// ============================================================
//  INTERMISSION OBJECT — Board Test
//  XIAO ESP32-S3 · Custom PCB
// ============================================================
//  Tests all five subsystems in sequence, looping forever.
//
//  GPIO  Label     Function
//  ----  --------  ------------------------------------------
//  1     D0/A0     I2S DIN   → MAX98357A
//  2     D1/A1     I2S LRC   → MAX98357A
//  3     D2/A2     I2S BCLK  → MAX98357A
//  4     D3        LED PWM   → MOSFET gate (Q1)
//  5     D4/SDA    I2C SDA   → TM6605 haptic driver
//  6     D5/SCL    I2C SCL   → TM6605 haptic driver
//  7     D8        Motor PWM → MOSFET gate (Q2)
//  8     D9/ADC1   Hall IN   → A3144 output (digital, active-low)
// ============================================================

#include <Arduino.h>
#include <Wire.h>
#include "driver/i2s.h"

// ── Pin definitions ──────────────────────────────────────────
#define PIN_I2S_DIN     1
#define PIN_I2S_LRC     2
#define PIN_I2S_BCLK    3
#define PIN_LED_PWM     4
#define PIN_I2C_SDA     5
#define PIN_I2C_SCL     6
#define PIN_MOTOR_PWM   7
#define PIN_HALL        8

// ── LEDC (PWM) ───────────────────────────────────────────────
#define PWM_FREQ_MOTOR  20000   // 20 kHz — inaudible motor whine
#define PWM_FREQ_LED    1000    // 1 kHz  — smooth LED dimming
#define PWM_RES         8       // 8-bit  → 0–255

// ── Motor test ───────────────────────────────────────────────
#define MOTOR_MEDIUM    140     // ~55 % duty — medium speed

// ── I2S / audio ──────────────────────────────────────────────
#define SAMPLE_RATE     22050
#define TONE_HZ         120     // low, resonant tone
#define TONE_AMPLITUDE  8000    // 0–32767; modest for speaker safety

// ── TM6605 haptic driver (I2C) ───────────────────────────────
// DFRobot Gravity TM6605 default I2C address
#define TM6605_ADDR     0x5A

// TM6605 register map (subset used here)
#define REG_STATUS      0x00
#define REG_MODE        0x01
#define REG_RTP         0x02    // real-time playback level
#define REG_LIB         0x03    // waveform library select
#define REG_WAVEFORM_1  0x04    // first waveform sequence slot
#define REG_GO          0x0C

// ────────────────────────────────────────────────────────────
//  Hall sensor ISR
// ────────────────────────────────────────────────────────────
volatile uint32_t hallPulseCount = 0;
volatile uint32_t lastPulseMs    = 0;

void IRAM_ATTR hallISR() {
  hallPulseCount++;
  lastPulseMs = millis();
}

// ────────────────────────────────────────────────────────────
//  I2S helpers
// ────────────────────────────────────────────────────────────
void i2s_init() {
  i2s_config_t cfg = {
    .mode                 = (i2s_mode_t)(I2S_MODE_MASTER | I2S_MODE_TX),
    .sample_rate          = SAMPLE_RATE,
    .bits_per_sample      = I2S_BITS_PER_SAMPLE_16BIT,
    .channel_format       = I2S_CHANNEL_FMT_RIGHT_LEFT,
    .communication_format = I2S_COMM_FORMAT_STAND_I2S,
    .intr_alloc_flags     = ESP_INTR_FLAG_LEVEL1,
    .dma_buf_count        = 8,
    .dma_buf_len          = 256,
    .use_apll             = false,
    .tx_desc_auto_clear   = true,
  };
  i2s_pin_config_t pins = {
    .bck_io_num   = PIN_I2S_BCLK,
    .ws_io_num    = PIN_I2S_LRC,
    .data_out_num = PIN_I2S_DIN,
    .data_in_num  = I2S_PIN_NO_CHANGE,
  };
  i2s_driver_install(I2S_NUM_0, &cfg, 0, NULL);
  i2s_set_pin(I2S_NUM_0, &pins);
}

// Synthesise a sine tone and stream it for durationMs milliseconds
void i2s_play_tone(uint32_t durationMs) {
  const int bufSamples = 256;
  int16_t   buf[bufSamples * 2]; // stereo
  uint32_t  start    = millis();
  double    phase    = 0.0;
  double    phaseInc = 2.0 * PI * TONE_HZ / SAMPLE_RATE;

  while (millis() - start < durationMs) {
    for (int i = 0; i < bufSamples; i++) {
      int16_t s      = (int16_t)(TONE_AMPLITUDE * sin(phase));
      buf[i * 2]     = s;  // L
      buf[i * 2 + 1] = s;  // R
      phase += phaseInc;
      if (phase > 2.0 * PI) phase -= 2.0 * PI;
    }
    size_t written;
    i2s_write(I2S_NUM_0, buf, sizeof(buf), &written, portMAX_DELAY);
  }
  i2s_zero_dma_buffer(I2S_NUM_0);
}

// ────────────────────────────────────────────────────────────
//  TM6605 helpers
// ────────────────────────────────────────────────────────────
void tm_write(uint8_t reg, uint8_t val) {
  Wire.beginTransmission(TM6605_ADDR);
  Wire.write(reg);
  Wire.write(val);
  uint8_t err = Wire.endTransmission();
  if (err) {
    Serial.printf("  [TM6605] I2C error %d on reg 0x%02X\n", err, reg);
  }
}

uint8_t tm_read(uint8_t reg) {
  Wire.beginTransmission(TM6605_ADDR);
  Wire.write(reg);
  Wire.endTransmission(false);
  Wire.requestFrom((uint8_t)TM6605_ADDR, (uint8_t)1);
  return Wire.available() ? Wire.read() : 0xFF;
}

