import { GetGroupChatData } from './GetGroupChatData';
import { MessengerFriend } from './MessengerFriend';
import { MessengerGroupType } from './MessengerGroupType';
import { MessengerThreadChat } from './MessengerThreadChat';
import { MessengerThreadChatGroup } from './MessengerThreadChatGroup';

export class MessengerThread
{
    public static MESSAGE_RECEIVED: string = 'MT_MESSAGE_RECEIVED';
    public static THREAD_ID: number = 0;
    private static MAX_CHATS: number = 250;

    private _threadId: number;
    private _participant: MessengerFriend;
    private _groups: MessengerThreadChatGroup[];
    private _lastUpdated: Date;
    private _unreadCount: number;

    constructor(participant: MessengerFriend)
    {
        this._threadId = ++MessengerThread.THREAD_ID;
        this._participant = participant;
        this._groups = [];
        this._lastUpdated = new Date();
        this._unreadCount = 0;
    }

    public addMessage(senderId: number, message: string, secondsSinceSent: number = 0, extraData: string = null, type: number = 0): MessengerThreadChat
    {
        const isGroupChat = (senderId < 0 && extraData);
        const userId = isGroupChat ? GetGroupChatData(extraData).userId : senderId;

        const group = this.getLastGroup(userId);

        if(!group) return;

        if(isGroupChat) group.type = MessengerGroupType.GROUP_CHAT;

        const chat = new MessengerThreadChat(senderId, message, secondsSinceSent, extraData, type);

        group.addChat(chat);
        this.pruneChats();

        this._lastUpdated = new Date();

        this._unreadCount++;

        return chat;
    }

    public getChat(chatId: number): MessengerThreadChat
    {
        for(const group of this._groups)
        {
            const chat = group.chats.find(existingChat => (existingChat.id === chatId));

            if(chat) return chat;
        }

        return null;
    }

    private pruneChats(): void
    {
        let totalChats = this._groups.reduce((total, current) => (total + current.chats.length), 0);

        while(totalChats > MessengerThread.MAX_CHATS)
        {
            const firstGroup = this._groups[0];

            if(!firstGroup) break;

            if(firstGroup.chats.length) firstGroup.chats.shift();

            if(!firstGroup.chats.length)
            {
                this._groups.shift();
            }

            totalChats--;
        }
    }

    private getLastGroup(userId: number): MessengerThreadChatGroup
    {
        let group = this._groups[(this._groups.length - 1)];

        if(group && (group.userId === userId)) return group;

        group = new MessengerThreadChatGroup(userId);

        this._groups.push(group);

        return group;
    }

    public setRead(): void
    {
        this._unreadCount = 0;
    }

    public setMessagesReadFromUser(userId: number): void
    {
        for(const group of this._groups)
        {
            if(group.userId !== userId) continue;

            for(const chat of group.chats) chat.setStatus(MessengerThreadChat.READ);
        }
    }

    public get threadId(): number
    {
        return this._threadId;
    }

    public get participant(): MessengerFriend
    {
        return this._participant;
    }

    public get groups(): MessengerThreadChatGroup[]
    {
        return this._groups;
    }

    public get lastUpdated(): Date
    {
        return this._lastUpdated;
    }

    public get unreadCount(): number
    {
        return this._unreadCount;
    }

    public get unread(): boolean
    {
        return (this._unreadCount > 0);
    }
}