from collections import defaultdict

from django.core.management.base import BaseCommand

from apps.users.email_identity import is_placeholder_email, normalize_email_identity
from apps.users.models import User


class Command(BaseCommand):
    help = "Audit legacy email identities for Google auto-link safety."

    def handle(self, *args, **options):
        duplicate_map: dict[str, list[User]] = defaultdict(list)
        placeholder_users: list[User] = []
        email_only_users: list[User] = []

        for user in User.all_objects.all().order_by("id"):
            normalized_email = normalize_email_identity(user.email)
            if normalized_email:
                duplicate_map[normalized_email].append(user)
            if is_placeholder_email(user.email):
                placeholder_users.append(user)
            if normalized_email and not user.mobile:
                email_only_users.append(user)

        duplicates = {email: users for email, users in duplicate_map.items() if len(users) > 1}

        self.stdout.write(self.style.WARNING(f"Case-insensitive duplicate emails: {len(duplicates)}"))
        for email, users in duplicates.items():
            user_ids = ", ".join(str(user.id) for user in users)
            self.stdout.write(f"  {email}: user_ids=[{user_ids}]")

        self.stdout.write(self.style.WARNING(f"Placeholder emails: {len(placeholder_users)}"))
        for user in placeholder_users[:50]:
            self.stdout.write(f"  user_id={user.id} email={user.email}")

        self.stdout.write(self.style.WARNING(f"Email-only users needing mobile bind: {len(email_only_users)}"))
        for user in email_only_users[:100]:
            self.stdout.write(f"  user_id={user.id} email={user.email}")

        if not duplicates and not placeholder_users:
            self.stdout.write(self.style.SUCCESS("No blocking legacy email issues were found."))