#include "scriptfilesystem.h"

#if defined(_WIN32)
#include <direct.h> // _getcwd
#include <Windows.h> // FindFirstFile, GetFileAttributes

#undef DeleteFile
#undef CopyFile

#else
#include <unistd.h> // getcwd
#include <dirent.h> // opendir, readdir, closedir
#include <sys/stat.h> // stat
#endif
#include <assert.h> // assert

using namespace std;

BEGIN_AS_NAMESPACE

// TODO: The file system should have a way to allow the application to define in
//       which sub directories it is allowed to make changes and/or read

CScriptFileSystem *ScriptFileSystem_Factory()
{
	return new CScriptFileSystem();
}

void RegisterScriptFileSystem_Native(asIScriptEngine *engine)
{
	int r;

	r = engine->RegisterObjectType("filesystem", 0, asOBJ_REF); assert( r >= 0 );
	r = engine->RegisterObjectBehaviour("filesystem", asBEHAVE_FACTORY, "filesystem @f()", asFUNCTION(ScriptFileSystem_Factory), asCALL_CDECL); assert( r >= 0 );
	r = engine->RegisterObjectBehaviour("filesystem", asBEHAVE_ADDREF, "void f()", asMETHOD(CScriptFileSystem,AddRef), asCALL_THISCALL); assert( r >= 0 );
	r = engine->RegisterObjectBehaviour("filesystem", asBEHAVE_RELEASE, "void f()", asMETHOD(CScriptFileSystem,Release), asCALL_THISCALL); assert( r >= 0 );
	
	r = engine->RegisterObjectMethod("filesystem", "bool changeCurrentPath(const string &in)", asMETHOD(CScriptFileSystem, ChangeCurrentPath), asCALL_THISCALL); assert( r >= 0 );
	r = engine->RegisterObjectMethod("filesystem", "string getCurrentPath() const", asMETHOD(CScriptFileSystem, GetCurrentPath), asCALL_THISCALL); assert( r >= 0 );
	r = engine->RegisterObjectMethod("filesystem", "array<string> @getDirs() const", asMETHOD(CScriptFileSystem, GetDirs), asCALL_THISCALL); assert( r >= 0 );
	r = engine->RegisterObjectMethod("filesystem", "array<string> @getFiles() const", asMETHOD(CScriptFileSystem, GetFiles), asCALL_THISCALL); assert( r >= 0 );
	r = engine->RegisterObjectMethod("filesystem", "bool isDir(const string &in) const", asMETHOD(CScriptFileSystem, IsDir), asCALL_THISCALL); assert( r >= 0 );
	r = engine->RegisterObjectMethod("filesystem", "bool isLink(const string &in) const", asMETHOD(CScriptFileSystem, IsLink), asCALL_THISCALL); assert(r >= 0);
	r = engine->RegisterObjectMethod("filesystem", "int64 getSize(const string &in) const", asMETHOD(CScriptFileSystem, GetSize), asCALL_THISCALL); assert(r >= 0);
	r = engine->RegisterObjectMethod("filesystem", "int makeDir(const string &in)", asMETHOD(CScriptFileSystem, MakeDir), asCALL_THISCALL); assert(r >= 0);
	r = engine->RegisterObjectMethod("filesystem", "int removeDir(const string &in)", asMETHOD(CScriptFileSystem, RemoveDir), asCALL_THISCALL); assert(r >= 0);
	r = engine->RegisterObjectMethod("filesystem", "int deleteFile(const string &in)", asMETHOD(CScriptFileSystem, DeleteFile), asCALL_THISCALL); assert(r >= 0);
	r = engine->RegisterObjectMethod("filesystem", "int copyFile(const string &in, const string &in)", asMETHOD(CScriptFileSystem, CopyFile), asCALL_THISCALL); assert(r >= 0);
	r = engine->RegisterObjectMethod("filesystem", "int move(const string &in, const string &in)", asMETHOD(CScriptFileSystem, Move), asCALL_THISCALL); assert(r >= 0);
}

void RegisterScriptFileSystem(asIScriptEngine *engine)
{
//	if( strstr(asGetLibraryOptions(), "AS_MAX_PORTABILITY") )
//		RegisterScriptFileSystem_Generic(engine);
//	else
		RegisterScriptFileSystem_Native(engine);
}

CScriptFileSystem::CScriptFileSystem()
{
	refCount = 1;

	// Gets the application's current working directory as the starting point
	// TODO: Replace backslash with slash to keep a unified naming convention
	char buffer[1000];
#if defined(_WIN32)
	currentPath = _getcwd(buffer, 1000);
#else
	currentPath = getcwd(buffer, 1000);
#endif
}

