upstream tx_api {
  server api:8080;
}

server {
  listen 80;
  server_name _;

  client_max_body_size 50m;

  # WebSocket / Socket.IO upgrade for /api/socket.io
  location /api/socket.io/ {
    proxy_pass http://tx_api;
    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_set_header X-Forwarded-Proto $scheme;
    proxy_read_timeout 3600s;
    proxy_send_timeout 3600s;
  }

  # Forward all /api requests to the Node API server
  location /api/ {
    proxy_pass http://tx_api;
    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;
    proxy_read_timeout 300s;
    proxy_send_timeout 300s;
  }

  # Static SPA assets with hashed filenames — cache aggressively
  location /assets/ {
    root /usr/share/nginx/html;
    expires 1y;
    access_log off;
    add_header Cache-Control "public, immutable";
    try_files $uri =404;
  }

  # Service worker MUST never be cached so we can ship SW updates.
  # Safari/iOS especially clings to old sw.js otherwise.
  location = /sw.js {
    root /usr/share/nginx/html;
    add_header Cache-Control "no-store, no-cache, must-revalidate, max-age=0";
    add_header Pragma "no-cache";
    add_header Expires "0";
    try_files $uri =404;
  }

  # SPA fallback — every unknown path returns index.html.
  # `no-cache` alone is unreliable on iOS Safari (sometimes the browser
  # serves a stale copy after a deploy). Pair it with `no-store` + the
  # legacy `Pragma`/`Expires` headers so every device — phones, iPads,
  # laptops — re-fetches index.html and picks up the freshly-hashed
  # assets/*.js bundle on every navigation.
  location / {
    root /usr/share/nginx/html;
    index index.html;
    try_files $uri $uri/ /index.html;
    add_header Cache-Control "no-store, no-cache, must-revalidate, max-age=0";
    add_header Pragma "no-cache";
    add_header Expires "0";
  }
}