/*
Open Tracker License

Terms and Conditions

Copyright (c) 1991-2000, Be Incorporated. All rights reserved.

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
of the Software, and to permit persons to whom the Software is furnished to do
so, subject to the following conditions:

The above copyright notice and this permission notice applies to all licensees
and shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF TITLE, MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
BE INCORPORATED BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF, OR IN CONNECTION
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Except as contained in this notice, the name of Be Incorporated shall not be
used in advertising or otherwise to promote the sale, use or other dealings in
this Software without prior written authorization from Be Incorporated.

Tracker(TM), Be(R), BeOS(R), and BeIA(TM) are trademarks or registered trademarks
of Be Incorporated in the United States and other countries. Other brand product
names are registered trademarks or trademarks of their respective holders.
All rights reserved.
*/

#include "TrackerString.h"

#include <stdio.h>
#include <stdlib.h>
#include <strings.h>


//	#pragma mark - TrackerString


TrackerString::TrackerString()
{
}


TrackerString::TrackerString(const char* string)
	:
	BString(string)
{
}


TrackerString::TrackerString(const TrackerString &string)
	:
	BString(string)
{
}


TrackerString::TrackerString(const char* string, int32 maxLength)
	:
	BString(string, maxLength)
{
}


TrackerString::~TrackerString()
{
}


bool
TrackerString::Matches(const char* string, bool caseSensitivity,
	TrackerStringExpressionType expressionType) const
{
	switch (expressionType) {
		default:
		case kNone:
			return false;

		case kStartsWith:
			return StartsWith(string, caseSensitivity);

		case kEndsWith:
			return EndsWith(string, caseSensitivity);

		case kContains:
			return Contains(string, caseSensitivity);

		case kGlobMatch:
			return MatchesGlob(string, caseSensitivity);

		case kRegexpMatch:
			return MatchesRegExp(string, caseSensitivity);
	}
}


bool
TrackerString::MatchesRegExp(const char* pattern, bool caseSensitivity) const
{
	BString patternString(pattern);
	BString textString(String());

	if (caseSensitivity == false) {
		patternString.ToLower();
		textString.ToLower();
	}

	RegExp expression(patternString);

	if (expression.InitCheck() != B_OK)
		return false;

	return expression.Matches(textString);
}


bool
TrackerString::MatchesGlob(const char* string, bool caseSensitivity) const
{
	return StringMatchesPattern(String(), string, caseSensitivity);
}


bool
TrackerString::EndsWith(const char* string, bool caseSensitivity) const
{
	// If "string" is longer than "this",
	// we should simply return false
	int32 position = Length() - (int32)strlen(string);
	if (position < 0)
		return false;

	if (caseSensitivity)
		return FindLast(string) == position;
	else
		return IFindLast(string) == position;
}


bool
TrackerString::StartsWith(const char* string, bool caseSensitivity) const
{
	if (caseSensitivity)
		return FindFirst(string) == 0;
	else
		return IFindFirst(string) == 0;
}


bool
TrackerString::Contains(const char* string, bool caseSensitivity) const
{
	if (caseSensitivity)
		return FindFirst(string) > -1;
	else
		return IFindFirst(string) > -1;
}


// MatchesBracketExpression() assumes 'pattern' to point to the
// character following the initial '[' in a bracket expression.
// The reason is that an encountered '[' will be taken literally.
// (Makes it possible to match a '[' with the expression '[[]').
bool
TrackerString::MatchesBracketExpression(const char* string,
	const char* pattern, bool caseSensitivity) const
{
	bool GlyphMatch = IsStartOfGlyph(string[0]);

	if (IsInsideGlyph(string[0]))
		return false;

	char testChar = ConditionalToLower(string[0], caseSensitivity);
	bool match = false;

	bool inverse = *pattern == '^' || *pattern == '!';
		// We allow both ^ and ! as a initial inverting character.

	if (inverse)
		pattern++;

	while (!match && *pattern != ']' && *pattern != '\0') {
		switch (*pattern) {
			case '-':
			{
				char start = ConditionalToLower(*(pattern - 1),
					caseSensitivity);
				char stop = ConditionalToLower(*(pattern + 1),
					caseSensitivity);

				if (IsGlyph(start) || IsGlyph(stop))
					return false;
						// Not a valid range!

				if ((islower(start) && islower(stop))
					|| (isupper(start) && isupper(stop))
					|| (isdigit(start) && isdigit(stop))) {
					// Make sure 'start' and 'stop' are of the same type.
					match = start <= testChar && testChar <= stop;
				} else {
					// If no valid range, we've got a syntax error.
					return false;
				}

				break;
			}

			default:
				if (GlyphMatch)
					match = UTF8CharsAreEqual(string, pattern);
				else
					match = CharsAreEqual(testChar, *pattern, caseSensitivity);
				break;
		}

		if (!match) {
			pattern++;
			if (IsInsideGlyph(pattern[0]))
				pattern = MoveToEndOfGlyph(pattern);
		}
	}

