/*
* Copyright (c) 2004-2005 Nokia Corporation and/or its subsidiary(-ies).
* All rights reserved.
* This component and the accompanying materials are made available
* under the terms of "Eclipse Public License v1.0"
* which accompanies this distribution, and is available
* at the URL "http://www.eclipse.org/legal/epl-v10.html".
*
* Initial Contributors:
* Nokia Corporation - initial contribution.
*
* Contributors:
*
* Description:
*
*/

/**    @file
   @internalComponent */

#include "ImageDisplayResolvrUtils.h"

//
// COpaqueDataParse
//    Class for reading and processing opaque data from the ECOM resource file
//    We store this as follows:
//		Version (1 byte)
// 		flags (2 bytes)
//		Main Uid (4 bytes)
//		Sub Uid (4 bytes)
//		Number extensions (1 byte)
//		{ ".XXX" \r } (x number extensions)
//		Number mime types (1 byte)
//		[ "mimetype" \r ] (for each mimetype)
//

// Note to avoid overhead, we only read the extensions and mime types on demand
// Until EnsureExtnsReadL() is called, ExtnsCount() and Extn is invalid. Similarly
// for mime types.

COpaqueDataParse* COpaqueDataParse::NewL(const TDesC8& aOpaqueData)
	{
	COpaqueDataParse* result = COpaqueDataParse::NewLC(aOpaqueData);
	CleanupStack::Pop(result);
	return result;
	}

COpaqueDataParse* COpaqueDataParse::NewLC(const TDesC8& aOpaqueData)
	{
	COpaqueDataParse* result = new (ELeave) COpaqueDataParse(aOpaqueData);
	CleanupStack::PushL(result);
	result->ConstructL();
	return result;
	}

COpaqueDataParse::COpaqueDataParse(const TDesC8& aOpaqueData):
	iOpaqueData(aOpaqueData)
	{
	}

void COpaqueDataParse::ConstructL()
	{
	ReadVersion();
	if (iVersion < KIclPluginFrameworkVersionOne || 
		iVersion > KIclPluginFrameworkVersionMax)
		User::Leave(KErrNotSupported);
	ReadFlags();
	ReadUids();
	}

COpaqueDataParse::~COpaqueDataParse()
	{
	iArray.Close();
	}

// Extract the Version number 
void COpaqueDataParse::ReadVersion()
	{
	ASSERT(iState<=EVersionProcessed); // should only call this on construction
	ASSERT(iOpaqueData.Length() >= KIndexForVersion + 1);
	//The version is one byte
	iVersion = iOpaqueData[KIndexForVersion];
	iState = EVersionProcessed;
	}


// Extract the (optional) flags
void COpaqueDataParse::ReadFlags()
	{
	ASSERT(iState<EFlagsProcessed);

	switch(iVersion)
		{
		case KIclPluginFrameworkVersionOne:
			ASSERT(iOpaqueData.Length() >= KIndexForFlags + 2); // opaque data not valid otherwise
			iFlags = (iOpaqueData[KIndexForFlags+0] << 8) | (iOpaqueData[KIndexForFlags+1]);
			iLenOfFlags = 2;
			break;
		}

	iStartOfUids = 1 + iLenOfFlags;
	iStartOfNumberOfExtns = 1 + iLenOfFlags + 8;
	iState = EFlagsProcessed;
	}

// Extract the two Uids 
void COpaqueDataParse::ReadUids()
	{
	ASSERT(iState<EUidsProcessed);
	ASSERT(iOpaqueData.Length() >= iStartOfUids + 4); // opaque data not valid otherwise
	// A given OpaqueData should either contain one Uid, in 4 bytes,
	// highest to lowest, with an implied second Uid set to KNullUid,
	// or two consecutive Uids, in 4 bytes each - 8 in all - main type followed by sub-type.
	// The 8 bytes may be followed, for basic types, by info on the file extensions
	// and MIME typesassociated with this plugin but this info is ignored here.
	iImageTypeUid.iUid = (iOpaqueData[iStartOfUids] << 24) | (iOpaqueData[iStartOfUids+1] << 16) | (iOpaqueData[iStartOfUids+2] << 8) | (iOpaqueData[iStartOfUids+3]);
	if (iOpaqueData.Length() == iStartOfUids + 4)
		{
		iImageSubTypeUid = KNullUid;
		}
	else
		{
		ASSERT(iOpaqueData.Length() >= iStartOfUids + 8);
		iImageSubTypeUid.iUid = (iOpaqueData[iStartOfUids+4] << 24) | (iOpaqueData[iStartOfUids+5] << 16) + (iOpaqueData[iStartOfUids+6] << 8) + (iOpaqueData[iStartOfUids+7]);
		}
	iState = EUidsProcessed;
	}

// read in the Extns from the opaque data
void COpaqueDataParse::EnsureExtnsReadL()
	{
	// if we've already read in the extensions, is a NOP
	if (iState>=EExtnsProcessed)
		{
		return;
		}

