/*
 * F-16 ICP — Final Schematic Firmware
 * Blue Pill (STM32F103C8T6) | stm32duino core
 *
 * Inputs:
 *   - 5x6 button matrix (26 buttons populated, 4 spare slots)
 *   - 2 rotary encoders (rotation only, no push function)
 *
 * Matrix layout (electrical):
 *   Col:    0       1       2       3       4       5
 *   Row 0:  T1      T2      T3      T4      T5      T6        (top strip)
 *   Row 1:  1       2       3       ENT     --      --        (keypad row 1 + 2 spares)
 *   Row 2:  4       5       6       RCL     SP+     SP-       (keypad row 2 + steerpoint)
 *   Row 3:  7       8       9       0       TGL+    TGL-      (keypad row 3 + 3-pos toggle)
 *   Row 4:  DCS_U   DCS_D   DCS_L   DCS_R   --      --        (DCS hat + 2 spares)
 *
 * Pin map:
 *   Cols (OUTPUT, idle HIGH):   PB0, PB1, PB10, PB11, PB8, PB9
 *   Rows (INPUT_PULLUP):        PB12, PB13, PB14, PB15, PB5
 *   Encoder 1 (CLK, DT):        PA0, PA1
 *   Encoder 2 (CLK, DT):        PA2, PA3
 */

// ============ Matrix ============

constexpr uint8_t NUM_ROWS = 5;
constexpr uint8_t NUM_COLS = 6;

const uint8_t COLS[NUM_COLS] = { PB0, PB1, PB10, PB11, PB8, PB9 };
const uint8_t ROWS[NUM_ROWS] = { PB12, PB13, PB14, PB15, PB5 };

const char* BTN_LABEL[NUM_ROWS][NUM_COLS] = {
  { "T1",    "T2",    "T3",    "T4",    "T5",   "T6"   },
  { "1",     "2",     "3",     "ENT",   "",     ""     },
  { "4",     "5",     "6",     "RCL",   "SP+",  "SP-"  },
  { "7",     "8",     "9",     "0",     "TGL+", "TGL-" },
  { "DCS_U", "DCS_D", "DCS_L", "DCS_R", "",     ""     }
};

const unsigned long DEBOUNCE_MS = 10;

bool          rawReading[NUM_ROWS][NUM_COLS]   = {{false}};
bool          stableState[NUM_ROWS][NUM_COLS]  = {{false}};
unsigned long lastChangeMs[NUM_ROWS][NUM_COLS] = {{0}};

// ============ Encoders ============

struct Encoder {
  uint8_t clkPin;
  uint8_t dtPin;
  const char* name;
  int      lastClk;
  long     count;
};

Encoder enc1 = { PA0, PA1, "ENC1", HIGH, 0 };
Encoder enc2 = { PA2, PA3, "ENC2", HIGH, 0 };

void readEncoder(Encoder& e) {
  int clkNow = digitalRead(e.clkPin);
  if (clkNow != e.lastClk) {
    e.lastClk = clkNow;
    if (clkNow == LOW) {
      int dtNow = digitalRead(e.dtPin);
      if (dtNow == HIGH) {
        e.count++;
        Serial.print(e.name); Serial.print(F(" CW   count="));  Serial.println(e.count);
      } else {
        e.count--;
        Serial.print(e.name); Serial.print(F(" CCW  count="));  Serial.println(e.count);
      }
    }
  }
}

// ============ Setup / Loop ============

void setup() {
  Serial.begin(115200);
  unsigned long t0 = millis();
  while (!Serial && (millis() - t0) < 2000) { /* wait for host */ }

  Serial.println();
  Serial.println(F("=== F-16 ICP firmware ready ==="));
  Serial.println(F("Top:    q w e r t y"));
  Serial.println(F("Keypad: 1-9 0  ENT=n  RCL=c"));
  Serial.println(F("Side:   i k (SP up/dn) | o l (TGL up/dn)"));
  Serial.println(F("DCS:    arrow keys"));
  Serial.println(F("Encs:   click KY-040 arrows"));
  Serial.println();

  for (uint8_t c = 0; c < NUM_COLS; c++) {
    pinMode(COLS[c], OUTPUT);
    digitalWrite(COLS[c], HIGH);
  }
  for (uint8_t r = 0; r < NUM_ROWS; r++) {
    pinMode(ROWS[r], INPUT_PULLUP);
  }
  pinMode(enc1.clkPin, INPUT_PULLUP);
  pinMode(enc1.dtPin,  INPUT_PULLUP);
  pinMode(enc2.clkPin, INPUT_PULLUP);
  pinMode(enc2.dtPin,  INPUT_PULLUP);
}

void scanMatrix() {
  for (uint8_t c = 0; c < NUM_COLS; c++) {
    digitalWrite(COLS[c], LOW);
    delayMicroseconds(5);

    for (uint8_t r = 0; r < NUM_ROWS; r++) {
      bool pressed = (digitalRead(ROWS[r]) == LOW);

      if (pressed != rawReading[r][c]) {
        rawReading[r][c]   = pressed;
        lastChangeMs[r][c] = millis();
      }
      if ((millis() - lastChangeMs[r][c]) >= DEBOUNCE_MS) {
        if (pressed != stableState[r][c]) {
          stableState[r][c] = pressed;
          if (BTN_LABEL[r][c][0] != '\0') {
            Serial.print(BTN_LABEL[r][c]);
            Serial.println(pressed ? F(" PRESSED") : F(" released"));
          }
        }
      }
    }

    digitalWrite(COLS[c], HIGH);
  }
}

void loop() {
  scanMatrix();
  readEncoder(enc1);
  readEncoder(enc2);
}