package main

import (
	"context"
	"sync"
	"time"

	tgbotapi "github.com/go-telegram-bot-api/telegram-bot-api"
)

type messageToClean struct {
	messID int
	chatID int64
	timer  *time.Timer
}

type messageCleaner struct {
	botApi   *tgbotapi.BotAPI
	wg       *sync.WaitGroup
	messages []*messageToClean
	mx       sync.Mutex
}

func newMessageCleaner(bot *tgbotapi.BotAPI, wg *sync.WaitGroup) *messageCleaner {
	return &messageCleaner{
		botApi:   bot,
		wg:       wg,
		messages: make([]*messageToClean, 0),
	}
}

func (m *messageCleaner) add(ctx context.Context, messID int, chatID int64, d time.Duration) {
	m.mx.Lock()
	defer m.mx.Unlock()

	for _, ms := range m.messages {
		if ms.chatID == chatID && ms.messID == messID {
			return
		}
	}

	m.wg.Add(1)

	go func() {
		defer m.wg.Done()

		ms := &messageToClean{
			messID: messID,
			chatID: chatID,
			timer:  time.NewTimer(d),
		}

		m.messages = append(m.messages, ms)

		select {
		case <-ms.timer.C:
		case <-ctx.Done():
		}

		m.remove(messID, chatID)

		_, _ = m.botApi.DeleteMessage(tgbotapi.DeleteMessageConfig{
			MessageID: messID,
			ChatID:    chatID,
		})
	}()
}

func (m *messageCleaner) remove(messID int, chatID int64) {
	m.mx.Lock()
	defer m.mx.Unlock()

	for i, ms := range m.messages {
		if ms.chatID == chatID && ms.messID == messID {
			m.messages = append(m.messages[:i], m.messages[i+1:]...)
			return
		}
	}
}

func (m *messageCleaner) resetTimer(messID int, chatID int64, d time.Duration) {
	m.mx.Lock()
	defer m.mx.Unlock()

	for _, ms := range m.messages {
		if ms.chatID == chatID && ms.messID == messID {
			ms.timer.Reset(d)
			return
		}
	}
}