// Copyright (c) 2015 YamaArashi

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <errno.h>
#include <limits.h>
#include "global.h"
#include "util.h"

bool ParseNumber(char *s, char **end, int radix, int *intValue)
{
	char *localEnd;

	if (end == NULL)
		end = &localEnd;

	errno = 0;

	const long longValue = strtol(s, end, radix);

	if (*end == s)
		return false; // not a number

	if ((longValue == LONG_MIN || longValue == LONG_MAX) && errno == ERANGE)
		return false;

	if (longValue > INT_MAX)
		return false;

	if (longValue < INT_MIN)
		return false;

	*intValue = (int)longValue;

	return true;
}

char *GetFileExtension(char *path)
{
	char *extension = path;

	while (*extension != 0)
		extension++;

	while (extension > path && *extension != '.')
		extension--;

	if (extension == path)
		return NULL;

	extension++;

	if (*extension == 0)
		return NULL;

	return extension;
}

void ExpectFileExtension(char *path, char *expectedExtension)
{
	char *extension = GetFileExtension(path);

	if (extension == NULL)
		FATAL_ERROR("\"%s\" has no file extension.\n", path);

	if (strcmp(extension, expectedExtension) != 0)
		FATAL_ERROR("Unexpected file extension \"%s\". Expected \"%s\".\n", extension, expectedExtension);
}

void AddFileExtension(char *path, char *extension)
{
	int pathLength = strlen(path);
	int extensionLength = strlen(extension);

	if (pathLength + 1 + extensionLength > GBAGFX_MAX_PATH)
		FATAL_ERROR("\"%s\" is too long a path to add the extension \"%s\".\n", path, extension);

	path[pathLength] = '.';
	memcpy(path + pathLength + 1, extension, extensionLength);
	path[pathLength + 1 + extensionLength] = 0;
}

void RemoveFileExtension(char *path)
{
	char *extension = GetFileExtension(path);

	if (extension == NULL)
		FATAL_ERROR("\"%s\" doesn't have a file extension.\n", path);

	extension--;

	*extension = 0;
}

void ChangeFileExtension(char *path, char *extension)
{
	RemoveFileExtension(path);
	AddFileExtension(path, extension);
}

unsigned char *ReadWholeFile(char *path, int *size)
{
	FILE *fp = fopen(path, "rb");

	if (fp == NULL)
		FATAL_ERROR("Failed to open \"%s\" for reading.\n", path);

	fseek(fp, 0, SEEK_END);

	*size = ftell(fp);

	unsigned char *buffer = malloc(*size);

	if (buffer == NULL)
		FATAL_ERROR("Failed to allocate memory for reading \"%s\".\n", path);

	rewind(fp);

	if (fread(buffer, *size, 1, fp) != 1)
		FATAL_ERROR("Failed to read \"%s\".\n", path);

	fclose(fp);

	return buffer;
}

void WriteWholeFile(char *path, void *buffer, int bufferSize)
{
	FILE *fp = fopen(path, "wb");

	if (fp == NULL)
		FATAL_ERROR("Failed to open \"%s\" for writing.\n", path);

	if (fwrite(buffer, bufferSize, 1, fp) != 1)
		FATAL_ERROR("Failed to write to \"%s\".\n", path);

	fclose(fp);
}