(** Configuration loading: round-tripping, backward compatibility, and rejection
    of malformed files and out-of-range values. *)

open Test_helpers

let test_round_trip () =
  with_temp_file "ogit" ".toml" (fun file ->
      let config =
        Ogit.Config.
          {
            user_name = "alice";
            default_branch = "main";
            git_project_root = "/srv/git";
            commits_max_displayed = 25;
            root_title = "";
            nav_logo = "/branding/logo.svg";
            host = "127.0.0.1";
            port = 9000;
            favorite_repositories = [];
            archived_repositories = [];
          }
      in
      Ogit.Config.write_file ~file (Ogit.Config.to_table config);
      match Ogit.Config.read_file ~file () with
      | Ok config' ->
          Alcotest.(check string) "user_name" config.user_name config'.user_name;
          Alcotest.(check string)
            "branch" config.default_branch config'.default_branch;
          Alcotest.(check string)
            "root" config.git_project_root config'.git_project_root;
          Alcotest.(check int)
            "commits" config.commits_max_displayed config'.commits_max_displayed;
          Alcotest.(check string) "host" config.host config'.host;
          Alcotest.(check string) "nav_logo" config.nav_logo config'.nav_logo;
          Alcotest.(check int) "port" config.port config'.port
      | Error error -> fail_config_error error)

let test_backward_compat () =
  with_temp_file "ogit" ".toml" (fun file ->
      Out_channel.with_open_text file (fun channel ->
          Printf.fprintf channel
            "default_branch = \"main\"\n\
             git_project_root = \"/srv/git\"\n\
             commits_max_displayed = 10\n\
             title = \"Legacy repositories\"\n");
      match Ogit.Config.read_file ~file () with
      | Ok config ->
          Alcotest.(check string) "default user_name" "" config.user_name;
          Alcotest.(check string)
            "legacy title" "Legacy repositories" config.root_title;
          Alcotest.(check string)
            "default nav logo" "/static/git_icon.svg" config.nav_logo;
          Alcotest.(check string) "default host" "127.0.0.1" config.host;
          Alcotest.(check int) "default port" 8081 config.port
      | Error error -> fail_config_error error)

(* Every key has a default, so a file overriding a single setting is valid;
   the untouched settings keep their defaults. *)
let test_partial_file () =
  with_temp_file "ogit-partial" ".toml" (fun file ->
      Out_channel.with_open_text file (fun channel ->
          output_string channel "port = 9999\n");
      match Ogit.Config.read_file ~file () with
      | Ok config ->
          Alcotest.(check int) "overridden port" 9999 config.port;
          Alcotest.(check string)
            "default root" Ogit.Config.default.git_project_root
            config.git_project_root;
          Alcotest.(check string)
            "default branch" Ogit.Config.default.default_branch
            config.default_branch;
          Alcotest.(check int)
            "default commits" Ogit.Config.default.commits_max_displayed
            config.commits_max_displayed
      | Error error -> fail_config_error error)

(* A key that is present with the wrong type is still an error: only absence
   falls back to the default. *)
let test_mistyped_key () =
  with_temp_file "ogit-mistyped" ".toml" (fun file ->
      Out_channel.with_open_text file (fun channel ->
          output_string channel "git_project_root = 5\n");
      match Ogit.Config.read_file ~file () with
      | Error (Ogit.Config.Invalid_value _) -> ()
      | Error error -> fail_config_error error
      | Ok _ -> Alcotest.fail "mistyped key was accepted")

let test_malformed () =
  with_temp_file "ogit-malformed" ".toml" (fun file ->
      Out_channel.with_open_text file (fun channel ->
          output_string channel "user = [\n");
      match Ogit.Config.read_file ~file () with
      | Error (Ogit.Config.Parse_error _) -> ()
      | Error error -> fail_config_error error
      | Ok _ -> Alcotest.fail "malformed configuration was accepted")

let test_invalid_value () =
  with_temp_file "ogit-invalid" ".toml" (fun file ->
      let invalid = Ogit.Config.{ default with commits_max_displayed = 0 } in
      Ogit.Config.write_file ~file (Ogit.Config.to_table invalid);
      match Ogit.Config.read_file ~file () with
      | Error (Ogit.Config.Invalid_value _) -> ()
      | Error error -> fail_config_error error
      | Ok _ -> Alcotest.fail "invalid commit limit was accepted")

