#include <cstddef>
#include <cstdint>
#include <array>
#include "pico/stdlib.h"
#include "pico/sleep.h"
#include "hardware/gpio.h"

static constexpr std::size_t button_gpio = 6;
static constexpr std::size_t led_gpio = 2;
static constexpr std::array<std::size_t, 3> gpio_on_sequence { 3, 4, 5 };
static constexpr std::array<std::size_t, 3> gpio_off_sequence { 5, 4, 3 };
static constexpr std::size_t delay_ms = 100;

int main()
{
    bool state = false;

    // init LED
    gpio_init(led_gpio);
    gpio_set_dir(led_gpio, GPIO_OUT);
    gpio_put(led_gpio, state);

    // init relay GPIOs
    for (auto const & relay : gpio_off_sequence)
    {
        gpio_init(relay);
        gpio_set_dir(relay, GPIO_OUT);
        gpio_put(relay, state);
    }

    while (true)
    {
        sleep_run_from_xosc();
        sleep_goto_dormant_until_edge_high(button_gpio);
        sleep_power_up();

        state = !state;
        gpio_put(led_gpio, state);

        auto const & sequence = state ? gpio_on_sequence : gpio_off_sequence;
        for (auto const & relay : sequence)
        {
            gpio_put(relay, state);
            sleep_ms(delay_ms);
        }
    }
}