URL Encoder

URL encode and decode for non-utf8 encodings

Version vom 20.07.2023. Aktuellste Version

Dieses Skript sollte nicht direkt installiert werden. Es handelt sich hier um eine Bibliothek für andere Skripte, welche über folgenden Befehl in den Metadaten eines Skriptes eingebunden wird // @require https://update.greatest.deepsurf.us/scripts/471280/1222824/URL%20Encoder.js

/* eslint-disable no-multi-spaces */

// ==UserScript==
// @name               URL Encoder
// @namespace          URL-Encoder
// @version            0.1
// @description        URL encode and decode for non-utf8 encodings
// @author             EtherDream, PY-DNG
// @license            MIT
// ==/UserScript==

let $URL = (function () {
    const str2big5 = (function () {
        'use strict'

        let table;
        return str2big5;

        function initBig5Table() {
            // https://en.wikipedia.org/wiki/Big5
            const ranges = [
                [0xA1, 0xF9, 0x40, 0x7E],
                [0xA1, 0xF9, 0xA1, 0xFE],
            ]
            const codePoints = new Uint16Array(13973); // 13973 === (0xF9-0xA1+1)*(0x7E-0x40+1 + 0xFE-0xA1+1)
            let i = 0;

            for (const [b1Begin, b1End, b2Begin, b2End] of ranges) {
                for (let b2 = b2Begin; b2 <= b2End; b2++) {
                    for (let b1 = b1Begin; b1 <= b1End; b1++) {
                        codePoints[i++] = b2 << 8 | b1;
                    }
                }
            }
            table = {};

            const str = [...new TextDecoder('big5').decode(codePoints)];
            for (let i = 0; i < str.length; i++) {
                table[str[i].charCodeAt(0)] = codePoints[i];
            }
        }

        function str2big5(str) {
            if (!table) {
                initBig5Table();
            }

            const buf = [];

            for (let i = 0; i < str.length; i++) {
                const codePoint = str.codePointAt(i);
                const code = String.fromCodePoint(codePoint);
                i += code.length-1;

                if (codePoint < 0x80) {
                    buf.push(codePoint);
                    continue;
                }
                const big5 = table[codePoint];

                if (table.hasOwnProperty(codePoint)) {
                    const uarr = new Uint8Array(2);
                    uarr[0] = big5;
                    uarr[1] = big5 >> 8;
                    buf.push(uarr[0], uarr[1]);
                } else {
                    const encoded = str2big5(`&#${codePoint};`);
                    for (const charcode of encoded) {
                        buf.push(charcode);
                    }
                }
            }
            return buf;
        }
    }) ();

    const str2gbk = (function () {
        'use strict'

        let table;
        return str2gbk;

        function initGbkTable() {
            // https://en.wikipedia.org/wiki/GBK_(character_encoding)#Encoding
            const ranges = [
                [0xA1, 0xA9, 0xA1, 0xFE],
                [0xB0, 0xF7, 0xA1, 0xFE],
                [0x81, 0xA0, 0x40, 0xFE],
                [0xAA, 0xFE, 0x40, 0xA0],
                [0xA8, 0xA9, 0x40, 0xA0],
                [0xAA, 0xAF, 0xA1, 0xFE],
                [0xF8, 0xFE, 0xA1, 0xFE],
                [0xA1, 0xA7, 0x40, 0xA0],
            ]
            const codePoints = new Uint16Array(23940);
            let i = 0;

            for (const [b1Begin, b1End, b2Begin, b2End] of ranges) {
                for (let b2 = b2Begin; b2 <= b2End; b2++) {
                    if (b2 !== 0x7F) {
                        for (let b1 = b1Begin; b1 <= b1End; b1++) {
                            codePoints[i++] = b2 << 8 | b1;
                        }
                    }
                }
            }
            table = {}

            const str = [...new TextDecoder('gbk').decode(codePoints)];
            for (let i = 0; i < str.length; i++) {
                 table[str[i].charCodeAt(0)] = codePoints[i];
            }
        }

        function str2gbk(str, opt = {}) {
            if (!table) {
                initGbkTable();
            }

            const buf = [];

            for (let i = 0; i < str.length; i++) {
                const codePoint = str.codePointAt(i);
                const code = String.fromCodePoint(codePoint);
                i += code.length-1;

                if (codePoint < 0x80) {
                    buf.push(codePoint);
                    continue;
                }
                const gbk = table[codePoint];

                if (table.hasOwnProperty(codePoint)) {
                    const uarr = new Uint8Array(2);
                    uarr[0] = gbk;
                    uarr[1] = gbk >> 8;
                    buf.push(uarr[0], uarr[1]);
                } else if (codePoint === 8364) {
                    // 8364 == '€'.charCodeAt(0)
                    // Code Page 936 has a single-byte euro sign at 0x80
                    buf.push(0x80);
                } else {
                    const encoded = str2gbk(`&#${codePoint};`);
                    for (const charcode of encoded) {
                        buf.push(charcode);
                    }
                }
            }
            return buf;
        }
    }) ();

    return {
        big5: {
            encode: str => buf2url(str2big5(str)),
            decode: url => decodeURL(url, 'big5')
        },
        gbk: {
            encode: str => buf2url(str2gbk(str)),
            decode: url => decodeURL(url, 'gbk')
        },
    }

    function buf2url(buf) {
        return buf.map(charcode => '%' + charcode.toString(16).toUpperCase()).join('');
    }

    function decodeURL(url, encoding) {
        const arr = [];
        let inCharcode = false, charcode = '';
        for (const char of url) {
            if (inCharcode) {
                charcode += char;
                if (charcode.length === 2) {
                    arr.push(parseInt(charcode, 16));
                    inCharcode = false;
                    charcode = '';
                }
            } else if (char === '%') {
                inCharcode = true;
            } else {
                arr.push(char.charCodeAt(0));
            }
        }
        const buf = arr.reduce((buf, charcode, i) => {
            buf[i] = charcode;
            return buf;
        }, new Uint8Array(arr.length));

        return new TextDecoder(encoding).decode(buf);
    }
})()[document.characterSet.toLowerCase()];