#!/usr/bin/env python3
"""
Fetch contributors data from Github using their API, convert it to structured
JSON data for the /team page contributors section.
"""

import os
import sys

sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..'))
from scripts.lib.setup_path import setup_path
setup_path()

from typing import Any, Dict, List, Optional, Union
from typing_extensions import TypedDict

import argparse
from time import sleep
from datetime import date
from random import randrange
import logging

os.environ['DJANGO_SETTINGS_MODULE'] = 'zproject.settings'
import django
django.setup()

from django.conf import settings

import requests
import json

duplicate_commits_file = os.path.join(os.path.dirname(__file__), 'duplicate_commits.json')

parser = argparse.ArgumentParser()
parser.add_argument('--max-retries', type=int, default=10,
                    help='Number of times to retry fetching data from Github')
args = parser.parse_args()

ContributorsJSON = TypedDict('ContributorsJSON', {
    'date': str,
    'contrib': List[Dict[str, Union[str, int]]],
})

logger = logging.getLogger('zulip.fetch_contributors_json')

def fetch_contributors(repo_link: str) -> Optional[List[Dict[str, Dict[str, Any]]]]:
    r = requests.get(repo_link, verify=os.environ.get('CUSTOM_CA_CERTIFICATES'))  # type: requests.Response
    return r.json() if r.status_code == 200 else None

def write_to_disk(json_data: ContributorsJSON, out_file: str) -> None:
    with open(out_file, 'w') as f:
        try:
            f.write("{}\n".format(json.dumps(json_data, indent=2, sort_keys=True)))
        except OSError as e:
            logger.warning(e)
            sys.exit(1)

def update_contributor_data_file() -> None:
    """
    Get contributors data from Github and insert them into a temporary
    dictionary. Retry fetching each repository if responded with non HTTP 200
    status.
    """

    # This dictionary should hold all repositories that should be included in
    # the total count, including those that should *not* have tabs on the team
    # page (e.g. if they are deprecated).
    repositories = {
        'server': 'https://api.github.com/repos/zulip/zulip/stats/contributors',
        'desktop': 'https://api.github.com/repos/zulip/zulip-desktop/stats/contributors',
        'mobile': 'https://api.github.com/repos/zulip/zulip-mobile/stats/contributors',
        'python-zulip-api': 'https://api.github.com/repos/zulip/python-zulip-api/stats/contributors',
        'zulip-js': 'https://api.github.com/repos/zulip/zulip-js/stats/contributors',
        'zulipbot': 'https://api.github.com/repos/zulip/zulipbot/stats/contributors',
        'terminal': 'https://api.github.com/repos/zulip/zulip-terminal/stats/contributors',
        'zulip-ios-legacy': 'https://api.github.com/repos/zulip/zulip-ios-legacy/stats/contributors',
        'zulip-android': 'https://api.github.com/repos/zulip/zulip-android/stats/contributors',
    }

    data = dict(date=str(date.today()), contrib=[])  # type: ContributorsJSON
    contribs_list = {}  # type: Dict[str, Dict[str, Union[str, int]]]
    retry_attempts = 0

    while True:
        repos_done = []
        for name, link in repositories.items():
            contribs = fetch_contributors(link)
            if contribs:
                repos_done.append(name)
                for contrib in contribs:
                    assert contrib is not None  # TODO: To improve/clarify

                    author = contrib.get('author')
                    if author is None:
                        # This happens for users who've deleted their GitHub account.
                        continue

                    username = author.get('login')
                    assert username is not None  # TODO: To improve/clarify

                    avatar = author.get('avatar_url')
                    assert avatar is not None  # TODO: To improve/clarify
                    total = contrib.get('total')
                    assert total is not None  # TODO: To improve/clarify

                    contrib_data = {
                        'avatar': avatar,
                        name: total,
                    }
                    if username in contribs_list:
                        contribs_list[username].update(contrib_data)
                    else:
                        contribs_list[username] = contrib_data
                retry_attempts = 0
            else:
                retry_attempts += 1
                if retry_attempts > args.max_retries:
                    logger.warning("Failed retries fetching contributors data from Github.")
                    sys.exit(1)

                sleep_time = randrange(0, min(64, 2**retry_attempts))
                sleep(sleep_time)

        # remove duplicate contributions count
        # find commits at the time of split and subtract from zulip-server
        with open(duplicate_commits_file) as f:
            duplicate_commits = json.load(f)
            for committer in duplicate_commits:
                if committer in contribs_list and contribs_list[committer].get('server'):
                    total_commits = contribs_list[committer]['server']
                    assert isinstance(total_commits, int)
                    duplicate_commits_count = duplicate_commits[committer]
                    original_commits = total_commits - duplicate_commits_count
                    contribs_list[committer]['server'] = original_commits

        for repo in repos_done:
            del repositories[repo]

        if not repositories:
            break

    for contributor_name, contributor_data in contribs_list.items():
        contributor_data['name'] = contributor_name
        data['contrib'].append(contributor_data)

    write_to_disk(data, settings.CONTRIBUTOR_DATA_FILE_PATH)

if __name__ == "__main__":
    update_contributor_data_file()