#ifndef UART_IO_H
#define UART_IO_H

#include <stdint.h>

#define UART0_BASE 0x3F201000
#define UART0_DR   (*((volatile uint32_t *)(UART0_BASE + 0x00)))
#define UART0_FR   (*((volatile uint32_t *)(UART0_BASE + 0x18)))

typedef struct UART_IO {
    void (*putc)(char c);
    void (*puts)(const char* str);
    char (*getc)(void);
    void (*print_int)(unsigned int value);
} UART_IO;

// Function implementations

static void uart_putc(char c)
{
    while (UART0_FR & (1 << 5)) { } // Wait while TXFF is set
    UART0_DR = c;
}

static void uart_puts(const char* str)
{
    while (*str)
        uart_putc(*str++);
}

static char uart_getc(void)
{
    while (UART0_FR & (1 << 4)) { } // Wait while RXFE is set
    return (char)(UART0_DR & 0xFF);
}

static void uart_print_int(unsigned int value)
{
    char buffer[10];
    int i = 0;

    if (value == 0) {
        uart_putc('0');
        return;
    }

    while (value > 0 && i < 10) {
        buffer[i++] = (value % 10) + '0';
        value /= 10;
    }

    while (i--)
        uart_putc(buffer[i]);
}

// UART_IO instance with function pointers assigned
static const UART_IO uart_io = {
    .putc = uart_putc,
    .puts = uart_puts,
    .getc = uart_getc,
    .print_int = uart_print_int,
};

#endif // UART_IO_H