#include "util/FileUtils.hpp"

#ifndef _WIN32
#include <sys/types.h>
#include <dirent.h>
#include <limits.h>
#else
#define WIN32_MEAN_AND_LEAN
#include <windows.h>
#include "util/win32/errormsg.hpp"
#include "win32/tcharutils.h"
#endif

#include <sstream>
#include <stdexcept>
#include <cstring>
#include <cerrno>

using namespace std;

#ifndef _WIN32
static vector<string> directory_entries_unix( const string &dir, bool absolute, bool recursive )
{
	vector<string> files;
	
	DIR *d = opendir( dir.c_str( ) );
	if( d == NULL ) {
		ostringstream ss;
		ss << "opendir failed with '" << dir << "': " << strerror( errno );
		throw runtime_error( ss.str( ) );
	}

	struct dirent *entry = readdir( d );
	while( entry != NULL ) {
		if( entry->d_type == DT_DIR ) {
			if( strcmp( entry->d_name, "." ) == 0 ||
				strcmp( entry->d_name, ".." ) == 0 ) {
				entry = readdir( d );
				continue;
			}
			if( recursive ) {
				ostringstream ss;
				ss << dir << "/" << entry->d_name;
				vector<string> subfiles = directory_entries_unix( ss.str( ), absolute, recursive );
				files.insert( files.end( ), subfiles.begin( ), subfiles.end( ) );
			}
		} else if( entry->d_type == DT_REG ) {
			if( absolute ) {
				ostringstream ss;
				ss << dir << "/" << entry->d_name;
				files.push_back( ss.str( ) );
			} else {
				files.push_back( string( entry->d_name ) );
			}
		}
		entry = readdir( d );
	}
	
	closedir( d );

	return files;
}
#endif

#ifdef _WIN32
static vector<string> directory_entries_win32( const string &dir, bool absolute, bool recursive )
{
	vector<string> files;
		
	wstringstream wpath;
	wpath << utf8toucs2( dir ) << L"\\*";
	
	WIN32_FIND_DATAW fd;
	HANDLE h = FindFirstFileW( wpath.str( ).c_str( ), &fd );
	if( h == INVALID_HANDLE_VALUE ) {
		DWORD err = GetLastError( );
		if( err == ERROR_NO_MORE_FILES ) {
			FindClose( h );
			return files;
		}
		ostringstream ss;
		ss << "FindFirstFileW failed with '" << dir << "': " << getLastError( );
		throw runtime_error( ss.str( ) );
	}

	while( h != INVALID_HANDLE_VALUE ) {
		if( ( fd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY ) != 0 ) {
			if( wcscmp( fd.cFileName, L"." ) == 0 ||
				wcscmp( fd.cFileName, L".." ) == 0 ) {
				goto NEXT;
			}
			if( recursive ) {
				ostringstream ss;
				ss << dir << "\\" << wchartoutf8( fd.cFileName );
				vector<string> subfiles = directory_entries_win32( ss.str( ), absolute, recursive );
				files.insert( files.end( ), subfiles.begin( ), subfiles.end( ) );
			}
		} else if( ( fd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY ) == 0 ) {
			if( absolute ) {
				ostringstream ss;
				ss << dir << "\\" << wchartoutf8( fd.cFileName );
				files.push_back( ss.str( ) );
			} else {
				files.push_back( string( wchartoutf8( fd.cFileName ) ) );
			}
		}
NEXT:
		if( !FindNextFileW( h, &fd ) ) {
			DWORD err = GetLastError( );
			if( err == ERROR_NO_MORE_FILES ) {
				// finish iterating
				FindClose( h );
				return files;
			} else { 
				FindClose( h );
				ostringstream ss;
				ss << "FindNextFileW failed with '" << dir << "': " << getLastError( );
				throw runtime_error( ss.str( ) );
			}
		}
	}

	FindClose( h );

	return files;
}
#endif

UTIL_DLL_VISIBLE vector<string> directory_entries( const string &dir, bool absolute, bool recursive )
{
#ifdef _WIN32
	return directory_entries_win32( dir, absolute, recursive );
#else
	return directory_entries_unix( dir, absolute, recursive );
#endif
}