open Lwt.Infix

let full_path path = Filename.concat Config.git_directory path

let head_commit_hash repo_path =
  let%lwt store_result = Git_unix.Store.v @@ Fpath.v @@ full_path repo_path in
  match store_result with
  | Error _ -> Lwt.return_error "Could not open the Git repository."
  | Ok store -> (
      Git_unix.Store.Ref.resolve store Git.Reference.head >|= function
      | Error _ -> Error ("Failed to resolve HEAD for repo " ^ repo_path)
      | Ok hash -> Ok (Git_unix.Store.Hash.to_hex hash))

let latest_commits repo_path count =
  let cmd =
    Printf.sprintf "git -C %s log --pretty=format:'%%ad %%s' --date=short -n %d"
      (full_path repo_path) count
  in
  Lwt.catch
    (fun () ->
      let%lwt output = Lwt_process.pread ("", [| "sh"; "-c"; cmd |]) in
      let lines = String.split_on_char '\n' output in
      Lwt.return_ok lines)
    (fun exn -> Lwt.return_error (Printexc.to_string exn))

let all_branches repo_path =
  let cmd =
    Printf.sprintf "git -C %s branch --format=%%(refname:short)"
    @@ full_path repo_path
  in
  Lwt.catch
    (fun () ->
      let%lwt output = Lwt_process.pread ("", [| "sh"; "-c"; cmd |]) in
      let branches =
        String.split_on_char '\n' output
        |> List.filter (fun s -> String.trim s <> "")
      in
      Lwt.return_ok branches)
    (fun exn -> Lwt.return_error (Printexc.to_string exn))