# standard imports
import os
import typing

# external imports
import yaml

# bsie imports
from bsie.extractor import ExtractorBuilder
from bsie.lib import PipelineBuilder
from bsie.lib.pipeline import Pipeline
from bsie.reader import ReaderBuilder

# constants
DEFAULT_CONFIG_FILE = os.path.join(os.path.dirname(__file__), 'default_config.yaml')
# exports
__all__: typing.Sequence[str] = (
    'DEFAULT_CONFIG_FILE',
    'load_pipeline',
    )


## code ##

def load_pipeline(path: str = DEFAULT_CONFIG_FILE) -> Pipeline:
    """Load a pipeline according to a config at *path*."""
    # load config file
    with open(path, 'rt', encoding='utf-8') as ifile:
        cfg = yaml.safe_load(ifile)

    # reader builder
    rbuild = ReaderBuilder(cfg['ReaderBuilder'])
    # extractor builder
    ebuild = ExtractorBuilder(cfg['ExtractorBuilder'])
    # pipeline builder
    pbuild = PipelineBuilder(
        rbuild,
        ebuild,
        )
    # build pipeline
    pipeline = pbuild.build()

    # return pipeline
    return pipeline

## EOF ##