//---
// fxos.util: Utility functions
//---

#ifndef LIBFXOS_UTIL_H
#define LIBFXOS_UTIL_H

#include <memory>
#include <iostream>
#include <string>
#include <memory>
#include <cstdio>

/* Format a string with printf() syntax */
template<typename ... Args>
std::string format(std::string const &format, Args ... args)
{
	/* Reserve space for snprintf() to put its NUL */
	size_t size = snprintf(nullptr, 0, format.c_str(), args ...) + 1;

	std::unique_ptr<char[]> buf(new char[size]);
	snprintf(buf.get(), size, format.c_str(), args ...);

	/* Remove the NUL from the string */
	return std::string(buf.get(), buf.get() + size - 1);
}

/* An RAII contiguous memory buffer */
class Buffer
{
public:
	/* Empty buffer initialized with given byte */
	Buffer(int size, int fill=0x00);

	/* Buffer initialized from file, reading the given size and offset.
	   * Default offset is beginning of file.
	   * Default size (-1) is file size. If the specified region ends after
	     the end of the file, the buffer is padded. */
	Buffer(std::string filepath, int size=-1, int offset=0, int fill=0x00);

	/* Create a buffer by copying (and possibly resizing) another buffer */
	Buffer(Buffer const &other, int new_size=-1);

	/* Size */
	int size() const noexcept;
};

/* A file abstraction that supports both direct load and memory mapping */
class File
{
public:
	/* Load a file, either by buffer or by memory mapping */
	File(std::string path, bool mmap=false);

	/* Get the path, size and loading address of the file */
	std::string path() const noexcept;
	size_t size() const noexcept;
	char *data() const noexcept;

	/* Free the allocated buffers */
	~File();

private:
	/* Path to file */
	std::string m_path;
	/* Size of buffer, or mapping */
	size_t m_size;
	/* Whether mmap() was used on the file */
	bool m_mmap;
	/* Data buffer (m_mmap=false) or mapping address (m_mmap=true) */
	char *m_addr;
};

#endif /* LIBFXOS_UTIL_H */