/*

 * Copyright (C) 2009, 2010 Apple Inc. All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY

 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY

 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 

 */

#include "config.h"

#include "UserContentURLPattern.h"

#include "KURL.h"

#include <wtf/StdLibExtras.h>

namespace WebCore {

bool UserContentURLPattern::matchesPatterns(const KURL& url, const Vector<String>* whitelist, const Vector<String>* blacklist)

{

    // In order for a URL to be a match it has to be present in the whitelist and not present in the blacklist.

    // If there is no whitelist at all, then all URLs are assumed to be in the whitelist.

    bool matchesWhitelist = !whitelist || whitelist->isEmpty();

    if (!matchesWhitelist) {

        for (unsigned i = 0; i < whitelist->size(); ++i) {

            UserContentURLPattern contentPattern(whitelist->at(i));

            if (contentPattern.matches(url)) {

                matchesWhitelist = true;

                break;

            }

        }

    }

    bool matchesBlacklist = false;

    if (blacklist) {

        for (unsigned i = 0; i < blacklist->size(); ++i) {

            UserContentURLPattern contentPattern(blacklist->at(i));

            if (contentPattern.matches(url)) {

                matchesBlacklist = true;

                break;

            }

        }

    }

    return matchesWhitelist && !matchesBlacklist;

}

bool UserContentURLPattern::parse(const String& pattern)

{

    DEFINE_STATIC_LOCAL(const String, schemeSeparator, ("://"));

    int schemeEndPos = pattern.find(schemeSeparator);

    if (schemeEndPos == -1)

        return false;

    m_scheme = pattern.left(schemeEndPos);

    int hostStartPos = schemeEndPos + schemeSeparator.length();

    if (hostStartPos >= static_cast<int>(pattern.length()))

        return false;

    int pathStartPos = 0;

    if (equalIgnoringCase(m_scheme, "file"))

        pathStartPos = hostStartPos;

    else {

        int hostEndPos = pattern.find("/", hostStartPos);

        if (hostEndPos == -1)

            return false;

        m_host = pattern.substring(hostStartPos, hostEndPos - hostStartPos);

        m_matchSubdomains = false;

        if (m_host == "*") {

            // The pattern can be just '*', which means match all domains.

            m_host = "";

            m_matchSubdomains = true;

        } else if (m_host.startsWith("*.")) {

            // The first component can be '*', which means to match all subdomains.

            m_host = m_host.substring(2); // Length of "*."

            m_matchSubdomains = true;

        }

        // No other '*' can occur in the host.

        if (m_host.find("*") != -1)

            return false;

        pathStartPos = hostEndPos;

    }

    m_path = pattern.right(pattern.length() - pathStartPos);

    return true;

}

bool UserContentURLPattern::matches(const KURL& test) const

{

    if (m_invalid)

        return false;

    if (!equalIgnoringCase(test.protocol(), m_scheme))

        return false;

    if (!equalIgnoringCase(m_scheme, "file") && !matchesHost(test))

        return false;

    return matchesPath(test);

}

bool UserContentURLPattern::matchesHost(const KURL& test) const

{

    const String& host = test.host();

    if (equalIgnoringCase(host, m_host))

        return true;

    if (!m_matchSubdomains)

        return false;

    // If we're matching subdomains, and we have no host, that means the pattern

    // was <scheme>://*/<whatever>, so we match anything.

    if (!m_host.length())

        return true;

    // Check if the domain is a subdomain of our host.

    if (!host.endsWith(m_host, false))

        return false;

    ASSERT(host.length() > m_host.length());

    // Check that the character before the suffix is a period.

    return host[host.length() - m_host.length() - 1] == '.';

}

struct MatchTester

{

    const String m_pattern;

    unsigned m_patternIndex;

    const String m_test;

    unsigned m_testIndex;

    MatchTester(const String& pattern, const String& test)

    : m_pattern(pattern)

    , m_patternIndex(0)

    , m_test(test)

    , m_testIndex(0)

    {

    }

    bool testStringFinished() const { return m_testIndex >= m_test.length(); }

    bool patternStringFinished() const { return m_patternIndex >= m_pattern.length(); }

    void eatWildcard()

    {

        while (!patternStringFinished()) {

            if (m_pattern[m_patternIndex] != '*')

                return;

            m_patternIndex++;

        }

    }

    void eatSameChars()

    {

        while (!patternStringFinished() && !testStringFinished()) {

            if (m_pattern[m_patternIndex] == '*')

                return;

            if (m_pattern[m_patternIndex] != m_test[m_testIndex])

                return;

            m_patternIndex++;

            m_testIndex++;

        }

    }

    bool test()

    {

        // Eat all the matching chars.

        eatSameChars();

        // If the string is finished, then the pattern must be empty too, or contains

        // only wildcards.

        if (testStringFinished()) {

            eatWildcard();

            if (patternStringFinished())

                return true;

            return false;

        }

        // Pattern is empty but not string, this is not a match.

        if (patternStringFinished())

            return false;

        // If we don't encounter a *, then we're hosed.

        if (m_pattern[m_patternIndex] != '*')

            return false;

        while (!testStringFinished()) {

            MatchTester nextMatch(*this);

            nextMatch.m_patternIndex++;

            if (nextMatch.test())

                return true;

            m_testIndex++;

        }

        // We reached the end of the string.  Let's see if the pattern contains only

        // wildcards.

        eatWildcard();

        return patternStringFinished();

    }

};

bool UserContentURLPattern::matchesPath(const KURL& test) const

{

    MatchTester match(m_path, test.path());

    return match.test();

}

} // namespace WebCore