#include "../libc/stdio.h"
#include "../drivers/serial.h"
#include "gdt.h"
#include "idt.h"
#include "system.h"
#include "paging.h"
#include "../drivers/ata.h"
#include <stdint.h>
#include "../drivers/framebuffer.h"

typedef struct {
    uint32_t type;
    uint32_t size;
    uint64_t framebuffer_addr;
    uint32_t framebuffer_pitch;
    uint32_t framebuffer_width;
    uint32_t framebuffer_height;
    uint8_t framebuffer_bpp;
    uint8_t framebuffer_type;
    uint16_t reserved;
} multiboot2_tag_framebuffer;

typedef struct {
    uint32_t total_size;
    uint32_t reserved;
    uint8_t tags[0];
} multiboot2_info;

unsigned int g_multiboot_info_address;

uint32_t* framebuffer;
int scanline;

// in characters, not pixels
uint32_t VGA_WIDTH;
uint32_t VGA_HEIGHT;


void kmain(multiboot2_info *mb_info)
{

	multiboot2_tag_framebuffer *fb_info = NULL;

uint8_t *tags = mb_info->tags;
    while (1) {
        uint32_t tag_type = *((uint32_t*) tags);
        uint32_t tag_size = *((uint32_t*) (tags + 4));

        if (tag_type == 0) break;
        if (tag_type == 8) {
            fb_info = (multiboot2_tag_framebuffer*) tags;
        }

        tags += ((tag_size + 7) & ~7);
    }

    	serial_printf(3, "Framebuffer Address: 0x%x\r", fb_info->framebuffer_addr);
	serial_printf(3, "Framebuffer Width: %u\r\n", fb_info->framebuffer_width);
	serial_printf(3, "Framebuffer Height: %u\r\n", fb_info->framebuffer_height);
	serial_printf(3, "Framebuffer Pitch: %u\r\n", fb_info->framebuffer_pitch);
	serial_printf(3, "Framebuffer BPP: %u\r\n", fb_info->framebuffer_bpp);


    if (fb_info) {
        framebuffer = (uint32_t *)(uintptr_t) fb_info->framebuffer_addr;

        uint32_t width = fb_info->framebuffer_width;
        uint32_t height = fb_info->framebuffer_height;
        //uint32_t pitch = fb_info->framebuffer_pitch;
        uint32_t bpp = fb_info->framebuffer_bpp;

	
	//8x16 font, not padded 
	VGA_WIDTH = width/8;
	VGA_HEIGHT = height/16;

	scanline = width * (bpp/8);	

	
	/* TEST print charset
	int y_offset = 2;
	for (int i=0; i<512; i++)
	{
		if (i%(width/9)==0) y_offset++;
		draw_char(0+i, 0+i, y_offset, white, black);
	}
	*/
    }

    printf("[kernel] multiboot2 info at 0x%x, size=%u\n", mb_info, mb_info->total_size);
    printf("[kernel] framebuffer discovered at 0x%x\n", fb_info->framebuffer_addr);
    printf("[kernel] fb0: width=%u, height=%u, pitch=%u, bpp=%u\n", fb_info->framebuffer_width, fb_info->framebuffer_height, fb_info->framebuffer_pitch, fb_info->framebuffer_bpp);


  init_serial();
  gdt_install();
  idt_install();
  isr_install();
  irq_install();
  __asm__ __volatile__("sti");
 
  //init_paging();

  //test_read_sector();

  //uint32_t *ptr = (uint32_t*)0xA0000000;
  //uint32_t do_page_fault = *ptr;

  timer_install();
  keyboard_install();
  printf("[kernel] spawning shell...\n"); 
  shell_install();
 
}