import definition = require("xml");
import easysax = require("js-libs/easysax");

export class ParserEventType implements definition.ParserEventType {
    static StartElement = "StartElement";
    static EndElement = "EndElement";
    static Text = "Text";
    static CDATA = "CDATA";
    static Comment = "Comment";
}

export class ParserEvent implements definition.ParserEvent {
    private _eventType: string;
    private _position: definition.Position;
    private _prefix: string;
    private _namespace: string;
    private _elementName: string;
    private _attributes: Object;
    private _data: string;

    constructor(eventType: string, position: definition.Position, prefix?: string, namespace?: string, elementName?: string, attributes?: Object, data?: string) {
        this._eventType = eventType;
        this._position = position;
        this._prefix = prefix;
        this._namespace = namespace;
        this._elementName = elementName;
        this._attributes = attributes;
        this._data = data;
    }

    public toString(): string {
        return JSON.stringify({
            eventType: this.eventType,
            position: this.position,
            prefix: this.prefix,
            namespace: this.namespace,
            elementName: this.elementName,
            attributes: this.attributes,
            data: this.data
        });
    }

    public get eventType(): string {
        return this._eventType;
    }
    
    public get position(): definition.Position {
        return this._position;
    }

    public get prefix(): string {
        return this._prefix;
    }

    public get namespace(): string {
        return this._namespace;
    }

    public get elementName(): string {
        return this._elementName;
    }

    public get attributes(): Object {
        return this._attributes;
    }

    public get data(): string {
        return this._data;
    }
}

var _ampCodes;
var _entitySearchRegEx = /&#(\d+);|&#x([0123456789abcdef]+);|&(\w+);/ig;

