"""Gmail draft creation via Gmail API (OAuth2)."""

from __future__ import annotations

import base64
import logging
from email.mime.text import MIMEText

from googleapiclient.discovery import build

from .google_auth import get_credentials

log = logging.getLogger(__name__)


class GmailDraftClient:
    """Create email drafts in Gmail via the API."""

    def __init__(self):
        creds = get_credentials()
        self._service = build("gmail", "v1", credentials=creds)

    def create_draft(
        self,
        to: str,
        subject: str,
        body: str,
        cc: list[str] | None = None,
    ) -> str:
        """Create a draft email in the authenticated user's Gmail.

        Args:
            to: Recipient email address.
            subject: Email subject line.
            body: Plain text email body.
            cc: Optional list of CC email addresses.

        Returns:
            The Gmail draft ID.
        """
        message = MIMEText(body)
        message["to"] = to
        message["subject"] = subject
        if cc:
            message["cc"] = ", ".join(cc)

        raw = base64.urlsafe_b64encode(message.as_bytes()).decode("ascii")
        draft = (
            self._service.users()
            .drafts()
            .create(userId="me", body={"message": {"raw": raw}})
            .execute()
        )
        draft_id = draft["id"]
        log.info("Created Gmail draft %s (to=%s, subject=%s)", draft_id, to, subject)
        return draft_id