/*

 * Copyright (C) 2008 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 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 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 "ManifestParser.h"

#if ENABLE(OFFLINE_WEB_APPLICATIONS)

#include "CharacterNames.h"

#include "KURL.h"

#include "TextResourceDecoder.h"

using namespace std;

namespace WebCore {

enum Mode { Explicit, Fallback, OnlineWhitelist, Unknown };

bool parseManifest(const KURL& manifestURL, const char* data, int length, Manifest& manifest)

{

    ASSERT(manifest.explicitURLs.isEmpty());

    ASSERT(manifest.onlineWhitelistedURLs.isEmpty());

    ASSERT(manifest.fallbackURLs.isEmpty());

    manifest.allowAllNetworkRequests = false;

    Mode mode = Explicit;

    RefPtr<TextResourceDecoder> decoder = TextResourceDecoder::create("text/cache-manifest", "UTF-8");

    String s = decoder->decode(data, length);

    s += decoder->flush();

    // Look for the magic signature: "^\xFEFF?CACHE MANIFEST[ \t]?" (the BOM is removed by TextResourceDecoder).

    // Example: "CACHE MANIFEST #comment" is a valid signature.

    // Example: "CACHE MANIFEST;V2" is not.

    if (!s.startsWith("CACHE MANIFEST"))

        return false;

    const UChar* end = s.characters() + s.length();    

    const UChar* p = s.characters() + 14; // "CACHE MANIFEST" is 14 characters.

    if (p < end && *p != ' ' && *p != '\t' && *p != '\n' && *p != '\r')

        return false;

    // Skip to the end of the line.

    while (p < end && *p != '\r' && *p != '\n')

        p++;

    while (1) {

        // Skip whitespace

        while (p < end && (*p == '\n' || *p == '\r' || *p == ' ' || *p == '\t'))

            p++;

        if (p == end)

            break;

        const UChar* lineStart = p;

        // Find the end of the line

        while (p < end && *p != '\r' && *p != '\n')

            p++;

        // Check if we have a comment

        if (*lineStart == '#')

            continue;

        // Get rid of trailing whitespace

        const UChar* tmp = p - 1;

        while (tmp > lineStart && (*tmp == ' ' || *tmp == '\t'))

            tmp--;

        String line(lineStart, tmp - lineStart + 1);

        if (line == "CACHE:") 

            mode = Explicit;

        else if (line == "FALLBACK:")

            mode = Fallback;

        else if (line == "NETWORK:")

            mode = OnlineWhitelist;

        else if (line.endsWith(":"))

            mode = Unknown;

        else if (mode == Unknown)

            continue;

        else if (mode == Explicit || mode == OnlineWhitelist) {

            const UChar* p = line.characters();

            const UChar* lineEnd = p + line.length();

            // Look for whitespace separating the URL from subsequent ignored tokens.

            while (p < lineEnd && *p != '\t' && *p != ' ') 

                p++;

            if (mode == OnlineWhitelist && p - line.characters() == 1 && *line.characters() == '*') {

                // Wildcard was found.

                manifest.allowAllNetworkRequests = true;

                continue;

            }

            KURL url(manifestURL, String(line.characters(), p - line.characters()));

            if (!url.isValid())

                continue;

            if (url.hasFragmentIdentifier())

                url.removeFragmentIdentifier();

            if (!equalIgnoringCase(url.protocol(), manifestURL.protocol()))

                continue;

            if (mode == Explicit && manifestURL.protocolIs("https") && !protocolHostAndPortAreEqual(manifestURL, url))

                continue;

            if (mode == Explicit)

                manifest.explicitURLs.add(url.string());

            else

                manifest.onlineWhitelistedURLs.append(url);

        } else if (mode == Fallback) {

            const UChar* p = line.characters();

            const UChar* lineEnd = p + line.length();

            // Look for whitespace separating the two URLs

            while (p < lineEnd && *p != '\t' && *p != ' ') 

                p++;

            if (p == lineEnd) {

                // There was no whitespace separating the URLs.

                continue;

            }

            KURL namespaceURL(manifestURL, String(line.characters(), p - line.characters()));

            if (!namespaceURL.isValid())

                continue;

            if (namespaceURL.hasFragmentIdentifier())

                namespaceURL.removeFragmentIdentifier();

            if (!protocolHostAndPortAreEqual(manifestURL, namespaceURL))

                continue;

            // Skip whitespace separating fallback namespace from URL.

            while (p < lineEnd && (*p == '\t' || *p == ' '))

                p++;

            // Look for whitespace separating the URL from subsequent ignored tokens.

            const UChar* fallbackStart = p;

            while (p < lineEnd && *p != '\t' && *p != ' ') 

                p++;

            KURL fallbackURL(manifestURL, String(fallbackStart, p - fallbackStart));

            if (!fallbackURL.isValid())

                continue;

            if (fallbackURL.hasFragmentIdentifier())

                fallbackURL.removeFragmentIdentifier();

            if (!protocolHostAndPortAreEqual(manifestURL, fallbackURL))

                continue;

            manifest.fallbackURLs.append(make_pair(namespaceURL, fallbackURL));            

        } else 

            ASSERT_NOT_REACHED();

    }

    return true;

}

}

#endif // ENABLE(OFFLINE_WEB_APPLICATIONS)