The ultimate URL purifier
目前为
此脚本不应直接安装，它是一个供其他脚本使用的外部库。如果您需要使用该库，请在脚本元属性加入：// @require https://update.greasyfork.icu/scripts/492078/1363869/pURLfy.js
// Alternative class to URLSearchParams, which does not encode/decode the parameters
class SearchParams { // Adapted from https://github.com/yext/answers-search-ui/blob/b790f412a68bf64bdeed8eb0be065fb810b02231/src/ui/dom/searchparams.js#L9
constructor(url) {
this.size = 0;
this._params = this.parse(url);
}
parse(url) {
const params = {};
let search = url;
if (!search) {
return params;
}
if (url.indexOf('?') > -1) {
search = url.slice(url.indexOf('?') + 1);
}
const encodedParams = search.split('&');
for (let i = 0; i < encodedParams.length; i++) {
const keyVal = encodedParams[i].split('=');
if (keyVal.length > 1) {
params[keyVal[0]] = keyVal[1];
} else {
params[keyVal[0]] = '';
}
}
this.size = Object.keys(params).length;
return params;
}
get(query) {
if (typeof this._params[String(query)] === 'undefined') {
return null;
}
return this._params[String(query)];
}
set(name, value) {
this._params[String(name)] = String(value);
}
has(query) {
return query in this._params;
}
delete(name) {
delete this._params[String(name)];
this.size = Object.keys(this._params).length;
}
toString() {
const string = [];
for (const key in this._params) {
string.push(`${key}=${this._params[key]}`);
}
return string.join('&');
}
entries() {
const entries = [];
for (const key in this._params) {
entries.push([key, this._params[key]]);
}
return entries;
}
}
class Purlfy extends EventTarget {
redirectEnabled = false;
lambdaEnabled = false;
maxIterations = 5;
#log = console.log.bind(console, "\x1b[38;2;220;20;60m[pURLfy]\x1b[0m");
#getRedirectedUrl = async (url, ua) => {
const options = {
method: "HEAD",
redirect: "manual"
};
if (ua) {
options.headers = {
"User-Agent": ua
};
}
const r = await fetch(url, options);
if (r.status >= 300 && r.status < 400 && r.headers.has("location")) {
const dest = r.headers.get("location");
return dest;
}
return null;
};
#paramDecoders = {
"url": decodeURIComponent,
"base64": s => decodeURIComponent(escape(atob(s.replaceAll('_', '/').replaceAll('-', '+')))),
"slice": (s, start, end) => s.slice(parseInt(start), end ? parseInt(end) : undefined),
};
#zeroStatistics = {
url: 0,
param: 0,
decoded: 0,
redirected: 0,
char: 0
};
#statistics = { ...this.#zeroStatistics };
#rules = {};
#AsyncFunction = async function() {}.constructor;
constructor(options) {
super();
this.redirectEnabled = options?.redirectEnabled ?? this.redirectEnabled;
this.lambdaEnabled = options?.lambdaEnabled ?? this.lambdaEnabled;
this.maxIterations = options?.maxIterations ?? this.maxIterations;
Object.assign(this.#statistics, options?.statistics);
this.#log = options?.log ?? this.#log;
this.#getRedirectedUrl = options?.getRedirectedUrl ?? this.#getRedirectedUrl;
}
clearStatistics() {
const increment = {};
for (const [key, value] of Object.entries(this.#statistics)) {
increment[key] = -value;
}
this.#incrementStatistics(increment);
}
clearRules() {
this.#rules = {};
}
getStatistics() {
return { ...this.#statistics };
}
importRules(rules) {
Object.assign(this.#rules, rules);
}
#udfOrType(value, type) { // If the given value is of the given type or undefined
return value === undefined || typeof value === type;
}
#validRule(rule) { // Check if the given rule is valid
if (!rule || !rule.mode || !rule.description || !rule.author) return false;
switch (rule.mode) {
case "white":
case "black":
return Array.isArray(rule.params);
case "param":
return Array.isArray(rule.params) && (rule.decode === undefined || Array.isArray(rule.decode)) && this.#udfOrType(rule.continue, "boolean");
case "regex":
return Array.isArray(rule.regex) && Array.isArray(rule.replace) && this.#udfOrType(rule.continue, "boolean") && rule.regex.length === rule.replace.length;
