# Home Manager module: `services.maestro`.
#
# Maestro owns the user's interactive shells and tmux sessions, so the daemon
# is a *user* service, not a system one — same trust boundary as the tmux
# server it wraps. It serves the browser UI too; there is no second unit.
{ 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
    {
      imports = [
        (lib.mkRemovedOptionModule [ "services" "maestro" "web" "enable" ] ''
          The daemon serves the browser UI off its own listener now, so there is
          no second unit to enable. Point a browser at
          `services.maestro.settings.daemon.bind_addr` instead.
        '')
        (lib.mkRemovedOptionModule [ "services" "maestro" "web" "package" ] ''
          The `maestro-web` package is gone; the SPA is embedded in the
          `maestro` binary under its default-on `web` cargo feature.
        '')
      ];

      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.";
        };

        settings = lib.mkOption {
          type = tomlFormat.type;
          default = { };
          example = lib.literalExpression ''
            {
              daemon.bind_addr = "127.0.0.1:7070";
            }
          '';
          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. `daemon.bind_addr` is also the address the
            browser UI is served on. There is no auth layer — bind it to a
            LAN/VPN address only on a trusted segment, never a public IP.
          '';
        };
      };

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

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

        systemd.user.services = lib.mkIf cfg.daemon.enable {
          maestro-daemon = {
            Unit = {
              Description = "maestro daemon — tmux wrapper + session API + browser UI";
              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" ];
          };
        };
      };
    };
}