// I2S digital MEMS microphone driver (INMP441-family — L/R, WS, SCK, SD
// pinout, confirmed against the actual module in use).
//
// Unlike the browser-based EVP mode's client-side voice-band FFT
// (frontend/src/lib/evp.ts), this driver does NOT attempt on-device
// spectral analysis — it samples a short audio block per reporting cycle
// and reports its RMS energy level in dBFS as a plain numeric reading.
// The backend's existing statistical anomaly detector (the same one that
// already handles temperature/pressure) does the spike detection — no
// need to duplicate baseline-tracking logic on the device. This is
// simpler and more honest than pretending to replicate real voice-band
// filtering without ever having tested it.
//
// Implements the sensor_driver_t interface (see sensor_driver.h).
//
// Wiring (module pin names: L/R, WS, SCK, SD, VCC, GND):
//   Mic VCC -> 3V3
//   Mic GND -> GND
//   Mic L/R -> GND (selects left-channel output; tie to 3V3 instead for
//              right-channel — either is fine, this driver reads whichever
//              channel the mic is configured to output)
//   Mic WS  -> ESP32 GPIO (MEMS_MIC_I2S_WS_GPIO)   -- word select / LRCLK
//   Mic SCK -> ESP32 GPIO (MEMS_MIC_I2S_BCLK_GPIO) -- bit clock
//   Mic SD  -> ESP32 GPIO (MEMS_MIC_I2S_DIN_GPIO)  -- serial data OUT of
//              the mic, IN to the ESP32
// GPIO picks avoid this board's reserved SDIO range (14-19, 54), the
// BMP280's I2C pins (8/9), and the RD-03E's UART pins (4/5) -- see
// README.md's pinout table for the full picture.

#pragma once

#include "esp_err.h"
#include "sensor_driver.h"

#ifdef __cplusplus
extern "C" {
#endif

#ifndef MEMS_MIC_I2S_PORT
#define MEMS_MIC_I2S_PORT      0
#endif

#ifndef MEMS_MIC_I2S_BCLK_GPIO
#define MEMS_MIC_I2S_BCLK_GPIO 10
#endif

#ifndef MEMS_MIC_I2S_WS_GPIO
#define MEMS_MIC_I2S_WS_GPIO   11
#endif

#ifndef MEMS_MIC_I2S_DIN_GPIO
#define MEMS_MIC_I2S_DIN_GPIO  12
#endif

// 16kHz is standard for voice-band work (Nyquist covers the ~300Hz-3.4kHz
// band the browser-based EVP mode watches) without the data-rate/CPU cost
// of a higher rate this simple RMS-only driver doesn't need.
#ifndef MEMS_MIC_SAMPLE_RATE_HZ
#define MEMS_MIC_SAMPLE_RATE_HZ 16000
#endif

// One reporting cycle's sample block: 256ms at 16kHz. Long enough to
// average out single-sample noise, short enough to stay responsive to a
// genuine brief EVP-style spike.
#ifndef MEMS_MIC_SAMPLES_PER_READ
#define MEMS_MIC_SAMPLES_PER_READ 4096
#endif

// sensor_driver_t-compatible entry points.
esp_err_t mems_mic_init(void);
esp_err_t mems_mic_read(sensor_reading_t *out, size_t max_out, size_t *out_count);

#ifdef __cplusplus
}
#endif