// features -> score -> detector, or calibration while a session is active.
#include <stdio.h>
#include <string.h>
#include "esp_log.h"
#include "esp_task_wdt.h"
#include "esp_timer.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "audio_in.h"
#include "calibration.h"
#include "config_store.h"
#include "detector.h"
#include "fingerprint.h"
#include "led.h"
#include "matcher.h"
#include "notifier.h"
#include "processing.h"

static const char *TAG = "proc";
#define PROC_TASK_CORE 1
#define PROC_TASK_PRIO 8
#define PROC_TASK_STACK 6144

static portMUX_TYPE s_lock = portMUX_INITIALIZER_UNLOCKED;
static proc_stats_t s_stats;
static float s_last_fp[NUM_BANDS];
static volatile bool s_monitor;
static features_ctx_t s_ctx;

void processing_get_stats(proc_stats_t *out)
{
    portENTER_CRITICAL(&s_lock);
    *out = s_stats;
    portEXIT_CRITICAL(&s_lock);
}

void processing_get_last_fp(float fp[NUM_BANDS])
{
    portENTER_CRITICAL(&s_lock);
    memcpy(fp, s_last_fp, sizeof(s_last_fp));
    portEXIT_CRITICAL(&s_lock);
}

void processing_set_monitor(bool on) { s_monitor = on; }
bool processing_get_monitor(void) { return s_monitor; }

static void update_led(app_mode_t mode, det_state_t st, bool has_tpl)
{
    static int last = -1;
    int code;
    if (!has_tpl) code = 1;
    else if (mode != MODE_NORMAL) code = 2;
    else if (st != DET_IDLE) code = 3;
    else code = 0;
    if (code == last) return;
    last = code;
    switch (code) {
    case 1: led_set(20, 0, 0); break;      // red: needs template
    case 2: led_set(20, 12, 0); break;     // amber: calibration session
    case 3: led_set(20, 0, 20); break;     // magenta: alert / cooldown
    default: led_set(0, 0, 6); break;      // dim blue: listening
    }
}

static void processing_task(void *arg)
{
    ESP_ERROR_CHECK(esp_task_wdt_add(NULL));
    detector_t det;
    detector_init(&det);
    float fp[NUM_BANDS];
    uint32_t last_mon_ms = 0;

    for (;;) {
        esp_task_wdt_reset();
        audio_frame_t fr;
        if (!audio_in_get_frame(&fr, pdMS_TO_TICKS(1000))) {
            ESP_LOGW(TAG, "no audio frame for 1 s");
            continue;
        }

        int64_t t0 = esp_timer_get_time();
        float rms = 0.0f;
        bool valid = features_compute(&s_ctx, fr.pcm, fp, &rms);
        const bool has_tpl = matcher_has_template();
        const float score = (valid && has_tpl) ? matcher_score(fp) : 0.0f;
        uint32_t dt_us = (uint32_t)(esp_timer_get_time() - t0);
        audio_in_release_frame(fr.idx);          // pool slot back as early as possible

        const uint32_t now_ms = (uint32_t)(esp_timer_get_time() / 1000);
        app_config_t cfg;
        config_get(&cfg);
        const app_mode_t mode = calibration_get_mode();
        const bool match = has_tpl && detector_is_match(rms, score, cfg.min_rms, cfg.threshold);

        bool buzz_ended = false;
        uint32_t buzz_duration_ms = 0;
        if (mode == MODE_NORMAL) {
            if (has_tpl) {
                detector_cfg_t dc = { cfg.win_n, cfg.win_m, cfg.cooldown_ms };
                buzz_ended = detector_update(&det, match, now_ms, &dc, &buzz_duration_ms);
            } else {
                detector_reset(&det);
            }
        } else {
            calibration_on_frame(fp, valid, rms, score);   // detector paused: no alerts
            detector_reset(&det);
        }
        if (buzz_ended) {
            char message[96];
            snprintf(message, sizeof(message), "Buzzer detected: %lu ms",
                     (unsigned long)buzz_duration_ms);
            ESP_LOGW(TAG, "BUZZER EVENT ended, detected duration %lu ms",
                     (unsigned long)buzz_duration_ms);
            notifier_send(NOTIF_ALERT, message);
        }

        portENTER_CRITICAL(&s_lock);
        s_stats.frames++;
        s_stats.proc_avg_us = s_stats.frames == 1 ? dt_us : (s_stats.proc_avg_us * 15u + dt_us) / 16u;
        if (dt_us > s_stats.proc_max_us) s_stats.proc_max_us = dt_us;
        s_stats.last_rms = rms;
        s_stats.last_score = score;
        s_stats.last_match = match;
        s_stats.state = det.state;
        s_stats.triggers = det.triggers;
        if (buzz_ended) {
            s_stats.last_trigger_s = det.last_completed_start_ms / 1000;
            if (s_stats.last_trigger_s == 0) s_stats.last_trigger_s = 1;
            s_stats.last_buzz_ms = buzz_duration_ms;
        }
        memcpy(s_last_fp, fp, sizeof(s_last_fp));
        portEXIT_CRITICAL(&s_lock);

        update_led(mode, det.state, has_tpl);

        if (s_monitor && (uint32_t)(now_ms - last_mon_ms) >= cfg.monitor_ms) {
            last_mon_ms = now_ms;
            printf("[%8lu ms] rms=%7.1f score=%+.3f %s %s\n", (unsigned long)now_ms, rms, score,
                   match ? "MATCH" : "  -  ",
                   mode == MODE_NORMAL ? detector_state_name(det.state) : calibration_mode_name(mode));
        }
    }
}

esp_err_t processing_start(void)
{
    esp_err_t err = features_init();
    if (err != ESP_OK) return err;
    BaseType_t ok = xTaskCreatePinnedToCore(processing_task, "proc", PROC_TASK_STACK, NULL,
                                            PROC_TASK_PRIO, NULL, PROC_TASK_CORE);
    return ok == pdPASS ? ESP_OK : ESP_ERR_NO_MEM;
}