/**
 * Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#include <stdint.h>
#include "pico/stdlib.h"

// Enum with uint8_t to save RAM (1 byte)
typedef enum : uint8_t {
    LED_OFF = 0,
    LED_ON  = 1
} LedState;

typedef struct StatusIndicator StatusIndicator;

struct StatusIndicator {
    uint8_t gpio_pin;
    uint16_t interval_ms; // Heartbeat interval variable stored inside the struct
    void (*init)(StatusIndicator *this);
    void (*update)(StatusIndicator *this);
};

void status_indicator_init(StatusIndicator *this) {
    gpio_init(this->gpio_pin);
    gpio_set_dir(this->gpio_pin, GPIO_OUT);
}

void status_indicator_update(StatusIndicator *this) {
    gpio_put(this->gpio_pin, LED_ON);
    sleep_ms(this->interval_ms);
    gpio_put(this->gpio_pin, LED_OFF);
    sleep_ms(this->interval_ms);
}

StatusIndicator create_status_indicator(uint8_t pin, uint16_t interval_ms) {
    StatusIndicator indicator;
    indicator.gpio_pin = pin;
    indicator.interval_ms = interval_ms;
    indicator.init = status_indicator_init;
    indicator.update = status_indicator_update;
    return indicator;
}

int main(void) {
    // Pass 100 ms interval directly to the struct variable during instantiation
    const uint16_t INTERVAL = 100;
    StatusIndicator heartbeat = create_status_indicator(PICO_DEFAULT_LED_PIN, INTERVAL);
    heartbeat.init(&heartbeat);
    
    while (true) {
        heartbeat.update(&heartbeat);
    }
    
    return 0;
}