# The same session UUID must reach its owning SessionHub on every API/WS path.
map $uri $session_route_key {
    default $uri;
    "~^/ws/(?:control|call|observe|station)/([0-9a-fA-F-]{36})$" $1;
    "~^/api/sessions/([0-9a-fA-F-]{36})(?:/|$)" $1;
}

upstream backend_cluster {
    zone backend_cluster 64k;
    resolver 127.0.0.11 ipv6=off valid=2s;
    hash $session_route_key consistent;
    server backend:8000 resolve max_fails=1 fail_timeout=5s;
    server backend-b:8000 resolve max_fails=1 fail_timeout=5s;
}

server {
    listen 5173;
    server_name _;
    root /usr/share/nginx/html;

    gzip on;
    gzip_static on;
    gzip_vary on;
    gzip_comp_level 6;
    gzip_min_length 1024;
    gzip_types application/javascript application/json image/svg+xml text/css text/plain;

    location /api/ {
        proxy_pass http://backend_cluster;
        proxy_http_version 1.1;
        proxy_next_upstream error timeout http_403 http_500 http_502 http_503 http_504;
        proxy_next_upstream_tries 2;
        proxy_next_upstream_timeout 5s;
        proxy_set_header Host $host;
        proxy_set_header X-Forwarded-Host $http_host;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
    }

    location /ws/ {
        proxy_pass http://backend_cluster;
        proxy_http_version 1.1;
        proxy_next_upstream error timeout http_403 http_502 http_503 http_504;
        proxy_next_upstream_tries 2;
        proxy_next_upstream_timeout 5s;
        proxy_connect_timeout 1s;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_set_header Host $host;
        proxy_set_header X-Forwarded-Host $http_host;
        proxy_read_timeout 75s;
    }

    location ~* \.(?:css|js|woff2?|png|svg)$ {
        try_files $uri =404;
        expires 1y;
        add_header Cache-Control "public, immutable";
    }

    location / {
        try_files $uri $uri/ /index.html;
        add_header Cache-Control "no-cache";
    }
}