#pragma once

#include "../uart.h"

int uart_thre(enum UART port);
void uart_putc(const FILE *self, char a);
int uart_puts(const FILE *self, const char *string, int length);
void uart_flush(__attribute__((unused)) const FILE *self);

enum uart_16550_offset {
  Data = 0,             // read from receive buffer / write to transmit buffer | BaudDiv_l
  InterruptControl = 1, // interrupt enable | BaudDiv_h
  FifoControl = 2,      // interrupt ID and FIFO control
  LineControl = 3,      // most significant bit is the DLAB
  ModemControl = 4,
  LineStatus = 5,
  ModemStatus = 6,
  Scratch = 7,
};

// Line Control
// | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
// |dla|   | parity    | s | data  |
enum LineControl {
  d5bit = 0x00, // 0000 0000  data bits
  d6bit = 0x01, // 0000 0001
  d7bit = 0x02, // 0000 0010
  d8bit = 0x03, // 0000 0011
  // none = 0b00000000, // parity bits
  odd = 0x08,   // 0000 1000
  even = 0x18,  // 0001 1000
  mark = 0x28,  // 0010 1000
  space = 0x38, // 0011 1000
  // s1bit = 0b00000000, // stop bits
  s2bit = 0x04, // 0000 0100  1.5 for 5bit data; 2 otherwise
  dlab = 0x80   // 1000 0000  divisor latch access bit
};

// Line Status Register
enum LineStatus {
  DR = (1 << 0),   // data ready: see if there is data to read
  OE = (1 << 1),   // overrun error: see if there has been data lost
  PE = (1 << 2),   // parity error: see if there was error in transmission
  FE = (1 << 3),   // framing error: see if a stop bit was missing
  BI = (1 << 4),   // break indicator: see if there is a break in data input
  THRE = (1 << 5), // transmitter holding register empty: see if transmission buffer is empty
  TEMT = (1 << 6), // transmitter empty: see if transmitter is not doing anything
  ERRO = (1 << 7), // impending error: see if there is an error with a word in the input buffer
};