import { transports } from "./transports/index.js";
import { installTimerFunctions, byteLength } from "./util.js";
import { decode } from "./contrib/parseqs.js";
import { parse } from "./contrib/parseuri.js";
import debugModule from "debug"; // debug()
import { Emitter } from "@socket.io/component-emitter";
import { protocol } from "engine.io-parser";
const debug = debugModule("engine.io-client:socket"); // debug()
export class Socket extends Emitter {
    /**
     * Socket constructor.
     *
     * @param {String|Object} uri or options
     * @param {Object} opts - options
     * @api public
     */
    constructor(uri, opts = {}) {
        super();
        if (uri && "object" === typeof uri) {
            opts = uri;
            uri = null;
        }
        if (uri) {
            uri = parse(uri);
            opts.hostname = uri.host;
            opts.secure = uri.protocol === "https" || uri.protocol === "wss";
            opts.port = uri.port;
            if (uri.query)
                opts.query = uri.query;
        }
        else if (opts.host) {
            opts.hostname = parse(opts.host).host;
        }
        installTimerFunctions(this, opts);
        this.secure =
            null != opts.secure
                ? opts.secure
                : typeof location !== "undefined" && "https:" === location.protocol;
        if (opts.hostname && !opts.port) {
            // if no port is specified manually, use the protocol default
            opts.port = this.secure ? "443" : "80";
        }
        this.hostname =
            opts.hostname ||
                (typeof location !== "undefined" ? location.hostname : "localhost");
        this.port =
            opts.port ||
                (typeof location !== "undefined" && location.port
                    ? location.port
                    : this.secure
                        ? "443"
                        : "80");
        this.transports = opts.transports || ["polling", "websocket"];
        this.readyState = "";
        this.writeBuffer = [];
        this.prevBufferLen = 0;
        this.opts = Object.assign({
            path: "/engine.io",
            agent: false,
            withCredentials: false,
            upgrade: true,
            timestampParam: "t",
            rememberUpgrade: false,
            rejectUnauthorized: true,
            perMessageDeflate: {
                threshold: 1024
            },
            transportOptions: {},
            closeOnBeforeunload: true
        }, opts);
        this.opts.path = this.opts.path.replace(/\/$/, "") + "/";
        if (typeof this.opts.query === "string") {
            this.opts.query = decode(this.opts.query);
        }
        // set on handshake
        this.id = null;
        this.upgrades = null;
        this.pingInterval = null;
        this.pingTimeout = null;
        // set on heartbeat
        this.pingTimeoutTimer = null;
        if (typeof addEventListener === "function") {
            if (this.opts.closeOnBeforeunload) {
                // Firefox closes the connection when the "beforeunload" event is emitted but not Chrome. This event listener
                // ensures every browser behaves the same (no "disconnect" event at the Socket.IO level when the page is
                // closed/reloaded)
                addEventListener("beforeunload", () => {
                    if (this.transport) {
                        // silently close the transport
                        this.transport.removeAllListeners();
                        this.transport.close();
                    }
                }, false);
            }
            if (this.hostname !== "localhost") {
                this.offlineEventListener = () => {
                    this.onClose("transport close", {
                        description: "network connection lost"
                    });
                };
                addEventListener("offline", this.offlineEventListener, false);
            }
        }
        this.open();
    }
    /**
     * Creates transport of the given type.
     *
     * @param {String} transport name
     * @return {Transport}
     * @api private
     */
    createTransport(name) {
        debug('creating transport "%s"', name);
        const query = Object.assign({}, this.opts.query);
        // append engine.io protocol identifier
        query.EIO = protocol;
        // transport name
        query.transport = name;
        // session id if we already have one
        if (this.id)
            query.sid = this.id;
        const opts = Object.assign({}, this.opts.transportOptions[name], this.opts, {
            query,
            socket: this,
            hostname: this.hostname,
            secure: this.secure,
            port: this.port
        });
        debug("options: %j", opts);
        return new transports[name](opts);
    }
    /**
     * Initializes transport to use and starts probe.
