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

with lib;

let
  cfg = config.services.asjon;

in {

  options.services.asjon = {
    enable = mkEnableOption "Asjon: our chat bot";

     dataDir = mkOption {
       type = types.path;
       default = "/var/lib/asjon";
       description = ''
         Path where the settings and source tree will exist.
       '';
     };

     user = mkOption {
       type = types.str;
       default = "asjon";
       description = ''
         Asjon will be run under this user (user will be created if it doesn't exist.
         This can be your user name).
       '';
     };

     group = mkOption {
       type = types.str;
       default = "asjon";
       description = ''
         Asjon will be run under this group (user will be created if it doesn't exist.
         This can be your user name).
       '';
     };

  };

  config = mkIf cfg.enable {

    users.users.${cfg.user} = {
      group = cfg.group;
      home = cfg.dataDir;
      isSystemUser = true;
      createHome  = true;
      description = "asjon user";
      shell = "${pkgs.bash}/bin/bash";
    };
    users.groups.${cfg.group} = { };

    systemd.services.asjon = {
      description = "asjon: our chat bot";
      after    = [ "nginx.service" "matrix-synapse.service" "asjon-init.service" ];
      partOf   = [ "nginx.service" "matrix-synapse.service" "asjon-init.service" ];
      wantedBy = [ "multi-user.target" ];

      path = with pkgs; [
        nodejs nodePackages.coffee-script
        yarn openssh graphicsmagick git
        bash
      ];

      environment = {
        # Matrix login
        HUBOT_MATRIX_HOST_SERVER = "https://${config.var.hostname}";

        # Git integration
        HUBOT_GIT_URL   = "https://${config.var.hostname}/git";
        HUBOT_GIT_API   = "https://${config.var.hostname}/git/api/v1";
        HUBOT_GIT_REPO  = "rnhmjoj/asjon";

        # Scripts
        AUTO_KILL_ON_UPDATE  = "1";
        AUTO_INFORM_ON_START = "!XQJXsOXfTevAiEbDTA:eurofusion.eu";
        ADMIN_ROOM           = "!XQJXsOXfTevAiEbDTA:eurofusion.eu";
        REV_REMOTE_HOST      = "proxy@rnhmjoj.ydns.eu";
        REV_REMOTE_PORT      = "22";
        REV_KEY              = "~/.ssh/proxy";
        REDIS_URL            = "redis:///run/redis-asjon/redis.sock";
      };

      serviceConfig = {
        User      = cfg.user;
        ExecStart = "${cfg.dataDir}/tree/bin/hubot -a matrix";
        Restart   = "always";
        WorkingDirectory = "${cfg.dataDir}/tree";
        # API keys and passwords definitions
        EnvironmentFile = config.secrets.environments.asjon;
      };

    };

    systemd.services.asjon-init = {
      description = "Initialize Asjon service (first time only)";
      wants    = [ "network.target" ];
      wantedBy = [ "multi-user.target" ];

      serviceConfig.User = cfg.user;
      path = with pkgs; [ git yarn acl ];

      script = ''
        if test -d ${cfg.dataDir}/tree/.git; then
          exit 0
        fi

        # clone repository and install packages
        git clone https://github.com/rnhmjoj/asjon.git ${cfg.dataDir}/tree
        cd ${cfg.dataDir}/tree
        yarn install
      '';
    };

  };

}