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

    # Backend upstream (unified container: localhost:8080)
    set $backend http://127.0.0.1:8080;

    # Gzip
    gzip on;
    gzip_vary on;
    gzip_min_length 1024;
    gzip_proxied expired no-cache no-store private auth;
    gzip_types text/plain text/css text/xml text/javascript application/x-javascript application/xml application/javascript;

    # Static assets — long cache
    location ~* \.(jpg|jpeg|png|gif|ico|css|js|woff|woff2)$ {
        expires 1y;
        add_header Cache-Control "public, immutable";
    }

    # ── API + WebSocket → backend ────────────
    location ^~ /api/ {
        proxy_pass $backend;
        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 {
        proxy_pass $backend;
    }

    location = /ws {
        proxy_pass $backend;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        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_read_timeout 86400s;
        proxy_send_timeout 86400s;
    }

    # ── Page routes → backend (Go templates) ─
    location = / {
        proxy_pass $backend;
        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 = /login {
        proxy_pass $backend;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
    }

    location ~ ^/chat/[^/]+$ {
        proxy_pass $backend;
        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 /admin  { proxy_pass $backend; proxy_set_header Host $host; proxy_set_header X-Real-IP $remote_addr; }
    location /editor { proxy_pass $backend; proxy_set_header Host $host; proxy_set_header X-Real-IP $remote_addr; }
    location /notes  { proxy_pass $backend; proxy_set_header Host $host; proxy_set_header X-Real-IP $remote_addr; }
    location /settings { proxy_pass $backend; proxy_set_header Host $host; proxy_set_header X-Real-IP $remote_addr; }

    # Fallback: redirect unknown paths to root
    location / {
        try_files $uri $uri/ /index.html;
    }

    # Security headers
    add_header X-Frame-Options "SAMEORIGIN" always;
    add_header X-Content-Type-Options "nosniff" always;
    add_header X-XSS-Protection "1; mode=block" always;
}