     *
     * @api private
     */
    open() {
        let transport;
        if (this.opts.rememberUpgrade &&
            Socket.priorWebsocketSuccess &&
            this.transports.indexOf("websocket") !== -1) {
            transport = "websocket";
        }
        else if (0 === this.transports.length) {
            // Emit error on next tick so it can be listened to
            this.setTimeoutFn(() => {
                this.emitReserved("error", "No transports available");
            }, 0);
            return;
        }
        else {
            transport = this.transports[0];
        }
        this.readyState = "opening";
        // Retry with the next transport if the transport is disabled (jsonp: false)
        try {
            transport = this.createTransport(transport);
        }
        catch (e) {
            debug("error while creating transport: %s", e);
            this.transports.shift();
            this.open();
            return;
        }
        transport.open();
        this.setTransport(transport);
    }
    /**
     * Sets the current transport. Disables the existing one (if any).
     *
     * @api private
     */
    setTransport(transport) {
        debug("setting transport %s", transport.name);
        if (this.transport) {
            debug("clearing existing transport %s", this.transport.name);
            this.transport.removeAllListeners();
        }
        // set up transport
        this.transport = transport;
        // set up transport listeners
        transport
            .on("drain", this.onDrain.bind(this))
            .on("packet", this.onPacket.bind(this))
            .on("error", this.onError.bind(this))
            .on("close", reason => this.onClose("transport close", reason));
    }
    /**
     * Probes a transport.
     *
     * @param {String} transport name
     * @api private
     */
    probe(name) {
        debug('probing transport "%s"', name);
        let transport = this.createTransport(name);
        let failed = false;
        Socket.priorWebsocketSuccess = false;
        const onTransportOpen = () => {
            if (failed)
                return;
            debug('probe transport "%s" opened', name);
            transport.send([{ type: "ping", data: "probe" }]);
            transport.once("packet", msg => {
                if (failed)
                    return;
                if ("pong" === msg.type && "probe" === msg.data) {
                    debug('probe transport "%s" pong', name);
                    this.upgrading = true;
                    this.emitReserved("upgrading", transport);
                    if (!transport)
                        return;
                    Socket.priorWebsocketSuccess = "websocket" === transport.name;
                    debug('pausing current transport "%s"', this.transport.name);
                    this.transport.pause(() => {
                        if (failed)
                            return;
                        if ("closed" === this.readyState)
                            return;
                        debug("changing transport and sending upgrade packet");
                        cleanup();
                        this.setTransport(transport);
                        transport.send([{ type: "upgrade" }]);
                        this.emitReserved("upgrade", transport);
                        transport = null;
                        this.upgrading = false;
                        this.flush();
                    });
                }
                else {
                    debug('probe transport "%s" failed', name);
                    const err = new Error("probe error");
                    // @ts-ignore
                    err.transport = transport.name;
                    this.emitReserved("upgradeError", err);
                }
            });
        };
        function freezeTransport() {
            if (failed)
                return;
            // Any callback called by transport should be ignored since now
            failed = true;
            cleanup();
            transport.close();
            transport = null;
        }
        // Handle any error that happens while probing
        const onerror = err => {
            const error = new Error("probe error: " + err);
            // @ts-ignore
            error.transport = transport.name;
            freezeTransport();
            debug('probe transport "%s" failed because of error: %s', name, err);
            this.emitReserved("upgradeError", error);
        };
        function onTransportClose() {
            onerror("transport closed");
        }
        // When the socket is closed while we're probing
        function onclose() {
            onerror("socket closed");
        }
        // When the socket is upgraded while we're probing
        function onupgrade(to) {
            if (transport && to.name !== transport.name) {
                debug('"%s" works - aborting "%s"', to.name, transport.name);
                freezeTransport();
            }
        }
        // Remove all listeners on the transport and on self
        const cleanup = () => {
            transport.removeListener("open", onTransportOpen);
            transport.removeListener("error", onerror);
            transport.removeListener("close", onTransportClose);
            this.off("close", onclose);
            this.off("upgrading", onupgrade);
        };
        transport.once("open", onTransportOpen);
        transport.once("error", onerror);
        transport.once("close", onTransportClose);
        this.once("close", onclose);
        this.once("upgrading", onupgrade);
        transport.open();
    }
    /**
     * Called when connection is deemed open.
