"""Define argument parser class."""

import argparse

from pathlib import Path

class ArgParser(object):

    """Argument parser for label.py"""

    def __init__(self):

        """Initialize argument parser."""

        parser = argparse.ArgumentParser()

        # Input report parameters.

        parser.add_argument('--reports_path',

                            required=True,

                            help='Path to file with radiology reports.')

        parser.add_argument('--sections_to_extract',

                            nargs='*',

                            default=[],

                            help='Titles of the sections to extract from ' +

                                 'each report.')

        parser.add_argument('--extract_strict',

                            action='store_true',

                            help='Instructs the labeler to only extract the ' +

                                 'sections given by sections_to_extract. ' +

                                 'If this argument is given and a report is ' +

                                 'encountered that does not contain any of ' +

                                 'the provided sections, instead of loading ' +

                                 'the original document, that report will be ' +

                                 'loaded as an empty document.')

        # Phrases

        parser.add_argument('--mention_phrases_dir',

                            default='phrases/mention',

                            help='Directory containing mention phrases for ' +

                                 'each observation.')

        parser.add_argument('--unmention_phrases_dir',

                            default='phrases/unmention',

                            help='Directory containing unmention phrases ' +

                                 'for each observation.')

        # Rules

        parser.add_argument('--pre_negation_uncertainty_path',

                            default='patterns/pre_negation_uncertainty.txt',

                            help='Path to pre-negation uncertainty rules.')

        parser.add_argument('--negation_path',

                            default='patterns/negation.txt',

                            help='Path to negation rules.')

        parser.add_argument('--post_negation_uncertainty_path',

                            default='patterns/post_negation_uncertainty.txt',

                            help='Path to post-negation uncertainty rules.')

        # Output parameters.

        parser.add_argument('--output_path',

                            default='labeled_reports.csv',

                            help='Output path to write labels to.')

        # Misc.

        parser.add_argument('-v', '--verbose',

                            action='store_true',

                            help='Print progress to stdout.')

        self.parser = parser

    def parse_args(self):

        """Parse and validate the supplied arguments."""

        args = self.parser.parse_args()

        args.reports_path = Path(args.reports_path)

        args.mention_phrases_dir = Path(args.mention_phrases_dir)

        args.unmention_phrases_dir = Path(args.unmention_phrases_dir)

        args.output_path = Path(args.output_path)

        return args