package domain

import (
	"fmt"

	"github.com/google/uuid"
)

type Channel struct {
	ID           uuid.UUID
	TelegramID   int64
	Username     string
	Title        string
	AccessHash   int64
	Pts          int
	InviteLink   string
	IsAccessible bool
}

const channelIDOffset int64 = 1000000000000

// ChannelID returns the positive channel identifier expected by Telegram API.
func (c Channel) ChannelID() int64 {
	return ChannelIDFromChatID(c.TelegramID)
}

// ChannelIDFromChatID converts stored chat IDs (Bot API style) to channel IDs used by TDLib.
func ChannelIDFromChatID(chatID int64) int64 {
	if chatID >= 0 {
		return chatID
	}

	return -chatID - channelIDOffset
}

// ChatIDFromChannelID converts Telegram channel IDs to Bot API style chat IDs (-100...).
func ChatIDFromChannelID(channelID int64) int64 {
	return -channelIDOffset - channelID
}

// NormalizeChatID ensures that TelegramID is stored in chat-id form (negative).
func NormalizeChatID(id int64) int64 {
	if id < 0 {
		return id
	}

	return ChatIDFromChannelID(id)
}

func (c Channel) String() string {
	return fmt.Sprintf(
		"Channel{id=%s telegram_id=%d username=%q title=%q access_hash=%d pts=%d invite_link=%t}",
		c.ID,
		c.TelegramID,
		c.Username,
		c.Title,
		c.AccessHash,
		c.Pts,
		c.InviteLink != "",
	)
}

type ChannelDiff struct {
	NewPts         int
	NewPosts       []Post
	DeletedPosts   []Post
	UpdatedChannel *Channel
}