# TODO: submit burningalchemist's sql_exporter to nixpkgs
{ config, lib, pkgs, ... }:

let
  sqlExporter = pkgs.callPackage ./default.nix {};
  cfg = config.services.prometheus-sql-exporter;
  configFile =  builtins.toFile "config.yaml" (builtins.toJSON cfg.config);
in
{
  options.services.prometheus-sql-exporter = {
    enable = lib.mkEnableOption "sql-exporter";
    port = lib.mkOption {
      type = lib.types.int;
    };
    config = lib.mkOption {
      type = (pkgs.formats.json {}).type;
    };
  };

  config = lib.mkIf cfg.enable {
    systemd.services.prometheus-sql-exporter = {
      serviceConfig = {
        ExecStart = "${sqlExporter}/bin/sql_exporter -config.file ${configFile} -web.listen-address :${toString cfg.port}";
        DynamicUser = "true";
        User = "prometheus-sql-exporter";
      };
      wantedBy = ["multi-user.target"];
    };
  };
}