"""Conversation — user별 최근 대화 기억."""

from __future__ import annotations

from collections import defaultdict
from dataclasses import dataclass, field
from time import time

MAX_HISTORY = 10  # user당 최근 대화 수
HISTORY_TTL = 3600.0  # 1시간 이후 대화 만료
DRAFT_TTL = 300.0  # pending_draft 5분 만료


@dataclass
class Message:
    role: str  # "user" | "assistant"
    content: str
    timestamp: float = field(default_factory=time)


class ConversationStore:
    def __init__(self) -> None:
        self._history: dict[str, list[Message]] = defaultdict(list)
        self._pending_drafts: dict[str, tuple[dict, float]] = {}  # user_id → (draft_data, created_at)

    def add(self, user_id: str, role: str, content: str) -> None:
        msgs = self._history[user_id]
        msgs.append(Message(role=role, content=content))
        # 최대 개수 제한
        if len(msgs) > MAX_HISTORY:
            self._history[user_id] = msgs[-MAX_HISTORY:]

    def get(self, user_id: str) -> list[Message]:
        """만료되지 않은 최근 대화 반환."""
        now = time()
        msgs = self._history.get(user_id, [])
        # TTL 필터
        fresh = [m for m in msgs if now - m.timestamp < HISTORY_TTL]
        self._history[user_id] = fresh
        return fresh

    def format_for_prompt(self, user_id: str) -> str:
        """EXAONE에 전달할 대화 이력 포맷."""
        msgs = self.get(user_id)
        lines = []
        for m in msgs[-6:]:  # 최근 6개만
            prefix = "사용자" if m.role == "user" else "이드"
            lines.append(f"{prefix}: {m.content}")
        # pending_draft 표시
        draft = self.get_pending_draft(user_id)
        if draft:
            lines.append(f"[시스템: pending_draft 있음 — {draft.get('title', '일정')} {draft.get('date', '')} {draft.get('time', '')}]")
        if not lines:
            return ""
        return "\n".join(lines)

    def set_pending_draft(self, user_id: str, draft_data: dict) -> None:
        self._pending_drafts[user_id] = (draft_data, time())

    def get_pending_draft(self, user_id: str) -> dict | None:
        entry = self._pending_drafts.get(user_id)
        if not entry:
            return None
        data, created_at = entry
        if time() - created_at > DRAFT_TTL:
            del self._pending_drafts[user_id]
            return None
        return data

    def clear_pending_draft(self, user_id: str) -> None:
        self._pending_drafts.pop(user_id, None)


conversation_store = ConversationStore()