package telegram

import (
	"fmt"

	"github.com/gotd/td/tg"
)

func extractMessages(resp tg.MessagesMessagesClass) ([]*tg.Message, error) {
	switch v := resp.(type) {
	case *tg.MessagesMessages:
		return filterMessages(v.Messages), nil
	case *tg.MessagesMessagesSlice:
		return filterMessages(v.Messages), nil
	case *tg.MessagesChannelMessages:
		return filterMessages(v.Messages), nil
	case *tg.MessagesMessagesNotModified:
		return nil, fmt.Errorf("messages not modified")
	default:
		return nil, fmt.Errorf("unsupported response type %T", resp)
	}
}

func filterMessages(values []tg.MessageClass) []*tg.Message {
	result := make([]*tg.Message, 0, len(values))
	for _, m := range values {
		if msg, ok := m.(*tg.Message); ok {
			result = append(result, msg)
		}
	}
	return result
}

func extractMessageByID(resp tg.MessagesMessagesClass, id int) (*tg.Message, error) {
	messages, err := extractMessages(resp)
	if err != nil {
		return nil, err
	}
	for _, msg := range messages {
		if msg.ID == id {
			return msg, nil
		}
	}
	return nil, fmt.Errorf("message %d not found", id)
}

func isFromBot(msg *tg.Message, botID int64) bool {
	if msg == nil || msg.Out {
		return false
	}

	if peer, ok := msg.GetPeerID().(*tg.PeerUser); ok && peer.UserID == botID {
		return true
	}

	if fromClass, ok := msg.GetFromID(); ok {
		if from, ok := fromClass.(*tg.PeerUser); ok && from.UserID == botID {
			return true
		}
	}

	return false
}