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

    ηMatrix - a browser extension to black/white list requests.
    Copyright (C) 2014-2019 Raymond Hill
    Copyright (C) 2019 Alessio Vanni

    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://libregit.org/heckyel/ematrix
    uMatrix Home: https://github.com/gorhill/uMatrix
*/

'use strict';

Components.utils.import('chrome://ematrix/content/lib/Punycode.jsm');
Components.utils.import('chrome://ematrix/content/lib/PublicSuffixList.jsm');

var EXPORTED_SYMBOLS = ['UriTools'];

var reRFC3986 = /^([^:\/?#]+:)?(\/\/[^\/?#]*)?([^?#]*)(\?[^#]*)?(#.*)?/;
var reSchemeFromURI = /^[^:\/?#]+:/;
var reAuthorityFromURI = /^(?:[^:\/?#]+:)?(\/\/[^\/?#]+)/;
var reOriginFromURI = /^(?:[^:\/?#]+:)?(?:\/\/[^\/?#]+)/;
var reCommonHostnameFromURL = /^https?:\/\/([0-9a-z_][0-9a-z._-]*[0-9a-z])\//;
var rePathFromURI = /^(?:[^:\/?#]+:)?(?:\/\/[^\/?#]*)?([^?#]*)/;
var reMustNormalizeHostname = /[^0-9a-z._-]/;

// These are to parse authority field, not parsed by above official regex
// IPv6 is seen as an exception: a non-compatible IPv6 is first tried, and
// if it fails, the IPv6 compatible regex istr used. This helps
// peformance by avoiding the use of a too complicated regex first.

// https://github.com/gorhill/httpswitchboard/issues/211
// "While a hostname may not contain other characters, such as the
// "underscore character (_), other DNS names may contain the underscore"
var reHostPortFromAuthority  = /^(?:[^@]*@)?([^:]*)(:\d*)?$/;
var reIPv6PortFromAuthority  = /^(?:[^@]*@)?(\[[0-9a-f:]*\])(:\d*)?$/i;

var reHostFromNakedAuthority = /^[0-9a-z._-]+[0-9a-z]$/i;
var reHostFromAuthority = /^(?:[^@]*@)?([^:]+)(?::\d*)?$/;
var reIPv6FromAuthority = /^(?:[^@]*@)?(\[[0-9a-f:]+\])(?::\d*)?$/i;

// Coarse (but fast) tests
var reValidHostname = /^([a-z\d]+(-*[a-z\d]+)*)(\.[a-z\d]+(-*[a-z\d])*)*$/;
var reIPAddressNaive = /^\d+\.\d+\.\d+\.\d+$|^\[[\da-zA-Z:]+\]$/;

var reNetworkScheme = /^(?:https?|wss?|ftps?)\b/;
var reSecureScheme = /^(?:https|wss|ftps)\b/;

function reset(o) {
    o.scheme = '';
    o.hostname = '';
    o._ipv4 = undefined;
    o._ipv6 = undefined;
    o.port = '';
    o.path = '';
    o.query = '';
    o.fragment = '';
    return o;
}

function resetAuthority(o) {
    o.hostname = '';
    o._ipv4 = undefined;
    o._ipv6 = undefined;
    o.port = '';
    return o;
}

function URI() {
    this.scheme = '',
    this.authority = '',
    this.hostname = '',
    this._ipv4 = undefined,
    this._ipv6 = undefined,
    this.port = '',
    this.domain = undefined,
    this.path = '',
    this.query = '',
    this.fragment = '',
    this.schemeBit = (1 << 0),
    this.userBit = (1 << 1),
    this.passwordBit = (1 << 2),
    this.hostnameBit = (1 << 3),
    this.portBit = (1 << 4),
    this.pathBit = (1 << 5),
    this.queryBit = (1 << 6),
    this.fragmentBit = (1 << 7),
    this.allBits = (0xFFFF),
    this.authorityBit =
        (this.userBit | this.passwordBit | this.hostnameBit | this.portBit);
    this.normalizeBits =
        (this.schemeBit | this.hostnameBit | this.pathBit | this.queryBit);
}

var cached = new URI();

var domainCache = new Map();
var cacheCountLow = 75;
var cacheCountHigh = 100;
var cacheJunkyard = [];
var junkyardMax = cacheCountHigh - cacheCountLow;

function DomainCacheEntry(domain) {
    this.init(domain);
}

DomainCacheEntry.prototype.init = function (domain) {
    this.domain = domain;
    this.tstamp = Date.now();
    return this;
};

