#include "precompiled.h"

#include "StringConvert.h"
#include "lib/types.h"
#include "scripting/SpiderMonkey.h"

#if SDL_BYTE_ORDER == SDL_BIG_ENDIAN
#define ucs2le_to_wchart(ptr) (wchar_t)( (u16) ((u8*)ptr)[0] | (u16) ( ((u8*)ptr)[1] << 8) )
#else
#define ucs2le_to_wchart(ptr) (wchar_t)(*ptr);
#endif


JSString* StringConvert::wchars_to_jsstring(JSContext* cx, const wchar_t* chars, size_t len)
{
	if (len == 0)
		return JSVAL_TO_STRING(JS_GetEmptyStringValue(cx));

	jschar* data = (jschar*)JS_malloc(cx, len*sizeof(jschar));

	if (!data)
		return NULL;

	// Copy the string data, doing wchar_t->jschar conversion (since they're not equal in GCC)
	for (size_t i=0; i<len; ++i)
		data[i] = chars[i];

	return JS_NewUCString(cx, data, len);
}

JSString* StringConvert::wchars_to_jsstring(JSContext* cx, const wchar_t* chars)
{
	return wchars_to_jsstring(cx, chars, wcslen(chars));
}

JSString* StringConvert::wstring_to_jsstring(JSContext* cx, const std::wstring& str)
{
	return wchars_to_jsstring(cx, str.data(), str.length());
}



void StringConvert::jsstring_to_wstring(JSString* str, std::wstring& result)
{
	jschars_to_wstring(JS_GetStringChars(str), JS_GetStringLength(str), result);
}

void StringConvert::jschars_to_wstring(const jschar* chars, size_t len, std::wstring& result)
{
	debug_assert(result.empty());
	result.resize(len);

	for (size_t i = 0; i < len; ++i)
		result[i] = chars[i];
}


void StringConvert::ucs2le_to_wstring(const char* start, const char* end, std::wstring& result)
{
	debug_assert(result.empty());
	result.resize((end-start)/2);

	size_t i = 0;
	for (const char* pos = start; pos < end; pos += 2)
		result[i++] = ucs2le_to_wchart(pos);
}
