#include <AccelStepper.h>

AccelStepper stepper(AccelStepper::DRIVER, 3, 2); // Initialize stepper with Step and Dir pins

String inputString = "";          // Buffer for incoming serial data
boolean stringComplete = false;    // Flag to indicate if a complete command is received
int value[8] = {0};                // Array to store parsed values from commands
int32_t GR = 8;                    // Gear ratio or movement multiplier
int mode = 4;                      // Initial mode setting for the motor
int corner;                        // Stores corner value based on mode
bool moveComplete = false;         // Flag to indicate if the motor has completed a move

void setup() {
  stepper.setAcceleration(1200); // Set motor acceleration
  stepper.setMaxSpeed(2500);     // Set maximum speed for the stepper
  Serial.begin(115200);          // Initialize serial communication at 115200 baud
  inputString.reserve(400);      // Reserve 400 bytes for the input buffer
  modeSwitch(mode);              // Set initial motor mode
}

void loop() {
  serialRead();                  // Read and process serial input
  MoveMotor();                   // Handle motor movement
}

void serialRead() {
  // Reads characters from the serial input buffer and builds the input string
  while (Serial.available() > 0) {
    char inChar = (char)Serial.read();
    inputString += inChar;       // Append each character to the input string
    if (inChar == '\n') {
      stringComplete = true;     // Set flag when a full line is received
    }
  }

  if (stringComplete) {
    SerialProc();                // Process the completed command
    inputString = "";            // Clear the input string after processing
    stringComplete = false;      // Reset flag for next command
  }
}

void SerialProc() {
  // Process commands based on specific string patterns
  if (inputString.substring(0, 5) == "CT();") {
    SendReply();                 // Simple acknowledgment reply
  } else if (inputString.substring(0, 8) == "CT+START") {
    movetable();                 // Parse table data from command
    motor_X();                   // Execute motor command based on parsed data
  }
}

void movetable() {
  // Parse comma-separated values from the command string
  int index = inputString.lastIndexOf('(');
  int index2 = inputString.lastIndexOf(')');
  String sub_S = inputString.substring(index + 1, index2); // Extract values inside parentheses

  for (int i = 0; i < 8; i++) {
    int i2 = sub_S.indexOf(',');
    if (i2 == -1) break;         // Stop parsing if no more commas are found
    value[i] = sub_S.substring(0, i2).toInt(); // Convert each value to integer
    sub_S = sub_S.substring(i2 + 1); // Move to the next value
  }
}

void SendReply() {
  Serial.println("CR+OK;#");     // Send acknowledgment reply
}

void motor_X() {
  // Set motor target position based on parsed values
  int direction = value[0] ? 1 : -1;       // Determine direction from value[0]
  stepper.move(direction * value[3] * GR); // Set relative target position
  moveComplete = false;                    // Reset completion flag when a new movement starts
  stepper.runToPosition();                 // Move motor to target position
}

void MoveMotor() {
  // Control motor movement and send event when target is reached
  stepper.runSpeed();             // Use runSpeed for constant speed movement

  // Check if the motor has reached the target and if the message was not sent
  if (stepper.distanceToGo() == 0 && !moveComplete) {
    Serial.println("CR+OK;CR+EVENT=TB_PAUSE;CR+EVENT=TB_END;#"); // Notify when movement is done
    moveComplete = true;          // Set flag to indicate completion, preventing repeated messages
  }
}

void modeSwitch(int f) {
  // Update motor corner setting based on mode value 'f'
  if (f > 6) f = 0;               // Default to 0 if 'f' is out of range
  switch(f) {
    case 0: corner = 90;  break;  // Mode 0: 4 steps
    case 1: corner = 60;  break;  // Mode 1: 6 steps
    case 2: corner = 45;  break;  // Mode 2: 8 steps
    case 3: corner = 30;  break;  // Mode 3: 12 steps
    case 4: corner = 20;  break;  // Mode 4: 18 steps
    case 5: corner = 15;  break;  // Mode 5: 15 steps
    case 6: corner = 10;  break;  // Mode 6: 36 steps
  }
}