DomainCacheEntry.prototype.dispose = function () {
    this.domain = '';
    if (cacheJunkyard.length < junkyardMax) {
        cacheJunkyard.push(this);
    }
};

var domainCacheEntryFactory = function (domain) {
    let entry = cacheJunkyard.pop();
    if (entry) {
        return entry.init(domain);
    }
    return new DomainCacheEntry(domain);
};

var domainCacheAdd = function (hostname, domain) {
    let entry = domainCache.get(hostname);

    if (entry !== undefined) {
        entry.tstamp = Date.now();
    } else {
        domainCache.set(hostname, domainCacheEntryFactory(domain));
        if (domainCache.size === cacheCountHigh) {
            domainCachePrune();
        }
    }

    return domain;
};

var domainCacheSort = function (a, b) {
    return domainCache.get(b).tstamp - domainCache.get(a).tstamp;
};

var domainCachePrune = function () {
    let hostnames =
        Array.from(domainCache.keys()).sort(domainCacheSort).slice(cacheCountLow);

    for (let i=hostnames.length-1; i>=0; --i) {
        domainCache.get(hostnames[i]).dispose();
        domainCache.delete(hostnames[i]);
    }
};

var domainCacheReset = function () {
    domainCache.clear();
};

publicSuffixList.onChanged.addListener(domainCacheReset);

var UriTools = {
    set: function (uri) {
        if (uri === undefined) {
            return reset(cached);
        }

        let matches = reRFC3986.exec(uri);
        if (!matches) {
            return reset(cached);
        }

        cached.scheme = matches[1] !== undefined ?
            matches[1].slice(0, -1) :
            '';
        cached.authority = matches[2] !== undefined ?
            matches[2].slice(2).toLowerCase() :
            '';
        cached.path = matches[3] !== undefined ?
            matches[3] :
            '';

        // As per RFC3986
        if (cached.authority !== '' && cached.path === '') {
            cached.path = '/';
        }

        cached.query = matches[4] !== undefined ?
            matches[4].slice(1) :
            '';
        cached.fragment = matches[5] !== undefined ?
            matches[5].slice(1) :
            '';

        if (reHostFromNakedAuthority.test(cached.authority)) {
            cached.hostname = cached.authority;
            cached.port = '';
            return cached;
        }

        matches = reHostPortFromAuthority.exec(cached.authority);
        if (!matches) {
            matches = reIPv6PortFromAuthority.exec(cached.authority);
            if (!matches) {
                return resetAuthority(cached);
            }
        }

        cached.hostname = matches[1] !== undefined ?
            matches[1] :
            '';

        if (cached.hostname.slice(-1) === '.') {
            cached.hostname = cached.hostname.slice(0, -1);
        }

        cached.port = matches[2] !== undefined ?
            matches[2].slice(1) :
            '';

        return cached;
    },
    assemble: function (bits) {
        if (bits === undefined) {
            bits = cached.allBits;
        }

        let s = [];

        if (cached.scheme && (bits && cached.schemeBit)) {
            s.push(cached.scheme, ':');
        }
        if (cached.hostname && (bits & cached.hostnameBit)) {
            s.push('//', cached.hostname);
        }
        if (cached.port && (bits & cached.portBit)) {
            s.push(':', cached.port);
        }
        if (cached.path && (bits & cached.pathBit)) {
            s.push(cached.path);
        }
        if (cached.query && (bits & cached.queryBit)) {
            s.push('?', cached.query);
        }
        if (cached.fragment && (bits & cached.fragmentBit)) {
            s.push('#', cached.fragment);
        }

