import json
import os
import pathlib
import subprocess
import tempfile

from .step_tree import normalize_deleted_paths


class FreeCADWorker:
    def __init__(self, freecad_cmd="FreeCADCmd"):
        self.freecad_cmd = freecad_cmd

    def trim_step_file(self, file_name, file_bytes, deleted_paths):
        normalized_paths = normalize_deleted_paths(deleted_paths)
        with tempfile.TemporaryDirectory(prefix="o3dv-step-") as temp_dir:
            temp_path = pathlib.Path(temp_dir)
            input_path = temp_path / file_name
            output_name = self._build_output_name(file_name)
            output_path = temp_path / output_name
            delete_manifest_path = temp_path / "deleted_paths.json"

            input_path.write_bytes(file_bytes)
            delete_manifest_path.write_text(
                json.dumps(normalized_paths),
                encoding="utf-8",
            )

            subprocess.run(
                [
                    self.freecad_cmd,
                    os.fspath(pathlib.Path(__file__).with_name("freecad_trim_step.py")),
                    os.fspath(input_path),
                    os.fspath(delete_manifest_path),
                    os.fspath(output_path),
                ],
                check=True,
                capture_output=True,
                text=True,
            )

            return output_path.read_bytes(), output_name

    def _build_output_name(self, file_name):
        lower_name = file_name.lower()
        if lower_name.endswith(".step"):
            return file_name[:-5] + "-edited.step"
        if lower_name.endswith(".stp"):
            return file_name[:-4] + "-edited.stp"
        return file_name + "-edited.step"