/*

* Copyright (c) 2002-2004 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:   Namespace class NICalUtil.Its an utility class.

*

*/

// Class include.

#include "ICalUtil.h"	// NICalUtil

//debug

#include "calendarengines_debug.h"

// User includes.

#include "ICalErrors.h"			// Error codes

#include "ICalKeyWords.h"		// Literals

#include "ICalProperty.h"		// CICalProperty

#include "ICalPropertyParam.h"	// CICalPropertyParam

namespace NICalUtil

	{

	/**

	Finds the first occurence of a character within a string which does not occur

	between a pair of double quotes.

	@param aString The string to search.

	@param aChar The character to search for.

	@return The position of the character within the string, or KErrNotFound.

	@internalTechnology

	*/

	TInt FindFirstUnquoted(const TDesC& aString, const TChar& aChar)

		{

		TRACE_ENTRY_POINT;

		TBool quoted(EFalse);

		for (TInt pos = 0; pos < aString.Length(); ++pos)

			{

			TChar val(aString[pos]);

			if (val == KICalQuoteChar)

				{

				quoted = !quoted;

				}

			else if ((val == aChar) && (!quoted))

				{

				TRACE_EXIT_POINT;

				return pos;

				}

			}

		return KErrNotFound;

		}

	/**

	Finds the first occurence of a character within a string which is not escaped

	by a backslash character. Searching for a comma will find it in the following

	strings: "abc," and "abc\\," but will not find it in "abc\," and "abc\\\,".

	Note that backslash cannot exist unescaped, so cannot be searched for.

	@param aString The string to search.

	@param aChar The character to search for.

	@return The position of the character within the string, or KErrNotFound.

	@internalTechnology

	*/

	TInt FindFirstUnescaped(const TDesC& aString, const TChar& aChar)

		{

		TRACE_ENTRY_POINT;

		TBool escaped(EFalse);

		for (TInt pos = 0; pos < aString.Length(); ++pos)

			{

			TChar val(aString[pos]);

			if (val == KICalBackslashChar)

				{

				escaped = !escaped;

				}

			else 

				{

				if ((val == aChar) && (!escaped))

					{

					TRACE_EXIT_POINT;

					return pos;

					}

				escaped = EFalse;

				}

			}

		TRACE_EXIT_POINT;	

		return KErrNotFound;	

		}

	/**

	Finds the first occurence of a character within a string, whether or not it

	is escaped by a backslash character. If it was escaped, however, the

	aWasEscaped parameter will be set to true. Note that backslash cannot exist

	unescaped, so cannot be searched for.

	@param aString The string to search.

	@param aChar The character to search for.

	@param aWasEscaped True if the character was escaped, otherwise false.

	@return The position of the character within the string, or KErrNotFound.

	@internalTechnology

	*/

	TInt FindFirstAndUnescape(const TDesC& aString, const TChar& aChar, TBool& aWasEscaped)

		{

		TRACE_ENTRY_POINT;

		aWasEscaped = EFalse;

		TBool escaped(EFalse);

		for (TInt pos = 0; pos < aString.Length(); ++pos)

			{

			TChar val(aString[pos]);

			if (val == KICalBackslashChar)

				{

				escaped = !escaped;

				}

			else 

				{

				if (val == aChar)

					{

					aWasEscaped = escaped;

					TRACE_EXIT_POINT;

					return pos;

					}

				escaped = EFalse;

				}

			}

		TRACE_EXIT_POINT;	

		return KErrNotFound;	

		}

	/**

	Take a line and extract the name, parameter and value sections.

	@param aLine A line of text in which to find the data.

	@param aName A TPtrC referencing the section of aLine containing the name.

	@param aParameters A TPtrC referencing the section of aLine containing the

	parameters.

	@param aValues A TPtrC referencing the section of aLine containing the

	values.

	@return An error code: either KErrNone or KErrPropertyHasNoValue - avoid

	leaving so we can try and recover without the overhead of a trap.

