#!/usr/bin/env python3

import sys
import os

def modify_gcode(input_file):
    # Generate the output file name by appending "_modded" to the input file name
    base, ext = os.path.splitext(input_file)
    output_file = f"{base}_modded{ext}"

    # Read the contents of the G-code file
    with open(input_file, 'r') as file:
        lines = file.readlines()

    # Buffer to store the additional commands
    buffer = []

    # First Pass: Identify and extract lines between G0 and the first G4, add M5
    i = 0
    while i < len(lines):
        line = lines[i].strip()
        if line.startswith("G0") and "X" in line and "Y" in line:  # Detect G0 X??.? Y??.?
            if i + 1 < len(lines) and lines[i + 1].strip() == "G92 Z0.":  # Check for G92 Z0. immediately after
                temp_buffer = []
                temp_buffer.append(line)  # Add G0 line
                temp_buffer.append(lines[i + 1].strip())  # Add G92 line
                i += 2
                while i < len(lines) and not lines[i].strip().startswith("G4"):  # Collect until G4
                    temp_buffer.append(lines[i].strip())
                    i += 1
                if i < len(lines):  # Include the G4 line
                    temp_buffer.append("G4 P2.0")
                temp_buffer.append("M5\nG0 Z30.0\nG4 P5.0 (Cool Down)\n")  # Add M5 after the sequence
                buffer.extend(temp_buffer)
        i += 1

    # Append the additional commands to the buffer
    buffer.append("G4 P30.0")

    # Second Pass: Insert buffer after the first H0 line while keeping all original lines
    with open(output_file, 'w') as file:
        inserted = False
        for line in lines:
            file.write(line)
            if not inserted and line.startswith("H0"):
                file.write("\n\n(Pierce the stock only, change to a fresh tip later for the actual cuts)\n\n")
                file.write("\n".join(buffer) + "\n")
                inserted = True

    print(f"Modified file written to: {output_file}")

# Entry point for the script
if __name__ == "__main__":
    if len(sys.argv) != 2:
        print("Usage: python3 modify_gcode.py <input_file>")
        sys.exit(1)

    input_file = sys.argv[1]
    if not os.path.exists(input_file):
        print(f"Error: File '{input_file}' not found.")
        sys.exit(1)

    modify_gcode(input_file)