const express = require('express');
const { WebSocketServer } = require('ws');
const cors = require('cors');
const http = require('http');
const path = require('path');
const fs = require('fs');
const { v4: uuidv4 } = require('uuid');
const { CATEGORY_META, buildSeedData, mergeSeedData } = require('./seed-data');

const app = express();
const server = http.createServer(app);
const wss = new WebSocketServer({ server });

const DEFAULT_DATA_DIR = path.join(__dirname, 'data');
const DATA_DIR = process.env.DATA_DIR
  ? path.resolve(process.env.DATA_DIR)
  : DEFAULT_DATA_DIR;
const DATA_FILE = process.env.DATA_FILE
  ? path.resolve(process.env.DATA_FILE)
  : path.join(DATA_DIR, 'votes.json');

app.use(cors());
app.use(express.json());

app.get('/admin', (req, res) => {
  res.sendFile(path.join(__dirname, 'public', 'admin.html'));
});

app.use(express.static(path.join(__dirname, 'public')));

function loadData() {
  if (!fs.existsSync(DATA_DIR)) fs.mkdirSync(DATA_DIR, { recursive: true });

  if (!fs.existsSync(DATA_FILE)) {
    const seed = buildSeedData();
    fs.writeFileSync(DATA_FILE, JSON.stringify(seed, null, 2));
    return seed;
  }

  const existing = JSON.parse(fs.readFileSync(DATA_FILE, 'utf8'));
  const merged = mergeSeedData(existing);

  if (JSON.stringify(existing) !== JSON.stringify(merged)) {
    fs.writeFileSync(DATA_FILE, JSON.stringify(merged, null, 2));
  }

  return merged;
}

function saveData(nextData) {
  fs.writeFileSync(DATA_FILE, JSON.stringify(nextData, null, 2));
}

function approvedOptionsWithVoteSummary() {
  return data.options
    .filter((option) => option.approved)
    .map((option) => ({
      id: option.id,
      votes: option.votes.length,
      voters: option.votes.map((vote) => vote.name),
    }));
}

function broadcast(payload) {
  const msg = JSON.stringify(payload);
  wss.clients.forEach((client) => {
    if (client.readyState === 1) client.send(msg);
  });
}

function buildRealtimeSnapshot() {
  return {
    type: 'init',
    pollsOpen: data.pollsOpen,
    categories: data.categories,
    options: data.options.filter((option) => option.approved),
    results: approvedOptionsWithVoteSummary(),
    totalVoters: data.voters.length,
    budgetScenarios: data.budgetScenarios || [],
    priceUpdatedAt: data.priceUpdatedAt || null,
  };
}

function createUserOption({ categoryId, name, desc, url, voterName, lat, lng, approved }) {
  return {
    id: uuidv4(),
    seedKey: null,
    categoryId,
    name: name.trim(),
    desc: (desc || '').trim(),
    url: url ? url.trim() : null,
    links: url ? [{ label: 'Website', url: url.trim() }] : [],
    lat: lat || null,
    lng: lng || null,
    addedBy: voterName,
    approved,
    votes: [],
    details: [],
    categoryColor: CATEGORY_META[categoryId]?.color || '#888',
  };
}

let data = loadData();

app.get('/api/categories', (req, res) => {
  res.json(data.categories);
});

app.get('/api/options', (req, res) => {
  const { category, includeUnapproved } = req.query;
  let options = data.options;

  if (category) options = options.filter((option) => option.categoryId === category);
  if (!includeUnapproved) options = options.filter((option) => option.approved);

  res.json(options);
});

app.get('/api/results', (req, res) => {
  const results = data.categories.map((category) => ({
    ...category,
    options: data.options
      .filter((option) => option.approved && option.categoryId === category.id)
      .map((option) => ({ ...option, voteCount: option.votes.length })),
  }));

  res.json({
    pollsOpen: data.pollsOpen,
    results,
    totalVoters: data.voters.length,
    budgetScenarios: data.budgetScenarios || [],
    priceUpdatedAt: data.priceUpdatedAt || null,
  });
});

app.get('/api/budgets', (req, res) => {
  res.json({
    updatedAt: data.priceUpdatedAt || null,
    scenarios: data.budgetScenarios || [],
  });
});

app.post('/api/vote', (req, res) => {
  const { optionId, voterName } = req.body;

  if (!voterName || !optionId) {
    return res.status(400).json({ error: 'Missing fields' });
  }
  if (!data.pollsOpen) {
    return res.status(403).json({ error: 'Polls are closed' });
  }

  const option = data.options.find((candidate) => candidate.id === optionId);
  if (!option || !option.approved) {
    return res.status(404).json({ error: 'Option not found' });
  }

  const previousVote = data.options.find((candidate) => (
    candidate.categoryId === option.categoryId
    && candidate.votes.some((vote) => vote.name === voterName)
  ));

  if (previousVote) {
    previousVote.votes = previousVote.votes.filter((vote) => vote.name !== voterName);
  }

  option.votes.push({ name: voterName, timestamp: Date.now() });

  if (!data.voters.find((voter) => voter.name === voterName)) {
    data.voters.push({ name: voterName, joinedAt: Date.now() });
  }

  saveData(data);
  broadcast({ type: 'vote_update', results: approvedOptionsWithVoteSummary() });
  res.json({ success: true, voteCount: option.votes.length });
});

app.delete('/api/vote/:optionId', (req, res) => {
  const { voterName } = req.body;
  const option = data.options.find((candidate) => candidate.id === req.params.optionId);

