/*******************************************************************************

    uBlock Origin - a comprehensive, efficient content blocker
    Copyright (C) 2019-present Raymond Hill

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see {http://www.gnu.org/licenses/}.

    Home: https://github.com/gorhill/uBlock

*/

import { registerScriptlet } from './base.js';

/******************************************************************************/

export function proxyApplyFn(
    target = '',
    handler = ''
) {
    let context = globalThis;
    let prop = target;
    for (;;) {
        const pos = prop.indexOf('.');
        if ( pos === -1 ) { break; }
        context = context[prop.slice(0, pos)];
        if ( context instanceof Object === false ) { return; }
        prop = prop.slice(pos+1);
    }
    const fn = context[prop];
    if ( typeof fn !== 'function' ) { return; }
    if ( proxyApplyFn.CtorContext === undefined ) {
        proxyApplyFn.ctorContexts = [];
        proxyApplyFn.CtorContext = class {
            constructor(...args) {
                this.init(...args);
            }
            init(callFn, callArgs) {
                this.callFn = callFn;
                this.callArgs = callArgs;
                return this;
            }
            reflect() {
                const r = Reflect.construct(this.callFn, this.callArgs);
                this.callFn = this.callArgs = this.private = undefined;
                proxyApplyFn.ctorContexts.push(this);
                return r;
            }
            static factory(...args) {
                return proxyApplyFn.ctorContexts.length !== 0
                    ? proxyApplyFn.ctorContexts.pop().init(...args)
                    : new proxyApplyFn.CtorContext(...args);
            }
        };
        proxyApplyFn.applyContexts = [];
        proxyApplyFn.ApplyContext = class {
            constructor(...args) {
                this.init(...args);
            }
            init(callFn, thisArg, callArgs) {
                this.callFn = callFn;
                this.thisArg = thisArg;
                this.callArgs = callArgs;
                return this;
            }
            reflect() {
                const r = Reflect.apply(this.callFn, this.thisArg, this.callArgs);
                this.callFn = this.thisArg = this.callArgs = this.private = undefined;
                proxyApplyFn.applyContexts.push(this);
                return r;
            }
            static factory(...args) {
                return proxyApplyFn.applyContexts.length !== 0
                    ? proxyApplyFn.applyContexts.pop().init(...args)
                    : new proxyApplyFn.ApplyContext(...args);
            }
        };
        proxyApplyFn.isCtor = new Map();
        proxyApplyFn.proxies = new WeakMap();
        proxyApplyFn.nativeToString = Function.prototype.toString;
        const proxiedToString = new Proxy(Function.prototype.toString, {
            apply(target, thisArg) {
                let proxied = thisArg;
                for(;;) {
                    const fn = proxyApplyFn.proxies.get(proxied);
                    if ( fn === undefined ) { break; }
                    proxied = fn;
                }
                return proxyApplyFn.nativeToString.call(proxied);
            }
        });
        proxyApplyFn.proxies.set(proxiedToString, proxyApplyFn.nativeToString);
        Function.prototype.toString = proxiedToString;
    }
    if ( proxyApplyFn.isCtor.has(target) === false ) {
        proxyApplyFn.isCtor.set(target, fn.prototype?.constructor === fn);
    }
    const proxyDetails = {
        apply(target, thisArg, args) {
            return handler(proxyApplyFn.ApplyContext.factory(target, thisArg, args));
        }
    };
    if ( proxyApplyFn.isCtor.get(target) ) {
        proxyDetails.construct = function(target, args) {
            return handler(proxyApplyFn.CtorContext.factory(target, args));
        };
    }
    const proxiedTarget = new Proxy(fn, proxyDetails);
    proxyApplyFn.proxies.set(proxiedTarget, fn);
    context[prop] = proxiedTarget;
}
registerScriptlet(proxyApplyFn, {
    name: 'proxy-apply.fn',
});
