import express from 'express';
import { nanoid } from 'nanoid';
import db, { stmts, setFiddleTags, snapshotVersion } from './db.js';

const app = express();
app.use(express.json({ limit: '2mb' }));

// HTML routes must be defined before static middleware (which would serve index.html for /)
app.get('/', (_req, res) => {
  res.sendFile('browse.html', { root: 'public' });
});

app.get('/new', (_req, res) => {
  res.sendFile('index.html', { root: 'public' });
});

app.get('/embed/:id', (_req, res) => {
  res.sendFile('embed.html', { root: 'public' });
});

app.get('/f/:id', (_req, res) => {
  res.sendFile('index.html', { root: 'public' });
});

app.use(express.static('public', { index: false }));

// API: Create fiddle
app.post('/api/fiddles', (req, res) => {
  const id = nanoid(10);
  const { title = 'Untitled', html = '', css = '', css_type = 'css', js = '', js_type = 'javascript', listed = 1, options = '{}', tags = [] } = req.body;
  try {
    stmts.insert.run({ id, title, html, css, css_type, js, js_type, listed: listed ? 1 : 0, options });
    if (tags.length) setFiddleTags(id, tags);
    const fiddleTags = stmts.getTagsForFiddle.all(id);
    res.json({ id, title, html, css, css_type, js, js_type, listed, options, tags: fiddleTags });
  } catch (e) {
    res.status(500).json({ error: e.message });
  }
});

// API: List/search fiddles
app.get('/api/fiddles', (req, res) => {
  const { q = '', js_type = '', tag = '', page = '1', limit = '20', sort = 'updated' } = req.query;
  const pageNum = Math.max(1, parseInt(page, 10) || 1);
  const limitNum = Math.min(100, Math.max(1, parseInt(limit, 10) || 20));
  const offset = (pageNum - 1) * limitNum;

  let where = 'WHERE f.listed = 1';
  const params = {};

  if (q) {
    where += ' AND f.title LIKE @q';
    params.q = `%${q}%`;
  }
  if (js_type) {
    where += ' AND f.js_type = @js_type';
    params.js_type = js_type;
  }
  if (tag) {
    where += ' AND EXISTS (SELECT 1 FROM fiddle_tags ft2 JOIN tags t2 ON t2.id = ft2.tag_id WHERE ft2.fiddle_id = f.id AND t2.name = @tag COLLATE NOCASE)';
    params.tag = tag;
  }

  const orderBy = sort === 'created' ? 'f.created_at DESC' : 'f.updated_at DESC';

  try {
    const countRow = db.prepare(`SELECT COUNT(*) as total FROM fiddles f ${where}`).get(params);
    const fiddles = db.prepare(`
      SELECT f.id, f.title, f.css_type, f.js_type, f.created_at, f.updated_at, f.screenshot,
        SUBSTR(f.html, 1, 200) as html_preview, SUBSTR(f.js, 1, 200) as js_preview
      FROM fiddles f ${where}
      ORDER BY ${orderBy}
      LIMIT @limit OFFSET @offset
    `).all({ ...params, limit: limitNum, offset });

    // Attach tags to each fiddle
    for (const f of fiddles) {
      f.tags = stmts.getTagsForFiddle.all(f.id);
    }

    res.json({ fiddles, total: countRow.total, page: pageNum, limit: limitNum });
  } catch (e) {
    res.status(500).json({ error: e.message });
  }
});

// API: Get fiddle
app.get('/api/fiddles/:id', (req, res) => {
  const fiddle = stmts.get.get(req.params.id);
  if (!fiddle) return res.status(404).json({ error: 'Not found' });
  fiddle.tags = stmts.getTagsForFiddle.all(fiddle.id);
  res.json(fiddle);
});

// API: Update fiddle
app.put('/api/fiddles/:id', (req, res) => {
  const existing = stmts.get.get(req.params.id);
  if (!existing) return res.status(404).json({ error: 'Not found' });