CScriptFileSystem::~CScriptFileSystem()
{
}

void CScriptFileSystem::AddRef() const
{
	asAtomicInc(refCount);
}

void CScriptFileSystem::Release() const
{
	if( asAtomicDec(refCount) == 0 )
		delete this;
}

CScriptArray *CScriptFileSystem::GetFiles() const
{
	// Obtain a pointer to the engine
	asIScriptContext *ctx = asGetActiveContext();
	asIScriptEngine *engine = ctx->GetEngine();

	// TODO: This should only be done once
	// TODO: This assumes that CScriptArray was already registered
	asITypeInfo *arrayType = engine->GetTypeInfoByDecl("array<string>");

	// Create the array object
	CScriptArray *array = CScriptArray::Create(arrayType);

#if defined(_WIN32)
	// Windows uses UTF16 so it is necessary to convert the string
	wchar_t bufUTF16[10000];
	string searchPattern = currentPath + "/*";
	MultiByteToWideChar(CP_UTF8, 0, searchPattern.c_str(), -1, bufUTF16, 10000);

	WIN32_FIND_DATAW ffd;
	HANDLE hFind = FindFirstFileW(bufUTF16, &ffd);
	if( INVALID_HANDLE_VALUE == hFind ) 
		return array;
	
	do
	{
		// Skip directories
		if( (ffd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) )
			continue;

		// Convert the file name back to UTF8
		char bufUTF8[10000];
		WideCharToMultiByte(CP_UTF8, 0, ffd.cFileName, -1, bufUTF8, 10000, 0, 0);
		
		// Add the file to the array
		array->Resize(array->GetSize()+1);
		((string*)(array->At(array->GetSize()-1)))->assign(bufUTF8);
	}
	while( FindNextFileW(hFind, &ffd) != 0 );

	FindClose(hFind);
#else
	dirent *ent = 0;
	DIR *dir = opendir(currentPath.c_str());
	while( (ent = readdir(dir)) != NULL ) 
	{
		const string filename = ent->d_name;

		// Skip . and ..
		if( filename[0] == '.' )
			continue;

		// Skip sub directories
		const string fullname = currentPath + "/" + filename;
		struct stat st;
		if( stat(fullname.c_str(), &st) == -1 )
			continue;
		if( (st.st_mode & S_IFDIR) != 0 )
			continue;

		// Add the file to the array
		array->Resize(array->GetSize()+1);
		((string*)(array->At(array->GetSize()-1)))->assign(filename);
	}
	closedir(dir);
#endif

	return array;
}

CScriptArray *CScriptFileSystem::GetDirs() const
{
	// Obtain a pointer to the engine
	asIScriptContext *ctx = asGetActiveContext();
	asIScriptEngine *engine = ctx->GetEngine();

	// TODO: This should only be done once
	// TODO: This assumes that CScriptArray was already registered
	asITypeInfo *arrayType = engine->GetTypeInfoByDecl("array<string>");

	// Create the array object
	CScriptArray *array = CScriptArray::Create(arrayType);

#if defined(_WIN32)
	// Windows uses UTF16 so it is necessary to convert the string
	wchar_t bufUTF16[10000];
	string searchPattern = currentPath + "/*";
	MultiByteToWideChar(CP_UTF8, 0, searchPattern.c_str(), -1, bufUTF16, 10000);
	
	WIN32_FIND_DATAW ffd;
	HANDLE hFind = FindFirstFileW(bufUTF16, &ffd);
	if( INVALID_HANDLE_VALUE == hFind ) 
		return array;
	
	do
	{
		// Skip files
		if( !(ffd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) )
			continue;

		// Convert the file name back to UTF8
		char bufUTF8[10000];
		WideCharToMultiByte(CP_UTF8, 0, ffd.cFileName, -1, bufUTF8, 10000, 0, 0);

		if( strcmp(bufUTF8, ".") == 0 || strcmp(bufUTF8, "..") == 0 )
			continue;
		
		// Add the dir to the array
		array->Resize(array->GetSize()+1);
		((string*)(array->At(array->GetSize()-1)))->assign(bufUTF8);
	}
	while( FindNextFileW(hFind, &ffd) != 0 );

	FindClose(hFind);
#else
	dirent *ent = 0;
	DIR *dir = opendir(currentPath.c_str());
	while( (ent = readdir(dir)) != NULL ) 
	{
		const string filename = ent->d_name;

		// Skip . and ..
		if( filename[0] == '.' )
			continue;

		// Skip files
		const string fullname = currentPath + "/" + filename;
		struct stat st;
		if( stat(fullname.c_str(), &st) == -1 )
			continue;
		if( (st.st_mode & S_IFDIR) == 0 )
			continue;