case "redirect":
return this.redirectEnabled && this.#udfOrType(rule.ua, "string") && this.#udfOrType(rule.continue, "boolean");
case "lambda":
return this.lambdaEnabled && typeof rule.lambda === "string" && this.#udfOrType(rule.continue, "boolean");
default:
return false;
}
}
#matchRule(parts) { // Iteratively match the longest rule for the given URL parts
let fallbackRule = null; // Most precise fallback rule
let currentRules = this.#rules;
for (const part of parts) {
if (currentRules.hasOwnProperty("")) {
fallbackRule = currentRules[""];
}
if (currentRules.hasOwnProperty(part + "/")) {
currentRules = currentRules[part + "/"]; // Exact match - continue to the next level
} else if (currentRules.hasOwnProperty(part)) {
const rule = currentRules[part];
if (this.#validRule(rule)) {
return rule; // Exact match found
}
} else { // No exact match found, try to match with regex
let found = false;
// Iterate through current rules to match RegExp
for (const [key, val] of Object.entries(currentRules)) {
if (!key.startsWith("/")) continue; // Skip non-RegExp keys
try {
const sub = key.endsWith("/"); // Has sub-rules
const regex = new RegExp(sub ? key.slice(1, -1) : key.slice(1));
if (regex.test(part)) { // Regex matches
if (!sub && this.#validRule(val)) {
return val; // Regex match found
} else if (sub) {
currentRules = val; // Continue to the next level
found = true;
break;
}
}
} catch (e) {
this.#log("Invalid regex:", key.slice(1));
}
}
if (!found) break; // No matching rule found
}
}
if (currentRules.hasOwnProperty("")) { // Fallback rule
fallbackRule = currentRules[""];
}
if (this.#validRule(fallbackRule)) {
return fallbackRule;
}
return null;
}
async #applyRule(urlObj, rule, logFunc) { // Apply the given rule to the given URL object, returning the new URL object, whether to continue and the mode-specific incremental statistics
const mode = rule.mode;
const increment = { ...this.#zeroStatistics }; // Incremental statistics
const lengthBefore = urlObj.href.length;
const paramsCntBefore = urlObj.searchParams.size;
let shallContinue = false;
switch (mode) { // Purifies `urlObj` based on the rule
case "white": { // Whitelist mode
const newParams = new SearchParams();
const oldParams = new SearchParams(urlObj.search);
for (const param of rule.params) {
if (oldParams.has(param)) {
newParams.set(param, oldParams.get(param));
}
}
urlObj.search = newParams.toString();
break;
}
case "black": { // Blacklist mode
const params = new SearchParams(urlObj.search);
for (const param of rule.params) {
params.delete(param);
}
urlObj.search = params.toString();
break;
}
case "param": { // Specific param mode
// Decode given parameter to be used as a new URL
const params = new SearchParams(urlObj.search);
let paramValue = null;
for (const param of rule.params) { // Find the first available parameter value
if (params.has(param)) {
paramValue = params.get(param);
break;
}
}
if (!paramValue) {
logFunc("Parameter(s) not found:", rule.params.join(", "));
break;
}
let dest = paramValue;
let success = true;
for (const cmd of (rule.decode ?? ["url"])) {
const args = cmd.split(":");
const name = args[0];
const decoder = this.#paramDecoders[name];
if (!decoder) {
logFunc("Invalid decoder:", cmd);
success = false;
break;
}
try {
dest = decoder(dest, ...args.slice(1));
} catch (e) {
logFunc(`Error decoding parameter with decoder "${name}":`, e);
break;
}
}
if (!success) break;
if (URL.canParse(dest, urlObj.href)) { // Valid URL
urlObj = new URL(dest, urlObj.href);
} else { // Invalid URL
logFunc("Invalid URL:", dest);
break;
}
shallContinue = rule.continue ?? true;
increment.decoded++;
break;
}
case "regex": { // Regex mode
let newUrl = urlObj.href;
for (let i = 0; i < rule.regex.length; i++) {
