'use strict';

var TextMessageFormat = require('./TextMessageFormat.js');
var Utils = require('./Utils.js');

// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
/** @private */
class HandshakeProtocol {
    // Handshake request is always JSON
    writeHandshakeRequest(handshakeRequest) {
        return TextMessageFormat.TextMessageFormat.write(JSON.stringify(handshakeRequest));
    }
    parseHandshakeResponse(data) {
        let messageData;
        let remainingData;
        if (Utils.isArrayBuffer(data)) {
            // Format is binary but still need to read JSON text from handshake response
            const binaryData = new Uint8Array(data);
            const separatorIndex = binaryData.indexOf(TextMessageFormat.TextMessageFormat.RecordSeparatorCode);
            if (separatorIndex === -1) {
                throw new Error("Message is incomplete.");
            }
            // content before separator is handshake response
            // optional content after is additional messages
            const responseLength = separatorIndex + 1;
            messageData = String.fromCharCode.apply(null, Array.prototype.slice.call(binaryData.slice(0, responseLength)));
            remainingData = (binaryData.byteLength > responseLength) ? binaryData.slice(responseLength).buffer : null;
        }
        else {
            const textData = data;
            const separatorIndex = textData.indexOf(TextMessageFormat.TextMessageFormat.RecordSeparator);
            if (separatorIndex === -1) {
                throw new Error("Message is incomplete.");
            }
            // content before separator is handshake response
            // optional content after is additional messages
            const responseLength = separatorIndex + 1;
            messageData = textData.substring(0, responseLength);
            remainingData = (textData.length > responseLength) ? textData.substring(responseLength) : null;
        }
        // At this point we should have just the single handshake message
        const messages = TextMessageFormat.TextMessageFormat.parse(messageData);
        const response = JSON.parse(messages[0]);
        if (response.type) {
            throw new Error("Expected a handshake response from the server.");
        }
        const responseMessage = response;
        // multiple messages could have arrived with handshake
        // return additional data to be parsed as usual, or null if all parsed
        return [remainingData, responseMessage];
    }
}

exports.HandshakeProtocol = HandshakeProtocol;
//# sourceMappingURL=HandshakeProtocol.js.map
