import WS from 'ws'
import * as Utils from './Utils'
import { WAMessage, WAChat, WAContact, MessageLogLevel, WANode, KEEP_ALIVE_INTERVAL_MS } from './Constants'
import {WAConnection as Base} from './1.Validation'
import Decoder from '../Binary/Decoder'

export class WAConnection extends Base {
    /**
     * Connect to WhatsAppWeb
     * @param timeoutMs timeout after which the connect will fail, set to null for an infinite timeout
     * @param waitForChats should the chats be waited for
     */
    async connect(timeoutMs: number = null, waitForChats: boolean = true) {
        // if we're already connected, throw an error
        if (this.state !== 'closed') throw new Error('cannot connect when state=' + this.state)
        
        this.state = 'connecting'
        this.emit ('connecting')

        this.conn = new WS('wss://web.whatsapp.com/ws', null, { origin: 'https://web.whatsapp.com' })

        const promise: Promise<void> = Utils.promiseTimeout(timeoutMs, (resolve, reject) => {
            this.conn.on('open', () => {
                this.log('connected to WhatsApp Web server, authenticating...', MessageLogLevel.info)
                // start sending keep alive requests (keeps the WebSocket alive & updates our last seen)
                this.authenticate()
                .then(() => {
                    this.startKeepAliveRequest()

                    this.conn.removeAllListeners ('error')
                    this.conn.removeAllListeners ('close')
                    this.conn.on ('close', () => this.unexpectedDisconnect ('closed'))

                    this.state = 'open'
                    resolve()
                })
                .catch(reject)
            })
            this.conn.on('message', m => this.onMessageRecieved(m))
            // if there was an error in the WebSocket
            this.conn.on('error', reject)
            this.conn.on('close', () => reject(new Error('closed')))
        })

        try {
            await promise
            waitForChats && await this.receiveChatsAndContacts(timeoutMs, true)

            this.phoneConnected = true
            this.state = 'open'
            
            this.user.imgUrl = await this.getProfilePicture (this.user.id).catch (err => '')
            
            this.emit ('open')

            this.releasePendingRequests ()
            this.log ('opened connection to WhatsApp Web', MessageLogLevel.info)
            return this
        } catch (error) {
            this.closeInternal (error.message)
            throw error
        }
    }
    /** Get the URL to download the profile picture of a person/group */
    async getProfilePicture(jid: string | null) {
        const response = await this.query({ json: ['query', 'ProfilePicThumb', jid || this.user.id] })
        return response.eurl as string
    }
    /**
     * Sets up callbacks to receive chats, contacts & messages.
     * Must be called immediately after connect
     * @returns [chats, contacts]
     */
    protected async receiveChatsAndContacts(timeoutMs: number = null, stopAfterMostRecentMessage: boolean=false) {
        this.contacts = {}
        this.chats.clear ()

        let receivedContacts = false
        let receivedMessages = false
        let convoResolve: () => void

        const waitForConvos = () =>
            Utils.promiseTimeout(timeoutMs, resolve => {
                convoResolve = () => {
                    // de-register the callbacks, so that they don't get called again
                    this.deregisterCallback(['action', 'add:last'])
                    if (!stopAfterMostRecentMessage) {
                        this.deregisterCallback(['action', 'add:before'])
                        this.deregisterCallback(['action', 'add:unread'])
                    }
                    resolve()
                }
                const chatUpdate = json => {
                    receivedMessages = true
                    const isLast = json[1].last || stopAfterMostRecentMessage
                    const messages = json[2] as WANode[]

                    if (messages) {
                        messages.reverse().forEach (([,, message]: ['message', null, WAMessage]) => {
                            const jid = message.key.remoteJid
                            const chat = this.chats.get(jid)
                            chat?.messages.unshift (message)
                        })
                    }
                    // if received contacts before messages
                    if (isLast && receivedContacts) convoResolve ()
                }

                // wait for actual messages to load, "last" is the most recent message, "before" contains prior messages
                this.registerCallback(['action', 'add:last'], chatUpdate)
                
                if (!stopAfterMostRecentMessage) {
                    this.registerCallback(['action', 'add:before'], chatUpdate)
                    this.registerCallback(['action', 'add:unread'], chatUpdate)
                }
            })
        const waitForChats = async () => (
            Utils.promiseTimeout (timeoutMs, resolve => {
                this.registerCallback(['response', 'type:chat'], json => {
                    if (json[1].duplicate || !json[2]) return
    
                    json[2]
                    .forEach(([item, chat]: [any, WAChat]) => {
                        if (!chat) {
                            this.log (`unexpectedly got null chat: ${item}, ${chat}`, MessageLogLevel.info)
                            return
                        }
                        chat.jid = Utils.whatsappID (chat.jid)
                        chat.t = +chat.t
                        chat.count = +chat.count
                        chat.messages = []
                        this.chats.insert (chat) // chats data (log json to see what it looks like)
                    })
                    
                    this.deregisterCallback(['response', 'type:chat'])
                    
                    this.log ('received chats list', MessageLogLevel.info)
                    
                    if (this.chats.all().length > 0) waitForConvos().then (resolve)
                    else resolve ()
                })   
            })
        )
        const waitForContacts = async () => (
            new Promise (resolve => {
                this.registerCallback(['response', 'type:contacts'], json => {
                    if (json[1].duplicate) return

                    receivedContacts = true
                    
                    json[2].forEach(([type, contact]: ['user', WAContact]) => {
                        if (!contact) return this.log (`unexpectedly got null contact: ${type}, ${contact}`, MessageLogLevel.info)
                        
