from __future__ import annotations

from datetime import datetime, timedelta

import pytz
from google.auth.transport.requests import Request
from google.oauth2.credentials import Credentials
from googleapiclient.discovery import build
from googleapiclient.errors import HttpError

from scripts.edoxid_calendar_config import GoogleConfig

JAKARTA_TZ = pytz.timezone("Asia/Jakarta")

TYPE_LABELS = {
    1: "Seminar Proposal",
    2: "Seminar Hasil",
    3: "Sidang Akhir",
}

DAY_NAMES = {
    "Monday": "Senin", "Tuesday": "Selasa", "Wednesday": "Rabu", "Thursday": "Kamis",
    "Friday": "Jumat", "Saturday": "Sabtu", "Sunday": "Minggu",
}

MONTH_NAMES = {
    "January": "Januari", "February": "Februari", "March": "Maret", "April": "April",
    "May": "Mei", "June": "Juni", "July": "Juli", "August": "Agustus",
    "September": "September", "October": "Oktober", "November": "November", "December": "Desember",
}


# --- Fungsi format, dipakai bareng oleh event Calendar & email reminder (edoxid_calendar_gmail_reminder.py) ---

def get_schedule_datetime(submission: dict) -> datetime:
    schedule = submission["schedule"]
    if isinstance(schedule, str):
        schedule = datetime.fromisoformat(schedule)
    if schedule.tzinfo is not None:
        return schedule
    return JAKARTA_TZ.localize(schedule)


def get_type_label(submission: dict) -> str:
    return TYPE_LABELS.get(submission["type_id"], "Sidang")


def format_indonesian_date(date: datetime) -> str:
    day = DAY_NAMES.get(date.strftime("%A"), date.strftime("%A"))
    month = MONTH_NAMES.get(date.strftime("%B"), date.strftime("%B"))
    return f"{day}, {date.strftime('%d')} {month} {date.strftime('%Y')}"


def build_description(submission: dict) -> str:
    schedule = get_schedule_datetime(submission)
    type_label = get_type_label(submission)
    pembimbing = [v["name"] for v in submission["verificators"] if v["type"] == "Pembimbing"]
    penguji = [v["name"] for v in submission["verificators"] if v["type"] == "Penguji"]

    lines = [
        f"UNDANGAN {type_label.upper()} SECARA LURING",
        "JURUSAN INFORMATIKA",
        "",
        "Mengundang Bapak dan Ibu dosen tim pembimbing dan penguji untuk hadir pada "
        f"{type_label.lower()} mahasiswa yang dilaksanakan secara Luring.",
        "",
        f"👨‍🎓 {submission['student_name']} - {submission['student_nim']}",
        "",
        f"📖 {submission['title']}",
        "",
        f"📅 {format_indonesian_date(schedule)}",
        f"🕑 {schedule.strftime('%H:%M')} WIB",
        "",
    ]

    for i, name in enumerate(pembimbing, start=1):
        lines.append(f"📕 Pembimbing {i} : {name}")
    for i, name in enumerate(penguji, start=1):
        lines.append(f"📒 Penguji {i} : {name}")

    lines += [
        "",
        "Tempat:",
        submission.get("room") or "-",
        "",
        "Terimakasih.",
        "ttd",
        "Kajur Informatika",
    ]

    return "\n".join(lines)


def format_submission_summary(submission: dict) -> str:
    """Ringkasan 1-baris untuk log Airflow — supaya kelihatan jelas di task log
    siapa yang dapat undangan/reminder tanpa perlu buka Calendar/email manual."""
    schedule = get_schedule_datetime(submission)
    pembimbing = [v["name"] for v in submission["verificators"] if v["type"] == "Pembimbing"]
    penguji = [v["name"] for v in submission["verificators"] if v["type"] == "Penguji"]

    return (
        f"{submission['student_name']} ({submission['student_nim']}) — "
        f"{get_type_label(submission)} — \"{submission['title']}\" — "
        f"{format_indonesian_date(schedule)} {schedule.strftime('%H:%M')} WIB "
        f"@ {submission.get('room') or '-'} | "
        f"Pembimbing: {', '.join(pembimbing) or '-'} | "
        f"Penguji: {', '.join(penguji) or '-'}"
    )


def build_attendee_emails(submission: dict) -> list[str]:
    emails = [submission["student_email"]] + [v["email"] for v in submission["verificators"]]
    seen = set()
    deduped = []
    for email in emails:
        if email and email not in seen:
            seen.add(email)
            deduped.append(email)
    return deduped


class GoogleCalendarService:
    """Auth via OAuth refresh token sebagai tu@informatika.untan.ac.id LANGSUNG
    (bukan service account) — service account tidak bisa invite attendee tanpa
    Domain-Wide Delegation of Authority (dicoba & ditolak Google 2026-07-27)."""

    def __init__(self, config: GoogleConfig):
        self._calendar_id = config.calendar_id

        # Sengaja TIDAK set `scopes=` — lihat catatan di GmailService.__init__
        # (edoxid_calendar_gmail.py) soal `invalid_scope` yang muncul di
        # container Airflow (google-auth versi lain) saat scope refresh
        # diminta lebih sempit dari yang tercakup refresh_token aslinya.
        creds = Credentials(
            token=None,
            refresh_token=config.refresh_token,
            token_uri="https://oauth2.googleapis.com/token",
            client_id=config.client_id,
            client_secret=config.client_secret,
        )
        creds.refresh(Request())

        self._service = build("calendar", "v3", credentials=creds, cache_discovery=False)

    def create_event(self, submission: dict) -> str:
        event = self._build_event(submission)
        result = (
            self._service.events()
            .insert(calendarId=self._calendar_id, body=event, sendUpdates="all")
            .execute()
        )
        return result["id"]

    def update_event(self, event_id: str, submission: dict) -> None:
        event = self._build_event(submission)
        self._service.events().update(
            calendarId=self._calendar_id, eventId=event_id, body=event, sendUpdates="all"
        ).execute()

    def delete_event(self, event_id: str) -> None:
        try:
            self._service.events().delete(
                calendarId=self._calendar_id, eventId=event_id, sendUpdates="all"
            ).execute()
        except HttpError as e:
            # 404/410 berarti event sudah tidak ada (mis. dihapus manual) — aman diabaikan
            if e.resp.status not in (404, 410):
                raise

    def _build_event(self, submission: dict) -> dict:
        schedule = get_schedule_datetime(submission)
        end = schedule + timedelta(hours=1)

        return {
            "summary": f"{get_type_label(submission)} — {submission['student_name']}",
            "description": build_description(submission),
            "location": submission.get("room") or "",
            "start": {"dateTime": schedule.isoformat(), "timeZone": "Asia/Jakarta"},
            "end": {"dateTime": end.isoformat(), "timeZone": "Asia/Jakarta"},
            "attendees": [{"email": email} for email in build_attendee_emails(submission)],
            "reminders": {"useDefault": False, "overrides": self._build_reminders(schedule)},
        }

    @staticmethod
    def _build_reminders(schedule: datetime) -> list[dict]:
        h1 = schedule.replace(hour=7, minute=0, second=0, microsecond=0) - timedelta(days=1)
        minutes_h1 = max(0, int((schedule - h1).total_seconds() // 60))
        return [
            {"method": "popup", "minutes": minutes_h1},
            {"method": "popup", "minutes": 60},
        ]