#include "uart.h"
#include <errno.h>
#include <libopencm3/cm3/nvic.h>
#include <libopencm3/stm32/gpio.h>
#include <libopencm3/stm32/rcc.h>
#include <libopencm3/stm32/usart.h>
#include <stdio.h>
#include <sys/stat.h>
#include <unistd.h>

#include <unistd.h>

int _write(int file, char *ptr, int len);

void usart_setup(void) {
    /* Setup GPIO pin GPIO_USART1_RE_TX on GPIO port B for transmit. */
    gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_USART1_TX);

    usart_set_baudrate(USART1, 115200);
    usart_set_databits(USART1, 8);
    usart_set_stopbits(USART1, USART_STOPBITS_1);
    usart_set_parity(USART1, USART_PARITY_NONE);
    usart_set_flow_control(USART1, USART_FLOWCONTROL_NONE);
    usart_set_mode(USART1, USART_MODE_TX);

    usart_enable(USART1);
}

int _write(int file, char *ptr, int len) {
    if (file == STDOUT_FILENO || file == STDERR_FILENO) {
        for (int i = 0; i < len; i++) {
            if (ptr[i] == '\n') {
                usart_send_blocking(USART1, '\r');
            }
            usart_send_blocking(USART1, ptr[i]);
        }
        return len;
    }
    errno = EIO;
    return -1;
}

int _close(int file);
int _close(int file) {
    (void)file;
    return -1;
}

int _fstat(int file, struct stat *st);
int _fstat(int file, struct stat *st) {
    (void)file;
    st->st_mode = S_IFCHR;
    return 0;
}

int _isatty(int file);
int _isatty(int file) {
    (void)file;
    return 1;
}

int _lseek(int file, int ptr, int dir);
int _lseek(int file, int ptr, int dir) {
    (void)file;
    (void)ptr;
    (void)dir;
    return 0;
}

// Optional — stubbed read (e.g. for scanf), returns 0 bytes
int _read(int file, char *ptr, int len);
int _read(int file, char *ptr, int len) {
    (void)file;
    (void)ptr;
    (void)len;
    return 0;
}