                        contact.jid = Utils.whatsappID (contact.jid)
                        this.contacts[contact.jid] = contact
                    })
                    // if you receive contacts after messages
                    // should probably resolve the promise
                    if (receivedMessages) convoResolve()
                    resolve ()

                    this.deregisterCallback(['response', 'type:contacts'])

                    this.log ('received contacts list', MessageLogLevel.info)
                })
            })
        )
        // wait for the chats & contacts to load
        await Promise.all( [waitForChats(), waitForContacts()] )

        this.chats.all ().forEach (chat => {
            const respectiveContact = this.contacts[chat.jid]
            chat.title = respectiveContact?.name || respectiveContact?.notify
        })
    }
    private releasePendingRequests () {
        this.pendingRequests.forEach (({resolve}) => resolve()) // send off all pending request
        this.pendingRequests = []
    }
    private onMessageRecieved(message) {
        if (message[0] === '!') {
            // when the first character in the message is an '!', the server is updating the last seen
            const timestamp = message.slice(1, message.length)
            this.lastSeen = new Date(parseInt(timestamp))
        } else {
            const decrypted = Utils.decryptWA (message, this.authInfo.macKey, this.authInfo.encKey, new Decoder())
            if (!decrypted) {
                return
            }
            const [messageTag, json] = decrypted

            if (this.logLevel === MessageLogLevel.all) {
                this.log(messageTag + ', ' + JSON.stringify(json), MessageLogLevel.all)
            }
            /*
             Check if this is a response to a message we sent
            */
            if (this.callbacks[messageTag]) {
                const q = this.callbacks[messageTag]
                q.callback(json)
                delete this.callbacks[messageTag]
                return
            }
            /*
             Check if this is a response to a message we are expecting
            */
            if (this.callbacks['function:' + json[0]]) {
                const callbacks = this.callbacks['function:' + json[0]]
                let callbacks2
                let callback
                for (const key in json[1] || {}) {
                    callbacks2 = callbacks[key + ':' + json[1][key]]
                    if (callbacks2) {
                        break
                    }
                }
                if (!callbacks2) {
                    for (const key in json[1] || {}) {
                        callbacks2 = callbacks[key]
                        if (callbacks2) {
                            break
                        }
                    }
                }
                if (!callbacks2) {
                    callbacks2 = callbacks['']
                }
                if (callbacks2) {
                    callback = callbacks2[json[2] && json[2][0][0]]
                    if (!callback) {
                        callback = callbacks2['']
                    }
                }
                if (callback) {
                    callback(json)
                    return
                }
            }
            if (this.logLevel === MessageLogLevel.unhandled) {
                this.log('[Unhandled] ' + messageTag + ', ' + JSON.stringify(json), MessageLogLevel.unhandled)
            }
        }
    }
    /** Send a keep alive request every X seconds, server updates & responds with last seen */
    private startKeepAliveRequest() {
        this.keepAliveReq = setInterval(() => {
            const diff = (new Date().getTime() - this.lastSeen.getTime())
            /*
				check if it's been a suspicious amount of time since the server responded with our last seen
				it could be that the network is down
			*/
            if (diff > KEEP_ALIVE_INTERVAL_MS+5000) this.unexpectedDisconnect ('lost')
            else this.send ('?,,') // if its all good, send a keep alive request
        }, KEEP_ALIVE_INTERVAL_MS)
    }
    protected async reconnectLoop () {
        this.cancelledReconnect = false
        try {
            while (true) {
                const {delay, cancel} = Utils.delayCancellable (5000)
                this.cancelReconnect = cancel
                
                await delay
                try {
                    await this.connect ()
                    this.cancelReconnect = null
                    break
                } catch (error) {
                    this.log (`error in reconnecting: ${error}, reconnecting...`, MessageLogLevel.info)
                }
            }
        } catch {

        }
    }
    /**
     * Check if your phone is connected
     * @param timeoutMs max time for the phone to respond
     */
    async checkPhoneConnection(timeoutMs = 5000) {
        try {
            const response = await this.query({json: ['admin', 'test'], timeoutMs})
            return response[1] as boolean
        } catch (error) {
            return false
        }
    }
}