import os
import subprocess
import tempfile
import shutil
from pathlib import Path

def convert_to_bgcode(gcode: str, name_part: str, compress: bool = True) -> bytes:
    """
    Converts a G-code string to binary BGCode using the internal bgcode tool.
    Returns the binary content of the converted file.
    """
    addon_dir = os.path.dirname(os.path.dirname(os.path.dirname(__file__)))
    bgcode_bin = os.path.join(addon_dir, "infra", "bin", "bgcode")
    
    if not os.path.exists(bgcode_bin):
        raise FileNotFoundError(f"bgcode binary not found at {bgcode_bin}")

    with tempfile.TemporaryDirectory() as tmpdir:
        tmp_gcode = Path(tmpdir) / (name_part + ".gcode")
        tmp_gcode.write_text(gcode, encoding="utf-8")
        
        # Run conversion: bgcode <input>
        cmd = [bgcode_bin, str(tmp_gcode)]
        if compress:
            # Recommended settings for true binary bgcode
            cmd.extend([
                "--slicer_metadata_compression=1",
                "--gcode_compression=3", 
                "--gcode_encoding=2"
            ])

        res = subprocess.run(cmd, capture_output=True, text=True)
        if res.returncode != 0:
            err_msg = res.stderr.strip() or res.stdout.strip() or "Unknown error"
            raise RuntimeError(f"bgcode conversion failed: {err_msg}")
        
        tmp_bgcode = tmp_gcode.with_suffix(".bgcode")
        if tmp_bgcode.exists():
            return tmp_bgcode.read_bytes()
        else:
            raise FileNotFoundError("Failed to find generated .bgcode file")