# HTTP → HTTPS redirect
server {
    listen 80;
    server_name _;
    return 301 https://$host$request_uri;
}

# HTTPS
server {
    listen 443 ssl;
    server_name _;

    ssl_certificate     /certs/server.crt;
    ssl_certificate_key /certs/server.key;

    ssl_protocols       TLSv1.2 TLSv1.3;
    ssl_ciphers         ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305;
    ssl_prefer_server_ciphers off;
    ssl_session_cache   shared:SSL:10m;
    ssl_session_timeout 1d;

    # Security headers. CSP allows self, inline styles (React style props +
    # runtime-injected stylesheets), data/blob images (QR codes), and the
    # OpenStreetMap tile + Nominatim geocoding hosts the maps use.
    add_header Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data: blob: https://*.tile.openstreetmap.org; connect-src 'self' https://nominatim.openstreetmap.org; font-src 'self' data:; frame-ancestors 'none'; base-uri 'self'; object-src 'none'; form-action 'self'" always;
    add_header X-Content-Type-Options "nosniff" always;
    add_header X-Frame-Options "DENY" always;
    add_header Referrer-Policy "strict-origin-when-cross-origin" always;
    add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;

    # Gzip compression
    gzip on;
    gzip_vary on;
    gzip_min_length 1024;
    gzip_types text/plain text/css text/xml application/json application/javascript application/xml+rss application/atom+xml image/svg+xml;

    # Frontend static files
    root /usr/share/nginx/html;
    index index.html;

    # API proxy to backend
    location /api/ {
        proxy_pass http://backend:3001;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        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;
        proxy_cache_bypass $http_upgrade;
        proxy_read_timeout 120s;
        proxy_connect_timeout 10s;
    }

    # WebSocket proxy (Socket.io)
    location /socket.io/ {
        proxy_pass http://backend:3001;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        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_read_timeout 86400;
    }

    # React SPA - serve index.html for all non-API routes.
    # Security headers are repeated here because an add_header in a location
    # block suppresses inheritance of the server-level ones.
    location / {
        try_files $uri $uri/ /index.html;
        add_header Cache-Control "no-cache, no-store, must-revalidate";
        add_header Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data: blob: https://*.tile.openstreetmap.org; connect-src 'self' https://nominatim.openstreetmap.org; font-src 'self' data:; frame-ancestors 'none'; base-uri 'self'; object-src 'none'; form-action 'self'" always;
        add_header X-Content-Type-Options "nosniff" always;
        add_header X-Frame-Options "DENY" always;
        add_header Referrer-Policy "strict-origin-when-cross-origin" always;
        add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
    }

    # Cache static assets
    location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg|woff|woff2|ttf|eot)$ {
        expires 1y;
        add_header Cache-Control "public, immutable";
        try_files $uri =404;
    }
}