# ===================================================================
# Nginx Configuration for Meldestelle Web App
# Optimized for Kotlin/JS Single Page Application
# ===================================================================

# Run as a less privileged user for better security
user nginx;
worker_processes auto;

# Error log configuration
error_log /var/log/nginx/error.log warn;
pid /var/run/nginx.pid;

# Event handling configuration
events {
    worker_connections 1024;
    use epoll;
    multi_accept on;
}

http {
    # MIME types
    include /etc/nginx/mime.types;
    default_type application/octet-stream;

    # Logging configuration
    log_format main '$remote_addr - $remote_user [$time_local] "$request" '
                    '$status $body_bytes_sent "$http_referer" '
                    '"$http_user_agent" "$http_x_forwarded_for"';

    access_log /var/log/nginx/access.log main;

    # Performance optimizations
    sendfile on;
    tcp_nopush on;
    tcp_nodelay on;
    keepalive_timeout 65;
    types_hash_max_size 2048;
    client_max_body_size 16M;

    # Compression
    gzip on;
    gzip_vary on;
    gzip_min_length 1000;
    gzip_proxied any;
    gzip_comp_level 6;
    gzip_types
        application/atom+xml
        application/javascript
        application/json
        application/ld+json
        application/manifest+json
        application/rss+xml
        application/vnd.geo+json
        application/vnd.ms-fontobject
        application/x-font-ttf
        application/x-web-app-manifest+json
        application/xhtml+xml
        application/xml
        font/opentype
        image/bmp
        image/svg+xml
        image/x-icon
        text/cache-manifest
        text/css
        text/plain
        text/vcard
        text/vnd.rim.location.xloc
        text/vtt
        text/x-component
        text/x-cross-domain-policy;

    # Security headers
    add_header X-Frame-Options DENY always;
    add_header X-Content-Type-Options nosniff always;
    add_header X-XSS-Protection "1; mode=block" always;
    add_header Referrer-Policy "strict-origin-when-cross-origin" always;
    add_header Content-Security-Policy "default-src 'self'; script-src 'self' 'unsafe-inline' 'unsafe-eval'; style-src 'self' 'unsafe-inline'; font-src 'self'; img-src 'self' data:; connect-src 'self' http://localhost:8080 ws://localhost:8080;" always;

    # Server configuration
    server {
        listen 80 default_server;
        listen [::]:80 default_server;

        server_name _;
        root /usr/share/nginx/html;
        index index.html;

        # Health check endpoint
        location /health {
            access_log off;
            return 200 "healthy\n";
            add_header Content-Type text/plain;
        }

        # Static assets with caching
        location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg|woff|woff2|ttf|eot)$ {
            expires 1y;
            add_header Cache-Control "public, immutable";
            add_header Vary Accept-Encoding;
            access_log off;

            # Handle CORS for fonts
            location ~* \.(woff|woff2|ttf|eot)$ {
                add_header Access-Control-Allow-Origin *;
            }
        }

        # API proxy to backend (development)
        location /api/ {
            proxy_pass http://api-gateway:8080/;
            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;

            # CORS headers for API requests
            add_header Access-Control-Allow-Origin $http_origin always;
            add_header Access-Control-Allow-Credentials true always;
            add_header Access-Control-Allow-Methods "GET, POST, PUT, DELETE, OPTIONS" always;
            add_header Access-Control-Allow-Headers "DNT,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Range,Authorization" always;

            # Handle preflight requests
            if ($request_method = 'OPTIONS') {
                add_header Access-Control-Allow-Origin $http_origin always;
                add_header Access-Control-Allow-Credentials true always;
                add_header Access-Control-Allow-Methods "GET, POST, PUT, DELETE, OPTIONS" always;
                add_header Access-Control-Allow-Headers "DNT,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Range,Authorization" always;
                add_header Access-Control-Max-Age 1728000;
                add_header Content-Type 'text/plain charset=UTF-8';
                add_header Content-Length 0;
                return 204;
            }
        }

        # SPA routing - serve index.html for all routes
        location / {
            try_files $uri $uri/ /index.html;

            # No caching for HTML files
            add_header Cache-Control "no-cache, no-store, must-revalidate";
            add_header Pragma "no-cache";
            add_header Expires "0";
        }

        # Security - deny access to dotfiles
        location ~ /\.(?!well-known) {
            deny all;
        }

        # Security - deny access to backup files
        location ~ ~$ {
            deny all;
        }
    }
}