	@internalTechnology

	*/

	TInt ExtractSectionsL(const TDesC& aLine, TPtrC& aName, TPtrC& aParameters, TPtrC& aValues)

		{

		TRACE_ENTRY_POINT;

		// Find the value delimiter.

		const TInt colon = FindFirstUnquoted(aLine, KICalColonChar);

		// Vague check that the property has a value.

		if ((colon == KErrNotFound) || (colon == (aLine.Length() - 1)))

			{

			TRACE_EXIT_POINT;

			return KErrPropertyHasNoValue;	// No value given - the property is invalid.

			}

		// Find the first parameter delimiter.

		const TInt firstSemiColon = aLine.Locate(KICalSemiColonChar);

		// Find the characters dividing each section:

		TUint endOfName(colon);

		if ((firstSemiColon != KErrNotFound) && (firstSemiColon < colon))

			{

			endOfName = firstSemiColon;

			}

		// Set the name, parameters and values:

		aName.Set(aLine.Left(endOfName));

		if (endOfName < colon)

			{

			const TInt startOfParameters = endOfName + 1;

			aParameters.Set(aLine.Mid(startOfParameters, colon - startOfParameters));

			}

		else

			{

			aParameters.Set(aLine.Left(0));	// No parameters.

			}

		aValues.Set(aLine.Mid(colon + 1));

		TRACE_EXIT_POINT;

		return KErrNone;

		}

	/**

	Takes two strings, representing the parameters and values of a property, and

	the property itself, and populates the latter with the contents of the first

	two.

	@param aParameters A string of parameters.

	@param aValues A string of values.

	@param aProperty A property to add the parameters and values to.

	@internalTechnology

	*/

	void ExtractPropertyL(const TDesC& aParameters, const TDesC& aValues, CICalProperty& aProperty)

		{

		TRACE_ENTRY_POINT;

		ExtractParametersL(aParameters, aProperty);

		ExtractPropertyValuesL(aValues, aProperty);

		TRACE_EXIT_POINT;

		}

	/**

	Takes a string representing the parameters of a property, and the property

	itself, and populates the property with the contents of the string.

	@param aParameters A string of parameters.

	@param aProperty A property to add the parameters and values to.

	@internalTechnology

	*/

	void ExtractParametersL(const TDesC& aParameters, CICalProperty& aProperty)

		{

		TRACE_ENTRY_POINT;

		TPtrC remainder(aParameters);

		while (remainder.Length() > 0)

			{

			TInt endOfParameter(FindFirstUnquoted(remainder, KICalSemiColonChar));

			if (endOfParameter == KErrNotFound)

				{

				endOfParameter = remainder.Length();

				}

			CICalPropertyParam& param = aProperty.AddPropertyParamL();

			ExtractParameterL(remainder.Left(endOfParameter), param);

			// Remove the parameter if it has no value.

			if (param.Values().Count() == 0)

				{

				aProperty.RemovePropertyParamL(param);

				}

			if (endOfParameter < remainder.Length())

				{

				remainder.Set(remainder.Mid(endOfParameter + 1));

				}

			else

				{

				break;

				}

			}

		TRACE_EXIT_POINT;

		}

	/**

	Takes a string representing a single parameter, and a class to store it in.

	@param aParameter A string of the form <parameter>[=<value>[,value]*].

	@param aPropertyParam A property parameter to store the data in.

	@internalTechnology

	*/

	void ExtractParameterL(const TDesC& aParameter, CICalPropertyParam& aPropertyParam)

		{

		TRACE_ENTRY_POINT;

		TInt firstEquals(aParameter.Locate(KICalEqualsChar));

		TUint endOfType(aParameter.Length());

		if (firstEquals != KErrNotFound)

			{

			endOfType = firstEquals;

			}

		aPropertyParam.SetTypeL(aParameter.Left(endOfType));

		if (endOfType < aParameter.Length())

			{

			ExtractParameterValuesL(aParameter.Mid(endOfType + 1), aPropertyParam);

			}

		TRACE_EXIT_POINT;

		}

	/**

	Takes a string of comma separated values and adds them to a parameter.