	// Consider an unmatched bracket a failure
	// (i.e. when detecting a '\0' instead of a ']'.)
	if (*pattern == '\0')
		return false;

	return (match ^ inverse) != 0;
}


bool
TrackerString::StringMatchesPattern(const char* string, const char* pattern,
	bool caseSensitivity) const
{
	// One could do this dynamically, counting the number of *'s,
	// but then you have to free them at every exit of this
	// function, which is awkward and ugly.
	const int32 kWildCardMaximum = 100;
	const char* pStorage[kWildCardMaximum];
	const char* sStorage[kWildCardMaximum];

	int32 patternLevel = 0;

	if (string == NULL || pattern == NULL)
		return false;

	while (*pattern != '\0') {
		switch (*pattern) {
			case '?':
				pattern++;
				string++;
				if (IsInsideGlyph(string[0]))
					string = MoveToEndOfGlyph(string);
				break;

			case '*':
			{
				// Collapse any ** and *? constructions:
				while (*pattern == '*' || *pattern == '?') {
					pattern++;
					if (*pattern == '?' && *string != '\0') {
						string++;
						if (IsInsideGlyph(string[0]))
							string = MoveToEndOfGlyph(string);
					}
				}

				if (*pattern == '\0') {
					// An ending * matches all strings.
					return true;
				}

				bool match = false;
				const char* pBefore = pattern - 1;

				if (*pattern == '[') {
					pattern++;

					while (!match && *string != '\0') {
						match = MatchesBracketExpression(string++, pattern,
							caseSensitivity);
					}

					while (*pattern != ']' && *pattern != '\0') {
						// Skip the rest of the bracket:
						pattern++;
					}

					if (*pattern == '\0') {
						// Failure if no closing bracket;
						return false;
					}
				} else {
					// No bracket, just one character:
					while (!match && *string != '\0') {
						if (IsGlyph(string[0]))
							match = UTF8CharsAreEqual(string++, pattern);
						else {
							match = CharsAreEqual(*string++, *pattern,
								caseSensitivity);
						}
					}
				}

				if (!match)
					return false;
				else {
					pStorage[patternLevel] = pBefore;
					if (IsInsideGlyph(string[0]))
						string = MoveToEndOfGlyph(string);

					sStorage[patternLevel++] = string;
					if (patternLevel > kWildCardMaximum)
						return false;

					pattern++;
					if (IsInsideGlyph(pattern[0]))
						pattern = MoveToEndOfGlyph(pattern);
				}
				break;
			}

			case '[':
				pattern++;

				if (!MatchesBracketExpression(string, pattern,
						caseSensitivity)) {
					if (patternLevel > 0) {
						pattern = pStorage[--patternLevel];
						string = sStorage[patternLevel];
					} else
						return false;
				} else {
					// Skip the rest of the bracket:
					while (*pattern != ']' && *pattern != '\0')
						pattern++;

					// Failure if no closing bracket;
					if (*pattern == '\0')
						return false;

					string++;
					if (IsInsideGlyph(string[0]))
						string = MoveToEndOfGlyph(string);
					pattern++;
				}
				break;

			default:
			{
				bool equal = false;
				if (IsGlyph(string[0]))
					equal = UTF8CharsAreEqual(string, pattern);
				else
					equal = CharsAreEqual(*string, *pattern, caseSensitivity);

				if (equal) {
					pattern++;
					if (IsInsideGlyph(pattern[0]))
						pattern = MoveToEndOfGlyph(pattern);
					string++;
					if (IsInsideGlyph(string[0]))
						string = MoveToEndOfGlyph(string);
				} else if (patternLevel > 0) {
						pattern = pStorage[--patternLevel];
						string = sStorage[patternLevel];
				} else
					return false;
				break;
			}
		}

		if (*pattern == '\0' && *string != '\0' && patternLevel > 0) {
			pattern = pStorage[--patternLevel];
			string = sStorage[patternLevel];
		}
	}

	return *string == '\0' && *pattern == '\0';
}


bool
TrackerString::UTF8CharsAreEqual(const char* string1,
	const char* string2) const
{
	const char* s1 = string1;
	const char* s2 = string2;

	if (IsStartOfGlyph(*s1) && *s1 == *s2) {
		s1++;
		s2++;

		while (IsInsideGlyph(*s1) && *s1 == *s2) {
			s1++;
			s2++;
		}

		return !IsInsideGlyph(*s1)
			&& !IsInsideGlyph(*s2) && *(s1 - 1) == *(s2 - 1);
	} else
		return false;
}


const char*
TrackerString::MoveToEndOfGlyph(const char* string) const
{
	const char* ptr = string;

	while (IsInsideGlyph(*ptr))
		ptr++;

	return ptr;
}


bool
TrackerString::IsGlyph(char ch) const
{
	return (ch & 0x80) == 0x80;
}


bool
TrackerString::IsInsideGlyph(char ch) const
{
	return (ch & 0xC0) == 0x80;
}


bool
TrackerString::IsStartOfGlyph(char ch) const
{
	return (ch & 0xC0) == 0xC0;
}