/*
 * File:	SearchPath.cpp
 *
 * Copyright (c) Freescale Semiconductor, Inc. All rights reserved.
 * See included license file for license details.
 */

#include "SearchPath.h"
#include <stdio.h>

#if defined(WIN32)
	#define PATH_SEP_CHAR '\\'
	#define PATH_SEP_STRING "\\"
#else
	#define PATH_SEP_CHAR '/'
	#define PATH_SEP_STRING "/"
#endif

PathSearcher * PathSearcher::s_searcher = NULL;

//! This function will create the global path search object if it has
//! not already been created.
PathSearcher & PathSearcher::getGlobalSearcher()
{
	if (!s_searcher)
	{
		s_searcher = new PathSearcher;
	}
	
	return *s_searcher;
}

void PathSearcher::addSearchPath(std::string & path)
{
	m_paths.push_back(path);
}

//! The \a base path argument can be either a relative or absolute path. If the path
//! is relative, then it is joined with search paths one after another until a matching
//! file is located or all search paths are exhausted. If the \a base is absolute,
//! only that path is tested and if invalid false is returned.
//!
//! \param base A path to the file that is to be found.
//! \param targetType Currently ignored. In the future it will let you select whether to
//!		find a file or directory.
//! \param searchCwd If set to true, the current working directory is searched before using
//!		any of the search paths. Otherwise only the search paths are considered.
//! \param[out] result When true is returned this string is set to the first path at which
//!		a valid file was found.
//!
//! \retval true A matching file was found among the search paths. The contents of \a result
//!		are a valid path.
//! \retval false No match could be made. \a result has been left unmodified.
bool PathSearcher::search(const std::string & base, target_type_t targetType, bool searchCwd, std::string & result)
{
	FILE * tempFile;
	bool absolute = isAbsolute(base);
	
	// Try cwd first if requested. Same process applies to absolute paths.
	if (absolute || searchCwd)
	{
		tempFile = fopen(base.c_str(), "r");
		if (tempFile)
		{
			fclose(tempFile);
			result = base;
			return true;
		}
	}
	
	// If the base path is absolute and the previous test failed, then we don't go any further.
	if (absolute)
	{
		return false;
	}
	
	// Iterate over all search paths.
	string_list_t::const_iterator it = m_paths.begin();
	for (; it != m_paths.end(); ++it)
	{
		std::string searchPath = joinPaths(*it, base);
		
		tempFile = fopen(searchPath.c_str(), "r");
		if (tempFile)
		{
			fclose(tempFile);
			result = searchPath;
			return true;
		}
	}
	
	// Couldn't find anything matching the base path.
	return false;
}

bool PathSearcher::isAbsolute(const std::string & path)
{
#if __WIN32__
	return path.size() >= 3 && path[1] == ':' && path[2] == '\\';
#else
	return path.size() >= 1 && path[0] == '/';
#endif
}

std::string PathSearcher::joinPaths(const std::string & first, const std::string & second)
{
	// Start with first string.
	std::string result = first;
	
	// Add path separator if needed
	if ((first[first.size() - 1] != PATH_SEP_CHAR) && (second[0] != PATH_SEP_CHAR))
	{
		result += PATH_SEP_STRING;
	}
	
	// Append the second string.
	result += second;
	
	// And return the whole mess.
	return result;
}