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

    gzip on;
    gzip_types text/plain text/css text/javascript application/javascript application/json image/svg+xml;
    gzip_min_length 1024;

    location = /health {
        access_log off;
        add_header Content-Type text/plain;
        return 200 "ok\n";
    }

    location = /index.html {
        add_header Cache-Control "no-store, no-cache, must-revalidate" always;
    }

    # SPA route that shares the "/auth" prefix used by the auth API block
    # below. Exact matches always win over prefix/regex locations in nginx,
    # so this keeps the client-side callback page from being swallowed by
    # the API proxy.
    location = /auth/callback {
        try_files $uri /index.html;
    }

    location / {
        try_files $uri $uri/ /index.html;
    }

    # Generic passthrough used by a few call sites that fetch "/api/..."
    # directly. Prefix is stripped: /api/foo -> $BACKEND_URL/foo
    location /api/ {
        proxy_pass ${BACKEND_URL}/;
        proxy_http_version 1.1;
        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 $scheme;
        proxy_read_timeout 300s;
        proxy_connect_timeout 300s;
        proxy_send_timeout 300s;
        client_max_body_size 50M;
    }

    # Per-module API prefixes the SPA calls directly (see the VITE_*_APP_URL
    # build args in the Dockerfile and src/shared/api-url.ts). Path is kept
    # as-is (no stripping) so it lines up with what $BACKEND_URL serves.
    # This is what lets the app work behind a public tunnel: the browser
    # only ever talks to this same origin, never to the backend's local IP.
    location ~ ^/(auth|efficiency|efficiency-core|optimumoh|pfi|lcca|reliability|risk-matrix|monitoring|rbd|ahm|ops-dock)/ {
        proxy_pass ${BACKEND_URL};
        proxy_http_version 1.1;
        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 $scheme;
        proxy_read_timeout 300s;
        proxy_connect_timeout 300s;
        proxy_send_timeout 300s;
        client_max_body_size 50M;
    }

    # IRCFA is served by a separate backend host and doesn't expect an
    # "/ircfa" prefix itself, so it's stripped here: /ircfa/chat -> $BACKEND_URL_IRCFA/chat
    location /ircfa/ {
        proxy_pass ${BACKEND_URL_IRCFA}/;
        proxy_http_version 1.1;
        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 $scheme;
        proxy_read_timeout 300s;
        proxy_connect_timeout 300s;
        proxy_send_timeout 300s;
        client_max_body_size 50M;
    }

    location ~* \.(js|css|woff2?|ttf|eot|ico)$ {
        expires 1y;
        add_header Cache-Control "public, immutable";
        access_log off;
    }

    location ~* \.(png|jpg|jpeg|gif|svg|webp)$ {
        expires 7d;
        add_header Cache-Control "public";
        access_log off;
    }

    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;
}