let test_invalid_port_high () =
  with_temp_file "ogit-port-high" ".toml" (fun file ->
      let invalid = Ogit.Config.{ default with port = 65536 } in
      Ogit.Config.write_file ~file (Ogit.Config.to_table invalid);
      match Ogit.Config.read_file ~file () with
      | Error (Ogit.Config.Invalid_value _) -> ()
      | Error error -> fail_config_error error
      | Ok _ -> Alcotest.fail "port 65536 was accepted")

let test_invalid_port_zero () =
  with_temp_file "ogit-port-zero" ".toml" (fun file ->
      let invalid = Ogit.Config.{ default with port = 0 } in
      Ogit.Config.write_file ~file (Ogit.Config.to_table invalid);
      match Ogit.Config.read_file ~file () with
      | Error (Ogit.Config.Invalid_value _) -> ()
      | Error error -> fail_config_error error
      | Ok _ -> Alcotest.fail "port 0 was accepted")

let test_directory_rejected () =
  with_temp_directory "ogit-config-directory" (fun directory ->
      match Ogit.Config.read_file ~file:directory () with
      | Error (Ogit.Config.Io_error _) -> ()
      | Error error -> fail_config_error error
      | Ok _ -> Alcotest.fail "a directory was accepted as a config file")

let test_invalid_implicit () =
  with_temp_directory "ogit-xdg" (fun config_home ->
      let directory = Filename.concat config_home "ogit" in
      Unix.mkdir directory 0o755;
      let file = Filename.concat directory "config.toml" in
      Out_channel.with_open_text file (fun channel ->
          output_string channel "user = [\n");
      with_environment "OGIT_CONFIG" "" (fun () ->
          with_environment "XDG_CONFIG_HOME" config_home (fun () ->
              match Ogit.Config.load () with
              | Error (Ogit.Config.Parse_error _) -> ()
              | Error error -> fail_config_error error
              | Ok _ -> Alcotest.fail "invalid implicit config should fail")))

let test_explicit_missing () =
  let missing = Filename.temp_file "ogit-missing" ".toml" in
  Sys.remove missing;
  with_environment "OGIT_CONFIG" missing (fun () ->
      match Ogit.Config.load () with
      | Error (Ogit.Config.Not_found file) ->
          Alcotest.(check string) "path" missing file
      | Error error -> fail_config_error error
      | Ok _ -> Alcotest.fail "explicitly missing config should fail")

let test_location () =
  with_environment "OGIT_CONFIG" "" (fun () ->
      with_environment "XDG_CONFIG_HOME" "/tmp/xdg-config" (fun () ->
          let expected =
            Filename.concat
              (Filename.concat "/tmp/xdg-config" "ogit")
              "config.toml"
          in
          Alcotest.(check string)
            "XDG path" expected
            (Ogit.Config.locate_config_file ())));
  with_environment "OGIT_CONFIG" "/tmp/custom-ogit.toml" (fun () ->
      Alcotest.(check string)
        "explicit path" "/tmp/custom-ogit.toml"
        (Ogit.Config.locate_config_file ()))

let suite =
  ( "config",
    [
      Alcotest.test_case "round trip" `Quick test_round_trip;
      Alcotest.test_case "backward compat" `Quick test_backward_compat;
      Alcotest.test_case "partial file" `Quick test_partial_file;
      Alcotest.test_case "mistyped key" `Quick test_mistyped_key;
      Alcotest.test_case "malformed" `Quick test_malformed;
      Alcotest.test_case "invalid value" `Quick test_invalid_value;
      Alcotest.test_case "port too high" `Quick test_invalid_port_high;
      Alcotest.test_case "port zero" `Quick test_invalid_port_zero;
      Alcotest.test_case "directory rejected" `Quick test_directory_rejected;
      Alcotest.test_case "invalid implicit" `Quick test_invalid_implicit;
      Alcotest.test_case "explicit missing" `Quick test_explicit_missing;
      Alcotest.test_case "location" `Quick test_location;
    ] )