(** Resolving paths within a Git tree, including unreachable objects. *)

open Test_helpers

let test_root_tree () =
  with_temp_directory "ogit-paths" (fun root ->
      let name = "project" in
      let path = Filename.concat root name in
      Unix.mkdir path 0o755;
      ignore (git [ "-C"; path; "init"; "-q"; "-b"; "main" ]);
      ignore (git [ "-C"; path; "config"; "user.name"; "Test" ]);
      ignore (git [ "-C"; path; "config"; "user.email"; "t@t.invalid" ]);
      Out_channel.with_open_text (Filename.concat path "file.txt") (fun ch ->
          output_string ch "data\n");
      ignore (git [ "-C"; path; "add"; "." ]);
      ignore (git [ "-C"; path; "commit"; "-q"; "-m"; "init" ]);
      let root_tree = git [ "-C"; path; "rev-parse"; "HEAD^{tree}" ] in
      let config = Ogit.Config.{ default with git_project_root = root } in
      let repository =
        match Lwt_main.run (Ogit.Resolvers.open_repository config name) with
        | Ok r -> r
        | Error e -> Alcotest.failf "%a" Ogit.Resolvers.pp_error e
      in
      Fun.protect
        ~finally:(fun () ->
          Lwt_main.run (Ogit.Resolvers.close_repository repository))
        (fun () ->
          match
            Lwt_main.run (Ogit.Resolvers.Tree.find_path repository root_tree)
          with
          | Ok trail ->
              Alcotest.(check (list (pair string string)))
                "empty trail" [] trail
          | Error e -> Alcotest.failf "%a" Ogit.Resolvers.pp_error e))

let test_nested () =
  with_temp_directory "ogit-paths" (fun root ->
      let name = "project" in
      let path = Filename.concat root name in
      Unix.mkdir path 0o755;
      ignore (git [ "-C"; path; "init"; "-q"; "-b"; "main" ]);
      ignore (git [ "-C"; path; "config"; "user.name"; "Test" ]);
      ignore (git [ "-C"; path; "config"; "user.email"; "t@t.invalid" ]);
      let dir = Filename.concat path "dir" in
      Unix.mkdir dir 0o755;
      Out_channel.with_open_text (Filename.concat dir "nested.txt") (fun ch ->
          output_string ch "nested\n");
      ignore (git [ "-C"; path; "add"; "." ]);
      ignore (git [ "-C"; path; "commit"; "-q"; "-m"; "init" ]);
      let nested_tree = git [ "-C"; path; "rev-parse"; "HEAD:dir" ] in
      let nested_blob =
        git [ "-C"; path; "rev-parse"; "HEAD:dir/nested.txt" ]
      in
      let config = Ogit.Config.{ default with git_project_root = root } in
      let repository =
        match Lwt_main.run (Ogit.Resolvers.open_repository config name) with
        | Ok r -> r
        | Error e -> Alcotest.failf "%a" Ogit.Resolvers.pp_error e
      in
      Fun.protect
        ~finally:(fun () ->
          Lwt_main.run (Ogit.Resolvers.close_repository repository))
        (fun () ->
          match
            Lwt_main.run (Ogit.Resolvers.Tree.find_path repository nested_blob)
          with
          | Ok trail ->
              Alcotest.(check (list (pair string string)))
                "nested trail"
                [ ("dir", nested_tree); ("nested.txt", nested_blob) ]
                trail
          | Error e -> Alcotest.failf "%a" Ogit.Resolvers.pp_error e))

let test_unreachable () =
  with_temp_directory "ogit-paths" (fun root ->
      let name = "project" in
      let path = Filename.concat root name in
      Unix.mkdir path 0o755;
      ignore (git [ "-C"; path; "init"; "-q"; "-b"; "main" ]);
      ignore (git [ "-C"; path; "config"; "user.name"; "Test" ]);
      ignore (git [ "-C"; path; "config"; "user.email"; "t@t.invalid" ]);
      Out_channel.with_open_text (Filename.concat path "file.txt") (fun ch ->
          output_string ch "data\n");
      ignore (git [ "-C"; path; "add"; "." ]);
      ignore (git [ "-C"; path; "commit"; "-q"; "-m"; "init" ]);
      let dangling_file = Filename.concat root "dangling.txt" in
      Out_channel.with_open_text dangling_file (fun ch ->
          output_string ch "dangling\n");
      let dangling_blob =
        git [ "-C"; path; "hash-object"; "-w"; dangling_file ]
      in
      let config = Ogit.Config.{ default with git_project_root = root } in
      let repository =
        match Lwt_main.run (Ogit.Resolvers.open_repository config name) with
        | Ok r -> r
        | Error e -> Alcotest.failf "%a" Ogit.Resolvers.pp_error e
      in
      Fun.protect
        ~finally:(fun () ->
          Lwt_main.run (Ogit.Resolvers.close_repository repository))
        (fun () ->
          match
            Lwt_main.run
              (Ogit.Resolvers.Tree.find_path repository dangling_blob)
          with
          | Error (Ogit.Resolvers.Not_found _) -> ()
          | Error e -> Alcotest.failf "%a" Ogit.Resolvers.pp_error e
          | Ok _ -> Alcotest.fail "unreachable object should return Not_found"))

let suite =
  ( "tree paths",
    [
      Alcotest.test_case "root tree" `Slow test_root_tree;
      Alcotest.test_case "nested path" `Slow test_nested;
      Alcotest.test_case "unreachable object" `Slow test_unreachable;
    ] )