     *
     * @api private
     */
    onOpen() {
        debug("socket open");
        this.readyState = "open";
        Socket.priorWebsocketSuccess = "websocket" === this.transport.name;
        this.emitReserved("open");
        this.flush();
        // we check for `readyState` in case an `open`
        // listener already closed the socket
        if ("open" === this.readyState &&
            this.opts.upgrade &&
            this.transport.pause) {
            debug("starting upgrade probes");
            let i = 0;
            const l = this.upgrades.length;
            for (; i < l; i++) {
                this.probe(this.upgrades[i]);
            }
        }
    }
    /**
     * Handles a packet.
     *
     * @api private
     */
    onPacket(packet) {
        if ("opening" === this.readyState ||
            "open" === this.readyState ||
            "closing" === this.readyState) {
            debug('socket receive: type "%s", data "%s"', packet.type, packet.data);
            this.emitReserved("packet", packet);
            // Socket is live - any packet counts
            this.emitReserved("heartbeat");
            switch (packet.type) {
                case "open":
                    this.onHandshake(JSON.parse(packet.data));
                    break;
                case "ping":
                    this.resetPingTimeout();
                    this.sendPacket("pong");
                    this.emitReserved("ping");
                    this.emitReserved("pong");
                    break;
                case "error":
                    const err = new Error("server error");
                    // @ts-ignore
                    err.code = packet.data;
                    this.onError(err);
                    break;
                case "message":
                    this.emitReserved("data", packet.data);
                    this.emitReserved("message", packet.data);
                    break;
            }
        }
        else {
            debug('packet received with socket readyState "%s"', this.readyState);
        }
    }
    /**
     * Called upon handshake completion.
     *
     * @param {Object} data - handshake obj
     * @api private
     */
    onHandshake(data) {
        this.emitReserved("handshake", data);
        this.id = data.sid;
        this.transport.query.sid = data.sid;
        this.upgrades = this.filterUpgrades(data.upgrades);
        this.pingInterval = data.pingInterval;
        this.pingTimeout = data.pingTimeout;
        this.maxPayload = data.maxPayload;
        this.onOpen();
        // In case open handler closes socket
        if ("closed" === this.readyState)
            return;
        this.resetPingTimeout();
    }
    /**
     * Sets and resets ping timeout timer based on server pings.
     *
     * @api private
     */
    resetPingTimeout() {
        this.clearTimeoutFn(this.pingTimeoutTimer);
        this.pingTimeoutTimer = this.setTimeoutFn(() => {
            this.onClose("ping timeout");
        }, this.pingInterval + this.pingTimeout);
        if (this.opts.autoUnref) {
            this.pingTimeoutTimer.unref();
        }
    }
    /**
     * Called on `drain` event
     *
     * @api private
     */
    onDrain() {
        this.writeBuffer.splice(0, this.prevBufferLen);
        // setting prevBufferLen = 0 is very important
        // for example, when upgrading, upgrade packet is sent over,
        // and a nonzero prevBufferLen could cause problems on `drain`
        this.prevBufferLen = 0;
        if (0 === this.writeBuffer.length) {
            this.emitReserved("drain");
        }
        else {
            this.flush();
        }
    }
    /**
     * Flush write buffers.
     *
     * @api private
     */
    flush() {
        if ("closed" !== this.readyState &&
            this.transport.writable &&
            !this.upgrading &&
            this.writeBuffer.length) {
            const packets = this.getWritablePackets();
            debug("flushing %d packets in socket", packets.length);
            this.transport.send(packets);
            // keep track of current length of writeBuffer
            // splice writeBuffer and callbackBuffer on `drain`
            this.prevBufferLen = packets.length;
            this.emitReserved("flush");
        }
    }
    /**
     * Ensure the encoded size of the writeBuffer is below the maxPayload value sent by the server (only for HTTP
     * long-polling)
     *
     * @private
     */
    getWritablePackets() {
        const shouldCheckPayloadSize = this.maxPayload &&
            this.transport.name === "polling" &&
            this.writeBuffer.length > 1;
        if (!shouldCheckPayloadSize) {
            return this.writeBuffer;
        }
        let payloadSize = 1; // first packet type
        for (let i = 0; i < this.writeBuffer.length; i++) {
            const data = this.writeBuffer[i].data;
            if (data) {
                payloadSize += byteLength(data);
            }
            if (i > 0 && payloadSize > this.maxPayload) {
                debug("only send %d out of %d packets", i, this.writeBuffer.length);
                return this.writeBuffer.slice(0, i);
            }
            payloadSize += 2; // separator + packet type
        }
        debug("payload size is %d (max: %d)", payloadSize, this.maxPayload);
        return this.writeBuffer;
    }
    /**
     * Sends a message.
