import { Pipe, PipeTransform } from '@angular/core';

import { ChatMessage } from '../store/entities';

function translate(messages: ChatMessage[], count: number = 15) {

    return messages.filter((m, i) => i >= messages.length - count);

}

@Pipe({
    name: 'chatMessageFilter'
})
export class ChatMessageFilterPipe implements PipeTransform {
    public transform(messages: ChatMessage[], args: number[]): ChatMessage[] {
        return translate(messages, args && args.length ? args[0] : 15);
    }
}