const express = require('express');
const router = express.Router();
const { db } = require('../db');
const { getAllCoursesFromDB, getLayoutsForCourse, updateLayoutRating, saveCourseToDB, getOrCreateLayout } = require('../models/course');
const { searchTjingCourses, getTjingCourse } = require('../scrapers/tjing');
const { launchBrowser } = require('../scrapers/browser');
const { layoutEventCache, scrapeCourseDirectory, scrapeCourseLayouts, scrapeEventResults } = require('../scrapers/course-puppeteer');
const logger = require('../logger');

// Request locking to prevent concurrent scrapes of the same resource
const activeScrapes = new Map();

router.get('/partials/course-table', async (req, res) => {
  try {
    const oneYearAgo = new Date();
    oneYearAgo.setDate(oneYearAgo.getDate() - 365);
    const oneYearAgoStr = oneYearAgo.toISOString().slice(0, 10);

    const allCourses = await new Promise((resolve, reject) => {
      db.all(
        `SELECT c.*,
                COUNT(l.id) AS layoutCount,
                SUM(CASE WHEN l.last_played >= ? THEN 1 ELSE 0 END) AS activeLayoutCount
         FROM courses c
         LEFT JOIN layouts l ON l.course_id = c.id
         GROUP BY c.id
         ORDER BY c.name ASC`,
        [oneYearAgoStr],
        (err, rows) => {
          if (err) reject(err);
          else resolve(rows);
        }
      );
    });

    res.render('../partials/course-table', { courses: allCourses });
  } catch (error) {
    logger.error({ err: error }, 'Error loading course table');
    res.status(500).send('<p>Error loading courses. Please try again.</p>');
  }
});

router.get('/partials/course-layouts/:courseId', async (req, res) => {
  try {
    const { courseId } = req.params;
    const layouts = await getLayoutsForCourse(courseId);
    res.render('../partials/course-layouts', { layouts, courseId });
  } catch (error) {
    logger.error('Error loading course layouts:', error.message);
    res.status(500).send('<div class="no-layouts">Error loading layouts</div>');
  }
});

router.get('/api/courses', async (req, res) => {
  try {
    const courses = await getAllCoursesFromDB();
    res.json(courses);
  } catch (error) {
    logger.error('Error fetching courses:', error.message);
    res.status(500).json({ error: 'Failed to fetch courses' });
  }
});

router.get('/api/layouts/:courseId', async (req, res) => {
  try {
    const { courseId } = req.params;
    const layouts = await getLayoutsForCourse(courseId);
    res.json(layouts);
  } catch (error) {
    logger.error('Error fetching layouts:', error.message);
    res.status(500).json({ error: 'Failed to fetch layouts' });
  }
});

router.post('/api/scrape-courses', async (req, res) => {
  req.setTimeout(600000);
  res.setTimeout(600000);

  let browser = null;
  try {
    logger.info('Starting course directory scraping...');

    browser = await launchBrowser();

    const courses = await scrapeCourseDirectory(browser);

    await browser.close();
    browser = null;

    res.json({
      success: true,
      coursesFound: courses.length,
      message: `Successfully scraped ${courses.length} courses`
    });
  } catch (error) {
    logger.error({ err: error }, 'Error scraping courses');
    if (browser) {
      try { await browser.close(); } catch (e) {}
    }
    res.status(500).json({ error: 'Failed to scrape courses' });
  }
});

router.post('/api/scrape-layouts/:courseId', async (req, res) => {
  req.setTimeout(600000);
  res.setTimeout(600000);

  const { courseId } = req.params;
  const lockKey = `layout-${courseId}`;

  if (activeScrapes.has(lockKey)) {
    logger.info(`⚠️ Scrape already in progress for course ${courseId}`);
    return res.status(409).json({
      error: 'Scrape already in progress for this course',
      message: 'Please wait for the current scrape to complete'
    });
  }

  let browser = null;

  const scrapePromise = (async () => {
    try {
      const course = await new Promise((resolve, reject) => {
        db.get('SELECT * FROM courses WHERE id = ?', [courseId], (err, row) => {
          if (err) reject(err);
          else resolve(row);
        });
      });

      if (!course) {
        throw new Error('Course not found');
      }

      logger.info(`Starting layout scraping for course: ${course.name}`);

      browser = await launchBrowser();

      const layouts = await scrapeCourseLayouts(browser, course.link, courseId);

      logger.info(`\n=== Starting event results scraping for ${course.name} ===`);

