/*
 * Host implementation of relay.h -- a fake furnace.
 *
 * Lets the real control loop run on the desktop: hysteresis, minimum on and
 * off times and the cycles-per-hour ceiling all behave exactly as they will on
 * the device, with the relay changes printed instead of switching 24VAC.
 *
 * Timestamps are wall-clock relative to start-up so a log can be read against
 * the protection timings in thermostat.h without arithmetic.
 */

#include <stdbool.h>
#include <stdio.h>
#include <time.h>

#include "relay.h"

static bool relay_state[RELAY_COUNT];
static struct timespec t0;

static double seconds_since_start(void)
{
    struct timespec now;
    clock_gettime(CLOCK_MONOTONIC, &now);
    return (double)(now.tv_sec - t0.tv_sec) +
           (double)(now.tv_nsec - t0.tv_nsec) / 1e9;
}

esp_err_t relay_init(void)
{
    clock_gettime(CLOCK_MONOTONIC, &t0);
    for (int i = 0; i < RELAY_COUNT; i++) {
        relay_state[i] = false;
    }
    fprintf(stderr, "[relay-sim] both relays idle\n");
    return ESP_OK;
}

void relay_set(relay_id_t id, bool energized)
{
    if (id < 0 || id >= RELAY_COUNT || relay_state[id] == energized) {
        return;
    }
    relay_state[id] = energized;
    fprintf(stderr, "[relay-sim] %7.1fs  %-8s -> %s\n",
            seconds_since_start(), relay_name(id), energized ? "ON" : "OFF");
}

bool relay_get(relay_id_t id)
{
    if (id < 0 || id >= RELAY_COUNT) {
        return false;
    }
    return relay_state[id];
}

const char *relay_name(relay_id_t id)
{
    switch (id) {
    case RELAY_HEAT: return "heat(W)";
    case RELAY_FAN:  return "fan(G)";
    default:         return "?";
    }
}