{pkgs, lib, config, system, ...}:
let
  inherit (builtins) readFile;
  inherit (builtins.extraBuiltins) pass;
  inherit (lib) types;
  inherit (pkgs.lib) loadFile;
  inherit (config) networking;
  inherit (config.services) nginx;
  domainDir = dom: lib.concatStringsSep "/" (lib.reverseList (lib.splitString "." dom));
in
{
imports = [
  nginx/gitweb.nix
  nginx/www.nix
];
options = {
  services.nginx = {
    x509Dir = lib.mkOption {
      type    = types.str;
      default = "/var/lib/nginx/x509";
    };
    webDir = lib.mkOption {
      type    = types.str;
      default = "/var/www";
    };
    logDir = lib.mkOption {
      type    = types.str;
      default = "/var/log/nginx";
    };
  };
};
config = {
  systemd.services.nginx = {
    preStart = lib.mkBefore ''
      install -D -d -o ${nginx.user} -g ${nginx.group} -m 0700 \
       ${nginx.x509Dir} \
       ${nginx.webDir} \
       ${nginx.logDir}
    '';
    after = [
      "${networking.domain}.key.pem-key.service"
    ];
  };
  services.nginx = {
    enable = true;
    stateDir = "/dev/shm/nginx";
    eventsConfig = ''
      multi_accept on;
      use epoll;
      worker_connections 1024;
    '';
    clientMaxBodySize = "20m";
    recommendedProxySettings = true;
    recommendedTlsSettings = true;
    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";
    sslDhparam = ../../../sec/openssl/dh.pem;
    #sslCiphers = "EECDH+aRSA+AESGCM:EDH+aRSA:EECDH+aRSA:+AES256:+AES128:+SHA1:!CAMELLIA:!SEED:!3DES:!DES:!RC4:!eNULL;";
    #sslProtocols = "TLSv1.2";
    commonHttpConfig = ''
      log_format main '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';
      #charset UTF-8;
      '' +
      lib.concatStringsSep "\n" (lib.attrValues {
        default = ''
          default_type application/octet-stream;
          root ${nginx.webDir};
        '';
        security = ''
          #error_page 403 = 404;

          # Add HSTS header with preloading to HTTPS requests.
          # Adding this header to HTTP requests is discouraged
          #map $scheme $hsts_header {
          #    https   "max-age=31536000; includeSubdomains; preload";
          #}
          #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";

          # This might create errors
          proxy_cookie_path / "/; secure; HttpOnly; SameSite=strict";
        '';
        log = ''
          access_log ${nginx.logDir}/access.log main buffer=32k;
          error_log  ${nginx.logDir}/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 ${nginx.stateDir}/proxy_temp 1 2;
        '';
        fastcgi = ''
          # DOC: http://wiki.nginx.org/HttpFastcgiModule
          fastcgi_buffer_size 128k;
          fastcgi_buffers 256 4k;
          fastcgi_busy_buffers_size 256k;
          fastcgi_cache_key "$request_method $scheme://$http_host$request_uri";
          fastcgi_cache_path ${nginx.stateDir}/fastcgi_cache
                             inactive=10m
                             keys_zone=microcache:2M
                             levels=1:2
                             loader_files=100000
                             loader_sleep=1
                             loader_threshold=2592000000
                             max_size=64M;
          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 ${nginx.stateDir}/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 2048;
          #server_names_hash_bucket_size 128;
        '';
        map = ''
          # 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;
          #}
        '';
        gzip = ''
          gzip on;
          gzip_buffers 16 8k;
          gzip_comp_level 6;
          gzip_disable "MSIE [1-6]\.";
          gzip_http_version 1.1;
          gzip_min_length 1024;
          gzip_proxied any;
          gzip_static on;
          gzip_vary on;
          gzip_types application/atom+xml
                     application/javascript
                     application/json
                     application/rss+xml
                     application/vnd.ms-fontobject
                     application/x-font-ttf
                     application/x-javascript
                     application/xml
                     application/xml+rss
                     font/opentype
                     font/truetype
                     image/svg+xml
                     text/css
                     text/javascript
                     text/plain
                     text/x-component
                     text/xml;
        '';
        cache = ''
          client_body_buffer_size 4K;
            # getconf PAGESIZE
            # 4096
          client_body_temp_path ${nginx.stateDir}/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 4;
    '';
    virtualHosts."_" = {
      forceSSL = false;
      # Convoluted way to load the certificate in the store and using ${networking.domainBase} to find it.
      # NOTE: no ssl_stapling while the certificate remains self-signed.
      sslCertificate = loadFile (../../../sec + "/openssl/${networking.domain}/cert.self-signed.pem");
      sslCertificateKey = "/run/keys/${networking.domain}.key.pem";
    };
  };
};
}