{ config, pkgs, lib, ... }:
let
  cfg = config.services.lenticular-cloud;
  python = pkgs.python3;
  format = pkgs.formats.json {};
  types = lib.types;
  config_oauth_secret = "${cfg.settings.DATA_FOLDER}/lenticular_oauth_secret.toml";
  python_env = python.withPackages (ps: with ps; [ lenticular-cloud gevent setuptools ]);
in
{
  options = with lib.options; {
    services.lenticular-cloud = {
      enable = mkEnableOption "lenticluar service enable";
      domain = mkOption {
        type = lib.types.str;
        example = "example.com";
      };
      username = mkOption {
        type = lib.types.str;
        description = mdDoc "user to run the service";
        default = "lenticular_cloud";
      };
      service_domain = mkOption {
        type = lib.types.str;
        example = "account.example.com";
      };
      settings = mkOption {
        description = mdDoc ''
          Lenticular cloud settings
        '';

        default = { };

        type  = types.submodule {
          freeformType = format.type;
          options = {
            DOMAIN = mkOption {
              type = types.str;
              description = mdDoc "Top level Domain of the service";
              default = cfg.domain;
            };
            PUBLIC_URL = mkOption {
              type = types.str;
              description = mdDoc "public service url";
              default = "https://${cfg.service_domain}";
            };
            ADMINS = mkOption {
              type = types.listOf types.str;
              description = mdDoc "list of admin users";
              example = [ "tuxcoder" ];
            };
            DATA_FOLDER = mkOption {
              type = types.str;
              default = "/var/lib/${cfg.username}";
            };
            PKI_PATH = mkOption {
              type = types.str;
              default = "${cfg.settings.DATA_FOLDER}/pki";
            };
            SQLALCHEMY_DATABASE_URI = mkOption {
              type = types.str;
              default = "postgresql://${cfg.username}@/${cfg.username}?host=/run/postgresql";
            }; 
            HYDRA_ADMIN_URL = mkOption {
              type = types.str;
              default = "https://${config.services.ory-hydra.admin_domain}";
            }; 
            HYDRA_PUBLIC_URL = mkOption {
              type = types.str;
              default = "https://${config.services.ory-hydra.public_domain}";
            }; 
          };
        };
      };
    };
  };
  config = {
    environment.systemPackages = [ pkgs.lenticular-cloud ];

    nixpkgs.overlays = [
      (import ./overlay.nix)
    ];
    
    users = {
      groups."${cfg.username}" = {
      };
      users."${cfg.username}" = {
        createHome = true;
        home = "/var/lib/${cfg.username}";
        description = "web server";
        extraGroups = [
          # "ory-hydra"
        ];
        group = cfg.username;
        isSystemUser = true;
      };
    };

    services.postgresql = {
      enable = true;
      ensureDatabases = [ cfg.username ];
      ensureUsers = [
        {
          name = cfg.username;
          ensureDBOwnership = true;
        }
      ];
    };

    services.ory-hydra.settings = {
      urls = {
        login = "${cfg.settings.PUBLIC_URL}/auth/login";
        logout = "${cfg.settings.PUBLIC_URL}/auth/logout";
        consent = "${cfg.settings.PUBLIC_URL}/auth/consent";
        error = "${cfg.settings.PUBLIC_URL}/auth/error";
      };
    };

    services.nginx.enable = true;
    services.nginx.virtualHosts."${cfg.service_domain}" = {
      addSSL = true;
      enableACME = true;
      serverName = cfg.service_domain;
      locations."/" = {
        recommendedProxySettings = true;
        proxyPass = "http://unix:/run/${cfg.username}/web.sock";
      };
    };
    users.users.nginx.extraGroups = [ cfg.username ];

    systemd.services.lenticular-cloud = {
      description = "lenticular account";
      after = [ "network.target" ];
      wantedBy = [ "multi-user.target" ];
      requires = [ "ory-hydra.service" "postgresql.service" ];
      enable = cfg.enable;

      environment = let
        config_file = format.generate "lenticular-cloud.json" cfg.settings;
      in {
        # CONFIG_FILE = "/etc/lenticular_cloud/production.conf";
        CONFIG_FILE = "${config_file}:${config_oauth_secret}";
      };
      preStart = ''
        if [[ ! -e "${config_oauth_secret}" ]]; then
          SECRET_KEY=`${pkgs.openssl}/bin/openssl rand --hex 16`
          echo 'OAUTH_SECRET="$${SECRET_KEY}"' > ${config_oauth_secret}
          echo "oauth secreted generated"
        fi
        ${pkgs.lenticular-cloud}/bin/lenticular_cloud-cli db_upgrade
      '';

      serviceConfig = {
        Type = "simple";
        WorkingDirectory = cfg.settings.DATA_FOLDER;
        User = cfg.username;
        ExecStart = ''${python_env}/bin/gunicorn lenticular_cloud.wsgi --name lenticular_cloud \
              --workers 2 --log-level=info \
              --bind=unix:/run/${cfg.username}/web.sock \
              -k gevent'';
        Restart = "on-failure";
        RuntimeDirectory = cfg.username;
      };
    };

  };
}