# nginx config for the Dialectic SPA.
# - Static SPA assets under /; falls back to /index.html for client-side
#   router (BrowserRouter needs all unknown paths to serve the shell).
# - /api/ reverse-proxies to the dialectic-backend container. The compose
#   service name + port is settable via DIALECTIC_BACKEND env at run time
#   (default = http://dialectic-backend:8090). We inject it via envsubst
#   at container start so the same image works for sim + prod.

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

    # Long-lived caching for hashed asset bundles.
    location /assets/ {
        access_log off;
        add_header Cache-Control "public, max-age=31536000, immutable";
        try_files $uri =404;
    }

    # SPA fallback: any unknown path serves index.html so React Router
    # can take over client-side.
    location / {
        try_files $uri /index.html;
    }

    # API reverse-proxy. Same-origin from the browser's POV so we sidestep
    # CORS. nginx upstream must point to the dialectic-backend service.
    # Substitution happens at container start via envsubst (see Dockerfile
    # entrypoint pattern; for v1 we hard-code the compose default).
    location /api/ {
        proxy_pass http://dialectic-backend:8090/api/;
        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_read_timeout 30s;
    }
}