# Map ISO timestamp to date-only string for daily log rotation
map $time_iso8601 $log_date {
    "~^(?<date>\d{4}-\d{2}-\d{2})"  $date;
    default                       "unknown";
}

log_format kmtn_json escape=json
    '{'
        '"time":"$time_iso8601",'
        '"remote_addr":"$remote_addr",'
        '"x_forwarded_for":"$http_x_forwarded_for"'
    '}';

access_log /logs/access-$log_date.log kmtn_json;

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

    # SPA fallback — Angular router handles its own paths
    location / {
        try_files $uri $uri/ /index.html;
    }

    # Proxy API calls to the backend service
    location /api/ {
        proxy_pass __API_UPSTREAM__;
        proxy_set_header Host $host;
        proxy_set_header Origin $http_origin;
        proxy_set_header Referer $http_referer;
        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 $http_x_forwarded_proto;
        proxy_set_header X-Forwarded-Host $host;

        # Disable caching through the double-proxy chain (NPM → frontend nginx → API)
        # Without this, browsers cache responses keyed by the HTTPS origin, then send
        # conditional requests (If-None-Match) that get lost or mismatched in the proxy chain.
        proxy_cache off;
        add_header Cache-Control "no-store, no-cache, must-revalidate" always;
        add_header Pragma "no-cache" always;
        add_header Vary "*" always;
    }
}