#!/usr/bin/env python3
"""
Cache-Busting Patch for server.js
This script adds dynamic asset versioning to force browser cache invalidation
"""

import re
import sys

def patch_server_js():
    server_file = "/home/uroma/obsidian-web-interface/server.js"

    with open(server_file, 'r') as f:
        lines = f.readlines()

    modified_lines = []
    modifications = []

    # Track if we've added cache-busting config
    cache_busting_added = False
    middleware_imported = False
    middleware_applied = False
    static_config_updated = False

    i = 0
    while i < len(lines):
        line = lines[i]

        # 1. Add cache-busting configuration after SESSION_SECRET
        if not cache_busting_added and "const SESSION_SECRET = 'obsidian-web-secret-'" in line:
            modified_lines.append(line)
            # Add cache-busting configuration
            cache_busting_config = """
// ============================================================
// CACHE-BUSTING CONFIGURATION
// ============================================================
// Build timestamp forces browser to reload all assets on server restart
const BUILD_TIMESTAMP = Date.now();
const ASSET_VERSION = `v=${BUILD_TIMESTAMP}`;

console.log(`[CACHE-BUSTING] Build timestamp initialized: ${BUILD_TIMESTAMP}`);
console.log(`[CACHE-BUSTING] All JavaScript files will be served with ?${ASSET_VERSION}`);
"""
            modified_lines.append(cache_busting_config)
            modifications.append("✓ Added cache-busting configuration")
            cache_busting_added = True
            i += 1
            continue

        # 2. Add cache-busting middleware import
        if not middleware_imported and "const { db } = require('./services/database');" in line:
            modified_lines.append(line)
            # Check if next line is "const app = express();"
            if i + 1 < len(lines) and "const app = express();" in lines[i + 1]:
                modified_lines.append("// Cache-busting middleware\n")
                modified_lines.append("const { createCacheBustingMiddleware } = require('./cache-bust-middleware');\n")
                modifications.append("✓ Added cache-busting middleware import")
                middleware_imported = True
            i += 1
            continue

        # 3. Apply cache-busting middleware after session middleware
        if not middleware_applied and "name: 'connect.sid'" in line:
            modified_lines.append(line)
            # Skip closing brace and add middleware
            i += 1
            if i < len(lines) and "});" in lines[i]:
                modified_lines.append(lines[i])  # Add the });
                modified_lines.append("\n")
                modified_lines.append("// Apply cache-busting middleware to HTML responses\n")
                modified_lines.append(f"app.use(createCacheBustingMiddleware(ASSET_VERSION));\n")
                modifications.append("✓ Applied cache-busting middleware")
                middleware_applied = True
                i += 1
                continue
            i += 1
            continue

        # 4. Update static file configuration
        if not static_config_updated and "// Serve static files (must come after specific routes)" in line:
            # Skip the old configuration lines until we reach the closing });
            modified_lines.append(line)
            i += 1

            # Add new enhanced configuration
            static_config = """// Disable caching for JS files to prevent browser from serving stale code
// CRITICAL: Cache-busting via query parameters (ASSET_VERSION) ensures fresh content
app.use('/claude', express.static(path.join(__dirname, 'public'), {
  etag: false,
  lastModified: false,
  setHeaders: (res, filePath) => {
    // Disable caching for all JavaScript and CSS files
    if (filePath.endsWith('.js') || filePath.endsWith('.css')) {
      res.setHeader('Cache-Control', 'no-store, no-cache, must-revalidate, proxy-revalidate, max-age=0');
      res.setHeader('Pragma', 'no-cache');
      res.setHeader('Expires', '0');
      res.removeHeader('ETag');
    }
  }
}));
"""
            modified_lines.append(static_config)

            # Skip old static config lines until we find the end
            while i < len(lines) and "});" not in lines[i]:
                i += 1
            i += 1  # Skip the });

            modifications.append("✓ Enhanced static file cache headers")
            static_config_updated = True
            continue

        modified_lines.append(line)
        i += 1

    # Write the modified content
    with open(server_file, 'w') as f:
        f.writelines(modified_lines)

    return modifications

if __name__ == "__main__":
    print("[CACHE-BUSTING] Patching server.js...")
    try:
        modifications = patch_server_js()
        print("[CACHE-BUSTING] Successfully applied the following modifications:")
        for mod in modifications:
            print(f"  {mod}")
        print("[CACHE-BUSTING] Patch complete!")
    except Exception as e:
        print(f"[CACHE-BUSTING] ERROR: {e}", file=sys.stderr)
        sys.exit(1)