// Soft pulse: triangle-envelope the RTP level up then back down
void tm_soft_pulse(uint32_t durationMs) {
  tm_write(REG_MODE, 0x05);  // enter RTP (real-time playback) mode
  uint32_t start = millis();

  while (millis() - start < durationMs) {
    float t   = (float)(millis() - start) / durationMs; // 0 → 1
    float env = (t < 0.5f) ? (t * 2.0f) : (2.0f - t * 2.0f); // triangle
    tm_write(REG_RTP, (uint8_t)(env * 80.0f));  // cap at 80/127 — gentle
    delay(10);
  }
  tm_write(REG_RTP,  0x00);  // silence
  tm_write(REG_MODE, 0x40);  // standby
}

// ────────────────────────────────────────────────────────────
//  setup()
// ────────────────────────────────────────────────────────────
void setup() {
  Serial.begin(115200);
  delay(600);
  Serial.println("\n=== INTERMISSION OBJECT — Board Test ===\n");

  // PWM channels
  ledcAttach(PIN_MOTOR_PWM, PWM_FREQ_MOTOR, PWM_RES);
  ledcAttach(PIN_LED_PWM,   PWM_FREQ_LED,   PWM_RES);
  ledcWrite(PIN_MOTOR_PWM, 0);
  ledcWrite(PIN_LED_PWM,   0);

  // I2C — TM6605 has onboard pull-ups, no external R needed
  Wire.begin(PIN_I2C_SDA, PIN_I2C_SCL);

  // I2S — MAX98357A
  i2s_init();

  // Hall sensor — A3144 output is active-low
  pinMode(PIN_HALL, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(PIN_HALL), hallISR, FALLING);

  Serial.println("All peripherals initialised. Starting test loop.\n");
}

// ────────────────────────────────────────────────────────────
//  loop()
// ────────────────────────────────────────────────────────────
void loop() {

  // ══════════════════════════════════════════════════════════
  //  TEST 1 — Motor at medium PWM
  // ══════════════════════════════════════════════════════════
  Serial.println("── TEST 1: Motor (medium PWM) ───────────────────────");
  Serial.printf("   duty=%d/255  freq=%d kHz\n", MOTOR_MEDIUM, PWM_FREQ_MOTOR / 1000);
  ledcWrite(PIN_MOTOR_PWM, MOTOR_MEDIUM);
  delay(3000);
  ledcWrite(PIN_MOTOR_PWM, 0);
  Serial.println("   Motor off.\n");
  delay(500);

  // ══════════════════════════════════════════════════════════
  //  TEST 2 — LED filaments, soft sine-wave pulse (two cycles)
  // ══════════════════════════════════════════════════════════
  Serial.println("── TEST 2: LED filaments (soft pulse) ───────────────");
  uint32_t ledStart = millis();
  while (millis() - ledStart < 4000) {
    // Sine envelope: one full pulse every 2 s
    float   t   = (float)(millis() - ledStart) / 2000.0f; // 0→2
    float   env = 0.5f * (1.0f - cosf(t * PI));           // 0→1→0
    uint8_t pwm = (uint8_t)(env * 220.0f);                 // cap at ~86 %
    ledcWrite(PIN_LED_PWM, pwm);
    delay(10);
  }
  ledcWrite(PIN_LED_PWM, 0);
  Serial.println("   LED pulse complete.\n");
  delay(500);

  // ══════════════════════════════════════════════════════════
  //  TEST 3 — Speaker, 120 Hz sine tone via I2S
  // ══════════════════════════════════════════════════════════
  Serial.println("── TEST 3: Speaker (I2S, 120 Hz) ────────────────────");
  Serial.printf("   Playing %d Hz for 3 s\n", TONE_HZ);
  i2s_play_tone(3000);
  Serial.println("   Tone complete.\n");
  delay(500);

  // ══════════════════════════════════════════════════════════
  //  TEST 4 — LRA haptic, two soft pulses via I2C
  // ══════════════════════════════════════════════════════════
  Serial.println("── TEST 4: LRA haptic (I2C, TM6605) ────────────────");
  uint8_t status = tm_read(REG_STATUS);
  if (status == 0xFF) {
    Serial.println("   WARNING: no ACK from TM6605 — check address / wiring");
  } else {
    Serial.printf("   TM6605 status=0x%02X (device OK)\n", status);
    for (int i = 0; i < 2; i++) {
      Serial.printf("   Pulse %d/2\n", i + 1);
      tm_soft_pulse(600);
      delay(400);
    }
    Serial.println("   Haptic complete.");
  }
  Serial.println();
  delay(500);

  // ══════════════════════════════════════════════════════════
  //  TEST 5 — Hall effect sensor
  //  Spin the rotor with magnets past the sensor during this window.
  // ══════════════════════════════════════════════════════════
  Serial.println("── TEST 5: Hall effect sensor (5 s window) ──────────");
  Serial.println("   → Spin the rotor now...");
  uint32_t prevCount = hallPulseCount;
  uint32_t hallStart = millis();

  while (millis() - hallStart < 5000) {
    if (hallPulseCount != prevCount) {
      Serial.printf("   ★ Magnet pass! count=%lu\n", hallPulseCount);
      prevCount = hallPulseCount;
    }
    delay(20);
  }
  Serial.printf("   Total pulses detected this session: %lu\n\n", hallPulseCount);

  // ══════════════════════════════════════════════════════════
  Serial.println("══ All tests complete. Repeating in 2 s... ══\n");
  delay(2000);
}