const regex = new RegExp(rule.regex[i], "g");
const replace = rule.replace[i];
newUrl = newUrl.replaceAll(regex, replace);
}
if (URL.canParse(newUrl, urlObj.href)) { // Valid URL
urlObj = new URL(newUrl);
} else { // Invalid URL
logFunc("Invalid URL:", newUrl);
break;
}
break;
}
case "redirect": { // Redirect mode
if (!this.redirectEnabled) {
logFunc("Redirect mode is disabled.");
break;
}
let dest = null;
try {
dest = await this.#getRedirectedUrl(urlObj.href, rule.ua);
} catch (e) {
logFunc("Error following redirect:", e);
break;
}
if (dest && URL.canParse(dest, urlObj.href)) {
const prevUrl = urlObj.href;
urlObj = new URL(dest, urlObj.href);
if (urlObj.href === prevUrl) { // No redirection
logFunc("No redirection made.");
break;
}
shallContinue = rule.continue ?? true;
increment.redirected++;
} else {
logFunc("Invalid redirect destination:", dest);
}
break;
}
case "lambda": {
if (!this.lambdaEnabled) {
logFunc("Lambda mode is disabled.");
break;
}
try {
const lambda = new this.#AsyncFunction("url", rule.lambda);
urlObj = await lambda(urlObj);
shallContinue = rule.continue ?? true;
} catch (e) {
logFunc("Error executing lambda:", e);
}
break;
}
default: {
logFunc("Invalid mode:", mode);
break;
}
}
const paramsCntAfter = urlObj.searchParams.size;
increment.param += (["white", "black"].includes(mode)) ? (paramsCntBefore - paramsCntAfter) : 0;
increment.char += Math.max(lengthBefore - urlObj.href.length, 0); // Prevent negative char count
return [urlObj, shallContinue, increment];
}
#incrementStatistics(increment) {
for (const [key, value] of Object.entries(increment)) {
this.#statistics[key] += value;
}
if (typeof CustomEvent === "function") {
this.dispatchEvent(new CustomEvent("statisticschange", {
detail: increment
}));
} else {
this.dispatchEvent(new Event("statisticschange"));
}
}
async purify(originalUrl) { // Purify the given URL based on `rules`
let increment = { ...this.#zeroStatistics }; // Incremental statistics of a single purification
let shallContinue = true;
let firstRule = null;
let iteration = 0;
let urlObj;
this.#log("Purifying URL:", originalUrl);
const optionalLocation = typeof location !== 'undefined' ? location.href : undefined;
if (URL.canParse(originalUrl, optionalLocation)) {
urlObj = new URL(originalUrl, optionalLocation);
} else {
this.#log(`Cannot parse URL ${originalUrl}`);
return {
url: originalUrl,
rule: "N/A"
}
}
while (shallContinue && iteration++ < this.maxIterations) {
const logi = (...args) => this.#log(`[#${iteration}]`, ...args);
const protocol = urlObj.protocol;
if (protocol !== "http:" && protocol !== "https:") { // Not a valid HTTP URL
logi(`Not a HTTP URL: ${urlObj.href}`);
break;
}
const hostAndPath = urlObj.host + urlObj.pathname;
const parts = hostAndPath.split("/").filter(part => part !== "");
const rule = this.#matchRule(parts);
if (!rule) { // No matching rule found
logi(`No matching rule found for ${urlObj.href}.`);
break;
}
firstRule ??= rule;
logi(`Matching rule: ${rule.description} by ${rule.author}`);
let singleIncrement; // Incremental statistics for the current iteration
[urlObj, shallContinue, singleIncrement] = await this.#applyRule(urlObj, rule, logi);
for (const [key, value] of Object.entries(singleIncrement)) {
increment[key] += value;
}
logi("Purified URL:", urlObj.href);
}
if (firstRule && originalUrl !== urlObj.href) { // Increment statistics only if a rule was applied and URL has been changed
increment.url++;
this.#incrementStatistics(increment);
}
return {
url: urlObj.href,
rule: firstRule ? `${firstRule.description} by ${firstRule.author}` : "N/A"
};
}
}
if (typeof module !== "undefined" && module.exports) {
module.exports = Purlfy; // Export for Node.js
} else {
this.Purlfy = Purlfy; // Export for browser
}