function _generateAmpMap(): any {
   var objCodes = {Tab: 9, NewLine: 10, excl: 33, quot: 34, QUOT: 34, num: 35, dollar: 36, percent: 37, amp: 38, AMP: 38, apos: 39, lpar: 40, rpar: 41, ast: 42, midast: 42, plus: 43, comma: 44, period: 46, sol: 47, colon: 58, semi: 59, lt: 60, LT: 60, equals: 61, gt: 62, GT: 62, quest: 63, commat: 64, lsqb: 91, lbrack: 91, bsol: 92, rsqb: 92, rbrack: 92, Hat: 94, lowbar: 95, grave: 96, DiacriticalGrave: 96, lcub: 123, lbrace: 123, verbar: 124, vert: 124, VerticalLine: 124, rcub: 125, rbrace: 125, nbsp: 160, iexcl: 161, cent: 162, pound:163, curren: 164, yen: 165, brvbar: 166, brkbar:166, sect:167, uml:168, copy:169, ordf:170, laquo:171, not: 172, shy:173, reg:174, macr:175, hibar: 175, deg:176, plusmn: 177, sup2: 178, sup3: 179, acute:180, micro:181, para:182, middot:183, cedil:184, sup1:185, ordm:186, raquo:187, frac14:188, frac12:189, frac34:190, iquest:191, Agrave:192, Aacute:193, Acirc:194, Atilde:195, Auml:196, Aring:197, AElig:198, Ccedil:199, Egrave:200, Eacute:201, Ecirc:202, Euml:203, Igrave:204, Iacute:205, Icirc:206, Iuml:207, ETH:208, Dstrok: 208, Ntilde:209, Ograve:210, Oacute:211, Ocirc:212, Otilde: 213, Ouml:214, times:215, Oslash:216, Ugrave:217, Uacute:218, Ucirc:219, Uuml:220, Yacute:221, THORN:222, szlig:223, agrave:224, aacute:225, acirc:226, atilde:227, auml:228, aring:229, aelig:230, ccedil:231, egrave:232, eacute:233, ecirc:234, euml:235, igrave:236, iacute:237, icirc:238, iuml:239, eth:240, ntilde:241, ograve:242, oacute:243, ocirc:244, otilde:245, ouml:246, divide:247, oslash:248, ugrave:249, uacute:250, ucirc:251, uuml:252, yacute:253, thorn:254, yuml: 255, fnof: 402, imped: 437, gacute: 501, jmath: 567, circ: 710, caron: 711, Hacek: 711, breve: 728, Breve: 728, dot: 729, DiacriticalDot: 729, ring: 730, ogon: 731, tilde: 732, DiacriticalTilde: 732, dblac: 733, DiacriticalDoubleAcute: 733, DownBreve: 785, UnderBar: 818, Alpha: 913, Beta: 914, Gamma: 915, Delta: 916, Epsilon: 917, Zeta: 918, Eta: 919, Theta: 920, Iota: 921, Kappa: 922, Lambda: 923, Mu: 924, Nu: 925, Xi: 926, Omicron: 927, Pi: 928, Rho: 929 /* 930 is not real */, Sigma: 931, Tau: 932, Upsilon: 933, Phi: 934, Chi: 935, Psi: 936, Omega: 937, alpha: 945, beta: 946, gamma: 947, delta: 948, epsilon: 949, epsiv: 949, varepsilon: 949, zeta: 950, eta: 951, theta: 952, iota: 953, kappa: 954, lambda: 955, mu: 956, nu: 957, xi: 958, omicron: 959, pi: 960, rho: 961, sigmaf: 962, sigmav: 962, varsigma: 962, sigma: 963, tau: 964, upsilon: 965, phi: 966, chi: 967, psi: 968, omega: 969, thetav: 977, vartheta: 977, thetasym: 977, Upsi: 978, upsih: 978, straightphi: 981, piv: 982, varpi: 982, Gammad: 988, gammad: 989, digamma: 989, kappav: 1008, varkappa: 1008, rhov: 1009, varrho: 1009, epsi:1013, straightepsilon: 1013, bepsi: 1014, backepsilon: 1014, /* Skipped Codes 1015 - 1119 */ euro: 8364, trade: 8482, TRADE: 8482, forall: 8704, part: 8706, larr: 8592, rarr: 8593, hyphen: 8208, dash: 8208, ndash: 8211, mdash: 8212, horbar: 8213, Vert: 8214, Verbar: 8214, lsquo: 8216, OpenCurlyQuote: 8216, rsquo: 8217, rsquor: 8217, CloseCurlyQuote: 8217, lsquor: 8218, sbquo: 8218, ldquo: 8220, OpenCurlyDoubleQuote: 8220, rdquo: 8221, rdquor: 8221, CloseCurlyDoubleQuote: 8221, ldquor: 8222, bdquo: 8222, dagger: 8224, Dagger: 8225, ddagger: 8225, bull: 8226, bullet: 8226, nldr: 8229, hellip: 8230, mldr: 8230, hybull: 8259, tdot: 8411, TripleDot: 8411 ,DotDot: 8412, star: 9734, phone: 9742, spades: 9824, clubs: 9827, hearts: 9829, diams: 9830, female: 9792, male: 9794, check: 10003, checkmark: 10003, cross: 10007, VerticalSeparator: 10072, EmptySmallSquare: 9723, FilledSmallSquare: 9724, starf: 9733, bigstar: 9733, square: 9633, squ: 9633, Square: 9633};
   var ampCodes = new Map();
    for (var key in objCodes) {
        if (objCodes.hasOwnProperty(key)) {
            ampCodes.set(key, objCodes[key]);
        }
    }
    return ampCodes;
}

function _HandleAmpEntities(found: string, decimalValue: string, hexValue: string, wordValue: string): string {

    if (wordValue) {
        if (!_ampCodes) {
            _ampCodes = _generateAmpMap();
        }
        var res = _ampCodes.get(wordValue);
        if (res) {
            return String.fromCharCode(res);
        }
        // Invalid word; so we just return it
        return found;
    }
    if (decimalValue) {
        return String.fromCharCode(parseInt(decimalValue, 10));
    }

    return String.fromCharCode(parseInt(hexValue, 16));
};

export class XmlParser implements definition.XmlParser {
    //TODO: Add option to configure whether the parser should report ignorable whitespace, i.e. document formatting whitespace.
    private _parser: easysax.EasySAXParser;

    private _processNamespaces: boolean;
    private _namespaceStack: Array<any>;

    constructor(onEvent: (event: definition.ParserEvent) => void, onError?: (error: Error, position: definition.Position) => void, processNamespaces?: boolean) {
        this._processNamespaces = processNamespaces;
        this._parser = new easysax.EasySAXParser();

        var that = this;
        this._parser.on('startNode', function (elem, attr, uq, tagend, str, pos) {
            var attributes = attr();

