.searchParams.set('safeSearch', params.safe);
  return url.toString();
}

async function fetchText(url, timeoutMs = DEFAULT_TIMEOUT_MS) {
  const controller = new AbortController();
  const timer = setTimeout(() => controller.abort(), timeoutMs);
  try {
    const response = await fetch(url, {
      signal: controller.signal,
      headers: {
        'User-Agent': USER_AGENT,
        'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
        'Accept-Language': 'zh-CN,zh;q=0.9,en;q=0.8',
      },
    });
    if (!response.ok) {
      throw new Error(`HTTP ${response.status} ${response.statusText}`);
    }
    return await response.text();
  } finally {
    clearTimeout(timer);
  }
}

function parseBingImages(html, count) {
  const results = [];
  const seen = new Set();
  const matcher = /m="([^"]+)"/g;
  let match;

  while ((match = matcher.exec(html)) && results.length < count) {
    const raw = decodeHtml(match[1]);
    let metadata;
    try {
      metadata = JSON.parse(raw);
    } catch {
      continue;
    }

    const imageUrl = typeof metadata.murl === 'string' ? metadata.murl.trim() : '';
    const thumbnailUrl = typeof metadata.turl === 'string' ? metadata.turl.trim() : '';
    const sourcePageUrl = typeof metadata.purl === 'string' ? metadata.purl.trim() : '';
    if (!imageUrl || seen.has(imageUrl)) continue;
    seen.add(imageUrl);

    results.push({
      id: stableId(imageUrl),
      title: stripBingHighlights(metadata.t || metadata.desc || ''),
      description: stripBingHighlights(metadata.desc || ''),
      imageUrl,
      thumbnailUrl,
      sourcePageUrl,
      sourceName: siteNameFromUrl(sourcePageUrl || imageUrl),
      width: Number.isFinite(Number(metadata.w)) ? Number(metadata.w) : undefined,
      height: Number.isFinite(Number(metadata.h)) ? Number(metadata.h) : undefined,
    });
  }

  return results;
}

async function downloadImage(result, outDir, index) {
  const controller = new AbortController();
  const timer = setTimeout(() => controller.abort(), DEFAULT_TIMEOUT_MS);
  try {
    const response = await fetch(result.imageUrl, {
      signal: controller.signal,
      redirect: 'follow',
      headers: {
        'User-Agent': USER_AGENT,
        'Accept': 'image/avif,image/webp,image/apng,image/svg+xml,image/*,*/*;q=0.8',
        'Referer': result.sourcePageUrl || 'https://www.bing.com/',
      },
    });
    if (!response.ok) {
      throw new Error(`HTTP ${response.status} ${response.statusText}`);
    }
    const contentType = response.headers.get('content-type') || '';
    if (!contentType.toLowerCase().startsWith('image/')) {
      throw new Error(`Not an image response: ${contentType || 'unknown content-type'}`);
    }
    const contentLength = Number(response.headers.get('content-length') || '0');
    if (contentLength > MAX_DOWNLOAD_BYTES) {
      throw new Error(`Image too large: ${contentLength} bytes`);
    }
    const bytes = Buffer.from(await response.arrayBuffer());
    if (bytes.byteLength > MAX_DOWNLOAD_BYTES) {
      throw new Error(`Image too large: ${bytes.byteLength} bytes`);
    }

    await mkdir(outDir, { recursive: true });
    const ext = extFromMime(contentType) || extFromUrl(result.imageUrl) || '.jpg';
    const fileName = `${String(index + 1).padStart(2, '0')}-${result.id || randomUUID()}${ext}`;
    const filePath = join(outDir, fileName);
    await writeFile(filePath, bytes);

    return {
      localPath: filePath,
      mimeType: contentType.split(';')[0].trim() || undefined,
      fileSize: bytes.byteLength,
    };
  } finally {
    clearTimeout(timer);
  }
}

async function main() {
  const args = parseArgs(process.argv.slice(2));
  if (!args.query) {
    printHelp();
    process.exit(2);
  }

  const searchUrl = buildBingImagesUrl(args);
  const startedAt = Date.now();
  const warnings = [
    'Web images may have copyright or usage restrictions. Use sourcePageUrl to verify rights before commercial use.',
  ];

  let results = [];
  try {
    const html = await fetchText(searchUrl);
    results = parseBingImages(html, args.count);
  } catch (error) {
    warnings.push(`Image search failed: ${error?.message || String(error)}`);
  }

  const resolvedOutDir = resolve(args.outDir.replace(/^~(?=$|\/)/, homedir()));
  const downloadCount = Math.min(args.download, results.length);
  for (let index = 0; index < downloadCount; index += 1) {
    try {
      const download = await downloadImage(results[index], resolvedOutDir, index);
      results[index] = { ...results[index], ...download };
    } catch (error) {
      results[index] = {
        ...results[index],
        downloadError: error?.message || String(error),
      };
    }
  }

  const payload = {
    success: results.length > 0,
    provider: 'bing-images-html',
    query: args.query,
    count: results.length,
    tookMs: Date.now() - startedAt,
    searchUrl,
    warnings,
    results,
  };

  const json = `${JSON.stringify(payload, null, 2)}\n`;
  if (args.output) {
    const outputPath = resolve(args.output.replace(/^~(?=$|\/)/, homedir()));
    await mkdir(dirname(outputPath), { recursive: true });
    await writeFile(outputPath, json, 'utf8');
  }
  process.stdout.write(json);
}

main().catch((error) => {
  process.stderr.write(`${error?.stack || error?.message || String(error)}\n`);
  process.exit(1);
});