import PubNub from 'pubnub'

/** 
 * Provider method holder
 * We always reference this object so
 * we don't have to hardcode provider specific
 * methods for doing chat things.
 * 
 * This gets overloaded later in the program
 */
const providerMethods = {
    publish: () => console.error('no provider publish method set'),
    subscribe: () => console.error('no provider subscribe method set'),
    listen: () => console.error('no provider listen method set')
}

/** 
 * Breaking out as much pubnub specific flavor
 */
const setupPubnub = async uuid => {
    if(!uuid) return console.error('no pubnub uuid set')
    
    const pubnubClient = await new PubNub({
        publishKey: import.meta.env.VITE_PUBNUB_PUBLISH_KEY,
        subscribeKey: import.meta.env.VITE_PUBNUB_SUBSCRIBE_KEY,
        uuid
    })
    // Pass pubnub specific methods to our placeholder obj
    providerMethods['publish'] = pubnubClient.publish
    providerMethods['subscribe'] = pubnubClient.subscribe
    providerMethods['listen'] = pubnubClient.addListener

    return pubnubClient
}


class ChatMessage {
    constructor({ title, description }) {
        this.title = title,
        this.description = description
    }
}

const testMessage = new ChatMessage({
    title: "testing",
    description: "hello world!",
})
const MAIN_CHANNEL = 'hello_world'

/** Singleton that holds all our chat information */
class Chatter {
    /**
     * Create our chatter instance
     * @return {Chatter} our chatter instance object
     */
    constructor() {
        // Map of each active chat
        this.groupings = {}

        // Our pubnub instance
        this.provider = null

        // UUID used to identify unique users
        this.uuid = null

        // Setup the main channel
        this.subscriptions = [MAIN_CHANNEL]
        this.listeners = {
            status: async e => {
                if (e.category !== "PNConnectedCategory") return
                await this.publish(this.subscriptions[0], testMessage)
            },
            message: this._onMessage,
            presence: this._onPresence
        }
    }
    /**
     * Callback that fires on every message
     * @param {event} e
     */
    async _onMessage(e) {
        console.log(e.message.title)
        console.log(e.message.description)
    }
    async _onPresence(e) {
        return
    }
    async setup(uuid) {
        this.uuid = uuid
        this.provider = await setupPubnub(this.uuid)

        this._listenFor({ listeners: this.listeners })
        this._subscribe(this.subscriptions)
    }
    /**
     * Send a message to a channel
     * example = new ChatMessage({ title: 'example', description: 'ni' })
     * Facade so we can hide provider specific methods
     * @param {string} channel
     * @param {ChatMessage} message
     * @return {object} timestamp
     */
    async publish(channel, message) {
        return await providerMethods['publish']({ channel, message })
    }
    /** 
     * Subscribe to a channels
     * Facade so we can hide provider specific methods
     * @param {array} channels
    */
    _subscribe(channels) {
        providerMethods['subscribe']({ channels })
    }
    /** 
     * Listen to events and set callbacks
     * Facade so we can hide provider specific methods
    */
    _listenFor({ listeners }) {
        providerMethods['listen'](listeners)
    }
}

export { Chatter }