export class Messages {
	constructor() {
		this.channels = {};
	}

	inChannel(channel) {
		return this.channels[channel] = (this.channels[channel] || []);
	}

	addMessage(channel, id, at, sender, body) {
		this.updateChannel(channel, (messages) => [...messages, { id, at, sender, body }]);
		return this;
	}

	setMessages(messages) {
		this.channels = {};
		for (let { channel, id, at, sender, body } of messages) {
			this.inChannel(channel).push({ id, at, sender, body, });
		}
		for (let channel in this.channels) {
			this.channels[channel].sort((a, b) => a.at - b.at);
		}
		return this;
	}


	deleteMessage(message) {
		for (let channel in this.channels) {
			this.updateChannel(channel, (messages) => messages.filter((msg) => msg.id != message));
		}
		return this;
	}

	deleteChannel(id) {
		delete this.channels[id];
		return this;
	}

	updateChannel(channel, callback) {
		let messages = callback(this.inChannel(channel));
		messages.sort((a, b) => a.at - b.at);
		this.channels[channel] = messages;
	}
}