// Native HomeKit garage door controller
// Seeed XIAO ESP32-C3  +  Challenger AC9500 (Allstar AC9000 series)
//
// Pairs directly with the Apple Home app. No hub, no cloud, no server.
// "Hey Siri, open the garage" works on the local network.
//
// WIRING
//   Relay COM + NO -> operator terminals 0 and 1, in PARALLEL with the
//                     existing wall push button (which keeps working).
//   D2 / GPIO4     -> relay module trigger, PLUS a 10k pulldown to GND
//   D3 / GPIO5     -> reed switch -> GND (magnet aligned = door CLOSED)
//   Leave terminals 4/5 (Safe Finish Photosystem) and 1/2/3 alone.
//
// OPENER QUIRKS THIS HANDLES
//   * Alternating action: mid-travel a button press means STOP, not
//     reverse. So we only ever pulse from a settled end state and
//     refuse commands while the door is moving.
//   * "Constant Contact To Close": if the photo eyes are misaligned or
//     faulty, a momentary pulse will NOT close the door -- the opener
//     demands the button be held for the entire cycle. We deliberately
//     do not automate that override (it exists so a human watching the
//     door can force it). Instead we detect the failure and raise
//     HomeKit's ObstructionDetected, which is exactly what it's for.

// BUILD NOTE
//   Requires the "Minimal SPIFFS (1.9MB APP with OTA)" partition scheme --
//   HomeSpan + WiFi + OTA overflows the stock 1.2MB app partition.
//   Arduino IDE:  Tools > Partition Scheme > Minimal SPIFFS
//   arduino-cli:  --fqbn esp32:esp32:XIAO_ESP32C3:PartitionScheme=min_spiffs
//   Or just use ../flash.sh, which sets it for you.

#include "HomeSpan.h"

// ---------- pins ----------
constexpr uint8_t RELAY_PIN = 4;   // D2 -- avoid strapping pins 2, 8, 9
constexpr uint8_t REED_PIN  = 5;   // D3

// ---------- timing ----------
constexpr uint32_t PULSE_MS    = 500;    // button press length
constexpr uint32_t DEBOUNCE_MS = 200;    // doors rattle
constexpr uint32_t LOCKOUT_MS  = 2000;   // min gap between presses
// The AC9000 control board run timer is 17s stock, or 29s if the jumper
// was cut (doors with >9 ft of travel). Set a few seconds above yours.
constexpr uint32_t TRAVEL_MS   = 20000;  // use 32000 if the jumper is cut

// ---------- HomeKit CurrentDoorState values ----------
constexpr uint8_t DOOR_OPEN    = 0;
constexpr uint8_t DOOR_CLOSED  = 1;
constexpr uint8_t DOOR_OPENING = 2;
constexpr uint8_t DOOR_CLOSING = 3;

// ---------- HomeKit TargetDoorState values ----------
constexpr uint8_t TARGET_OPEN   = 0;
constexpr uint8_t TARGET_CLOSED = 1;


struct GarageDoor : Service::GarageDoorOpener {

  Characteristic::CurrentDoorState  current{DOOR_CLOSED};
  Characteristic::TargetDoorState   target{TARGET_CLOSED};
  Characteristic::ObstructionDetected obstruction{false};

  // reed debounce
  bool     reedRaw     = true;
  bool     doorClosed  = true;
  uint32_t reedChanged = 0;

  // relay pulse
  bool     relayOn   = false;
  uint32_t pulseStart = 0;
  uint32_t lastPulse  = 0;

  // travel window
  bool     traveling   = false;
  bool     closingNow  = false;
  uint32_t travelStart = 0;

  GarageDoor() : Service::GarageDoorOpener() {
    pinMode(RELAY_PIN, OUTPUT);
    digitalWrite(RELAY_PIN, LOW);        // assert safe state immediately
    pinMode(REED_PIN, INPUT_PULLUP);

    reedRaw = doorClosed = (digitalRead(REED_PIN) == LOW);
    current.setVal(doorClosed ? DOOR_CLOSED : DOOR_OPEN);
    target.setVal(doorClosed ? TARGET_CLOSED : TARGET_OPEN);
  }

  void pressButton() {
    digitalWrite(RELAY_PIN, HIGH);
    relayOn    = true;
    pulseStart = millis();
    lastPulse  = pulseStart;
  }

  // Called when HomeKit (or Siri) writes TargetDoorState.
  boolean update() override {
    uint8_t want = target.getNewVal();

    if (traveling) {
      LOG1("Garage: refusing command, door is mid-travel\n");
      return false;                       // surfaces as an error in Home
    }
    if (millis() - lastPulse < LOCKOUT_MS) {
      LOG1("Garage: refusing command, lockout window\n");
      return false;
    }

    // Already where it wants to be -- accept, do nothing.
    if (want == TARGET_CLOSED &&  doorClosed) return true;
    if (want == TARGET_OPEN   && !doorClosed) return true;

    pressButton();
    traveling   = true;
    closingNow  = (want == TARGET_CLOSED);
    travelStart = millis();

    if (!closingNow) obstruction.setVal(false);   // opening clears the fault
    LOG1(closingNow ? "Garage: closing\n" : "Garage: opening\n");
    return true;
  }

  void loop() override {
    uint32_t now = millis();

    // --- end the relay pulse ---
    if (relayOn && now - pulseStart >= PULSE_MS) {
      digitalWrite(RELAY_PIN, LOW);
      relayOn = false;
    }

    // --- debounce the reed switch ---
    bool raw = (digitalRead(REED_PIN) == LOW);    // LOW = magnet = closed
    if (raw != reedRaw) { reedRaw = raw; reedChanged = now; }
    if (now - reedChanged >= DEBOUNCE_MS) doorClosed = reedRaw;

    // --- travel window expiring ---
    if (traveling && now - travelStart >= TRAVEL_MS) {
      traveling = false;
      if (closingNow) {
        // Didn't reach closed? The pulse was ignored or the door reversed.
        // On this opener that means the Safe Finish photo eyes are blocked,
        // misaligned, or failed. Report it -- do not retry, retrying can't
        // help when the opener wants constant contact.
        bool failed = !doorClosed;
        obstruction.setVal(failed);
        if (failed) LOG0("Garage: CLOSE FAILED -- check the photo eyes\n");
      }
    }

    // --- report state, including moves made from the wall button ---
    uint8_t want = traveling ? (closingNow ? DOOR_CLOSING : DOOR_OPENING)
                             : (doorClosed ? DOOR_CLOSED  : DOOR_OPEN);
    if (current.getVal() != want) current.setVal(want);

    if (!traveling) {
      uint8_t t = doorClosed ? TARGET_CLOSED : TARGET_OPEN;
      if (target.getVal() != t) target.setVal(t);
    }
  }
};


void setup() {
  Serial.begin(115200);

  homeSpan.setPairingCode("46637726");   // CHANGE THIS before pairing
  homeSpan.enableOTA();
  homeSpan.begin(Category::GarageDoorOpeners, "Garage Door");

  new SpanAccessory();
    new Service::AccessoryInformation();
      new Characteristic::Identify();
      new Characteristic::Name("Garage Door");
      new Characteristic::Manufacturer("DIY");
      new Characteristic::Model("XIAO ESP32-C3");
    new GarageDoor();
}

void loop() {
  homeSpan.poll();
}