#include <stdbool.h>

#include "kprintf.h"

#include "asm_inline.h"

// #define KDEBUG

int check_transmission() {
  return inb(COM1 + 5) & 0x20;
}

void write_serial_char(char a) {
  while (check_transmission() == 0);
  outb(COM1,a);
}

void write_serial_string(const char* str)
{
  while(*str != '\0')
  {
    if(*str == '\n')
    {
      write_serial_char('\r');
    }
    write_serial_char(*str);
    str++;
  }
}

char* convert_U_integer(uint64_t n, uint16_t base, bool caps)
{
    static char* format = "0123456789abcdef";
    static char* C_format = "0123456789ABCDEF";

    static char buffer[50]; 
    char *ptr; 

    ptr = &buffer[49];
    *ptr = '\0';

    do
    {
        if(caps)
        {
            *--ptr = C_format[n%base]; 
        }
        else
        {
            *--ptr = format[n%base]; 
        }
        n /= base; 
    } while(n != 0);

    return ptr;
}

void kprintf(const char* str, ...)
{
    va_list args;

    va_start(args, str);

    while(*str)
    {
        if(*str == '%')
        {
            #ifdef KDEBUG
            write_serial_string("{stradv}");
            #endif
            str++;
            if(*str == 'i' || *str == 'd')
            {
                #ifdef KDEBUG
                write_serial_string("[INT]");
                #endif
                int32_t n = va_arg(args, int32_t);
                char* s = convert_U_integer(n, 10, false);
                write_serial_string(s);
            }
            else if(*str == 'u')
            {
                #ifdef KDEBUG
                write_serial_string("[UINT]");
                #endif
                uint32_t n = va_arg(args, uint32_t);
                char* s = convert_U_integer(n, 10, false);
                write_serial_string(s);
            }
            else if(*str == 'x')
            {
                #ifdef KDEBUG
                write_serial_string("[HEX]");
                #endif
                uint32_t n = va_arg(args, uint32_t);
                char* s = convert_U_integer(n, 16, false);
                write_serial_string("0x");
                write_serial_string(s);
            }
            else if(*str == 'X')
            {
                #ifdef KDEBUG
                write_serial_string("[HEX]");
                #endif
                uint32_t n = va_arg(args, uint32_t);
                char* s = convert_U_integer(n, 16, true);
                write_serial_string("0x");
                write_serial_string(s);
            }
            else if(*str == 'l')
            {
                #ifdef KDEBUG
                write_serial_string("[LONG]");
                write_serial_string("{ladv}");
                #endif
                str++;
                if(*str == 'i' || *str == 'd')
                {
                    #ifdef KDEBUG
                    write_serial_string("[INT]");
                    #endif
                    int64_t n = va_arg(args, int64_t);
                    char* s = convert_U_integer(n, 10, false);
                    write_serial_string(s);
                }
                else if(*str == 'u')
                {
                    #ifdef KDEBUG
                    write_serial_string("[UINT]");
                    #endif
                    uint64_t n = va_arg(args, uint64_t);
                    char* s = convert_U_integer(n, 10, false);
                    write_serial_string(s);
                }
                else if(*str == 'x')
                {
                    #ifdef KDEBUG
                    write_serial_string("[HEX]");
                    #endif
                    uint64_t n = va_arg(args, uint64_t);
                    char* s = convert_U_integer(n, 16, false);
                    write_serial_string("0x");
                    write_serial_string(s);
                }
                else if(*str == 'X')
                {
                    #ifdef KDEBUG
                    write_serial_string("[HEX]");
                    #endif
                    uint64_t n = va_arg(args, uint64_t);
                    char* s = convert_U_integer(n, 16, true);
                    write_serial_string("0x");
                    write_serial_string(s);
                }
            }
            else if(*str == 'h')
            {
                #ifdef KDEBUG
                write_serial_string("[SHORT]");
                write_serial_string("{ladv}");
                #endif
                str++;
                if(*str == 'i' || *str == 'd')
                {
                    #ifdef KDEBUG
                    write_serial_string("[INT]");
                    #endif
                    int16_t n = va_arg(args, int);
                    char* s = convert_U_integer(n, 10, false);
                    write_serial_string(s);
                }
                else if(*str == 'u')
                {
                    #ifdef KDEBUG
                    write_serial_string("[UINT]");
                    #endif
                    uint16_t n = va_arg(args, int);
                    char* s = convert_U_integer(n, 10, false);
                    write_serial_string(s);
                }
                else if(*str == 'x')
                {
                    #ifdef KDEBUG
                    write_serial_string("[HEX]");
                    #endif
                    uint16_t n = va_arg(args, int);
                    char* s = convert_U_integer(n, 16, false);
                    write_serial_string("0x");
                    write_serial_string(s);
                }
                else if(*str == 'X')
                {
                    #ifdef KDEBUG
                    write_serial_string("[HEX]");
                    #endif
                    uint16_t n = va_arg(args, int);
                    char* s = convert_U_integer(n, 16, true);
                    write_serial_string("0x");
                    write_serial_string(s);
                }
            }
            else if(*str == 'p')
            {
                #ifdef KDEBUG
                write_serial_string("[PTR]");
                #endif
                void* p = va_arg(args, void*);
                uint64_t n = (uint64_t)p;
                char* s = convert_U_integer(n, 16, true);
                write_serial_string("0x");
                write_serial_string(s);
            }
            else if(*str == 'c')
            {
                #ifdef KDEBUG
                write_serial_string("[CHAR]");
                #endif
                char c = va_arg(args, int);
                write_serial_char(c);
            }
            else if(*str == 's')
            {
                #ifdef KDEBUG
                write_serial_string("[STR]");
                #endif
                char* s = va_arg(args, char*);
                write_serial_string(s);
            }
            else
            {
                write_serial_string("\nFailed to write malformed kprintf: ");
                write_serial_char(*str);
                write_serial_string("\n");
                va_end(args);
                return;
            }
            #ifdef KDEBUG
            write_serial_string("{pend}");
            #endif
        }
        else if(*str == '\n')
        {
            write_serial_char('\r');
            write_serial_char('\n');
        }
        else
        {
            write_serial_char(*str);
        }
        #ifdef KDEBUG
        write_serial_string("{oadv}");
        #endif
        str++;
    }

    //write_serial_string(str);

    va_end(args);
}