/*
 * Copyright 2016-2022 Haiku, Inc. All rights reserved.
 * Distributed under the terms of the MIT License.
 */


#include "debug.h"

#include <string.h>

#include <boot/platform.h>
#include <boot/stage2.h>
#include <boot/stdio.h>
#include <util/ring_buffer.h>

#include "efi_platform.h"
#include "serial.h"


static char sBuffer[16384];
static uint32 sBufferPosition;

static ring_buffer* sDebugSyslogBuffer = NULL;


static void
syslog_write(const char* buffer, size_t length)
{
	if (sDebugSyslogBuffer != NULL) {
		ring_buffer_write(sDebugSyslogBuffer, (const uint8*)buffer, length);
	} else if (sBufferPosition + length < sizeof(sBuffer)) {
		memcpy(sBuffer + sBufferPosition, buffer, length);
		sBufferPosition += length;
	}
}


static void
dprintf_args(const char *format, va_list args)
{
	char buffer[512];
	int length = vsnprintf(buffer, sizeof(buffer), format, args);
	if (length == 0)
		return;

	if (length >= (int)sizeof(buffer))
		length = sizeof(buffer) - 1;

	syslog_write(buffer, length);
	serial_puts(buffer, length);
}


extern "C" void
dprintf(const char *format, ...)
{
	va_list args;

	va_start(args, format);
	dprintf_args(format, args);
	va_end(args);
}


extern "C" void
panic(const char *format, ...)
{
	va_list args;

	platform_switch_to_text_mode();

	puts("*** PANIC ***");

	va_start(args, format);
	vprintf(format, args);
	va_end(args);

	while (true)
		kBootServices->Stall(1000000);
}


static void
allocate_ring_buffer(void)
{
	// allocate 1 MB memory
	void* buffer = NULL;
	size_t size = 1024 * 1024;

	if (platform_allocate_region(&buffer, size, 0, false) != B_OK)
		return;

	sDebugSyslogBuffer = create_ring_buffer_etc(buffer, size, 0);

	gKernelArgs.debug_output = sDebugSyslogBuffer;
	gKernelArgs.debug_size = sDebugSyslogBuffer->size;
}


void
debug_cleanup(void)
{
	allocate_ring_buffer();

	if (sDebugSyslogBuffer != NULL) {
		if (gKernelArgs.keep_debug_output_buffer) {
			// copy the output gathered so far into the ring buffer
			ring_buffer_clear(sDebugSyslogBuffer);
			ring_buffer_write(sDebugSyslogBuffer, (uint8*)sBuffer,
				sBufferPosition);
		}
	} else {
		gKernelArgs.keep_debug_output_buffer = false;
	}

	if (!gKernelArgs.keep_debug_output_buffer) {
		gKernelArgs.debug_output = kernel_args_malloc(sBufferPosition);
		if (gKernelArgs.debug_output != NULL) {
			memcpy(gKernelArgs.debug_output, sBuffer, sBufferPosition);
			gKernelArgs.debug_size = sBufferPosition;
		}
	}
}


char*
platform_debug_get_log_buffer(size_t *_size)
{
	if (_size != NULL)
		*_size = sizeof(sBuffer);

	return sBuffer;
}