# Home Manager module: `services.maestro`.
#
# Maestro owns the user's interactive shells and tmux sessions, so both units
# are *user* services, not system ones — same trust boundary as the tmux server
# they wrap.
{ self, ... }:
{
  flake.homeManagerModules.default =
    {
      config,
      lib,
      pkgs,
      ...
    }:
    let
      cfg = config.services.maestro;
      tomlFormat = pkgs.formats.toml { };

      # A user unit inherits almost no PATH. Give the daemon the profile dirs a
      # login shell would have, so the sessions it spawns can find the user's
      # own tools.
      profilePath = lib.concatStringsSep ":" [
        "%h/.local/bin"
        "%h/.nix-profile/bin"
        "/etc/profiles/per-user/%u/bin"
        "/run/current-system/sw/bin"
      ];
    in
    {
      options.services.maestro = {
        enable = lib.mkEnableOption "Maestro — installs the CLI/TUI and, unless disabled, runs the daemon";

        package = lib.mkOption {
          type = lib.types.package;
          default = self.packages.${pkgs.stdenv.hostPlatform.system}.maestro;
          defaultText = lib.literalExpression "maestro.packages.\${system}.maestro";
          description = "The unified `maestro` binary (CLI + daemon + TUI).";
        };

        daemon.enable = lib.mkOption {
          type = lib.types.bool;
          default = true;
          description = "Run `maestro daemon` as a systemd user service.";
        };

        web = {
          enable = lib.mkEnableOption "the `maestro-web` browser UI as a systemd user service";

          package = lib.mkOption {
            type = lib.types.package;
            default = self.packages.${pkgs.stdenv.hostPlatform.system}.maestro-web;
            defaultText = lib.literalExpression "maestro.packages.\${system}.maestro-web";
            description = "The `maestro-web` binary, with the SPA bundle embedded.";
          };
        };

        settings = lib.mkOption {
          type = tomlFormat.type;
          default = { };
          example = lib.literalExpression ''
            {
              daemon.bind_addr = "127.0.0.1:7070";
              web.bind_addr = "0.0.0.0:8081";
            }
          '';
          description = ''
            Contents of `~/.config/maestro/config.toml`, in the schema
            `maestro-config` defines. Every field has a default, so `{}` is
            valid and writes no file. There is no auth layer — bind the web UI
            to a LAN/VPN address only on a trusted segment, never a public IP.
          '';
        };
      };

      config = lib.mkIf cfg.enable {
        home.packages = [ cfg.package ] ++ lib.optional cfg.web.enable cfg.web.package;

        xdg.configFile."maestro/config.toml" = lib.mkIf (cfg.settings != { }) {
          source = tomlFormat.generate "maestro-config.toml" cfg.settings;
        };

        systemd.user.services = lib.mkMerge [
          (lib.mkIf cfg.daemon.enable {
            maestro-daemon = {
              Unit = {
                Description = "maestro daemon — tmux wrapper + session API";
                After = [ "network.target" ];
                # MUST stay 0: a fast-crashing daemon would burn the default
                # 5-starts-per-10s budget and park the unit in `failed` until a
                # manual `systemctl --user reset-failed`.
                StartLimitIntervalSec = 0;
              };
              Service = {
                Type = "simple";
                WorkingDirectory = "%h";
                ExecStart = "${lib.getExe cfg.package} daemon run";
                Environment = [
                  "PATH=${profilePath}"
                  # Keeps the daemon on the same tmux server the user's shell
                  # and TUI use, instead of a second one under /tmp.
                  "TMUX_TMPDIR=%t"
                ];
                Restart = "always";
                RestartSec = 2;
                # If this unit boots before any shell, the shared tmux server
                # lands in its cgroup; the default control-group kill would take
                # every session down on restart.
                KillMode = "process";
              };
              Install.WantedBy = [ "default.target" ];
            };
          })

          (lib.mkIf cfg.web.enable {
            maestro-web = {
              Unit = {
                Description = "maestro-web — browser UI for the local maestro daemon";
                After = [ "network.target" ] ++ lib.optional cfg.daemon.enable "maestro-daemon.service";
                Wants = lib.optional cfg.daemon.enable "maestro-daemon.service";
                StartLimitIntervalSec = 0;
              };
              Service = {
                Type = "simple";
                WorkingDirectory = "%h";
                ExecStart = lib.getExe cfg.web.package;
                Environment = [ "PATH=${profilePath}" ];
                Restart = "always";
                RestartSec = 2;
              };
              Install.WantedBy = [ "default.target" ];
            };
          })
        ];
      };
    };
}