#include <stddef.h>
#include <stdint.h>

#include "commands.h"
#include "debug.h"
#include "kpanic.h"
#include "memory.h"
#include "multiboot.h"
#include "utils.h"
#include "vbe.h"

uint32_t multiboot_page_table[1024] __attribute__((aligned(PAGE_SIZE)));
uint32_t vbe_page_table[1024] __attribute__((aligned(PAGE_SIZE)));
multiboot_memory_map_t *mmap_addr;
multiboot_uint32_t mmap_length;

static void init_mmap(multiboot_info_t *mbd_virt, size_t *pt_index)
{
	// Index mbd->mmap_addr pointers
	uint32_t i = 0;
	for (; i < mbd_virt->mmap_length; i++)
		multiboot_page_table[i + *pt_index] =
		    ((mbd_virt->mmap_addr + i * PAGE_SIZE) & PAGE_MASK) |
		    INIT_FLAGS;
	mmap_addr = (multiboot_memory_map_t *)(GET_PAGE_ADDR(1023, *pt_index) +
	                                       (uint32_t)mbd_virt->mmap_addr %
	                                           PAGE_SIZE);
	mmap_length = mbd_virt->mmap_length / sizeof(multiboot_memory_map_t);
	*pt_index += i;
}

static void init_vbe(multiboot_info_t *mbd_virt)
{
	const uint32_t framebuffer_size =
	    mbd_virt->framebuffer_height * mbd_virt->framebuffer_pitch;
	for (uint32_t i = 0; i < CEIL(framebuffer_size, PAGE_SIZE); i++) {
		vbe_page_table[i % 1024] =
		    ((mbd_virt->framebuffer_addr + i * PAGE_SIZE) & PAGE_MASK) |
		    INIT_FLAGS;
	}
	kernel_pd[800] = ((uint32_t)vbe_page_table - HEAP_END) | 0x03;
	display.buff = (uint32_t *)GET_PAGE_ADDR(800, 0) +
	               (mbd_virt->framebuffer_addr % PAGE_SIZE);
	display.height = mbd_virt->framebuffer_height;
	display.width = mbd_virt->framebuffer_width;
	display.pitch = mbd_virt->framebuffer_pitch;
	display.bpp = mbd_virt->framebuffer_bpp;
}

void init_multiboot(multiboot_info_t *mbd, uint32_t magic)
{
	if (magic != MULTIBOOT_BOOTLOADER_MAGIC)
		kpanic("invalid magic number! (git good skill issue)");

	init_page_table(multiboot_page_table, 0);
	kernel_pd[1023] = ((uint32_t)multiboot_page_table - HEAP_END) | 0x03;
	size_t pt_index = CEIL(
	    (uint32_t)mbd % PAGE_SIZE + sizeof(multiboot_info_t), PAGE_SIZE);

	// Index multiboot_info_t struct
	for (uint32_t i = 0; i < pt_index; i++)
		multiboot_page_table[i] =
		    (((uint32_t)mbd + PAGE_SIZE * i) & PAGE_MASK) | INIT_FLAGS;
	multiboot_info_t *mbd_virt =
	    (multiboot_info_t *)(GET_PAGE_ADDR(1023, 0) +
	                         (uint32_t)mbd % PAGE_SIZE);
	init_mmap(mbd_virt, &pt_index);
	init_vbe(mbd_virt);
}