{ config, lib, pkgs, ... }:

with lib;

let
  cfg = config.services.firefox.syncserver;
  syncServerIni = pkgs.writeText "syncserver.ini" ''
    [DEFAULT]
    overrides = ${cfg.privateConfig}

    [server:main]
    use = egg:Paste#http
    host = ${cfg.listen.address}
    port = ${toString cfg.listen.port}

    [app:main]
    use = egg:syncserver

    [syncserver]
    public_url = ${cfg.publicUrl}
    ${optionalString (cfg.sqlUri != "") "sqluri = ${cfg.sqlUri}"}
    allow_new_users = ${if cfg.allowNewUsers then "true" else "false"}

    [browserid]
    backend = tokenserver.verifiers.LocalVerifier
    audiences = ${removeSuffix "/" cfg.publicUrl}
  '';
in

{
  options = {
    services.firefox.syncserver = {
      enable = mkOption {
        type = types.bool;
        default = false;
        example = true;
        description = ''
          Whether to enable a Firefox Sync Server, this give the opportunity to
          Firefox users to store all synchronized data on their own server. To use this
          server, Firefox users should visit the <option>about:config</option>, and
          replicate the following change

          <screen>
          services.sync.tokenServerURI: http://localhost:5000/token/1.0/sync/1.5</screen>

          where <option>http://localhost:5000/</option> corresponds to the
          public url of the server.
        '';
      };

      listen.address = mkOption {
        type = types.str;
        default = "0.0.0.0";
        description = ''
          Address on which the sync server listen to.
        '';
      };

      listen.port = mkOption {
        type = types.int;
        default = 5000;
        description = ''
          Port on which the sync server listen to.
        '';
      };

      publicUrl = mkOption {
        type = types.str;
        default = "http://localhost:5000/";
        example = "http://sync.example.com/";
        description = ''
          Public URL with which firefox users can use to access the sync server.
        '';
      };

      allowNewUsers = mkOption {
        type = types.bool;
        default = true;
        example = false;
        description = ''
          Whether to allow new-user signups on the server. Only request by
          existing accounts will be honored.
        '';
      };

      sqlUri = mkOption {
        type = types.str;
        default = "sqlite:////var/db/firefox-sync-server.db";
        example = "postgresql://scott:tiger@localhost/test";
        description = ''
          The location of the database. This URL is composed of
          <option>dialect[+driver]://user:password@host/dbname[?key=value..]</option>,
          where <option>dialect</option> is a database name such as
          <option>mysql</option>, <option>oracle</option>, <option>postgresql</option>,
          etc., and <option>driver</option> the name of a DBAPI, such as
          <option>psycopg2</option>, <option>pyodbc</option>, <option>cx_oracle</option>,
          etc.
        '';
      };

      privateConfig = mkOption {
        type = types.str;
        default = "/etc/firefox/syncserver-secret.ini";
        description = ''
          If defined, this file would be used to set all fields which were omitted in the
          generated ini files used for configuring the syncserver.  This file is useful
          for storing secrets, such as the syncserver.secret or the syncserver.sqluri.

          If this file does not exists, it would be created with a unique secret.
        '';
      };
    };
  };

  config = {

    systemd.services.syncserver = {
      after = [ "network.target" ];
      description = "Firefox Sync Server";
      wantedBy = [ "multi-user.target" ];
      path = [ pkgs.pythonPackages.pasteScript pkgs.coreutils ];
      environment.PYTHONPATH = "${pkgs.pythonPackages.syncserver}/lib/${pkgs.pythonPackages.python.libPrefix}/site-packages";
      preStart = ''
        if ! test -e ${cfg.privateConfig}; then
          umask u=rwx,g=x,o=x
          mkdir -p $(dirname ${cfg.privateConfig})
          echo  > ${cfg.privateConfig} '[syncserver]'
          echo >> ${cfg.privateConfig} "secret = $(head -c 20 /dev/urandom | sha1sum | tr -d ' -')"
        fi
      '';
      serviceConfig.ExecStart = "paster serve ${syncServerIni}";
    };

  };
}