import { Router } from 'express';
import { mkdirSync } from 'fs';
import { join } from 'path';
import { scrapeForumPage, getPageUrl, detectMaxPage } from './scrapers/forum.js';
import { parseUserUrl, fetchAllPosts, downloadFiles } from './scrapers/coomer.js';
import { parseMediaUrl, fetchAllMedia, downloadMedia } from './scrapers/medialink.js';

const router = Router();
const MEDIA_PATH = process.env.MEDIA_PATH || './data/media';

const jobsMap = new Map();
let jobCounter = 0;
const MAX_COMPLETED = 50;
const MAX_LOGS = 200;

function createJob(type, config) {
  const id = `scrape_${Date.now()}_${++jobCounter}`;
  const job = {
    id,
    type,
    config,
    progress: { total: 0, completed: 0, errors: 0 },
    running: true,
    cancelled: false,
    logs: [],
    startedAt: new Date().toISOString(),
    completedAt: null,
    folderName: config.folderName || 'scrape',
  };
  jobsMap.set(id, job);
  return job;
}

function addLog(job, msg) {
  const ts = new Date().toLocaleTimeString('en-US', { hour12: false });
  job.logs.push(`[${ts}] ${msg}`);
  if (job.logs.length > MAX_LOGS) job.logs.shift();
}

function pruneCompleted() {
  const completed = [...jobsMap.values()]
    .filter(j => !j.running)
    .sort((a, b) => new Date(b.completedAt) - new Date(a.completedAt));
  if (completed.length > MAX_COMPLETED) {
    for (const old of completed.slice(MAX_COMPLETED)) {
      jobsMap.delete(old.id);
    }
  }
}

function jobToJson(job) {
  return {
    id: job.id,
    type: job.type,
    config: job.config,
    progress: job.progress,
    running: job.running,
    cancelled: job.cancelled,
    folderName: job.folderName,
    startedAt: job.startedAt,
    completedAt: job.completedAt,
    logCount: job.logs.length,
  };
}

// --- Forum Scrape ---

async function runForumScrape(job) {
  const { url, startPage, endPage, delay, folderName } = job.config;
  const outputDir = join(MEDIA_PATH, folderName);
  mkdirSync(outputDir, { recursive: true });

  const downloadedSet = new Set();
  let totalImages = 0;

  addLog(job, `Starting forum scrape: pages ${startPage}-${endPage}`);
  addLog(job, `Output: ${outputDir}`);

  job.progress.total = endPage - startPage + 1;

  try {
    for (let page = startPage; page <= endPage; page++) {
      if (job.cancelled) {
        addLog(job, 'Cancelled by user');
        break;
      }

      const pageUrl = getPageUrl(url, page);
      addLog(job, `--- Page ${page}/${endPage} ---`);

      const count = await scrapeForumPage(pageUrl, outputDir, downloadedSet, (msg) => addLog(job, msg));
      totalImages += count;
      job.progress.completed = page - startPage + 1;

      if (page < endPage && !job.cancelled) {
        await new Promise(r => setTimeout(r, delay * 1000));
      }
    }
  } catch (err) {
    addLog(job, `Error: ${err.message}`);
    job.progress.errors++;
  } finally {
    job.running = false;
    job.completedAt = new Date().toISOString();
    addLog(job, `Done! ${totalImages} images saved to ${folderName}/`);
    pruneCompleted();
  }
}

// --- Coomer Scrape ---

async function runCoomerScrape(job) {
  const { url, pages, workers, folderName } = job.config;
  const outputDir = join(MEDIA_PATH, folderName);
  mkdirSync(outputDir, { recursive: true });

  addLog(job, `Starting coomer scrape: ${url}`);
  addLog(job, `Pages: ${pages}, Workers: ${workers}`);

  try {
    const { base, service, userId } = parseUserUrl(url);
    addLog(job, `Site: ${base}, Service: ${service}, User: ${userId}`);

    // Phase 1: Collect files
    addLog(job, `Fetching up to ${pages} pages...`);
    const files = await fetchAllPosts(base, service, userId, pages,
      (msg) => addLog(job, msg),
      () => job.cancelled
    );

    if (job.cancelled) {
      addLog(job, 'Cancelled by user');
      return;
    }

    if (files.length === 0) {
      addLog(job, 'No files found');
      return;
    }

    job.progress.total = files.length;
    addLog(job, `Found ${files.length} files. Starting downloads...`);

    // Phase 2: Download
    const result = await downloadFiles(files, outputDir, workers,
      (msg) => addLog(job, msg),
      (completed, errors, total) => {
        job.progress.completed = completed;
        job.progress.errors = errors;
        job.progress.total = total;
      },
      () => job.cancelled
    );

    addLog(job, `Done! ${result.completed} downloaded, ${result.errors} failed, ${result.skipped} skipped`);
  } catch (err) {
    addLog(job, `Error: ${err.message}`);
    job.progress.errors++;
  } finally {
    job.running = false;
    job.completedAt = new Date().toISOString();
    pruneCompleted();
  }
}

