const express = require('express');
const path = require('path');
const fs = require('fs');
const markdownIt = require('markdown-it');

const app = express();
const PORT = 8100;
const MD_ROOT = path.resolve(__dirname, '..'); // serve the workspace root
const md = markdownIt({html:true, linkify:true, typographer:true});

// Serve static assets (client side)
app.use('/', express.static(path.join(__dirname, 'public')));

// API: list directory tree (relative to workspace root)
app.get('/api/tree', (req, res) => {
  const rel = req.query.path || '';
  const absPath = path.join(MD_ROOT, rel);
  fs.readdir(absPath, {withFileTypes: true}, (err, entries) => {
    if (err) return res.status(500).json({error: err.message});
    const items = entries.map(e => ({
      name: e.name,
      path: path.join(rel, e.name).replace(/\\/g,'/'),
      type: e.isDirectory() ? 'dir' : (e.isFile() && e.name.endsWith('.md') ? 'file' : 'other')
    })).filter(i => i.type !== 'other'); // hide non‑md files
    res.json(items);
  });
});

// API: get markdown content and render HTML
app.get('/api/md', (req, res) => {
  const rel = req.query.path;
  if (!rel) return res.status(400).json({error: 'path is required'});
  const absPath = path.join(MD_ROOT, rel);
  if (!absPath.startsWith(MD_ROOT)) return res.status(400).json({error: 'invalid path'});
  fs.readFile(absPath, 'utf8', (err, data) => {
    if (err) return res.status(404).json({error: err.message});
    const html = md.render(data);
    res.json({html});
  });
});

app.listen(PORT, () => {
  console.log(`🗂️  Markdown viewer running at http://localhost:${PORT}`);
});