import { writable } from "svelte/store";
import gateway, { GatewayEventType } from "./gateway";

class Store {
    constructor() {
        this._handlers = [];
    }

    subscribe(handler) {
        const newLength = this._handlers.push(handler);
        const handlerIndex = newLength - 1;
        handler(this.value);
        return () => {
            this._handlers.splice(handlerIndex, 1);
        };
    }

    updated() {
        this._handlers.forEach(e => {
            e(this.value);
        });
    }
}

class ChannelsStore extends Store {
    constructor() {
        super();

        this.value = gateway.channels || [];

        gateway.subscribe(GatewayEventType.Ready, ({ channels }) => {
            this.value = channels;
            this.updated();
        });
        gateway.subscribe(GatewayEventType.ChannelCreate, (channel) => {
            this.value.push(channel);
            this.updated();
        });
        gateway.subscribe(GatewayEventType.ChannelDelete, ({ id }) => {
            const index = this.value.findIndex(e => e.id === id);
            if (index === -1)
                return;

            this.value.splice(index, 1);
            this.updated();
        });
        gateway.subscribe(GatewayEventType.ChannelUpdate, (data) => {
            const index = this.value.findIndex(e => e.id === data.id);
            if (index === -1)
                return;
            if (!this.value[index])
                return;

            this.value[index] = data;
            this.updated();
        });
    }
}

class GatewayStatusStore extends Store {
    constructor() {
        super();
        this.value = { open: gateway.open, ready: gateway.authenticated };

        gateway.subscribe(GatewayEventType.Open, () => {
            this.value.open = true;
            this.updated();
        });

        gateway.subscribe(GatewayEventType.Close, () => {
            this.value.open = false;
            this.value.ready = false;
            this.updated();
        });

        gateway.subscribe(GatewayEventType.Ready, () => {
            this.value.ready = true;
            this.updated();
        });
    }
}

export const channels = new ChannelsStore();
export const gatewayStatus = new GatewayStatusStore();
export const selectedChannel = writable({ id: -1, name: "none", creator_id: -1 });