Source code for scfile.convert.convert

"""
Basic implementation of converting one format to another.
"""

from pathlib import Path
from typing import Optional, Type

from scfile import exceptions, types
from scfile.core import ContentType, FileDecoder, FileEncoder, Options




def convert(
    decoder: Type[FileDecoder[ContentType]],
    encoder: Type[FileEncoder[ContentType]],
    source: types.PathLike,
    output: types.OutputLike = None,
    options: Optional[Options] = None,
) -> None:
    """
    Convert one file between formats.

    Args:
        decoder: Decoder class for source format.
        encoder: Encoder class for output format.
        source: Path to source file.
        output (optional): Path to output file or directory. Defaults to source directory.
        options (optional): Shared handlers options.

    Raises:
        FileNotFound: Source file does not exist.

    Example:
        - ``convert(McsaDecoder, ObjEncoder, "model.mcsb", "model.obj")``
        - ``convert(McsaDecoder, ObjEncoder, "model.mcsb", "path/to/output/dir")``
    """

    src_path = Path(source)
    out_path = Path(output or src_path.parent)
    options = options or Options()

    if not src_path.exists() or not src_path.is_file():
        raise exceptions.FileNotFound(str(src_path))

    if out_path.suffix == encoder.format.suffix:
        out_dir = out_path.parent
        out_name = out_path.name
    else:
        out_dir = out_path
        out_name = f"{src_path.stem}{encoder.format.suffix}"

    if not out_dir.exists():
        out_dir.mkdir(exist_ok=True, parents=True)

    output_path = out_dir / out_name

    match options.on_conflict:
        case "skip" if output_path.exists():
            return
        case "rename":
            output_path = ensure_unique_path(output_path)

    with decoder(src_path, options) as src:
        with src.convert_to(encoder=encoder) as out:
            out.save(path=output_path)





def ensure_unique_path(path: Path) -> Path:
    """Append a counter to path if a file already exists."""

    filename, suffix = path.stem, path.suffix
    counter = 1

    while path.exists():
        path = path.parent / Path(f"{filename} ({counter}){suffix}")
        counter += 1

    return path