     *
     * @param {String} message.
     * @param {Function} callback function.
     * @param {Object} options.
     * @return {Socket} for chaining.
     * @api public
     */
    write(msg, options, fn) {
        this.sendPacket("message", msg, options, fn);
        return this;
    }
    send(msg, options, fn) {
        this.sendPacket("message", msg, options, fn);
        return this;
    }
    /**
     * Sends a packet.
     *
     * @param {String} packet type.
     * @param {String} data.
     * @param {Object} options.
     * @param {Function} callback function.
     * @api private
     */
    sendPacket(type, data, options, fn) {
        if ("function" === typeof data) {
            fn = data;
            data = undefined;
        }
        if ("function" === typeof options) {
            fn = options;
            options = null;
        }
        if ("closing" === this.readyState || "closed" === this.readyState) {
            return;
        }
        options = options || {};
        options.compress = false !== options.compress;
        const packet = {
            type: type,
            data: data,
            options: options
        };
        this.emitReserved("packetCreate", packet);
        this.writeBuffer.push(packet);
        if (fn)
            this.once("flush", fn);
        this.flush();
    }
    /**
     * Closes the connection.
     *
     * @api public
     */
    close() {
        const close = () => {
            this.onClose("forced close");
            debug("socket closing - telling transport to close");
            this.transport.close();
        };
        const cleanupAndClose = () => {
            this.off("upgrade", cleanupAndClose);
            this.off("upgradeError", cleanupAndClose);
            close();
        };
        const waitForUpgrade = () => {
            // wait for upgrade to finish since we can't send packets while pausing a transport
            this.once("upgrade", cleanupAndClose);
            this.once("upgradeError", cleanupAndClose);
        };
        if ("opening" === this.readyState || "open" === this.readyState) {
            this.readyState = "closing";
            if (this.writeBuffer.length) {
                this.once("drain", () => {
                    if (this.upgrading) {
                        waitForUpgrade();
                    }
                    else {
                        close();
                    }
                });
            }
            else if (this.upgrading) {
                waitForUpgrade();
            }
            else {
                close();
            }
        }
        return this;
    }
    /**
     * Called upon transport error
     *
     * @api private
     */
    onError(err) {
        debug("socket error %j", err);
        Socket.priorWebsocketSuccess = false;
        this.emitReserved("error", err);
        this.onClose("transport error", err);
    }
    /**
     * Called upon transport close.
     *
     * @api private
     */
    onClose(reason, description) {
        if ("opening" === this.readyState ||
            "open" === this.readyState ||
            "closing" === this.readyState) {
            debug('socket close with reason: "%s"', reason);
            // clear timers
            this.clearTimeoutFn(this.pingTimeoutTimer);
            // stop event from firing again for transport
            this.transport.removeAllListeners("close");
            // ensure transport won't stay open
            this.transport.close();
            // ignore further transport communication
            this.transport.removeAllListeners();
            if (typeof removeEventListener === "function") {
                removeEventListener("offline", this.offlineEventListener, false);
            }
            // set ready state
            this.readyState = "closed";
            // clear session id
            this.id = null;
            // emit close event
            this.emitReserved("close", reason, description);
            // clean buffers after, so users can still
            // grab the buffers on `close` event
            this.writeBuffer = [];
            this.prevBufferLen = 0;
        }
    }
    /**
     * Filters upgrades, returning only those matching client transports.
     *
     * @param {Array} server upgrades
     * @api private
     *
     */
    filterUpgrades(upgrades) {
        const filteredUpgrades = [];
        let i = 0;
        const j = upgrades.length;
        for (; i < j; i++) {
            if (~this.transports.indexOf(upgrades[i]))
                filteredUpgrades.push(upgrades[i]);
        }
        return filteredUpgrades;
    }
}
Socket.protocol = protocol;