	ASSERT(iArray.Count()==0); // assume nothing in there at the moment

	iExtnCount = iOpaqueData[iStartOfNumberOfExtns];
	TInt pos = iStartOfNumberOfExtns+1; // start just after the extn count byte	

	for (TInt index=0; index<iExtnCount; index++)
		{
		TPtrC8 restOfData = iOpaqueData.Mid(pos);
		TInt endPos = restOfData.Locate(TChar('\r')); // \r is used to terminate each suffix
		ASSERT(endPos != KErrNotFound); // if we have -1, would not have found the CR
		TPtrC8 extn = restOfData.Left(endPos);
		User::LeaveIfError(iArray.Append(extn));
		pos += endPos + 1; // skip over the CR
		}
	iStartOfMimeTypes = pos;
	iState = EExtnsProcessed;
	ASSERT(iArray.Count()==iExtnCount);
	}

void COpaqueDataParse::EnsureMIMETypesReadL()
	{
	// if we've already read in the mime types, is a NOP
	if (iState>=EMIMETypesProcessed)
		return;

	EnsureExtnsReadL();
	ASSERT(iState==EExtnsProcessed);

	TInt pos = iStartOfMimeTypes;
	const TInt numMimeTypes = iOpaqueData[pos];
	pos += 1;

	for (TInt index=0; index<numMimeTypes; index++)
		{
		TPtrC8 restOfData = iOpaqueData.Mid(pos);
		TInt endPos = restOfData.Locate(TChar('\r')); // \r is used to terminate each suffix
		ASSERT(endPos != KErrNotFound); // if we have -1, would not have found the CR
		TPtrC8 mimeType = restOfData.Left(endPos);
		User::LeaveIfError(iArray.Append(mimeType));
		pos += endPos + 1; // skip over the CR
		}
	iState = EMIMETypesProcessed;
	ASSERT(iArray.Count()==iExtnCount+numMimeTypes);
	}

TBool COpaqueDataParse::CompareMIMETypes(const TDesC8& aMimeType1, const TDesC8& aMimeType2)
	{
	if (aMimeType1.Length() != aMimeType2.Length())
		{
		return EFalse;
		}
	return aMimeType1.CompareF(aMimeType2)==0; // true if exactly the same, if we ignore the case
	}

TBool COpaqueDataParse::CompareFileSuffixL(const TDesC& aFileSuffix1, const TDesC8& aFileSuffix2)
	{
	//First do a quick compare
	if (aFileSuffix1.Length() != aFileSuffix2.Length())
		{
		return EFalse;
		}

	//Change aFileSuffix2 from TDesC8 to TDesC
	HBufC* fileSuffix = HBufC::NewL(aFileSuffix2.Length()); //Not on CleanupStack since nothing can leave
	TPtr fileSuffixPtr(fileSuffix->Des());
	fileSuffixPtr.Copy(aFileSuffix2);

	const TBool result = aFileSuffix1.CompareF(*fileSuffix)==0; // true if exactly the same, if we ignore the case
	delete fileSuffix;

	return result;
	}

/*
 * 
 * Searches for a match of aPluginString in aClientString. Match returns ETrue
 * if aPluginString is found within aImplementationType according to the
 * following rules:
 * 1) All bytes in aClientString are exact but instances of '?' (0x3F) in
 *    aPluginString are treated as wildcards - matching any byte value at that
 *    position in aClientString.
 * 2) If aClientString is longer than aPluginString, ignore any excess bytes.
 * 3) aClientString is treated as a single descriptor - the '||' delimiters
 *    are not recognised.
 * 4) ETrue is returned if aPluginString matches the start of aClientString
 *    exactly, subject to wildcards.
 * 5) aBytesMatched will be filled in with the number of non-wildcard bytes in
 *    aPluginString. This is used to rank matches.
 *
 * @param     "const TDesC8& aClientString"
 *            The string from the client to search for a match
 * @param     "const TDesC8& aPluginString"
 *            The data to search for from the plugin
 * @param     "TInt& aBytesMatched"
 *            The number of non-wildcard bytes matched, or "1" if the match pattern contains only "?"
				i.e. should match any data
 * @return    "TBool"
 *            ETrue if a match was found, EFalse otherwise
 */
TBool CImageDisplayResolverUtils::Match(const TDesC8& aClientString, const TDesC8& aPluginString, TInt& aBytesMatched)
	{
	TInt pluginStringLength = aPluginString.Length();
	aBytesMatched = 0;
	while (pluginStringLength>1 && (aPluginString[pluginStringLength - 1] == '?'))
		{ // Clip extraneous '?' wildcards off the end of the plugin match string
		pluginStringLength--;
		}
	if (pluginStringLength == 0)
		{ // Plugin has no match string
		return EFalse;
		}
	if (aClientString.Length() < pluginStringLength)
		{ // Client string too short - can't match
		return EFalse;
		}
	// Now let's run along the string
	for (TInt index = 0; index < pluginStringLength; index++)
		{
		const TUint8 pluginChar = aPluginString[index];
		if (pluginChar=='?') // just ignore a wildchar
			{
			continue;
			}
		if (aClientString[index] != pluginChar)
			{
			return EFalse;
			}
		// else we've matched expected byte, so keep going
		aBytesMatched += 1;
		}
	aBytesMatched += (aPluginString[0]=='?' && pluginStringLength==1);
	ASSERT(aBytesMatched>0); // if we get this far, must have matched something - since we no match string can't be empty
	return ETrue;
	}