events { worker_connections 1024; }

http {
    # Rate limiting
    limit_req_zone $binary_remote_addr zone=api:10m rate=30r/s;

    # Redirect HTTP → HTTPS
    server {
        listen 80;
        server_name samosachaat.art www.samosachaat.art;
        return 301 https://$host$request_uri;
    }

    server {
        listen 443 ssl;
        server_name samosachaat.art www.samosachaat.art;

        ssl_certificate     /etc/letsencrypt/live/samosachaat.art/fullchain.pem;
        ssl_certificate_key /etc/letsencrypt/live/samosachaat.art/privkey.pem;
        ssl_protocols       TLSv1.2 TLSv1.3;
        ssl_ciphers         HIGH:!aNULL:!MD5;

        client_max_body_size 10M;

        # Use Docker Compose's embedded DNS so upstream IPs are re-resolved
        # on every request. Without this nginx caches the IP at startup and
        # serves 502s after any upstream container is recreated by `compose up`.
        resolver 127.0.0.11 valid=10s ipv6=off;

        # Auth service — strip /api prefix, then forward to auth:8001/auth/...
        location /api/auth/ {
            limit_req zone=api burst=10 nodelay;
            set $upstream_auth auth;
            rewrite ^/api/auth/(.*)$ /auth/$1 break;
            proxy_pass http://$upstream_auth:8001;
            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;
        }

        # Chat API — pass through /api/conversations* unchanged
        location /api/conversations {
            limit_req zone=api burst=20 nodelay;
            set $upstream_chat chat-api;
            proxy_pass http://$upstream_chat:8002;
            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;

            # SSE streaming support
            proxy_buffering off;
            proxy_cache off;
            proxy_read_timeout 300s;
            proxy_set_header Connection '';
            chunked_transfer_encoding off;
        }

        # Grafana (optional) — strip /grafana/ prefix
        location /grafana/ {
            set $upstream_grafana grafana;
            rewrite ^/grafana/(.*)$ /$1 break;
            proxy_pass http://$upstream_grafana:3000;
            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;
        }

        # Everything else → Frontend (Next.js)
        # Next.js handles its own /api/* routes (conversations, chat/stream)
        # and proxies to backend services internally via CHAT_API_URL env var
        location / {
            set $upstream_frontend frontend;
            proxy_pass http://$upstream_frontend:3000;
            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;

            # SSE streaming support
            proxy_buffering off;
            proxy_cache off;
            proxy_read_timeout 300s;
            proxy_set_header Connection '';
            chunked_transfer_encoding off;

            # WebSocket support
            proxy_http_version 1.1;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection "upgrade";
        }
    }
}