// HWS API Gateway Signature
(function (root, factory) {
    "use strict";

    /*global define*/
    if (typeof define === 'function' && define.amd) {
        // AMD
        define(['CryptoJS'], function (CryptoJS) {
            var crypto_wrapper = {
                hmacsha256: function (keyByte, message) {
                    return CryptoJS.HmacSHA256(message, keyByte).toString(CryptoJS.enc.Hex)
                },
                HexEncodeSHA256Hash: function (body) {
                    return CryptoJS.SHA256(body)
                }
            };
            return factory(crypto_wrapper)
        });
    } else if (typeof wx === 'object') {
        // wechat
        var CryptoJS = require('./js/hmac-sha256.js');
        var crypto_wrapper = {
            hmacsha256: function (keyByte, message) {
                return CryptoJS.HmacSHA256(message, keyByte).toString(CryptoJS.enc.Hex)
            },
            HexEncodeSHA256Hash: function (body) {
                return CryptoJS.SHA256(body)
            }
        };
        module.exports = factory(crypto_wrapper);
    } else if (typeof module === 'object' && module.exports) {
        // Node
        var crypto = require('crypto');
        var crypto_wrapper = {
            hmacsha256: function (keyByte, message) {
                return crypto.createHmac('SHA256', keyByte).update(message).digest().toString('hex')
            },
            HexEncodeSHA256Hash: function (body) {
                return crypto.createHash('SHA256').update(body).digest().toString('hex')
            }
        };
        module.exports = factory(crypto_wrapper);
    } else {
        // Browser
        var CryptoJS = root.CryptoJS
        var crypto_wrapper = {
            hmacsha256: function (keyByte, message) {
                return CryptoJS.HmacSHA256(message, keyByte).toString(CryptoJS.enc.Hex)
            },
            HexEncodeSHA256Hash: function (body) {
                return CryptoJS.SHA256(body)
            }
        };
        root.signer = factory(crypto_wrapper);
    }
}(this, function (crypto_wrapper) {
    'use strict';

    var Algorithm = "SDK-HMAC-SHA256";
    var HeaderXDate = "X-Sdk-Date";
    var HeaderAuthorization = "Authorization";
    var HeaderContentSha256 = "x-sdk-content-sha256";

    const hexTable = new Array(256);
    for (var i = 0; i < 256; ++i)
        hexTable[i] = '%' + ((i < 16 ? '0' : '') + i.toString(16)).toUpperCase();

    const noEscape = [
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 0 - 15
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 16 - 31
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, // 32 - 47
        1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, // 48 - 63
        0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, // 64 - 79
        1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, // 80 - 95
        0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, // 96 - 111
        1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 0  // 112 - 127
    ];

    // function urlEncode is based on https://github.com/nodejs/node/blob/master/lib/querystring.js
    // Copyright Joyent, Inc. and other Node contributors.
    function urlEncode(str) {
        if (typeof str !== 'string') {
            if (typeof str === 'object')
                str = String(str);
            else
                str += '';
        }
        var out = '';
        var lastPos = 0;

        for (var i = 0; i < str.length; ++i) {
            var c = str.charCodeAt(i);

            // ASCII
            if (c < 0x80) {
                if (noEscape[c] === 1)
                    continue;
                if (lastPos < i)
                    out += str.slice(lastPos, i);
                lastPos = i + 1;
                out += hexTable[c];
                continue;
            }

            if (lastPos < i)
                out += str.slice(lastPos, i);

            // Multi-byte characters ...
            if (c < 0x800) {
                lastPos = i + 1;
                out += hexTable[0xC0 | (c >> 6)] + hexTable[0x80 | (c & 0x3F)];
                continue;
            }
            if (c < 0xD800 || c >= 0xE000) {
                lastPos = i + 1;
                out += hexTable[0xE0 | (c >> 12)] +
                    hexTable[0x80 | ((c >> 6) & 0x3F)] +
                    hexTable[0x80 | (c & 0x3F)];
                continue;
            }
            // Surrogate pair
            ++i;

            if (i >= str.length)
                throw new errors.URIError('ERR_INVALID_URI');

            var c2 = str.charCodeAt(i) & 0x3FF;

            lastPos = i + 1;
            c = 0x10000 + (((c & 0x3FF) << 10) | c2);
            out += hexTable[0xF0 | (c >> 18)] +
                hexTable[0x80 | ((c >> 12) & 0x3F)] +
                hexTable[0x80 | ((c >> 6) & 0x3F)] +
                hexTable[0x80 | (c & 0x3F)];
        }
        if (lastPos === 0)
            return str;
        if (lastPos < str.length)
            return out + str.slice(lastPos);
        return out;
    }

    function HttpRequest(method, url, headers, body) {
        if (method === undefined) {
            this.method = "";
        } else {
            this.method = method;
        }
        if (url === undefined) {
            this.host = "";
            this.uri = "";
            this.query = {};
        } else {
            this.query = {};
            var host, path;
            var i = url.indexOf("://");
            if (i !== -1) {
                url = url.substr(i + 3)
            }
            var i = url.indexOf("?");
            if (i !== -1) {
                var query_str = url.substr(i + 1);
                url = url.substr(0, i);
                var spl = query_str.split("&");
                for (var i in spl) {
                    var kv = spl[i];
                    var index = kv.indexOf('=');
                    var key, value;
                    if (index >= 0) {
                        key = kv.substr(0, index);
                        value = kv.substr(index + 1);
                    } else {
                        key = kv;
                        value = "";
                    }
                    if (key !== "") {
                        key = decodeURI(key);
                        value = decodeURI(value);
                        if (this.query[key] === undefined) {
                            this.query[key] = [value]
                        } else {
                            this.query[key].push(value)
                        }
                    }
                }
            }
            var i = url.indexOf("/");
            if (i === -1) {
                host = url;
                path = "/";
            } else {
                host = url.substr(0, i);
                path = url.substr(i);
            }
            this.host = host;
            this.uri = decodeURI(path);
        }
        if (headers === undefined) {
            this.headers = {};
        } else {
            this.headers = headers;
        }
        if (body === undefined) {
            this.body = "";
        } else {
            this.body = body;
        }
    }

    function findHeader(r, header) {
        for (var k in r.headers) {
            if (k.toLowerCase() === header.toLowerCase()) {
                return r.headers[k]
            }
        }
        return null;
    }

