(** debug command: interactive container for failed builds *)

open Cmdliner

let run profile_name profile_dir target keep command =
  match Common.load_profile ~profile_dir ~name:profile_name with
  | Error (`Msg e) -> Printf.eprintf "Error: %s\n%!" e; 1
  | Ok (_profile, paths) ->
  Common.with_eio @@ fun env ->
  let os_dir = paths.os_dir in
  (* Resolve target: hash or package name *)
  let node =
    match Day11_opam_layer.Build_meta.load_tree ~os_dir target with
    | Ok n -> n
    | Error _ ->
      (* Try as package name -- look up from history *)
      let packages_dir = match Common.latest_snapshot_dir paths with
        | Some sd -> Fpath.(sd / "packages")
        | None -> Fpath.(os_dir / "packages") in
      let entries = Day11_lib.History.read ~packages_dir ~pkg_str:target in
      let failure = List.find_opt (fun (e : Day11_lib.History.entry) ->
        e.status = "failure" && e.build_hash <> "none"
      ) entries in
      match failure with
      | Some e ->
        Printf.printf "Using %s\n%!" e.build_hash;
        (match Day11_opam_layer.Build_meta.load_tree ~os_dir e.build_hash with
         | Ok n -> n
         | Error (`Msg e) ->
           Printf.eprintf "Cannot load %s: %s\n" target e;
           exit 1)
      | None ->
        Printf.eprintf "No failed build found for %s\n" target;
        exit 1
  in
  match Day11_opam_build.Debug.setup env ~os_dir ~keep node with
  | Error (`Msg e) ->
    Printf.eprintf "Setup failed: %s\n" e; 1
  | Ok session ->
    Printf.printf "Debug container for %s\n%!"
      (OpamPackage.to_string session.pkg);
    let result = match command with
      | Some cmd -> Day11_opam_build.Debug.run_command env session cmd
      | None -> Day11_opam_build.Debug.run_interactive env session
    in
    if not keep then Day11_opam_build.Debug.teardown env session;
    if keep then
      Printf.printf "Debug dir kept at: %s\n%!"
        (Fpath.to_string session.temp_dir);
    result

let target_term =
  Arg.(required & pos 0 (some string) None & info [] ~docv:"TARGET"
    ~doc:"Package name or layer hash to debug")

let keep_term =
  let doc = "Keep debug container for re-entry" in
  Arg.(value & flag & info [ "keep" ] ~doc)

let command_term =
  let doc = "Run command instead of interactive shell" in
  Arg.(value & opt (some string) None & info [ "command"; "c" ] ~docv:"CMD" ~doc)

let cmd =
  let info = Cmd.info "debug" ~doc:"Launch interactive debug container" in
  let term = Term.(const run $ Common.profile_term $ Common.profile_dir_term
    $ target_term $ keep_term $ command_term) in
  Cmd.v info term