  // Snapshot current state as a version before overwriting
  snapshotVersion(req.params.id);

  const {
    title = existing.title,
    html = existing.html,
    css = existing.css,
    css_type = existing.css_type,
    js = existing.js,
    js_type = existing.js_type || 'javascript',
    listed = existing.listed,
    options = existing.options || '{}',
    screenshot,
    tags,
  } = req.body;
  stmts.update.run({ id: req.params.id, title, html, css, css_type, js, js_type, listed: listed ? 1 : 0, options });
  if (screenshot !== undefined) stmts.updateScreenshot.run(screenshot, req.params.id);
  if (Array.isArray(tags)) setFiddleTags(req.params.id, tags);
  const fiddleTags = stmts.getTagsForFiddle.all(req.params.id);
  res.json({ id: req.params.id, title, html, css, css_type, js, js_type, listed, options, tags: fiddleTags });
});

// API: List tags
app.get('/api/tags', (_req, res) => {
  res.json({ tags: stmts.listTags.all() });
});

// ===================== Version History API =====================

app.get('/api/fiddles/:id/versions', (req, res) => {
  const fiddle = stmts.get.get(req.params.id);
  if (!fiddle) return res.status(404).json({ error: 'Not found' });
  const versions = stmts.listVersions.all(req.params.id);
  res.json({ versions });
});

app.get('/api/fiddles/:id/versions/:ver', (req, res) => {
  const ver = parseInt(req.params.ver, 10);
  const version = stmts.getVersion.get(req.params.id, ver);
  if (!version) return res.status(404).json({ error: 'Version not found' });
  res.json(version);
});

app.post('/api/fiddles/:id/revert/:ver', (req, res) => {
  const existing = stmts.get.get(req.params.id);
  if (!existing) return res.status(404).json({ error: 'Not found' });
  const ver = parseInt(req.params.ver, 10);
  const version = stmts.getVersion.get(req.params.id, ver);
  if (!version) return res.status(404).json({ error: 'Version not found' });

  // Snapshot current state before reverting
  snapshotVersion(req.params.id);

  stmts.update.run({
    id: req.params.id,
    title: existing.title,
    html: version.html,
    css: version.css,
    css_type: version.css_type,
    js: version.js,
    js_type: version.js_type,
    listed: existing.listed,
    options: version.options || existing.options || '{}',
  });
  const updated = stmts.get.get(req.params.id);
  updated.tags = stmts.getTagsForFiddle.all(req.params.id);
  res.json(updated);
});

// ===================== Collections API =====================

app.post('/api/collections', (req, res) => {
  const id = nanoid(10);
  const { name = 'Untitled Collection', description = '' } = req.body;
  try {
    stmts.insertCollection.run({ id, name, description });
    res.json({ id, name, description, fiddle_count: 0 });
  } catch (e) {
    res.status(500).json({ error: e.message });
  }
});

app.get('/api/collections', (_req, res) => {
  res.json({ collections: stmts.listCollections.all() });
});

app.get('/api/collections/:id', (req, res) => {
  const col = stmts.getCollection.get(req.params.id);
  if (!col) return res.status(404).json({ error: 'Not found' });
  const fiddles = stmts.getCollectionFiddles.all(req.params.id);
  for (const f of fiddles) f.tags = stmts.getTagsForFiddle.all(f.id);
  res.json({ ...col, fiddles });
});

app.put('/api/collections/:id', (req, res) => {
  const col = stmts.getCollection.get(req.params.id);
  if (!col) return res.status(404).json({ error: 'Not found' });
  const { name = col.name, description = col.description } = req.body;
  stmts.updateCollection.run({ id: req.params.id, name, description });
  res.json({ id: req.params.id, name, description });
});

app.delete('/api/collections/:id', (req, res) => {
  const col = stmts.getCollection.get(req.params.id);
  if (!col) return res.status(404).json({ error: 'Not found' });
  stmts.deleteCollection.run(req.params.id);
  res.json({ ok: true });
});

app.post('/api/collections/:id/fiddles', (req, res) => {
  const col = stmts.getCollection.get(req.params.id);
  if (!col) return res.status(404).json({ error: 'Collection not found' });
  const { fiddle_id } = req.body;
  if (!fiddle_id) return res.status(400).json({ error: 'fiddle_id required' });
  stmts.addFiddleToCollection.run({ collection_id: req.params.id, fiddle_id });
  res.json({ ok: true });
});

app.delete('/api/collections/:id/fiddles/:fid', (req, res) => {
  stmts.removeFiddleFromCollection.run(req.params.id, req.params.fid);
  res.json({ ok: true });
});

const port = process.env.PORT || 3000;
app.listen(port, () => console.log(`Fiddle server running on http://localhost:${port}`));