        return s.join('');
    },
    isNetworkScheme: function (scheme) {
        return reNetworkScheme.test(scheme);
    },
    isSecureScheme: function(scheme) {
        return reSecureScheme.test(scheme);
    },
    originFromURI: function (uri) {
        let matches = reOriginFromURI.exec(uri);
        return matches !== null ? matches[0].toLowerCase() : '';
    },
    schemeFromURI: function (uri) {
        let matches = reSchemeFromURI.exec(uri);
        return matches !== null ? matches[0].slice(0, -1).toLowerCase() : '';
    },
    authorityFromURI: function (uri) {
        let matches = reAuthorityFromURI.exec(uri);
        return matches !== null ? matches[1].slice(1).toLowerCase() : '';
    },
    hostnameFromURI: function (uri) {
        let matches = reCommonHostnameFromURL.exec(uri);
        if (matches) {
            return matches[1];
        }

        matches = reAuthorityFromURI.exec(uri);
        if (!matches) {
            return '';
        }

        let auth = matches[1].slice(2);

        if (reHostFromNakedAuthority.test(auth)) {
            return auth.toLowerCase();
        }

        matches = reHostFromAuthority.exec(auth);
        if (!matches) {
            matches = reIPv6FromAuthority.exec(auth);
            if (!matches) {
                return '';
            }
        }

        let hostname = matches[1];
        while (hostname.endsWith('.')) {
            hostname = hostname.slice(0, -1);
        }

        if (reMustNormalizeHostname.test(hostname)) {
            Punycode.toASCII(hostname.toLowerCase());
        }

        return hostname;
    },
    domainFromHostname: function (hostname) {
        let entry = domainCache.get(hostname);
        if (entry !== undefined) {
            entry.tstamp = Date.now();
            return entry.domain;
        }

        if (reIPAddressNaive.test(hostname) == false) {
            return domainCacheAdd(hostname,
                                  publicSuffixList.getDomain(hostname));
        }

        return domainCacheAdd(hostname, hostname);
    },
    domainFromURI: function (uri) {
        if (!uri) {
            return '';
        }
        return UriTools.domainFromHostname(UriTools.hostnameFromURI(uri));
    },
    domain: function() {
        return UriTools.domainFromHostname(cached.hostname);
    },
    pathFromURI: function (uri) {
        let matches = rePathFromURI.exec(uri);
        return matches !== null ? matches[1] : '';
    },
    normalizedURI: function () {
        return UriTools.assemble(cached.normalizeBits);
    },
    rootURL: function () {
        if (!cached.hostname) {
            return '';
        }
        return UriTools.assemble(cached.scemeBit | cached.hostnameBit);
    },
    isValidHostname: function (hostname) {
        try {
            let r = reValidHostname.test(hostname);
            return r;
        } catch (e) {
            return false;
        }
    },
    parentHostnameFromHostname: function (hostname) {
        // "locahost" => ""
        // "example.org" => "example.org"
        // "www.example.org" => "example.org"
        // "tomato.www.example.org" => "example.org"
        let domain = UriTools.domainFromHostname(hostname);

        if (domain === '' || domain === hostname) {
            return undefined;
        }

        return hostname.slice(hostname.indexOf('.') + 1);
    },
    parentHostnamesFromHostname: function (hostname) {
        let domain = UriTools.domainFromHostname(hostname);
        if (domain === '' || domain === hostname) {
            return [];
        }

        let nodes = [];
        for (;;) {
            let pos = hostname.indexOf('.');
            if (pos < 0) {
                break;
            }

            hostname = hostname.slice(pos+1);
            nodes.push(hostname);
            if (hostname === domain) {
                break;
            }
        }

        return nodes;
    },
    allHostNamesFromHostname: function (hostname) {
        let nodes = UriTools.parentHostnamesFromHostname(hostname);
        nodes.unshift(hostname);
        return nodes;
    },
    toString: function () {
        return UriTools.assemble();
    },
};