# -*- coding: utf-8 -*-
"""Convert IDE TODOs to GitHub issues."""

import os
import re
from time import sleep
from io import StringIO
import itertools
import operator
from collections import defaultdict


if __name__ == "__main__":
    client: Client | None = None
    # Try to create a basic client for communicating with the remote version control server, automatically initialised with environment variables.
    try:
        # try to build a GitHub client
        client = GitHubClient()
    except EnvironmentError:
        # don't immediately give up
        pass
    # if needed, fall back to using a local client for testing
    client = client or LocalClient()

    # Get the diff from the last pushed commit.
    last_diff = client.get_last_diff()

    if last_diff:
        # Parse the diff for TODOs and create an Issue object for each.
        raw_issues = TodoParser().parse(StringIO(last_diff))
        # This is a simple, non-perfect check to filter out any TODOs that have just been moved.
        # It looks for items that appear in the diff as both an addition and deletion.
        # It is based on the assumption that TODOs will not have identical titles in identical files.
        # That is about as good as we can do for TODOs without issue URLs.
        issues_to_process = []
        for values, similar_issues_iter in itertools.groupby(raw_issues, key=operator.attrgetter('title', 'file_name',
                                                                                            'markdown_language')):
            similar_issues = list(similar_issues_iter)
            if (len(similar_issues) == 2 and all(issue.issue_url is None for issue in similar_issues)
                    and ((similar_issues[0].status == LineStatus.ADDED
                          and similar_issues[1].status == LineStatus.DELETED)
                     or (similar_issues[1].status == LineStatus.ADDED
                         and similar_issues[0].status == LineStatus.DELETED))):
                print(f'Issue "{values[0]}" appears as both addition and deletion. '
                      f'Assuming this issue has been moved so skipping.')
                continue
            issues_to_process.extend(similar_issues)

        # If a TODO with an issue URL is updated, it may appear as both an addition and a deletion.
        # We need to ignore the deletion so it doesn't update then immediately close the issue.
        # First store TODOs based on their status.
        todos_status = defaultdict(lambda: {'added': False, 'deleted': False})

        # Populate the status dictionary based on the issue URL.
        for raw_issue in issues_to_process:
            if raw_issue.issue_url:  # Ensuring we're dealing with TODOs that have an issue URL.
                if raw_issue.status == LineStatus.ADDED:
                    todos_status[raw_issue.issue_url]['added'] = True
                elif raw_issue.status == LineStatus.DELETED:
                    todos_status[raw_issue.issue_url]['deleted'] = True

        # Determine which issues are both added and deleted.
        update_and_close_issues = set()

        for _issue_url, _status in todos_status.items():
            if _status['added'] and _status['deleted']:
                update_and_close_issues.add(_issue_url)

        # Remove issues from issues_to_process if they are both to be updated and closed (i.e., ignore deletions).
        issues_to_process = [issue for issue in issues_to_process if
                             not (issue.issue_url in update_and_close_issues and issue.status == LineStatus.DELETED)]

        # Check to see if we should insert the issue URL back into the linked TODO.
        insert_issue_urls = os.getenv('INPUT_INSERT_ISSUE_URLS', 'false') == 'true'

        # Cycle through the Issue objects and create or close a corresponding GitHub issue for each.
        for j, raw_issue in enumerate(issues_to_process):
            print(f"Processing issue {j + 1} of {len(issues_to_process)}: '{raw_issue.title}' @ {raw_issue.file_name}:{raw_issue.start_line}")
            if raw_issue.status == LineStatus.ADDED:
                status_code, new_issue_number = client.create_issue(raw_issue)
                if status_code == 201:
                    print(f'Issue created: : #{new_issue_number} @ {client.get_issue_url(new_issue_number)}')
                    # Don't insert URLs for comments. Comments do not get updated.
                    if insert_issue_urls and not (raw_issue.ref and raw_issue.ref.startswith('#')):
                        line_number = raw_issue.start_line - 1
                        with open(raw_issue.file_name, 'r') as issue_file:
                            file_lines = issue_file.readlines()
                        if line_number < len(file_lines):
                            # Duplicate the line to retain the comment syntax.
                            new_line = file_lines[line_number]
                            remove = fr'{raw_issue.identifier}.*{raw_issue.title}'
                            insert = f'Issue URL: {client.get_issue_url(new_issue_number)}'
                            new_line = re.sub(remove, insert, new_line)
                            # Check if the URL line already exists, if so abort.
                            if line_number == len(file_lines) - 1 or file_lines[line_number + 1] != new_line:
                                file_lines.insert(line_number + 1, new_line)
                                with open(raw_issue.file_name, 'w') as issue_file:
                                    issue_file.writelines(file_lines)
                elif status_code == 200:
                    print(f'Issue updated: : #{new_issue_number} @ {client.get_issue_url(new_issue_number)}')
                else:
                    print('Issue could not be created')
            elif raw_issue.status == LineStatus.DELETED and os.getenv('INPUT_CLOSE_ISSUES', 'true') == 'true':
                if raw_issue.ref and raw_issue.ref.startswith('#'):
                    print('Issue looks like a comment, will not attempt to close.')
                    continue
                status_code = client.close_issue(raw_issue)
                if status_code in [200, 201]:
                    print('Issue closed')
                else:
                    print('Issue could not be closed')
            # Stagger the requests to be on the safe side.
            sleep(1)