// --- MediaLink Scrape ---

async function runMediaLinkScrape(job) {
  const { url, pages, workers, delay, folderName } = job.config;
  const outputDir = join(MEDIA_PATH, folderName);
  mkdirSync(outputDir, { recursive: true });

  addLog(job, `Starting medialink scrape: ${url}`);
  addLog(job, `Pages: ${pages}, Workers: ${workers}, Delay: ${delay}ms`);

  try {
    const { base, userId } = parseMediaUrl(url);
    addLog(job, `Site: ${base}, User ID: ${userId}`);

    // Phase 1: Collect all media via JSON API
    addLog(job, `Fetching up to ${pages} pages from API...`);
    const items = await fetchAllMedia(base, userId, pages, delay,
      (msg) => addLog(job, msg),
      () => job.cancelled
    );

    if (job.cancelled) {
      addLog(job, 'Cancelled by user');
      return;
    }

    if (items.length === 0) {
      addLog(job, 'No media found');
      return;
    }

    job.progress.total = items.length;
    addLog(job, `Found ${items.length} media items. Downloading...`);

    // Phase 2: Download all media files
    const result = await downloadMedia(items, outputDir, workers,
      (msg) => addLog(job, msg),
      (completed, errors, total) => {
        job.progress.completed = completed;
        job.progress.errors = errors;
        job.progress.total = total;
      },
      () => job.cancelled
    );

    addLog(job, `Done! ${result.completed} downloaded, ${result.errors} failed, ${result.skipped} skipped`);
  } catch (err) {
    addLog(job, `Error: ${err.message}`);
    job.progress.errors++;
  } finally {
    job.running = false;
    job.completedAt = new Date().toISOString();
    pruneCompleted();
  }
}

// --- Endpoints ---

router.post('/api/scrape/forum', (req, res) => {
  const { url, folderName, startPage, endPage, delay } = req.body;
  if (!url) return res.status(400).json({ error: 'URL is required' });
  if (!folderName) return res.status(400).json({ error: 'Folder name is required' });

  const config = {
    url: url.includes('page-') ? url : `${url.replace(/\/$/, '')}/page-1`,
    folderName,
    startPage: parseInt(startPage) || 1,
    endPage: parseInt(endPage) || 10,
    delay: parseFloat(delay) || 1.0,
  };

  const job = createJob('forum', config);
  runForumScrape(job).catch(err => {
    addLog(job, `Fatal error: ${err.message}`);
    job.running = false;
    job.completedAt = new Date().toISOString();
  });

  res.json({ jobId: job.id, message: 'Forum scrape started' });
});

router.post('/api/scrape/coomer', (req, res) => {
  const { url, folderName, pages, workers } = req.body;
  if (!url) return res.status(400).json({ error: 'URL is required' });
  if (!folderName) return res.status(400).json({ error: 'Folder name is required' });

  const config = {
    url,
    folderName,
    pages: parseInt(pages) || 10,
    workers: Math.min(Math.max(parseInt(workers) || 10, 1), 20),
  };

  const job = createJob('coomer', config);
  runCoomerScrape(job).catch(err => {
    addLog(job, `Fatal error: ${err.message}`);
    job.running = false;
    job.completedAt = new Date().toISOString();
  });

  res.json({ jobId: job.id, message: 'Coomer scrape started' });
});

router.post('/api/scrape/medialink', (req, res) => {
  const { url, folderName, pages, workers, delay } = req.body;
  if (!url) return res.status(400).json({ error: 'URL is required' });
  if (!folderName) return res.status(400).json({ error: 'Folder name is required' });

  const config = {
    url,
    folderName,
    pages: parseInt(pages) || 50,
    workers: Math.min(Math.max(parseInt(workers) || 3, 1), 10),
    delay: parseInt(delay) || 500,
  };

  const job = createJob('medialink', config);
  runMediaLinkScrape(job).catch(err => {
    addLog(job, `Fatal error: ${err.message}`);
    job.running = false;
    job.completedAt = new Date().toISOString();
  });

  res.json({ jobId: job.id, message: 'MediaLink scrape started' });
});

router.get('/api/scrape/jobs', (_req, res) => {
  const jobs = [...jobsMap.values()].map(jobToJson);
  jobs.sort((a, b) => new Date(b.startedAt) - new Date(a.startedAt));
  res.json(jobs);
});

router.get('/api/scrape/jobs/:jobId', (req, res) => {
  const job = jobsMap.get(req.params.jobId);
  if (!job) return res.status(404).json({ error: 'Job not found' });
  res.json({ ...jobToJson(job), logs: job.logs });
});

router.post('/api/scrape/jobs/:jobId/cancel', (req, res) => {
  const job = jobsMap.get(req.params.jobId);
  if (!job) return res.status(404).json({ error: 'Job not found' });
  if (!job.running) return res.status(400).json({ error: 'Job is not running' });
  job.cancelled = true;
  addLog(job, 'Cancel requested');
  res.json({ message: 'Cancel requested' });
});

// Auto-detect max page for forum URLs
router.post('/api/scrape/forum/detect-pages', async (req, res) => {
  const { url } = req.body;
  if (!url) return res.status(400).json({ error: 'URL is required' });
  const logs = [];
  const maxPage = await detectMaxPage(url, (msg) => logs.push(msg));
  res.json({ maxPage, logs });
});

export default router;