	@param aValues A string of the form <value>[,<value>]*.

	@param aPropertyParam A property parameter to store the values in.

	@internalTechnology

	*/

	void ExtractParameterValuesL(const TDesC& aValues, CICalPropertyParam& aPropertyParam)

		{

		TRACE_ENTRY_POINT;

		TPtrC remainder(aValues);

		while (remainder.Length() > 0)

			{

			TInt endOfValue(FindFirstUnquoted(remainder, KICalCommaChar));

			if (endOfValue == KErrNotFound)

				{

				endOfValue = remainder.Length();

				}

			// Add value.

			if (endOfValue > 0)

				{

				aPropertyParam.AddValueL(remainder.Left(endOfValue));

				}

			if (endOfValue < remainder.Length())

				{

				remainder.Set(remainder.Mid(endOfValue + 1));

				}

			else

				{

				break;

				}

			}

		TRACE_EXIT_POINT;

		}

	/**

	Takes a string of comma separated values and adds them to a property.

	@param aValues A string of the form <value>[,<value>]*.

	@param aProperty A property to store the values in.

	@param aEscaping Used for dealing with incorrect output from other applications.

	@leave Leaves with KErrUnknown if the value of aEscaping is not known.

	@internalTechnology

	*/

	void ExtractPropertyValuesL(const TDesC& aValues, CICalProperty& aProperty, TEscaping aEscaping)

		{

		TRACE_ENTRY_POINT;

		TPtrC remainder(aValues);

		TBool wasEscaped(EFalse);

		while (remainder.Length() > 0)

			{

			TInt endOfValue(KErrNotFound);

			switch (aEscaping)

				{

				case EEscapeNormal:

					endOfValue = FindFirstUnescaped(remainder, KICalCommaChar);

					break;

				case EEscapeValueSeparators:

					endOfValue = FindFirstAndUnescape(remainder, KICalCommaChar, wasEscaped);

					break;

				default:

					User::Leave(KErrUnknown);

					break;

				}

			if (endOfValue == KErrNotFound)

				{

				endOfValue = remainder.Length();

				}

			// Add value.

			if (endOfValue > 0)

				{

				aProperty.AddValueL(remainder.Left(endOfValue - (wasEscaped ? 1 : 0)));

				}

			if (endOfValue < remainder.Length())

				{

				remainder.Set(remainder.Mid(endOfValue + 1));

				}

			else

				{

				break;

				}

			}

		TRACE_EXIT_POINT;

		}

	/**

	Determines if the given property has a type which holds a text value.

	@param aProperty The property to test.

	@return ETrue if the property value is a "text" type.

	@internalTechnology

	*/

	TBool PropertyHasTextValueL(const CICalProperty& aProperty)

		{

		TRACE_ENTRY_POINT;

		const TDesC& type = aProperty.Type();

		// First check if it's an X-type.

		if ((type.Length() >= 2) && (type.Left(2).CompareF(KICalXProperty) == 0))

			{

			TRACE_EXIT_POINT;

			return ETrue;

			}

		// Else return ETrue if the property is PRODID, UID, CATEGORIES, COMMENT, CONTACT,

		// DESCRIPTION, LOCATION, RELATED-TO, RESOURCES, SUMMARY, TZID or TZNAME.

		TRACE_EXIT_POINT;

		return ((type.CompareF(KICalProdId) == 0) || (type.CompareF(KICalUid) == 0) ||

			(type.CompareF(KICalCategories) == 0) || (type.CompareF(KICalComment) == 0) ||

			(type.CompareF(KICalContact) == 0) || (type.CompareF(KICalDescription) == 0) || 

			(type.CompareF(KICalLocation) == 0) || (type.CompareF(KICalRelatedto) == 0) || 

			(type.CompareF(KICalResources) == 0) || (type.CompareF(KICalSummary) == 0) || 

			(type.CompareF(KICalTzid) == 0) || (type.CompareF(KICalTzname) == 0));

		}

	}

// End of File