#include "debug.hpp"

#include <cstddef>
#include <cstdint>
#include <cstring>

#include <tonc.h>

#include <mtl/string.hpp>
#include <mtl/string_view.hpp>

namespace debug {
/**
 * \brief MGBA debug registers and constants
 */
namespace reg {
/**
 * \brief MGBA debug enable register.
 *
 * When 0xC0DE is written to the register, debug output is enabled.
 * When 0 is written to the register, debug output is disabled.
 * Will be set to 0x1DEA when successfully enabled.
 */
static volatile uint16_t& enable = *reinterpret_cast<uint16_t*>(0x4FFF780);
/**
 * \brief MGBA debug flags register.
 */
static volatile uint16_t& flags = *reinterpret_cast<uint16_t*>(0x4FFF700);
/**
 * \brief MGBA debug string register.
 *
 * Max length of 0x100 (256) including null terminator.
 */
static char* string = reinterpret_cast<char*>(0x4FFF600);
constexpr static size_t string_len = 255;
}; // namespace reg

void puts(const mtl::string_view& msg, level lvl) {
	size_t count = msg.length();
	if (count > reg::string_len) { count = reg::string_len; }

	// Must be copied manually because the MGBA string register does
	// not allow copying in reverse (I think)
	msg.copy(reg::string, count);
	reg::flags = lvl | 0x100;
}

bool open() {
	reg::enable = 0xC0DE;
	return reg::enable == 0x1DEA;
}

void close() {
	reg::enable = 0;
}
}; // namespace debug