      const courseIdInt = parseInt(courseId);
      const layoutData = layoutEventCache.get(courseIdInt);

      if (!layoutData || layoutData.length === 0) {
        logger.info('No event data found in cache, skipping event results scraping');
        await browser.close();
        browser = null;

        return {
          success: true,
          layoutsFound: layouts.length,
          message: `Successfully scraped ${layouts.length} layouts for ${course.name} (no events found)`
        };
      }

      const eventGroups = {};
      layoutData.forEach(layout => {
        if (layout.eventUrl) {
          if (!eventGroups[layout.eventUrl]) {
            eventGroups[layout.eventUrl] = [];
          }
          eventGroups[layout.eventUrl].push(layout);
        }
      });

      const allLayoutRatings = {};

      let eventCount = 0;
      for (const eventUrl in eventGroups) {
        eventCount++;
        const eventLayouts = eventGroups[eventUrl];

        const results = await scrapeEventResults(browser, eventUrl, eventLayouts);

        for (const layoutKey in results) {
          const layoutDataResult = results[layoutKey];

          if (!allLayoutRatings[layoutKey]) {
            allLayoutRatings[layoutKey] = {
              name: layoutDataResult.name,
              par: layoutDataResult.par,
              allRatings: [],
              latestDate: layoutDataResult.eventDate
            };
          } else {
            if (layoutDataResult.eventDate && (!allLayoutRatings[layoutKey].latestDate ||
                new Date(layoutDataResult.eventDate) > new Date(allLayoutRatings[layoutKey].latestDate))) {
              allLayoutRatings[layoutKey].latestDate = layoutDataResult.eventDate;
            }
          }

          allLayoutRatings[layoutKey].allRatings.push(...layoutDataResult.ratings);
        }

        await new Promise(resolve => setTimeout(resolve, 2000));
      }

      logger.info(`\n=== Calculating final ratings for all layouts ===`);

      let savedCount = 0;
      for (const layoutKey in allLayoutRatings) {
        const layoutDataResult = allLayoutRatings[layoutKey];

        if (layoutDataResult.allRatings.length > 0) {
          const meanRating = Math.round(
            layoutDataResult.allRatings.reduce((sum, r) => sum + r, 0) / layoutDataResult.allRatings.length
          );

          logger.debug(`Layout: ${layoutDataResult.name} (Par ${layoutDataResult.par})`);
          logger.debug(`  Total ratings collected: ${layoutDataResult.allRatings.length}`);
          logger.debug(`  Mean rating: ${meanRating}`);
          logger.debug(`  Last played: ${layoutDataResult.latestDate || 'Unknown'}`);

          try {
            const changes = await updateLayoutRating(
              courseIdInt,
              layoutDataResult.name,
              layoutDataResult.par,
              meanRating,
              layoutDataResult.allRatings.length,
              layoutDataResult.latestDate
            );
            if (changes > 0) {
              logger.info(`  ✓ Updated in database`);
              savedCount++;
            }
          } catch (err) {
            logger.error(`  Error updating layout ${layoutDataResult.name}:`, err.message);
          }
        }
      }

      await browser.close();
      browser = null;

      return {
        success: true,
        layoutsFound: layouts.length,
        eventsProcessed: Object.keys(eventGroups).length,
        layoutsWithRatings: savedCount,
        message: `Successfully scraped ${layouts.length} layouts and processed ${Object.keys(eventGroups).length} events for ${course.name}`
      };
    } catch (error) {
      logger.error({ err: error }, 'Error scraping layouts');
      if (browser) {
        try { await browser.close(); } catch (e) {}
      }
      throw error;
    }
  })();

  activeScrapes.set(lockKey, scrapePromise);

  try {
    const result = await scrapePromise;
    res.json(result);
  } catch (error) {
    res.status(500).json({
      error: 'Failed to scrape layouts',
      message: error.message
    });
  } finally {
    activeScrapes.delete(lockKey);
    logger.info(`✓ Released lock for course ${courseId}`);
  }
});

router.post('/api/scrape-event-results/:courseId', async (req, res) => {
  req.setTimeout(600000);
  res.setTimeout(600000);

  let browser = null;
  try {
    const { courseId } = req.params;
    const courseIdInt = parseInt(courseId);

    const layoutData = layoutEventCache.get(courseIdInt);

    if (!layoutData || layoutData.length === 0) {
      return res.status(404).json({
        error: 'No layout data found in cache. Please scrape layouts first.'
      });
    }

