const express = require('express');
const router = express.Router();
const { fetchJSON, uploadJSON } = require('../services/pixelbin');
const { generateTemplates } = require('../services/openai2');
const DEFAULT_EVENTS = require('../config/defaultEvents');

function slugify(text) {
  return text.toLowerCase().trim().replace(/[^a-z0-9]+/g, '_').replace(/^_+|_+$/g, '');
}

// GET /api/events
router.get('/', async (req, res) => {
  try {
    const data = await fetchJSON(`brands/${process.env.MERCHANT_ID}`, 'events');
    res.json(data || { events: DEFAULT_EVENTS });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// POST /api/events — add custom event
router.post('/', async (req, res) => {
  try {
    const { label } = req.body;
    if (!label) return res.status(400).json({ error: 'label is required' });

    const folder = `brands/${process.env.MERCHANT_ID}`;
    const data = await fetchJSON(folder, 'events') || { events: [...DEFAULT_EVENTS] };
    const slug = slugify(label);

    if (data.events.some(e => e.slug === slug)) {
      return res.status(409).json({ error: 'An event with this name already exists' });
    }

    const newEvent = { slug, label, isDefault: false };
    data.events.push(newEvent);
    await uploadJSON(folder, 'events', data);
    res.json(newEvent);
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// DELETE /api/events/:slug
router.delete('/:slug', async (req, res) => {
  try {
    const { slug } = req.params;
    const folder = `brands/${process.env.MERCHANT_ID}`;
    const data = await fetchJSON(folder, 'events') || { events: [...DEFAULT_EVENTS] };
    const event = data.events.find(e => e.slug === slug);

    if (!event) return res.status(404).json({ error: 'Event not found' });
    if (event.isDefault) return res.status(403).json({ error: 'Cannot delete a default event' });

    data.events = data.events.filter(e => e.slug !== slug);
    await uploadJSON(folder, 'events', data);
    res.json({ ok: true });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// POST /api/events/:slug/generate
router.post('/:slug/generate', async (req, res) => {
  try {
    const { slug } = req.params;
    const folder = `brands/${process.env.MERCHANT_ID}`;

    const context = await fetchJSON(folder, 'context');
    if (!context) return res.status(400).json({ error: 'Register your business before generating templates.' });

    const eventsData = await fetchJSON(folder, 'events') || { events: DEFAULT_EVENTS };
    const event = eventsData.events.find(e => e.slug === slug);
    if (!event) return res.status(404).json({ error: 'Event not found' });

    const variants = await generateTemplates(context, slug, event.label);

    const templateJson = {
      eventSlug: slug,
      eventLabel: event.label,
      generatedVariants: variants,
      approvedVariant: null,
      whitelistStatus: 'pending',
      rawCurl: '',
      processedCurl: '',
      variableMap: {},
      selectedImagePath: '',
      updatedAt: new Date().toISOString(),
    };

    await uploadJSON(`${folder}/templates`, slug, templateJson);
    res.json({ variants });
  } catch (err) {
    console.error('Generate error:', err.message);
    res.status(500).json({ error: err.message });
  }
});

module.exports = router;