  if (!option) return res.status(404).json({ error: 'Not found' });

  option.votes = option.votes.filter((vote) => vote.name !== voterName);
  saveData(data);
  broadcast({ type: 'vote_update', results: approvedOptionsWithVoteSummary() });
  res.json({ success: true });
});

app.post('/api/options', (req, res) => {
  const { categoryId, name, desc, url, voterName, lat, lng } = req.body;

  if (!categoryId || !name || !voterName) {
    return res.status(400).json({ error: 'Missing required fields' });
  }

  const category = data.categories.find((candidate) => candidate.id === categoryId);
  if (!category) return res.status(404).json({ error: 'Category not found' });

  const newOption = createUserOption({
    categoryId,
    name,
    desc,
    url,
    voterName,
    lat,
    lng,
    approved: false,
  });

  data.options.push(newOption);
  saveData(data);
  broadcast({ type: 'option_added', option: newOption });
  res.json({ success: true, option: newOption });
});

app.post('/api/options/:id/approve', (req, res) => {
  const option = data.options.find((candidate) => candidate.id === req.params.id);
  if (!option) return res.status(404).json({ error: 'Not found' });

  option.approved = true;
  saveData(data);
  broadcast({ type: 'option_approved', option });
  res.json({ success: true });
});

app.delete('/api/options/:id', (req, res) => {
  const optionIndex = data.options.findIndex((candidate) => candidate.id === req.params.id);
  if (optionIndex === -1) return res.status(404).json({ error: 'Not found' });

  data.options.splice(optionIndex, 1);
  saveData(data);
  broadcast({ type: 'option_deleted', id: req.params.id });
  res.json({ success: true });
});

app.post('/api/polls', (req, res) => {
  data.pollsOpen = req.body.open !== undefined ? req.body.open : !data.pollsOpen;
  saveData(data);
  broadcast({ type: 'polls_status', open: data.pollsOpen });
  res.json({ success: true, pollsOpen: data.pollsOpen });
});

const YELP_API_KEY = process.env.YELP_API_KEY || '';

app.get('/api/yelp', async (req, res) => {
  const { term, location } = req.query;
  if (!term) return res.status(400).json({ error: 'term is required' });

  if (!YELP_API_KEY) {
    return res.status(503).json({
      error: 'YELP_API_KEY not configured on server. Add it as an environment variable.',
    });
  }

  try {
    const params = new URLSearchParams({
      term: `${term} in ${location}`,
      location: location || 'Los Cabos Mexico',
      limit: '15',
      sort_by: 'rating',
      categories: 'restaurants,nightlife,active,arts,health',
    });

    const response = await fetch(`https://api.yelp.com/v3/businesses/search?${params}`, {
      headers: {
        Authorization: `Bearer ${YELP_API_KEY}`,
        Accept: 'application/json',
      },
    });

    if (!response.ok) {
      const errorText = await response.text();
      return res.status(response.status).json({ error: `Yelp API error: ${errorText}` });
    }

    const payload = await response.json();
    const businesses = (payload.businesses || []).map((business) => ({
      name: business.name,
      image_url: business.image_url,
      url: business.url,
      rating: business.rating,
      price: business.price,
      coordinates: business.coordinates,
      location: business.location,
      categories: business.categories,
      display_phone: business.display_phone,
      distance: business.distance,
    }));

    res.json({ businesses, total: payload.total });
  } catch (error) {
    console.error('Yelp proxy error:', error);
    res.status(500).json({ error: 'Failed to fetch from Yelp' });
  }
});

wss.on('connection', (ws) => {
  ws.send(JSON.stringify(buildRealtimeSnapshot()));

  ws.on('message', (raw) => {
    try {
      const msg = JSON.parse(raw);

      if (msg.type === 'vote') {
        const { optionId, voterName, remove } = msg;
        if (!voterName || !optionId) return;
        if (!data.pollsOpen) {
          ws.send(JSON.stringify({ type: 'error', message: 'Polls closed' }));
          return;
        }

        const option = data.options.find((candidate) => candidate.id === optionId);
        if (!option || !option.approved) return;

        if (remove) {
          option.votes = option.votes.filter((vote) => vote.name !== voterName);
        } else {
          const previousVote = data.options.find((candidate) => (
            candidate.categoryId === option.categoryId
            && candidate.votes.some((vote) => vote.name === voterName)
          ));
          if (previousVote) {
            previousVote.votes = previousVote.votes.filter((vote) => vote.name !== voterName);
          }

          option.votes.push({ name: voterName, timestamp: Date.now() });
        }

        if (!data.voters.find((voter) => voter.name === voterName)) {
          data.voters.push({ name: voterName, joinedAt: Date.now() });
        }

        saveData(data);
        broadcast({ type: 'vote_update', results: approvedOptionsWithVoteSummary() });
      } else if (msg.type === 'add_option') {
        const { categoryId, name, desc, url, voterName, lat, lng } = msg;
        if (!categoryId || !name || !voterName) return;

        const newOption = createUserOption({
          categoryId,
          name,
          desc,
          url,
          voterName,
          lat,
          lng,
          approved: true,
        });

        data.options.push(newOption);
        saveData(data);
        broadcast({ type: 'option_added', option: newOption });
      }
    } catch {
      // Ignore malformed websocket payloads.
    }
  });
});

const PORT = process.env.PORT || 3001;
const HOST = process.env.HOST || '0.0.0.0';

server.listen(PORT, HOST, () => {
  console.log(`🏄 Cabo Voting App → http://${HOST}:${PORT}`);
});