		// Add the dir to the array
		array->Resize(array->GetSize()+1);
		((string*)(array->At(array->GetSize()-1)))->assign(filename);
	}
	closedir(dir);
#endif

	return array;
}

// Doesn't change anything if the new path is not valid
bool CScriptFileSystem::ChangeCurrentPath(const string &path)
{
	string newPath;
	if( path.find(":") != string::npos || path.find("/") == 0 || path.find("\\") == 0 )
		newPath = path;
	else
		newPath = currentPath + "/" + path;

	// TODO: Resolve internal /./ and /../
	// TODO: Replace backslash with slash to keep a unified naming convention

	// Remove trailing slashes from the path
	while(newPath.length() && (newPath[newPath.length()-1] == '/' || newPath[newPath.length()-1] == '\\') )
		newPath.resize(newPath.length()-1);

	if (!IsDir(newPath))
		return false;

	currentPath = newPath;
	return true;
}

bool CScriptFileSystem::IsDir(const string &path) const
{
	string search;
	if( path.find(":") != string::npos || path.find("/") == 0 || path.find("\\") == 0 )
		search = path;
	else
		search = currentPath + "/" + path;

#if defined(_WIN32)
	// Windows uses UTF16 so it is necessary to convert the string
	wchar_t bufUTF16[10000];
	MultiByteToWideChar(CP_UTF8, 0, search.c_str(), -1, bufUTF16, 10000);

	// Check if the path exists and is a directory
	DWORD attrib = GetFileAttributesW(bufUTF16);
	if( attrib == INVALID_FILE_ATTRIBUTES ||
		!(attrib & FILE_ATTRIBUTE_DIRECTORY) )
		return false;
#else
	// Check if the path exists and is a directory
	struct stat st;
	if( stat(search.c_str(), &st) == -1 )
		return false;
	if( (st.st_mode & S_IFDIR) == 0 )
		return false;
#endif

	return true;
}

bool CScriptFileSystem::IsLink(const string &path) const
{
	string search;
	if (path.find(":") != string::npos || path.find("/") == 0 || path.find("\\") == 0)
		search = path;
	else
		search = currentPath + "/" + path;

#if defined(_WIN32)
	// Windows uses UTF16 so it is necessary to convert the string
	wchar_t bufUTF16[10000];
	MultiByteToWideChar(CP_UTF8, 0, search.c_str(), -1, bufUTF16, 10000);

	// Check if the path exists and is a link
	DWORD attrib = GetFileAttributesW(bufUTF16);
	if (attrib == INVALID_FILE_ATTRIBUTES ||
		!(attrib & FILE_ATTRIBUTE_REPARSE_POINT))
		return false;
#else
	// Check if the path exists and is a link
	struct stat st;
	if (stat(search.c_str(), &st) == -1)
		return false;
	if ((st.st_mode & S_IFLNK) == 0)
		return false;
#endif

	return true;
}

asINT64 CScriptFileSystem::GetSize(const string &path) const
{
	string search;
	if (path.find(":") != string::npos || path.find("/") == 0 || path.find("\\") == 0)
		search = path;
	else
		search = currentPath + "/" + path;

#if defined(_WIN32)
	// Windows uses UTF16 so it is necessary to convert the string
	wchar_t bufUTF16[10000];
	MultiByteToWideChar(CP_UTF8, 0, search.c_str(), -1, bufUTF16, 10000);

	// Get the size of the file
	LARGE_INTEGER largeInt;
	HANDLE file = CreateFileW(bufUTF16, GENERIC_READ, FILE_SHARE_READ, 0, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
	BOOL success = GetFileSizeEx(file, &largeInt);
	CloseHandle(file);
	if( !success )
		return -1;
	return asINT64(largeInt.QuadPart);
#else
	// Get the size of the file
	struct stat st;
	if (stat(search.c_str(), &st) == -1)
		return -1;
	return asINT64(st.st_size);
#endif
}

// TODO: Should be able to return different codes for
//       - directory exists
//       - path not found
//       - access denied
// TODO: Should be able to define the permissions for the directory
int CScriptFileSystem::MakeDir(const string &path)
{
	string search;
	if (path.find(":") != string::npos || path.find("/") == 0 || path.find("\\") == 0)
		search = path;
	else
		search = currentPath + "/" + path;

#if defined(_WIN32)
	// Windows uses UTF16 so it is necessary to convert the string
	wchar_t bufUTF16[10000];
	MultiByteToWideChar(CP_UTF8, 0, search.c_str(), -1, bufUTF16, 10000);

	// Create the directory
	BOOL success = CreateDirectoryW(bufUTF16, 0);
	return success ? 0 : -1;
#else
	// Create the directory
	int failure = mkdir(search.c_str(), S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH);
	return !failure ? 0 : -1;
#endif
}