// Build a CanonicalRequest from a regular request string
//
// CanonicalRequest =
//  HTTPRequestMethod + '\n' +
//  CanonicalURI + '\n' +
//  CanonicalQueryString + '\n' +
//  CanonicalHeaders + '\n' +
//  SignedHeaders + '\n' +
//  HexEncode(Hash(RequestPayload))
    function CanonicalRequest(r, signedHeaders) {
        var hexencode = findHeader(r, HeaderContentSha256);
        if (hexencode === null) {
            var data = RequestPayload(r);
            hexencode = crypto_wrapper.HexEncodeSHA256Hash(data);
        }
        return r.method + "\n" + CanonicalURI(r) + "\n" + CanonicalQueryString(r) + "\n" + CanonicalHeaders(r, signedHeaders) + "\n" + signedHeaders.join(';') + "\n" + hexencode
    }

    function CanonicalURI(r) {
        var pattens = r.uri.split('/');
        var uri = [];
        for (var k in pattens) {
            var v = pattens[k];
            uri.push(urlEncode(v))
        }
        var urlpath = uri.join('/');
        if (urlpath[urlpath.length - 1] !== '/') {
            urlpath = urlpath + '/'
        }
        //r.uri = urlpath
        return urlpath;
    }

    function CanonicalQueryString(r) {
        var keys = [];
        for (var key in r.query) {
            keys.push(key)
        }
        keys.sort();
        var a = [];
        for (var i in keys) {
            var key = urlEncode(keys[i]);
            var value = r.query[keys[i]];
            if (Array.isArray(value)) {
                value.sort();
                for (var iv in value) {
                    a.push(key + '=' + urlEncode(value[iv]))
                }
            } else {
                a.push(key + '=' + urlEncode(value))
            }
        }
        return a.join('&');
    }

    function CanonicalHeaders(r, signedHeaders) {
        var headers = {};
        for (var key in r.headers) {
            headers[key.toLowerCase()] = r.headers[key];
        }
        var a = [];
        for (var i in signedHeaders) {
            var value = headers[signedHeaders[i]];
            a.push(signedHeaders[i] + ':' + value.trim())
        }
        return a.join('\n') + "\n"
    }

    function SignedHeaders(r) {
        var a = [];
        for (var key in r.headers) {
            a.push(key.toLowerCase())
        }
        a.sort();
        return a
    }

    function RequestPayload(r) {
        return r.body
    }

// Create a "String to Sign".
    function StringToSign(canonicalRequest, t) {
        var bytes = crypto_wrapper.HexEncodeSHA256Hash(canonicalRequest);
        return Algorithm + "\n" + t + "\n" + bytes
    }

// Create the HWS Signature.
    function SignStringToSign(stringToSign, signingKey) {
        return crypto_wrapper.hmacsha256(signingKey, stringToSign)
    }

// Get the finalized value for the "Authorization" header.  The signature
// parameter is the output from SignStringToSign
    function AuthHeaderValue(signature, Key, signedHeaders) {
        return Algorithm + " Access=" + Key + ", SignedHeaders=" + signedHeaders.join(';') + ", Signature=" + signature
    }

    function twoChar(s) {
        if (s >= 10) {
            return "" + s
        } else {
            return "0" + s
        }
    }

    function getTime() {
        var date = new Date();
        return "" + date.getUTCFullYear() + twoChar(date.getUTCMonth() + 1) + twoChar(date.getUTCDate()) + "T" +
            twoChar(date.getUTCHours()) + twoChar(date.getUTCMinutes()) + twoChar(date.getUTCSeconds()) + "Z"
    }

    function Signer() {
        this.Key = "";
        this.Secret = "";
    }

    Signer.prototype.Sign = function (r) {
        var headerTime = findHeader(r, HeaderXDate);
        if (headerTime === null) {
            headerTime = getTime();
            r.headers[HeaderXDate] = headerTime
        }
        if (r.method !== "PUT" && r.method !== "PATCH" && r.method !== "POST") {
            r.body = ""
        }
        var queryString = CanonicalQueryString(r);
        if (queryString !== "") {
            queryString = "?" + queryString
        }
        var options = {
            hostname: r.host,
            path: encodeURI(r.uri) + queryString,
            method: r.method,
            headers: r.headers
        };
        if (findHeader(r, 'host') === null) {
            r.headers.host = r.host;
        }
        var signedHeaders = SignedHeaders(r);
        var canonicalRequest = CanonicalRequest(r, signedHeaders);
        var stringToSign = StringToSign(canonicalRequest, headerTime);
        var signature = SignStringToSign(stringToSign, this.Secret);
        options.headers[HeaderAuthorization] = AuthHeaderValue(signature, this.Key, signedHeaders);
        return options
    };
    return {
        HttpRequest: HttpRequest,
        Signer: Signer,
        urlEncode: urlEncode,
        findHeader: findHeader,
        SignedHeaders: SignedHeaders,
        CanonicalRequest: CanonicalRequest,
        StringToSign: StringToSign,
    }
}));