"""This script determines the updated, added, and deleted properties from the '.properties-MERGED' files
and generates a csv file containing the items changed.  This script requires the python libraries:
gitpython and jproperties.  As a consequence, it also requires git >= 1.7.0 and python >= 3.4.
"""
import re
import sys
from envutil import get_proj_dir
from excelutil import write_results_to_xlsx
from gitutil import get_property_files_diff, get_commit_id, get_git_root
from itemchange import ItemChange, ChangeType
from csvutil import write_results_to_csv
import argparse
from typing import Union
from langpropsutil import get_commit_for_language, LANG_FILENAME
from outputresult import OutputResult
from outputtype import OutputType


def get_diff_to_write(repo_path: str, commit_1_id: str, commit_2_id: str, show_commits: bool, separate_deleted: bool,
                      value_regex: Union[str, None] = None) -> OutputResult:
    """Determines the changes made in '.properties-MERGED' files from one commit to another commit and returns results.

    Args:
        repo_path (str): The local path to the git repo.
        commit_1_id (str): The initial commit for the diff.
        commit_2_id (str): The latest commit for the diff.
        show_commits (bool): Show commits in the header row.
        separate_deleted (bool): put deletion items in a separate field in return type ('deleted').  Otherwise,
        include in regular results.
        value_regex (Union[str, None]): If non-none, only key value pairs where the value is a regex match with this
        value will be included.
    """

    row_header = ItemChange.get_headers()
    if show_commits:
        row_header += [get_commit_id(repo_path, commit_1_id), get_commit_id(repo_path, commit_2_id)]

    rows = []
    omitted = []
    deleted = []

    for entry in get_property_files_diff(repo_path, commit_1_id, commit_2_id):
        entry_row = entry.get_row()
        if separate_deleted and entry.type == ChangeType.DELETION:
            deleted.append(entry_row)
        if value_regex is not None and re.match(value_regex, entry.cur_val):
            omitted.append(entry_row)
        else:
            rows.append(entry_row)

    omitted_result = [row_header] + omitted if len(omitted) > 0 else None
    deleted_result = [row_header] + deleted if len(deleted) > 0 else None

    return OutputResult([row_header] + rows, omitted_result, deleted_result)


def main():
    # noinspection PyTypeChecker
    parser = argparse.ArgumentParser(description="Determines the updated, added, and deleted properties from the "
                                                 "'.properties-MERGED' files and generates a csv file containing "
                                                 "the items changed.",
                                     formatter_class=argparse.ArgumentDefaultsHelpFormatter)
    parser.add_argument(dest='output_path', type=str, help='The path to the output file.  The output path should '
                                                           'be specified as a relative path with the dot slash notation'
                                                           ' (i.e. \'./outputpath.xlsx\') or an absolute path.')

    parser.add_argument('-r', '--repo', dest='repo_path', type=str, required=False,
                        help='The path to the repo.  If not specified, path of script is used.')
    parser.add_argument('-fc', '--first-commit', dest='commit_1_id', type=str, required=False,
                        help='The commit for previous release.  This flag or the language flag need to be specified'
                             ' in order to determine a start point for the difference.')
    parser.add_argument('-lc', '--latest-commit', dest='commit_2_id', type=str, default='HEAD', required=False,
                        help='The commit for current release.')
    parser.add_argument('-nc', '--no-commits', dest='no_commits', action='store_true', default=False,
                        required=False, help="Suppresses adding commits to the generated csv header.")
    parser.add_argument('-o', '--output-type', dest='output_type', type=OutputType, choices=list(OutputType),
                        required=False, help="The output type.  Currently supports 'csv' or 'xlsx'.", default='xlsx')
    parser.add_argument('-l', '--language', dest='language', type=str, default=None, required=False,
                        help='Specify the language in order to determine the first commit to use (i.e. \'ja\' for '
                             'Japanese.  This flag overrides the first-commit flag.')

    args = parser.parse_args()
    repo_path = args.repo_path if args.repo_path is not None else get_git_root(get_proj_dir())
    output_path = args.output_path
    commit_1_id = args.commit_1_id
    output_type = args.output_type

    lang = args.language
    if lang is not None:
        commit_1_id = get_commit_for_language(lang)

    if commit_1_id is None:
        print('Either the first commit or language flag need to be specified.  If specified, the language file, ' +
              LANG_FILENAME + ', may not have the latest commit for the language.', file=sys.stderr)
        parser.print_help(sys.stderr)
        sys.exit(1)

    commit_2_id = args.commit_2_id
    show_commits = not args.no_commits

    processing_result = get_diff_to_write(repo_path, commit_1_id, commit_2_id, show_commits)

    # based on https://stackoverflow.com/questions/60208/replacements-for-switch-statement-in-python
    {
        OutputType.csv: write_results_to_csv,
        OutputType.xlsx: write_results_to_xlsx
    }[output_type](processing_result, output_path)

    sys.exit(0)


if __name__ == "__main__":
    main()