# Behind a TLS-terminating proxy (Traefik, NPM, Caddy) this nginx itself only
# sees plain http: passing $scheme on would tell the backend "http" for an
# https site. Keep what the outer proxy said, and fall back to our own scheme.
map $http_x_forwarded_proto $sp_forwarded_proto {
    default $http_x_forwarded_proto;
    ""      $scheme;
}

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

    # SPA fallback
    location / {
        try_files $uri $uri/ /index.html;
    }

    # API proxy
    location /api/ {
        proxy_pass http://backend:5008;
        # $http_host, not $host: $host drops the port, so with the default
        # "5009:80" mapping the OIDC redirect URI the backend derives from it
        # pointed at port 80.
        proxy_set_header Host $http_host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        # Without this uvicorn sees plain http even behind TLS, which would make
        # the OIDC redirect URI it derives wrong and the refresh cookie miss its
        # Secure flag.
        proxy_set_header X-Forwarded-Proto $sp_forwarded_proto;
        proxy_read_timeout 600s;
        # Stack backups (incl. volume data) can be large in both directions.
        client_max_body_size 0;
        proxy_request_buffering off;
        # A backup download carries its report in a response header; past the
        # default 4-8k header buffer nginx answers 502 for a backup that worked.
        proxy_buffer_size 16k;
        proxy_buffers 8 16k;
    }

    # WebSocket proxy
    location /ws/ {
        proxy_pass http://backend:5008;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_set_header Host $http_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 $sp_forwarded_proto;
        proxy_read_timeout 86400s;
    }

    # Basic security headers
    add_header X-Frame-Options "SAMEORIGIN" always;
    add_header X-Content-Type-Options "nosniff" always;
    add_header Referrer-Policy "strict-origin-when-cross-origin" always;
}