    browser = await launchBrowser();

    const eventGroups = {};
    layoutData.forEach(layout => {
      if (layout.eventUrl) {
        if (!eventGroups[layout.eventUrl]) {
          eventGroups[layout.eventUrl] = [];
        }
        eventGroups[layout.eventUrl].push(layout);
      }
    });

    const allLayoutRatings = {};

    let eventCount = 0;
    for (const eventUrl in eventGroups) {
      eventCount++;
      const eventLayouts = eventGroups[eventUrl];

      const results = await scrapeEventResults(browser, eventUrl, eventLayouts);

      for (const layoutKey in results) {
        const ld = results[layoutKey];

        if (!allLayoutRatings[layoutKey]) {
          allLayoutRatings[layoutKey] = {
            name: ld.name,
            par: ld.par,
            allRatings: [],
            latestDate: ld.eventDate
          };
        } else {
          if (ld.eventDate && (!allLayoutRatings[layoutKey].latestDate ||
              new Date(ld.eventDate) > new Date(allLayoutRatings[layoutKey].latestDate))) {
            allLayoutRatings[layoutKey].latestDate = ld.eventDate;
          }
        }

        allLayoutRatings[layoutKey].allRatings.push(...ld.ratings);
      }

      await new Promise(resolve => setTimeout(resolve, 2000));
    }

    await browser.close();
    browser = null;

    logger.info(`\n=== Calculating final ratings for all layouts ===`);

    let savedCount = 0;
    for (const layoutKey in allLayoutRatings) {
      const ld = allLayoutRatings[layoutKey];

      if (ld.allRatings.length > 0) {
        const meanRating = Math.round(
          ld.allRatings.reduce((sum, r) => sum + r, 0) / ld.allRatings.length
        );

        logger.debug(`Layout: ${ld.name} (Par ${ld.par})`);
        logger.debug(`  Total ratings collected: ${ld.allRatings.length}`);
        logger.debug(`  Mean rating: ${meanRating}`);
        logger.debug(`  Last played: ${ld.latestDate || 'Unknown'}`);

        try {
          const changes = await updateLayoutRating(
            courseIdInt,
            ld.name,
            ld.par,
            meanRating,
            ld.allRatings.length,
            ld.latestDate
          );
          if (changes > 0) {
            logger.info(`  ✓ Updated in database`);
            savedCount++;
          }
        } catch (err) {
          logger.error(`  Error updating layout ${ld.name}:`, err.message);
        }
      }
    }

    res.json({
      success: true,
      eventsProcessed: Object.keys(eventGroups).length,
      uniqueLayouts: Object.keys(allLayoutRatings).length,
      layoutsSaved: savedCount,
      message: `Processed ${Object.keys(eventGroups).length} events, updated ${savedCount} layouts`
    });
  } catch (error) {
    logger.error({ err: error }, 'Error scraping event results');
    if (browser) {
      try { await browser.close(); } catch (e) {}
    }
    res.status(500).json({ error: 'Failed to scrape event results' });
  }
});

// Search Tjing for courses
router.get('/api/tjing/search', async (req, res) => {
  const { q } = req.query;
  if (!q || q.trim().length === 0) {
    return res.json({ results: [] });
  }

  const result = await searchTjingCourses(q.trim());
  if (result.error) {
    logger.warn({ q, err: result.error }, 'Tjing search error');
    return res.status(502).json({ error: result.error });
  }

  res.json({ results: result.data });
});

// Import a course from Tjing
router.post('/api/tjing/import/:tjingId', async (req, res) => {
  const { tjingId } = req.params;

  const result = await getTjingCourse(tjingId);
  if (result.error) {
    logger.warn({ tjingId, err: result.error }, 'Tjing import error');
    return res.status(502).json({ error: result.error });
  }

  const courseData = result.data;

  try {
    const courseId = await saveCourseToDB({
      name: courseData.name,
      link: `https://tjing.se/courses/${tjingId}`,
      city: courseData.address || ''
    });

    let layoutsImported = 0;
    for (const layout of courseData.layouts) {
      await getOrCreateLayout(courseId, layout.name, layout.par);
      layoutsImported++;
    }

    logger.info({ courseId, name: courseData.name, layoutsImported }, 'Imported course from Tjing');
    res.json({ courseId, layoutsImported });
  } catch (err) {
    logger.error({ err, tjingId }, 'Failed to save Tjing course to DB');
    res.status(500).json({ error: 'Failed to save course to database' });
  }
});

module.exports = router;