#include "vga.h"
#include "string.h"

#define ROWS 25
#define COLUMNS 80

typedef struct
{
    u8 character;
    u8 color;
} vga_char;

vga_char* vga_buffer = (vga_char*)0xb8000;
u8 cursor_row = 0;
u8 cursor_col = 0;

void vga_set_char(u8 row, u8 col, vga_char character)
{
    vga_buffer[COLUMNS * row + col] = character;
}

vga_char vga_char_at(u8 row, u8 col)
{
    return vga_buffer[COLUMNS * row + col];
}

void vga_clear()
{
    for (u8 row = 0; row < ROWS; row++)
    {
        for (u8 col = 0; col < COLUMNS; col++)
        {
            vga_char character = {
                .character = ' ',
                .color = vga_default_color(),
            };
            vga_set_char(row, col, character);
        }
    }

    cursor_row = 0;
    cursor_col = 0;
}

void vga_set_cursor_position(u8 row, u8 col)
{
    if (row < ROWS && col < COLUMNS)
    {
        cursor_row = row;
        cursor_col = col;
    }
}

void vga_print_char_colored(char character, vga_color_t color)
{
    switch (character)
    {
    case '\n':
    {
        cursor_row += 1;
        cursor_col = 0;
        break;
    }
    case '\r':
    {
        cursor_col = 0;
        break;
    }
    case '\t':
    {
        u8 remainter = cursor_col % 4;
        cursor_col += remainter == 0 ? 4 : remainter;
        break;
    }
    default:
    {
        vga_char c = {
            .character = character,
            .color = color,
        };
        vga_set_char(cursor_row, cursor_col, c);
        cursor_col += 1;
        break;
    }
    }

    if (cursor_col >= COLUMNS)
    {
        cursor_col = 0;
        cursor_row += 1;
    }

    if (cursor_row >= ROWS)
    {
        for (u8 row = 1; row < ROWS; row++)
        {
            for (u8 col = 0; col < COLUMNS; col++)
            {
                vga_set_char(row - 1, col, vga_char_at(row, col));
            }
        }

        for (u8 col = 0; col < COLUMNS; col++)
        {
            vga_char c = {
                .character = ' ',
                .color = vga_default_color(),
            };
            vga_set_char(ROWS - 1, col, c);
        };

        cursor_row = ROWS - 1;
    }
}

void vga_print_colored(const char* string, vga_color_t color)
{
    for (u8 i = 0; string[i] != '\0'; i++)
    {
        vga_print_char_colored(string[i], color);
    }
}

void vga_print_success()
{
    vga_print("[ ");
    vga_print_colored("success", VGA_GREEN);
    vga_print(" ]");
}

void vga_print_error()
{
    vga_print("[ ");
    vga_print_colored("error", VGA_RED);
    vga_print(" ]");
}

void vga_print_uint(u32 value)
{
    char buffer[11];
    uitoa(value, buffer);
    vga_print(buffer);
}

void vga_print_int(i32 value)
{
    char buffer[12];
    itoa(value, buffer);
    vga_print(buffer);
}