defmodule BearCli.CLITest do
  use ExUnit.Case, async: false

  alias BearCli.CLI

  setup do
    old_creds = System.get_env("BEAR_CREDENTIALS")

    on_exit(fn ->
      restore_env("BEAR_CREDENTIALS", old_creds)
    end)

    :ok
  end

  describe "parse/1" do
    test "no args -> help" do
      assert {:help, %{}} = CLI.parse([])
    end

    test "--version" do
      assert {:version, %{}} = CLI.parse(["--version"])
    end

    test "-h alias -> help" do
      assert {:help, %{}} = CLI.parse(["-h"])
    end

    test "login --token X" do
      assert {:ok, :login, %{token: "X"}} = CLI.parse(["login", "--token", "X"])
    end

    test "global option before command" do
      assert {:ok, :whoami, %{json: true}} = CLI.parse(["--json", "whoami"])
    end

    test "global option after command" do
      assert {:ok, :status, %{json: true}} = CLI.parse(["status", "--json"])
    end

    test "token --refresh" do
      assert {:ok, :token, %{refresh: true}} = CLI.parse(["token", "--refresh"])
    end

    test "issuer flag is captured" do
      assert {:ok, :whoami, %{issuer: "https://x"}} =
               CLI.parse(["whoami", "--issuer", "https://x"])
    end

    test "unknown command -> usage error" do
      assert {:error, _, 2} = CLI.parse(["frobnicate"])
    end

    test "unknown option -> usage error" do
      assert {:error, _, 2} = CLI.parse(["--bogus"])
    end
  end

  describe "dispatch/2 (injected api)" do
    test "login --token writes credentials and prints email" do
      path = tmp_path()
      on_exit(fn -> File.rm(path) end)
      System.put_env("BEAR_CREDENTIALS", path)

      {code, out} =
        ExUnit.CaptureIO.with_io(fn ->
          CLI.dispatch(CLI.parse(["login", "--token", "good"]), api: fake_api())
        end)

      assert code == 0
      assert out =~ "已登入：alice@example.com"
      assert {:ok, %{"access_token" => "good"}} = BearCli.Credentials.load(path)
    end

    test "login with invalid token exits 1" do
      System.put_env("BEAR_CREDENTIALS", tmp_path())

      {code, err} =
        ExUnit.CaptureIO.with_io(
          :stderr,
          "",
          fn -> CLI.dispatch(CLI.parse(["login", "--token", "bad"]), api: fake_api()) end
        )

      assert code == 1
      assert err =~ "token 無效"
    end

    test "login without --token points to Device Flow being unavailable" do
      System.put_env("BEAR_CREDENTIALS", tmp_path())

      {code, err} =
        ExUnit.CaptureIO.with_io(
          :stderr,
          "",
          fn -> CLI.dispatch(CLI.parse(["login"]), api: fake_api()) end
        )

      assert code == 2
      assert err =~ "Device Flow"
    end

    test "whoami when not logged in exits 3" do
      System.put_env("BEAR_CREDENTIALS", "/nonexistent/credentials.json")

      {code, err} =
        ExUnit.CaptureIO.with_io(
          :stderr,
          "",
          fn -> CLI.dispatch(CLI.parse(["whoami"]), api: fake_api()) end
        )

      assert code == 3
      assert err =~ "未登入"
    end

    test "whoami prints claims" do
      path = tmp_path()
      on_exit(fn -> File.rm(path) end)
      System.put_env("BEAR_CREDENTIALS", path)
      BearCli.Credentials.save(%{"issuer" => "https://x", "access_token" => "good"}, path)

      {code, out} =
        ExUnit.CaptureIO.with_io(fn ->
          CLI.dispatch(CLI.parse(["whoami"]), api: fake_api())
        end)

      assert code == 0
      assert out =~ "email"
      assert out =~ "alice@example.com"
    end

    test "token prints only the token" do
      path = tmp_path()
      on_exit(fn -> File.rm(path) end)
      System.put_env("BEAR_CREDENTIALS", path)
      BearCli.Credentials.save(%{"issuer" => "https://x", "access_token" => "good-token"}, path)

      {code, out} =
        ExUnit.CaptureIO.with_io(fn ->
          CLI.dispatch(CLI.parse(["token"]), api: fake_api())
        end)

      assert code == 0
      assert String.trim(out) == "good-token"
    end

    test "status when logged in exits 0 and reports PAT mode" do
      path = tmp_path()
      on_exit(fn -> File.rm(path) end)
      System.put_env("BEAR_CREDENTIALS", path)

      BearCli.Credentials.save(
        %{"issuer" => "https://x", "email" => "a@b.c", "access_token" => "t"},
        path
      )

      {code, out} =
        ExUnit.CaptureIO.with_io(fn ->
          CLI.dispatch(CLI.parse(["status"]), api: fake_api())
        end)

      assert code == 0
      assert out =~ "已登入：a@b.c"
      assert out =~ "PAT"
    end

    test "logout clears credentials" do
      path = tmp_path()
      on_exit(fn -> File.rm(path) end)
      System.put_env("BEAR_CREDENTIALS", path)
      BearCli.Credentials.save(%{"issuer" => "https://x", "access_token" => "t"}, path)

      {code, _out} =
        ExUnit.CaptureIO.with_io(fn ->
          CLI.dispatch(CLI.parse(["logout"]), api: fake_api())
        end)

      assert code == 0
      assert :error == BearCli.Credentials.load(path)
    end
  end

  defp fake_api do
    fn _issuer, token ->
      case token do
        "good" -> {:ok, %{"sub" => "u1", "email" => "alice@example.com", "name" => "Alice"}}
        "bad" -> {:error, :unauthorized, "invalid_token"}
        _ -> {:error, :server_error, 500}
      end
    end
  end

  defp tmp_path do
    Path.join(System.tmp_dir!(), "bear_cli_cli_#{System.unique_integer([:positive])}.json")
  end

  defp restore_env(key, nil), do: System.delete_env(key)
  defp restore_env(key, value), do: System.put_env(key, value)
end