/*
 * Furnace call relays on the UART1-OUT plug.
 *
 * Pin assignment was measured on this board -- Elecrow documents the GPIO
 * numbers but not the connector pin order. See README, "UART1-OUT plug".
 *
 *   heat (W)  IO20, white wire
 *   fan  (G)  IO19, yellow wire
 *
 * Heat is on IO20 deliberately. IO20 is the ESP32-S3's USB D+, the line with
 * the hardware pull-up; with an active-low relay module a pull-up means
 * de-energized, so if the USB PHY is ever switched back on this pin fails
 * toward "no heat" rather than "heat stuck on". IO19 (D-) has no such pull-up.
 *
 * The simulator provides its own implementation of this interface, which is
 * why the API mentions no GPIOs.
 */
#ifndef RELAY_H
#define RELAY_H

#include <stdbool.h>

#include "esp_err.h"

typedef enum {
    RELAY_HEAT = 0,   /* W -- gas valve call */
    RELAY_FAN,        /* G -- blower, manual circulation only */
    RELAY_COUNT,
} relay_id_t;

/* Leaves both relays de-energized. Safe to call before anything else; it does
 * not depend on the display or the network. */
esp_err_t relay_init(void);

void relay_set(relay_id_t id, bool energized);
bool relay_get(relay_id_t id);

const char *relay_name(relay_id_t id);

#endif