# pl-fe Nginx for Docker.
# It's intended to be used by the official nginx image, which has templating functionality.
# Mount at: `/etc/nginx/templates/default.conf.template`

map_hash_bucket_size 128;

map $http_upgrade $connection_upgrade {
  default upgrade;
  ''      close;
}

# ActivityPub routing.
map $http_accept $activitypub_location {
  default @pl-fe;
  "application/activity+json" @backend;
  'application/ld+json; profile="https://www.w3.org/ns/activitystreams"' @backend;
}

proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=CACHE:10m inactive=7d max_size=1g;

# Fake backend for when BACKEND_URL isn't defined.
server {
  listen ${FALLBACK_PORT};
  listen [::]:${FALLBACK_PORT};

  location / {
    add_header Content-Type "application/json" always;
    return 404 '{"error": "Not implemented"}';
  }
}

server {
  listen ${PORT};
  listen [::]:${PORT};

  keepalive_timeout    70;
  sendfile             on;
  client_max_body_size 80m;

  root /usr/share/nginx/html;

  gzip on;
  gzip_disable "msie6";
  gzip_vary on;
  gzip_proxied any;
  gzip_comp_level 6;
  gzip_buffers 16 8k;
  gzip_http_version 1.1;
  gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript image/svg+xml image/x-icon;

  add_header Strict-Transport-Security "max-age=31536000" always;

  # Content Security Policy (CSP)
  # https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy
  add_header Content-Security-Policy "${CSP}";

  # Fallback route.
  # Try static files, then fall back to the SPA.
  location / {
    try_files $uri @pl-fe;
  }

  # Backend routes.
  # These are routes to the backend's API and important rendered pages.
  location ~ ^/(api|oauth|auth|admin|pghero|sidekiq|manifest.json|media|nodeinfo|unsubscribe|.well-known/(webfinger|host-meta|nodeinfo|change-password)|@(.+)/embed$) {
    try_files /dev/null @backend;
  }

  # Backend ActivityPub routes.
  # Conditionally send to the backend by Accept header.
  location ~ ^/(inbox|users|@(.+)) {
    try_files /dev/null $activitypub_location;
  }

  # pl-fe build files.
  # New builds produce hashed filenames, so these should be cached heavily.
  location /packs {
    add_header Cache-Control "public, max-age=31536000, immutable";
    add_header Strict-Transport-Security "max-age=31536000" always;
  }

  # pl-fe ServiceWorker.
  location = /sw.js {
    add_header Cache-Control "public, max-age=0";
    add_header Strict-Transport-Security "max-age=31536000" always;
  }

  # pl-fe SPA (Single Page App).
  location @pl-fe {
    try_files /index.html /dev/null;
  }

  # Proxy to the backend.
  location @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;
    proxy_set_header Proxy "";
    proxy_pass_header Server;

    proxy_pass "${BACKEND_URL}";
    proxy_buffering on;
    proxy_redirect off;
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection $connection_upgrade;

    proxy_cache CACHE;
    proxy_cache_valid 200 7d;
    proxy_cache_valid 410 24h;
    proxy_cache_use_stale error timeout updating http_500 http_502 http_503 http_504;
    add_header X-Cached $upstream_cache_status;
    add_header Strict-Transport-Security "max-age=31536000" always;

    tcp_nodelay on;
  }
}
