server {
    listen 80;
    server_name localhost;
    root /usr/share/nginx/html;
    index index.html;

    add_header X-Content-Type-Options "nosniff" always;
    add_header X-Frame-Options "SAMEORIGIN" always;
    add_header Referrer-Policy "strict-origin-when-cross-origin" always;
    add_header Permissions-Policy "camera=(), microphone=(), geolocation=()" always;

    # Docker-Embedded DNS: Hostname »backend« bei Container-Neustarts neu auflösen
    # — verringert sporadische 502, wenn sich nur die Backend-Container-IP geändert hat.
    resolver 127.0.0.11 valid=10s ipv6=off;

    # Uploads (Übungsmedien) und API erreichen Clients unter derselben Host-URL wie die SPA —
    # dafür muss Nginx zur FastAPI-Instanz im Compose-Netz weiterleiten.
    client_max_body_size 64m;

    location ^~ /api/ {
        set $docker_backend_svc backend;
        proxy_pass http://$docker_backend_svc:8000$request_uri;
        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;
        proxy_connect_timeout 60s;
        proxy_send_timeout 300s;
        proxy_read_timeout 300s;
    }

    location ^~ /media/ {
        set $docker_backend_svc backend;
        proxy_pass http://$docker_backend_svc:8000$request_uri;
        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;
    }

    location = /health {
        set $hc_upstream backend;
        proxy_pass http://$hc_upstream:8000/health;
        proxy_http_version 1.1;
        proxy_set_header Host $host;
    }

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

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