#include "alert.h"
#include "codec_bsp.h"
#include "i2c_bsp.h"
#include <esp_log.h>
#include <esp_timer.h>
#include <freertos/FreeRTOS.h>
#include <freertos/semphr.h>
#include <string.h>
#include <math.h>

static const char *TAG = "alert";

/* Audio params: 24kHz, 16-bit, stereo */
#define SAMPLE_RATE   24000
#define CHANNELS      2
#define BITS          16
#define TONE_FREQ     1000
#define TONE_DURATION_MS 200

/* Tone buffer: 200ms at 24kHz * 2ch * 2bytes = 19200 bytes */
#define TONE_SAMPLES  (SAMPLE_RATE * TONE_DURATION_MS / 1000)
#define TONE_BUF_SIZE (TONE_SAMPLES * CHANNELS * (BITS / 8))

static int16_t *s_tone_buf = NULL;
static bool s_muted = false;
static CodecPort *s_codec = NULL;
static SemaphoreHandle_t s_alert_mutex = NULL;

/* Per-type cooldown tracking (microseconds) */
static int64_t s_last_trigger[ALERT_TYPE_COUNT] = {};

/* Cooldown periods in microseconds */
static const int64_t s_cooldown_us[ALERT_TYPE_COUNT] = {
    60 * 1000000LL,  /* SERVICE_DOWN: 60s */
    60 * 1000000LL,  /* HIGH_TEMP: 60s */
    30 * 1000000LL,  /* WS_DISCONNECT: 30s */
    0,               /* CONNECT_OK: no cooldown */
};

/* Beep patterns: number of beeps per alert type */
static const int s_beep_count[ALERT_TYPE_COUNT] = {
    0,  /* SERVICE_DOWN: triple beep */ /* DISABLED FOR TESTING */
    2,  /* HIGH_TEMP: double beep */
    1,  /* WS_DISCONNECT: single beep */
    1,  /* CONNECT_OK: single short beep */
};

static void generate_tone_buffer(void)
{
    /* Allocate in PSRAM */
    s_tone_buf = (int16_t *)heap_caps_malloc(TONE_BUF_SIZE, MALLOC_CAP_SPIRAM);
    if (!s_tone_buf) {
        ESP_LOGE(TAG, "Failed to allocate tone buffer");
        return;
    }

    /* Generate 1kHz square wave */
    int half_period = SAMPLE_RATE / (TONE_FREQ * 2);
    int16_t amplitude = 16000; /* ~50% of max to avoid clipping */

    for (int i = 0; i < TONE_SAMPLES; i++) {
        int16_t val = ((i / half_period) % 2 == 0) ? amplitude : -amplitude;
        /* Stereo: write same value to L and R */
        s_tone_buf[i * 2]     = val;
        s_tone_buf[i * 2 + 1] = val;
    }
}

void alert_init(void)
{
    s_alert_mutex = xSemaphoreCreateMutex();
    generate_tone_buffer();
    memset(s_last_trigger, 0, sizeof(s_last_trigger));
    ESP_LOGI(TAG, "Alert system initialized");
}

void alert_set_codec(void *codec)
{
    s_codec = (CodecPort *)codec;
}

void alert_trigger(alert_type_t type)
{
    if (type >= ALERT_TYPE_COUNT) return;
    if (s_muted) return;
    if (!s_tone_buf || !s_codec) return;

    if (xSemaphoreTake(s_alert_mutex, pdMS_TO_TICKS(50)) != pdTRUE) return;

    /* Check cooldown */
    int64_t now = esp_timer_get_time();
    if (s_cooldown_us[type] > 0 && (now - s_last_trigger[type]) < s_cooldown_us[type]) {
        xSemaphoreGive(s_alert_mutex);
        return;
    }
    s_last_trigger[type] = now;

    ESP_LOGI(TAG, "Alert triggered: type=%d", type);

    /* Open codec for playback */
    s_codec->CodecPort_SetInfo("es8311", 1, SAMPLE_RATE, CHANNELS, BITS);
    s_codec->CodecPort_SetSpeakerVol(70);

    /* Play beep pattern */
    int beeps = s_beep_count[type];
    for (int b = 0; b < beeps; b++) {
        /* Play tone in chunks */
        uint8_t *ptr = (uint8_t *)s_tone_buf;
        int remaining = TONE_BUF_SIZE;
        while (remaining > 0) {
            int chunk = (remaining > 512) ? 512 : remaining;
            s_codec->CodecPort_PlayWrite(ptr, chunk);
            ptr += chunk;
            remaining -= chunk;
        }
        /* Gap between beeps */
        if (b < beeps - 1) {
            vTaskDelay(pdMS_TO_TICKS(150));
        }
    }

    xSemaphoreGive(s_alert_mutex);
}

void alert_mute(bool muted)
{
    s_muted = muted;
    ESP_LOGI(TAG, "Alerts %s", muted ? "MUTED" : "UNMUTED");
}

bool alert_is_muted(void)
{
    return s_muted;
}