package main

import (
	"errors"
	"testing"

	"go.uber.org/fx"
)

// errTestHook is the error returned by the test hooks that fail.
var errTestHook = errors.New("test hook failed")

// TestRunAppExitCode checks the exit code runApp returns: the one a
// shutdown request carries, 0 for a request without one (as for SIGINT or
// SIGTERM), and 1 when the app fails to start or to stop.
func TestRunAppExitCode(t *testing.T) {
	t.Parallel()

	cases := []struct {
		name string
		hook func(shutdowner fx.Shutdowner) fx.Hook
		want int
	}{
		{
			name: "shutdown requested with exit code 1",
			hook: func(shutdowner fx.Shutdowner) fx.Hook {
				return fx.StartHook(func() error {
					return shutdowner.Shutdown(fx.ExitCode(1))
				})
			},
			want: 1,
		},
		{
			name: "shutdown requested without an exit code",
			hook: func(shutdowner fx.Shutdowner) fx.Hook {
				return fx.StartHook(func() error {
					return shutdowner.Shutdown()
				})
			},
			want: 0,
		},
		{
			name: "start fails",
			hook: func(fx.Shutdowner) fx.Hook {
				return fx.StartHook(func() error { return errTestHook })
			},
			want: 1,
		},
		{
			name: "stop fails",
			hook: func(shutdowner fx.Shutdowner) fx.Hook {
				return fx.StartStopHook(
					func() error { return shutdowner.Shutdown() },
					func() error { return errTestHook },
				)
			},
			want: 1,
		},
	}

	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			t.Parallel()

			app := fx.New(
				fx.NopLogger,
				fx.Invoke(func(lc fx.Lifecycle, shutdowner fx.Shutdowner) {
					lc.Append(tc.hook(shutdowner))
				}),
			)

			got := runApp(app)
			t.Logf("runApp() = %d", got)

			if got != tc.want {
				t.Errorf("runApp() = %d, want %d", got, tc.want)
			}
		})
	}
}