package bot

import (
	"context"
	"errors"
	"net"
	"testing"
	"time"

	iptest "git.faercol.me/faercol/public-ip-tracker/tracker/ip/test"
	"github.com/ahugues/go-telegram-api/structs"
)

const expectedChatID = 42

// Need to mock the telegram bot, because no mock is provided by my own lib, what a shame.
type mockTGBot struct {
	SendMessageProp error
	SendMessageFunc func(context.Context, int64, string) error
}

// Do nothing here, it's not used by this bot
func (mb *mockTGBot) GetMe(ctx context.Context) (structs.User, error) {
	return structs.User{}, nil
}

func (mb *mockTGBot) SendMessage(ctx context.Context, chatID int64, content string) error {
	if mb.SendMessageFunc == nil {
		return mb.SendMessageProp
	}
	return mb.SendMessageFunc(ctx, chatID, content)
}

func TestInit(t *testing.T) {
	t.Parallel()

	ctx, cancel := context.WithCancel(context.Background())
	called := false

	tgBot := mockTGBot{
		SendMessageFunc: func(ctx context.Context, chatID int64, content string) error {
			if chatID != expectedChatID {
				t.Errorf("Unexpected chatID %d", chatID)
			}
			if content != "Public IP tracker initialized at 2023-01-28 14:17:12 +0000 UTC, public IP is 198.51.100.42" {
				t.Errorf("Unexpected message %s", content)
			}
			called = true
			return nil
		},
	}

	ipGetter := iptest.TestIPGetter{
		PublicIPProp: net.ParseIP("198.51.100.42"),
	}

	bot := Notifier{
		ctx:        ctx,
		cancel:     cancel,
		tgBot:      &tgBot,
		tgChatID:   expectedChatID,
		timeGetter: func() time.Time { return time.Date(2023, 1, 28, 14, 17, 12, 0, time.UTC) },
		ipGetter:   &ipGetter,
		frequency:  1 * time.Minute,
	}

	if err := bot.SendInitMessage(); err != nil {
		t.Fatalf("Unexpected error %s", err.Error())
	}
	if !called {
		t.Error("Telegram bot not called")
	}
}

func TestUpdateIP(t *testing.T) {
	t.Parallel()

	ctx, cancel := context.WithCancel(context.Background())
	called := false

	tgBot := mockTGBot{
		SendMessageFunc: func(ctx context.Context, chatID int64, content string) error {
			if chatID != expectedChatID {
				t.Errorf("Unexpected chatID %d", chatID)
			}
			if content != "Public IP has been changed, is now 198.51.100.42" {
				t.Errorf("Unexpected message %s", content)
			}
			called = true
			return nil
		},
	}

	ipGetter := iptest.TestIPGetter{
		PublicIPProp: net.ParseIP("198.51.100.42"),
	}

	bot := Notifier{
		ctx:        ctx,
		cancel:     cancel,
		tgBot:      &tgBot,
		tgChatID:   expectedChatID,
		timeGetter: func() time.Time { return time.Date(2023, 1, 28, 14, 17, 12, 0, time.UTC) },
		currentIP:  net.ParseIP("198.51.100.12"),
		exitChan:   make(chan struct{}, 1),
		errChan:    make(chan error, 5),
		ipGetter:   &ipGetter,
		frequency:  500 * time.Millisecond,
	}

	go bot.Run()

	select {
	case <-bot.Exit():
		t.Error("Unexpected exit")
	case <-time.After(1 * time.Second):
		break
	}

	cancel()

	select {
	case <-bot.Exit():
		break
	case <-time.After(2 * time.Second):
		t.Error("Unexpected timeout")
	}

	select {
	case err := <-bot.ErrChan():
		t.Errorf("Unexpected error %s", err.Error())
	default:
		break
	}

	if !called {
		t.Error("Telegram bot not called")
	}
}

func TestUpdateIPNoChange(t *testing.T) {
	t.Parallel()

	ctx, cancel := context.WithCancel(context.Background())

	tgBot := mockTGBot{
		SendMessageProp: errors.New("should not be called"),
	}

	ipGetter := iptest.TestIPGetter{
		PublicIPProp: net.ParseIP("198.51.100.42"),
	}

	bot := Notifier{
		ctx:        ctx,
		cancel:     cancel,
		tgBot:      &tgBot,
		tgChatID:   expectedChatID,
		timeGetter: func() time.Time { return time.Date(2023, 1, 28, 14, 17, 12, 0, time.UTC) },
		currentIP:  net.ParseIP("198.51.100.42"),
		exitChan:   make(chan struct{}, 1),
		errChan:    make(chan error, 5),
		ipGetter:   &ipGetter,
		frequency:  100 * time.Millisecond,
	}

	go bot.Run()

	select {
	case <-bot.Exit():
		t.Error("Unexpected exit")
	case <-time.After(500 * time.Millisecond):
		break
	}

	cancel()

	select {
	case <-bot.Exit():
		break
	case <-time.After(2 * time.Second):
		t.Error("Unexpected timeout")
	}

	select {
	case err := <-bot.ErrChan():
		t.Errorf("Unexpected error %s", err.Error())
	default:
		break
	}
}