#include <string.h>
#include "detector.h"

void detector_init(detector_t *d) { memset(d, 0, sizeof(*d)); d->state = DET_IDLE; }
void detector_reset(detector_t *d) { d->state = DET_IDLE; d->hist = 0; }

bool detector_is_match(float rms, float score, float min_rms, float threshold)
{
    return rms >= min_rms && score >= threshold;
}

bool detector_update(detector_t *d, bool match, uint32_t now_ms, const detector_cfg_t *cfg)
{
    uint32_t n = cfg->win_n < 1 ? 1 : (cfg->win_n > 32 ? 32 : cfg->win_n);
    uint32_t m = cfg->win_m < 1 ? 1 : (cfg->win_m > n ? n : cfg->win_m);

    switch (d->state) {
    case DET_IDLE: {
        d->hist = (d->hist << 1) | (match ? 1u : 0u);
        uint32_t mask = (n == 32) ? 0xFFFFFFFFu : ((1u << n) - 1u);
        if ((uint32_t)__builtin_popcount(d->hist & mask) >= m) {
            d->state = DET_TRIGGERED;
            d->triggers++;
            return true;
        }
        break;
    }
    case DET_TRIGGERED:
        d->state = DET_COOLDOWN;
        d->cooldown_start_ms = now_ms;
        d->hist = 0;
        break;
    case DET_COOLDOWN:
        if ((uint32_t)(now_ms - d->cooldown_start_ms) >= cfg->cooldown_ms) {
            d->state = DET_IDLE;
            d->hist = 0;
        }
        break;
    }
    return false;
}

const char *detector_state_name(det_state_t s)
{
    switch (s) {
    case DET_IDLE: return "IDLE";
    case DET_TRIGGERED: return "TRIGGERED";
    case DET_COOLDOWN: return "COOLDOWN";
    }
    return "?";
}