#!/usr/bin/env node
/**
 * Obsidian Vault Headless REST API Server
 * Reads vault files directly without requiring Obsidian Desktop app
 * Provides REST API compatible with obsidian-mcp-server expectations
 */

const fs = require('fs');
const path = require('path');
const crypto = require('crypto');

// Simple HTTP server (no dependencies needed)
const http = require('http');

const VAULT_PATH = process.env.VAULT_PATH || '/workspace/second-brain';
const PORT = process.env.PORT || 27123;
const API_KEY = process.env.OBSIDIAN_API_KEY || 'default-api-key-set-env-var';

console.log(`📚 Obsidian Vault Server`);
console.log(`Vault: ${VAULT_PATH}`);
console.log(`Port: ${PORT}`);
console.log(`API Key: ${API_KEY.slice(0, 8)}...`);

// Authenticate requests
const authenticateRequest = (req) => {
  const auth = req.headers['authorization'];
  if (!auth) return false;
  
  const token = auth.replace('Bearer ', '');
  return token === API_KEY;
};

// Read file safely
const readFile = (filePath) => {
  const fullPath = path.join(VAULT_PATH, filePath);
  
  // Prevent directory traversal
  if (!fullPath.startsWith(VAULT_PATH)) {
    return null;
  }
  
  try {
    return fs.readFileSync(fullPath, 'utf8');
  } catch (e) {
    return null;
  }
};

// List files in directory
const listDir = (dirPath) => {
  const fullPath = path.join(VAULT_PATH, dirPath);
  
  if (!fullPath.startsWith(VAULT_PATH)) {
    return [];
  }
  
  try {
    const entries = fs.readdirSync(fullPath, { withFileTypes: true });
    return entries
      .filter(e => !e.name.startsWith('.'))
      .map(e => ({
        name: e.name,
        isDirectory: e.isDirectory()
      }));
  } catch (e) {
    return [];
  }
};

// Search files
const searchVault = (query) => {
  const results = [];
  
  const search = (dir) => {
    try {
      const entries = fs.readdirSync(dir, { withFileTypes: true });
      
      for (const entry of entries) {
        if (entry.name.startsWith('.')) continue;
        
        const fullPath = path.join(dir, entry.name);
        
        if (entry.isDirectory()) {
          search(fullPath);
        } else if (entry.name.endsWith('.md')) {
          try {
            const content = fs.readFileSync(fullPath, 'utf8');
            if (content.includes(query)) {
              const relativePath = path.relative(VAULT_PATH, fullPath);
              results.push({
                file: relativePath,
                match: content.substring(0, 200)
              });
            }
          } catch (e) {
            // Skip unreadable files
          }
        }
      }
    } catch (e) {
      // Skip inaccessible directories
    }
  };
  
  search(VAULT_PATH);
  return results;
};

// Simple JSON response
const jsonResponse = (res, statusCode, data) => {
  res.writeHead(statusCode, { 'Content-Type': 'application/json' });
  res.end(JSON.stringify(data, null, 2));
};

// Create server
const server = http.createServer((req, res) => {
  // CORS
  res.setHeader('Access-Control-Allow-Origin', '*');
  res.setHeader('Access-Control-Allow-Methods', 'GET, POST, OPTIONS');
  res.setHeader('Access-Control-Allow-Headers', 'Content-Type, Authorization');
  
  if (req.method === 'OPTIONS') {
    res.writeHead(200);
    res.end();
    return;
  }
  
  // Authenticate
  if (!authenticateRequest(req)) {
    jsonResponse(res, 401, { error: 'Unauthorized' });
    return;
  }
  
  const url = new URL(req.url, `http://${req.headers.host}`);
  const pathname = url.pathname;
  
  // Routes
  if (pathname === '/' && req.method === 'GET') {
    // Health check
    jsonResponse(res, 200, { 
      app: 'obsidian-vault-server',
      vault: VAULT_PATH,
      status: 'running'
    });
    return;
  }
  
  if (pathname.startsWith('/vault/read') && req.method === 'GET') {
    // Read file
    const filePath = url.searchParams.get('path');
    if (!filePath) {
      jsonResponse(res, 400, { error: 'Missing path parameter' });
      return;
    }
    
    const content = readFile(filePath);
    if (content === null) {
      jsonResponse(res, 404, { error: 'File not found' });
      return;
    }
    
    jsonResponse(res, 200, {
      path: filePath,
      content: content,
      stat: {
        ctime: Date.now(),
        mtime: Date.now(),
        size: content.length
      }
    });
    return;
  }
  
  if (pathname.startsWith('/vault/search') && req.method === 'GET') {
    // Search vault
    const query = url.searchParams.get('query');
    if (!query) {
      jsonResponse(res, 400, { error: 'Missing query parameter' });
      return;
    }
    
    const results = searchVault(query);
    jsonResponse(res, 200, {
      query: query,
      results: results,
      count: results.length
    });
    return;
  }
  
  if (pathname.startsWith('/vault/list') && req.method === 'GET') {
    // List directory
    const dirPath = url.searchParams.get('path') || '/';
    const entries = listDir(dirPath);
    
    jsonResponse(res, 200, {
      path: dirPath,
      entries: entries,
      count: entries.length
    });
    return;
  }
  
  // 404
  jsonResponse(res, 404, { error: 'Not found' });
});

server.listen(PORT, () => {
  console.log(`✅ Vault server listening on http://127.0.0.1:${PORT}`);
  console.log(`\nEndpoints:`);
  console.log(`  GET  / - Health check`);
  console.log(`  GET  /vault/read?path=file.md - Read file`);
  console.log(`  GET  /vault/list?path=/ - List directory`);
  console.log(`  GET  /vault/search?query=text - Search vault`);
  console.log(`\nAll requests require: Authorization: Bearer <API_KEY>`);
});

server.on('error', (err) => {
  console.error('❌ Server error:', err);
  process.exit(1);
});

// Graceful shutdown
process.on('SIGINT', () => {
  console.log('\n👋 Shutting down...');
  server.close(() => {
    console.log('Goodbye!');
    process.exit(0);
  });
});