#include "Utils.hpp"

#ifdef _WIN32
#	include <Windows.h>
#endif

#ifdef _WIN32
#	define BRUSSEL_MODE_STRING(string) L##string
#else
#	define BRUSSEL_MODE_STRING(string) string
#endif

#if _WIN32
using FopenModeString = const wchar_t*;
#else
using FopenModeString = const char*;
#endif

static FopenModeString GetModeString(Utils::IoMode mode, bool binary) {
	using namespace Utils;
	if (binary) {
		switch (mode) {
			case Read: return BRUSSEL_MODE_STRING("rb");
			case WriteTruncate: return BRUSSEL_MODE_STRING("wb");
			case WriteAppend: return BRUSSEL_MODE_STRING("ab");
		}
	} else {
		switch (mode) {
			case Read: return BRUSSEL_MODE_STRING("r");
			case WriteTruncate: return BRUSSEL_MODE_STRING("w");
			case WriteAppend: return BRUSSEL_MODE_STRING("a");
		}
	}
	return nullptr;
}

FILE* Utils::OpenCstdioFile(const std::filesystem::path& path, IoMode mode, bool binary) {
#ifdef _WIN32
	// std::filesystem::path::c_str() returns `const wchar_t*` under Windows, because NT uses UTF-16 natively
	// NOTE: _wfopen() only affects the type of path parameter, otherwise the file stream created is identical to the one by fopen()
	return _wfopen(path.c_str(), ::GetModeString(mode, binary));
#else
	return fopen(path.c_str(), ::GetModeString(mode, binary));
#endif
}

FILE* Utils::OpenCstdioFile(const char* path, IoMode mode, bool binary) {
#ifdef _WIN32
	// On Windows, fopen() accepts ANSI codepage encoded path, convert our UTF-8 string to UTF-16 to ensure that no matter what the locale is, the path continues to work
	WCHAR platformPath[MAX_PATH];
	if (MultiByteToWideChar(CP_UTF8, 0, path, -1, platformPath, MAX_PATH) == 0) {
		return nullptr;
	}
	return _wfopen(platformPath, ::GetModeString(mode, binary));
#else
	return fopen(path, ::GetModeString(mode, binary));
#endif
}

bool Utils::InRangeInclusive(int n, int lower, int upper) {
	if (lower > upper) {
		std::swap(lower, upper);
	}
	return n >= lower && n <= upper;
}

bool Utils::LineContains(glm::ivec2 p1, glm::ivec2 p2, glm::ivec2 candidate) {
	bool verticalLine = p1.x == p2.x && InRangeInclusive(candidate.x, p1.x, p2.x);
	bool horizontalLine = p1.y == p2.y && InRangeInclusive(candidate.y, p1.y, p2.y);
	return verticalLine && horizontalLine;
}

bool Utils::IsColinear(glm::ivec2 p1, glm::ivec2 p2) {
	return p1.x == p2.x || p1.y == p2.y;
}