            if (attributes === true) {//HACK: For some reason easysax returns the true literal when an element has no attributes.
                attributes = undefined;
            }

            if (attributes) {
                var key;
                for (key in attributes) {
                    if (attributes.hasOwnProperty(key)) {
                        // Convert entities such as &gt; to >
                        attributes[key] = XmlParser._dereferenceEntities(attributes[key]);
                    }
                }
            }

            var prefix = undefined;
            var namespace = undefined;
            var name = elem;

            if (that._processNamespaces) {
                var stackEntry = XmlParser._getNamespacesStackEntry(attributes);    
                that._namespaceStack.push(stackEntry);

                var resolved = that._resolveNamespace(name);
                prefix = resolved.prefix;
                namespace = resolved.namespace;
                name = resolved.name;
            }

            onEvent(new ParserEvent(ParserEventType.StartElement, pos(), prefix, namespace, name, attributes, undefined));
        });

        this._parser.on('textNode', function (text, uq, pos) {
            var data = uq(XmlParser._dereferenceEntities(text));// Decode entity references such as &lt; and &gt;
            onEvent(new ParserEvent(ParserEventType.Text, pos(), undefined, undefined, undefined, undefined, data));
        });

        this._parser.on('endNode', function (elem, uq, tagstart, str, pos) {

            var prefix = undefined;
            var namespace = undefined;
            var name = elem;

            if (that._processNamespaces) {
                var resolved = that._resolveNamespace(name);
                prefix = resolved.prefix;
                namespace = resolved.namespace;
                name = resolved.name;
            }

            onEvent(new ParserEvent(ParserEventType.EndElement, pos(), prefix, namespace, name, undefined, undefined));

            if (that._processNamespaces) {
                that._namespaceStack.pop();
            }
        });

        this._parser.on('cdata', function (data, res, pos) {
            onEvent(new ParserEvent(ParserEventType.CDATA, pos(), undefined, undefined, undefined, undefined, data));
        });

        this._parser.on('comment', function (text, uq, pos) {
            onEvent(new ParserEvent(ParserEventType.Comment, pos(), undefined, undefined, undefined, undefined, text));
        });

        if (onError) {
            this._parser.on('error', function (msg, pos) {
                onError(new Error(msg), pos());
            });
        }
    }

    public get angularSyntax() : boolean {
        return this._parser.angularSyntax;
    }

    public set angularSyntax(value: boolean) {
        this._parser.angularSyntax = value;
    }

    public parse(xmlString: string): void {
        if (this._processNamespaces) {
            this._namespaceStack = [];
        }

        this._parser.parse(xmlString);
    }

    private static _getNamespacesStackEntry(attributes: any): any {
        var stackEntry = {};

        if (!attributes) {
            return stackEntry;
        }

        for (var key in attributes) {
            if (!attributes.hasOwnProperty(key)) {
                continue;
            }
            var attributeName = <string>key;
            if (attributeName.indexOf("xmlns") !== 0) {
                // This is a normal attribute, so go on.
                continue;
            }

            var namespacePrefix = "";
            if (attributeName.indexOf(":") !== -1) {
                namespacePrefix = attributeName.split(":")[1];
            }

            stackEntry[namespacePrefix] = attributes[key];
        }

        return stackEntry;
    }

    private _resolveNamespace(fullName: string): { prefix: string; namespace: string; name: string; } {
        var result: { prefix: string; namespace: string; name: string; } = { prefix: undefined, namespace: undefined, name: undefined }
        result.prefix = "";
        if (fullName.indexOf(":") !== -1) {
            var split = fullName.split(":");
            result.prefix = split[0];
            result.name = split[1];
        }
        else {
            result.name = fullName;
        }

        var i;
        var stackEntry;
        for (i = this._namespaceStack.length - 1; i >= 0; i--) {
            stackEntry = this._namespaceStack[i];

            for (var key in stackEntry) {
                if (!stackEntry.hasOwnProperty(key)) {
                    continue;
                }

                if (result.prefix === key) {
                    result.namespace = stackEntry[key];
                    return result;
                }
            }
        }

        return result;
    }

    private static _dereferenceEntities(s: string): string {
        s = String(s);
        if (s.length > 3 && s.indexOf('&') !== -1) {
            s = s.replace(_entitySearchRegEx, _HandleAmpEntities);
        }

        return s;
    }
}
