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

#include <kernel/tty.h>
#include "vga.h"

static const size_t TERM_WIDTH=80;
static const size_t TERM_HEIGHT=25;

static size_t terminal_row;
static size_t terminal_column;

static uint8_t current_color;
static uint16_t* term_buffer;

void screen_initialize(void) {
	
	static uint16_t* const vga_buffer = (uint16_t*) 0xB8000;
	terminal_row = 0;
	terminal_column = 0;
	current_color = vga_color_set(LIGHT_GREY, BLACK);
	term_buffer = vga_buffer;
	
	for (size_t y = 0; y < TERM_HEIGHT; y++) {
		for(size_t x = 0; x < TERM_WIDTH; x++) {
			const size_t offset = y * TERM_WIDTH + x;
			term_buffer[offset] = vga_entry(' ', current_color);
		}
	}
}

void term_setcolor(enum vga_colors color) {
	current_color = color;
}

void term_putentryat (unsigned char c, uint8_t color, size_t x, size_t y) {
	const size_t offset = y * TERM_WIDTH + x;
	term_buffer[offset] = vga_entry(c, color);
}

void term_putchar(char c) {
	unsigned char uc = c;
	term_putentryat(uc, current_color, terminal_column, terminal_row);
	
	if(++terminal_column == TERM_WIDTH) 
		terminal_column = 0;
		if(++terminal_row == TERM_HEIGHT){
			term_scroll();
			terminal_row = 0;
		}
}

void term_write(const char* data, size_t size) {
	for(size_t i = 0; i < size; i++)
		term_putchar(data[i]);
}

void puts(const char* string) {
	term_write(string + "\n", strlen(string));
}