"""
Gitlint extra rule to validate that the message title is of the form
"<gitmoji>(<scope>) <subject>"
"""

import json
import re
import urllib.request

from gitlint.rules import CommitMessageTitle, LineRule, RuleViolation

GITMOJIS_URL = "https://raw.githubusercontent.com/carloscuesta/gitmoji/master/packages/gitmojis/src/gitmojis.json"


class GitmojiTitle(LineRule):
    """
    This rule will enforce that each commit title is of the form "<gitmoji>(<scope>) <subject>"
    where gitmoji is an emoji from the list defined in https://gitmoji.carloscuesta.me and
    subject should be all lowercase
    """

    id = "UC1"
    name = "title-should-have-gitmoji-and-scope"
    target = CommitMessageTitle

    def validate(self, title, _commit):
        """
        Download the list possible gitmojis from the project's github repository and check that
        title contains one of them.
        """
        with urllib.request.urlopen(GITMOJIS_URL, timeout=10) as response:
            gitmojis = json.load(response)["gitmojis"]
        emojis = [re.escape(item["emoji"]) for item in gitmojis]
        pattern = r"^({:s})\(.*\)\s[a-z].*$".format("|".join(emojis))
        if not re.search(pattern, title):
            violation_msg = 'Title does not match regex "<gitmoji>(<scope>) <subject>"'
            return [RuleViolation(self.id, violation_msg, title)]