from sqlalchemy import select
from sqlalchemy.orm import Session

from app.character.service import CharacterService
from app.chat.notices import format_phase_completed_notice
from app.db.models import ChatSession, Message, PomodoroSession
from app.llm.client import LLMClient
from app.pomodoro.cycle import PHASE_LONG_BREAK, PHASE_SHORT_BREAK, PHASE_WORK, CycleManager
from app.pomodoro.service import PomodoroService

PHASE_LABELS = {
    PHASE_WORK: "работа",
    PHASE_SHORT_BREAK: "короткий перерыв",
    PHASE_LONG_BREAK: "длинный перерыв",
}


class PomodoroCompletionHandler:
    def __init__(self, db: Session):
        self.db = db
        self.pomodoro = PomodoroService(db)
        self.cycle = CycleManager(db)
        self.llm = LLMClient()
        self.character = CharacterService()

    def _latest_chat_session_id(self) -> int | None:
        stmt = select(ChatSession).order_by(ChatSession.updated_at.desc()).limit(1)
        session = self.db.scalar(stmt)
        return session.id if session else None

    def _save_chat_message(self, session_id: int, role: str, content: str) -> None:
        self.db.add(Message(session_id=session_id, role=role, content=content))
        chat = self.db.get(ChatSession, session_id)
        if chat:
            chat.updated_at = chat.updated_at  # trigger onupdate
        self.db.commit()

    async def _generate_llm_comment(
        self,
        session: PomodoroSession,
        next_phase: str | None,
    ) -> str:
        cycle = self.cycle.to_dict()
        phase_label = PHASE_LABELS.get(session.phase, session.phase)
        next_label = PHASE_LABELS.get(next_phase, "пауза") if next_phase else "отдых, цикл сброшен"
        work_done = cycle["completed_work_sessions"]
        if session.phase == PHASE_WORK:
            work_done += 1

        system = self.character.get_system_prompt()
        user_prompt = f"""Фаза помидоро «{phase_label}» только что завершилась.
Задача: {session.task_note or 'без описания'}
Прогресс цикла: {work_done}/{cycle['sessions_until_long_break']} работ.
Следующая фаза: {next_label}.

Напиши пользователю короткое сообщение (2-4 предложения) на русском: поздравь, поддержи или предложи отдохнуть. Без markdown."""

        result = await self.llm.complete(
            [
                {"role": "system", "content": system},
                {"role": "user", "content": user_prompt},
            ]
        )
        return (result.get("content") or "").strip() or "Фаза завершена! Отличная работа."

    def _resolve_next_phase(self, session: PomodoroSession) -> str | None:
        phase = session.phase
        cycle = self.cycle.get()
        if phase == PHASE_WORK:
            if cycle.completed_work_sessions + 1 >= cycle.sessions_until_long_break:
                return PHASE_LONG_BREAK
            return PHASE_SHORT_BREAK
        if phase == PHASE_SHORT_BREAK:
            return PHASE_WORK
        if phase == PHASE_LONG_BREAK:
            return None
        return None

    async def process(self, session: PomodoroSession) -> None:
        if session.completion_notified:
            return

        next_phase = self._resolve_next_phase(session)
        notice = format_phase_completed_notice(session, next_phase)

        chat_id = self._latest_chat_session_id()
        if not chat_id:
            chat = ChatSession(title="Помидоро")
            self.db.add(chat)
            self.db.commit()
            self.db.refresh(chat)
            chat_id = chat.id

        self._save_chat_message(chat_id, "notice", notice)

        comment = await self._generate_llm_comment(session, next_phase)
        self._save_chat_message(chat_id, "assistant", comment)

        self.cycle.bump_notify_seq()
        self.pomodoro.mark_notified(session)
        self.pomodoro.advance_after_completion(session)