#include <assert.h>
#include <fcntl.h>
#include <stdint.h>
#include <stdio.h>
#include <linux/gpio.h>
#include <sys/ioctl.h>
#include <time.h>

#include "gpio.h"
#include "timespec.h"
#include "ping_pong.h"

#define LAST_PONG_TIMEOUT (PING_INTERVAL * 3)

/*
  17 red (11)
  27 green (13)
  22 blue (15)
*/

#define RED   0b001
#define GREEN 0b010
#define BLUE  0b100

int gpio_open(const char * path,
	      struct gpio_state * gpio_state)
{
  gpio_state->chip_fd = open(path, O_RDWR);
  if (gpio_state->chip_fd == -1) {
    perror("open gpio");
    return -1;
  }

  struct gpio_v2_line_request request = {
    .offsets = { 17, 27, 22 },
    .consumer = "timer",
    .config = {
      .flags = GPIO_V2_LINE_FLAG_OUTPUT,
    },
    .num_lines = 3,
  };
  int ret = ioctl(gpio_state->chip_fd, GPIO_V2_GET_LINE_IOCTL, &request);
  assert(ret != -1);
  gpio_state->req_fd = request.fd;

  return 0;
}

void gpio_set_values(struct gpio_state * gpio_state, uint64_t bits)
{
  struct gpio_v2_line_values values = {
    .bits = bits,
    .mask = 0b111,
  };

  int ret = ioctl(gpio_state->req_fd, GPIO_V2_LINE_SET_VALUES_IOCTL, &values);
  assert(ret != -1);
}

void gpio_set_values_from_link_state(struct gpio_state * gpio_state,
				     struct link_state * link_state)
{
  struct timespec now;
  int ret = clock_gettime(CLOCK_MONOTONIC_RAW, &now);
  assert(ret != -1);

  struct timespec delta = timespec_sub(&now, &link_state->last_pong);
  if (delta.tv_sec >= LAST_PONG_TIMEOUT) {
    printf("gpio pong timeout %ld\n", delta.tv_sec);
    if (gpio_state->chip_fd != -1)
      gpio_set_values(gpio_state, RED);
  } else {
    printf("gpio pong ok %ld\n", delta.tv_sec);
    if (gpio_state->chip_fd != -1)
      gpio_set_values(gpio_state, GREEN);
  }
}

/*
int main()
{
  struct gpio_state gpio_state;
  gpio_open("/dev/gpiochip0", &gpio_state);
  set_gpio_values(&gpio_state, 0b000);
}
*/