# Define cache for API responses
proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=api_cache:10m max_size=100m inactive=60m use_temp_path=off;

# Rate limiting (per IP) — must be at http level, not inside server block
limit_req_zone $binary_remote_addr zone=api_limit:10m rate=20r/m;
limit_req_zone $binary_remote_addr zone=dav_limit:10m rate=100r/m;

server {
    listen 80;
    listen 443 ssl http2;

    server_name _;

    # TLS certs (you'll mount them into /etc/nginx/certs)
    ssl_certificate     /etc/nginx/certs/fullchain.pem;
    ssl_certificate_key /etc/nginx/certs/privkey.pem;

    # Security headers
    add_header X-Content-Type-Options nosniff;
    add_header X-Frame-Options DENY;
    add_header X-XSS-Protection "1; mode=block";
    add_header Content-Security-Policy "default-src 'self'; script-src 'self' 'unsafe-inline'; style-src 'self' 'unsafe-inline'; img-src 'self' data: https:; font-src 'self'; connect-src 'self'; frame-ancestors 'none';" always;

    # Serve static frontend
    root /usr/share/nginx/html;
    index index.html;

    # Cache immutable assets aggressively
    location ~ ^/_app/immutable/ {
        expires 1y;
        add_header Cache-Control "public, immutable";
    }

    # Normal frontend routes (SPA fallback)
    location / {
        try_files $uri /index.html;
    }

    # Proxy API requests to backend
    location /api/ {
        limit_req zone=api_limit burst=5 nodelay;

        proxy_pass http://backend:8080;
        proxy_http_version 1.1;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;

        # Optional lightweight caching for API responses
        proxy_cache api_cache;
        proxy_cache_valid 200 1m;
        proxy_cache_valid any 10s;
    }

    # SabreDAV - CardDAV and CalDAV
    location /dav/ {
        limit_req zone=dav_limit burst=20 nodelay;

        # Important: rewrite to remove /dav prefix for PHP processing
        rewrite ^/dav/(.*)$ /server.php/$1 break;
        
        # Pass to PHP-FPM in sabredav container
        fastcgi_pass sabredav:9000;
        fastcgi_index server.php;
        fastcgi_split_path_info ^(.+\.php)(/.+)$;
        
        include fastcgi_params;
        fastcgi_param SCRIPT_FILENAME /var/www/dav/server.php;
        fastcgi_param PATH_INFO $fastcgi_path_info;
        fastcgi_param REQUEST_URI $request_uri;
        
        # Required for DAV
        fastcgi_param HTTPS $https if_not_empty;
        fastcgi_read_timeout 300;
        fastcgi_buffering off;
        
        # Disable caching for DAV
        proxy_cache off;
        add_header Cache-Control "no-store, no-cache, must-revalidate";
        
        # Allow DAV methods
        if ($request_method = 'OPTIONS') {
            add_header 'Access-Control-Allow-Origin' '$http_origin';
            add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS, PUT, DELETE, PROPFIND, PROPPATCH, REPORT, MKCOL, MOVE, COPY';
            add_header 'Access-Control-Allow-Headers' 'DNT,User-Agent,X-Requested-With,If-None-Match,If-Modified-Since,Cache-Control,Content-Type,Range,Depth,Authorization,If-Match,Destination,Overwrite,Lock-Token,Timeout';
            add_header 'Access-Control-Max-Age' 1728000;
            add_header 'Content-Type' 'text/plain; charset=utf-8';
            add_header 'Content-Length' 0;
            return 204;
        }
        
        # Remove security headers that interfere with DAV
        add_header X-Content-Type-Options "" always;
        add_header X-Frame-Options "" always;
        add_header X-XSS-Protection "" always;
    }

    # Legacy CardDAV endpoint (backward compatibility)
    location /carddav/ {
        return 301 $scheme://$host/dav/addressbooks$request_uri;
    }

    # Legacy CalDAV endpoint (backward compatibility)
    location /caldav/ {
        return 301 $scheme://$host/dav/calendars$request_uri;
    }
}