// TODO: Should be able to return different codes for 
//       - directory doesn't exist
//       - directory is not empty
//       - access denied
// TODO: Should have an option to remove the directory and all content recursively
int CScriptFileSystem::RemoveDir(const string &path)
{
	string search;
	if (path.find(":") != string::npos || path.find("/") == 0 || path.find("\\") == 0)
		search = path;
	else
		search = currentPath + "/" + path;

#if defined(_WIN32)
	// Windows uses UTF16 so it is necessary to convert the string
	wchar_t bufUTF16[10000];
	MultiByteToWideChar(CP_UTF8, 0, search.c_str(), -1, bufUTF16, 10000);

	// Remove the directory
	BOOL success = RemoveDirectoryW(bufUTF16);
	return success ? 0 : -1;
#else
	// Remove the directory
	int failure = rmdir(search.c_str());
	return !failure ? 0 : -1;
#endif
}

int CScriptFileSystem::DeleteFile(const string &path)
{
	string search;
	if (path.find(":") != string::npos || path.find("/") == 0 || path.find("\\") == 0)
		search = path;
	else
		search = currentPath + "/" + path;

#if defined(_WIN32)
	// Windows uses UTF16 so it is necessary to convert the string
	wchar_t bufUTF16[10000];
	MultiByteToWideChar(CP_UTF8, 0, search.c_str(), -1, bufUTF16, 10000);

	// Remove the file
	BOOL success = DeleteFileW(bufUTF16);
	return success ? 0 : -1;
#else
	// Remove the file
	int failure = unlink(search.c_str());
	return !failure ? 0 : -1;
#endif
}

int CScriptFileSystem::CopyFile(const string &source, const string &target)
{
	string search1;
	if (source.find(":") != string::npos || source.find("/") == 0 || source.find("\\") == 0)
		search1 = source;
	else
		search1 = currentPath + "/" + source;

	string search2;
	if (target.find(":") != string::npos || target.find("/") == 0 || target.find("\\") == 0)
		search2 = target;
	else
		search2 = currentPath + "/" + target;

#if defined(_WIN32)
	// Windows uses UTF16 so it is necessary to convert the string
	wchar_t bufUTF16_1[10000];
	MultiByteToWideChar(CP_UTF8, 0, search1.c_str(), -1, bufUTF16_1, 10000);

	wchar_t bufUTF16_2[10000];
	MultiByteToWideChar(CP_UTF8, 0, search2.c_str(), -1, bufUTF16_2, 10000);

	// Copy the file
	BOOL success = CopyFileW(bufUTF16_1, bufUTF16_2, TRUE);
	return success ? 0 : -1;
#else
	// Copy the file manually as there is no posix function for this
	bool failure = false;
	FILE *src = 0, *tgt = 0;
	src = fopen(search1.c_str(), "r");
	if (src == 0) failure = true;
	if( !failure ) tgt = fopen(search2.c_str(), "w");
	if (tgt == 0) failure = true;
	char buf[1024];
	size_t n;
	while (!failure && (n = fread(buf, sizeof(char), sizeof(buf), src)) > 0)
	{
		if (fwrite(buf, sizeof(char), n, tgt) != n)
			failure = true;
	}
	if (src) fclose(src);
	if (tgt) fclose(tgt);
	return !failure ? 0 : -1;
#endif
}

int CScriptFileSystem::Move(const string &source, const string &target)
{
	string search1;
	if (source.find(":") != string::npos || source.find("/") == 0 || source.find("\\") == 0)
		search1 = source;
	else
		search1 = currentPath + "/" + source;

	string search2;
	if (target.find(":") != string::npos || target.find("/") == 0 || target.find("\\") == 0)
		search2 = target;
	else
		search2 = currentPath + "/" + target;

#if defined(_WIN32)
	// Windows uses UTF16 so it is necessary to convert the string
	wchar_t bufUTF16_1[10000];
	MultiByteToWideChar(CP_UTF8, 0, search1.c_str(), -1, bufUTF16_1, 10000);

	wchar_t bufUTF16_2[10000];
	MultiByteToWideChar(CP_UTF8, 0, search2.c_str(), -1, bufUTF16_2, 10000);

	// Move the file or directory
	BOOL success = MoveFileW(bufUTF16_1, bufUTF16_2);
	return success ? 0 : -1;
#else
	// Move the file or directory
	int failure = rename(search1.c_str(), search2.c_str());
	return !failure ? 0 : -1;
#endif
}

string CScriptFileSystem::GetCurrentPath() const
{
	return currentPath;
}


END_AS_NAMESPACE
