{ flakes, pkgs, lib, config, ... }:
let
  inherit (lib) types;
  inherit (config) networking;
  inherit (config.services) nginx;
in
{
options = {
  services.nginx = {
    configs = lib.mkOption {
      type = types.attrsOf types.lines;
      default = {};
      description = ''
        Make some configs available to all virtual hosts.
        Useful to workaround the reset of add_header:
        https://blog.g3rt.nl/nginx-add_header-pitfall.html
      '';
      #apply = lib.mapAttrs (name: pkgs.writeText "${name}.conf");
    };
  };
};
config = {
systemd.tmpfiles.rules = [
  "d '/dev/shm/nginx' '750' '${nginx.user}' '${nginx.group}' - -"
];
systemd.services.nginx = {
  serviceConfig = {
    # FIXME: remove all the mkForce in LogsDirectory
    # whenever upstream uses a list instead of a string.
    LogsDirectory = lib.mkForce ["nginx"];
    StateDirectory = ["nginx"];
    StateDirectoryMode = "2770";
    BindPaths = ["/dev/shm/nginx:/var/cache/nginx"];
  };
};
services.nginx = {
  eventsConfig = ''
    multi_accept on;
    use epoll;
    worker_connections 1024;
  '';
  clientMaxBodySize = "20m";
  recommendedGzipSettings = true;
  recommendedOptimisation = false;
  recommendedProxySettings = true;
  recommendedTlsSettings = true;
  resolver = {
    ipv6 = lib.mkDefault (networking.defaultGateway6 != null);
  };
  serverTokens = false;
  # Only allow PFS-enabled ciphers with AES256
  #sslCiphers = "AES256+EECDH:AES256+EDH:!aNULL";
  #sslCiphers = "HIGH:!ADH:!MD5:!CAMELLIA:!SEED:!3DES:!DES:!RC4:!eNULL";
  #sslCiphers = "EECDH+aRSA+AESGCM:EDH+aRSA:EECDH+aRSA:+AES256:+AES128:+SHA1:!CAMELLIA:!SEED:!3DES:!DES:!RC4:!eNULL";
  sslDhparam = flakes.secrets + "/openssl/dh.pem";
  sslProtocols = "TLSv1.3 TLSv1.2";
  configs = rec {
    http_add_headers = ''
      # Add HSTS header with preloading to HTTPS requests.
      # Adding this header to HTTP requests is discouraged
      # DOC: https://blog.qualys.com/securitylabs/2016/03/28/the-importance-of-a-proper-http-strict-transport-security-implementation-on-your-web-server
      add_header Strict-Transport-Security $hsts_header;

      # Enable CSP for your services.
      #add_header Content-Security-Policy "script-src 'self'; object-src 'none'; base-uri 'none';" always;

      # Minimize information leaked to other domains
      add_header 'Referrer-Policy' 'origin-when-cross-origin';

      # Disable embedding as a frame
      add_header X-Frame-Options DENY;

      # Prevent injection of code in other mime types (XSS Attacks)
      add_header X-Content-Type-Options nosniff;

      # Enable XSS protection of the browser.
      # May be unnecessary when CSP is configured properly (see above)
      add_header X-XSS-Protection "1; mode=block";
    '';
    https_add_headers = ''
      ${http_add_headers}
    '';
  };
  commonHttpConfig = ''
    log_format main '$remote_addr - $remote_user [$time_local] "$request" '
                    '$status $body_bytes_sent "$http_referer" '
                    '"$http_user_agent" "$http_x_forwarded_for"';

    log_format json escape=json
      '{'
        '"time_local":"$time_local",'
        '"remote_addr":"$remote_addr",'
        '"status": "$status",'
        '"request":"$request",'
        '"body_bytes_sent":"$body_bytes_sent",'
        '"http_referrer":"$http_referer",'
        '"http_user_agent":"$http_user_agent",'
        '"remote_user":"$remote_user",'
        '"request_time":"$request_time"'
      '}';
    charset UTF-8;
    types {
      text/html html5;
      text/plain md;
    }
    '' +
    lib.concatStringsSep "\n" (lib.attrValues {
      default = ''
        default_type application/octet-stream;
        root /var/lib/nginx;
      '';
      security = ''
        #error_page 403 = 404;

        ${nginx.configs.http_add_headers}

        # This might create errors
        proxy_cookie_path / "/; secure; HttpOnly; SameSite=strict";
      '';
      log = ''
        access_log /var/log/nginx/access.log main buffer=32k;
        error_log  /var/log/nginx/error.log warn;
        open_log_file_cache max=1000 inactive=20s min_uses=2 valid=1m;
      '';
      proxy = ''
        proxy_cache_use_stale updating;
        proxy_temp_path /var/cache/nginx/proxy_temp 1 2;
      '';
      fastcgi = ''
        # DOC: http://wiki.nginx.org/HttpFastcgiModule
        fastcgi_buffer_size 128k;
        fastcgi_buffers 256 4k;
        fastcgi_busy_buffers_size 256k;
        fastcgi_cache_key "$request_method $scheme://$http_host$request_uri";
        fastcgi_connect_timeout 60;
        fastcgi_ignore_client_abort off;
        fastcgi_intercept_errors on;
        fastcgi_max_temp_file_size 2M;
        #fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        fastcgi_param SCRIPT_FILENAME $request_filename;
        fastcgi_temp_path /var/cache/nginx/fastcgi_temp 1 2;
      '';
      connection = ''
        sendfile on;
        # If the client stops reading data,
        # free up the stale client connection after this much time.
        send_timeout 60;
        # Causes nginx to attempt to send its HTTP response head
        # in one packet, instead of using partial frames.
        # This is useful for prepending headers before calling sendfile,
        # or for throughput optimization.
        tcp_nopush on;
        # Don't buffer data-sends (disable Nagle algorithm).
        # Good for sending frequent small bursts of data in real time.
        tcp_nodelay on;
        keepalive_timeout 20;
        reset_timedout_connection on;
        types_hash_max_size 4096;
        server_names_hash_bucket_size 128;
      '';
      map = ''
        map $time_iso8601 $date {
          default 'date-not-found';
          '~^(?<year>\d{4})-(?<month>\d{2})-(?<day>\d{2})' $year-$month-$day;
        }

        map $scheme $hsts_header {
          https  "max-age=31536000; includeSubdomains; preload";
        }

        # User agents that are to be blocked.
        #map $http_user_agent $bad_bot {
        #  default 0;
        #  libwww-perl 1;
        #  ~(?i)(httrack|htmlparser|libwww) 1;
        #}
        # Referrers that are to be blocked.
        #map $http_referer $bad_referer {
        #  default 0;
        #  ~(?i)(babes|casino|click|diamond|forsale|girl|jewelry|love|nudit|organic|poker|porn|poweroversoftware|replica|sex|teen|webcam|zippo) 1;
        #}
        #geo $not_local {
        #  default 1;
        #  127.0.0.1 0;
        #}
      '';
      cache = ''
        client_body_buffer_size 4K;
          # getconf PAGESIZE
          # 4096
        client_body_temp_path /var/cache/nginx/client_body_temp 1 2;
        client_body_timeout 60;
        client_header_buffer_size 1k;
        client_header_timeout 60;
        large_client_header_buffers 4 8k;

        open_file_cache max=200000 inactive=20s;
        open_file_cache_errors on;
        open_file_cache_min_uses 2;
        open_file_cache_valid 30s;
      '';
    });
  appendConfig = ''
    worker_processes ${toString config.nix.maxJobs};
  '';
};
};
}