blocks_reader.py

# Copyright (c) 2022, Intrepid Control Systems, Inc.
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from pathlib import Path
import yaml
from os import environ


def main():
    """
    Main function, mostly only used for debugging if running this as main.
    """
    root_dir = Path(__file__).resolve().parent
    blocks = read_blocks(root_dir)
    print(blocks)


def read_blocks(root_dir, local_only=False):
    """
    Reads the blocks specification file at provided root dir
    and returns list of paths to blocks.
    If any specified blocks are external repos and local_only
    is not specified, the external repo's blocks spec will be read
    and imported into the local one.

    Args:
        root_dir: The directory containing the blocks specification file
        local_only: When true, only local blocks will be read

    Returns:
        A list of paths to blocks with manifests
    """
    blocks_file = Path(root_dir) / "blocks.yaml"
    if blocks_file.exists():
        with open(blocks_file) as file:
            # The FullLoader parameter handles the conversion from YAML
            # scalar values to Python the dictionary format
            blocks_arr = yaml.load(file, Loader=yaml.FullLoader)
    else:
        # Assume single manifest with no blocks declaration
        blocks_arr = []

    root_dir = Path(root_dir)
    blocks = []

    for block in blocks_arr:
        block = Path(block)
        block = root_dir / block
        blocks.append(block)

    if (root_dir / "manifest.yaml").exists():
        # Implicit self on base dir
        blocks.append(root_dir)

    external_blocks = []
    all_blocks = []
    for block in blocks:
        try:
            # If this works it's local, if not must be external
            rel_path = block.relative_to(root_dir)
            # Without a resolve this can happen, dump it back over to the exception to handle the same
            if str(rel_path).startswith(".."):
                raise ValueError
            all_blocks.append(block)
        except ValueError:
            if not local_only:
                external_blocks.extend(read_blocks(block))
    all_blocks.extend(external_blocks)

    return all_blocks