from __future__ import annotations

import time
from typing import Any


class MessageHistory:
    MAX_MESSAGES = 500
    TTL_SECONDS = 3600

    def __init__(self) -> None:
        self._history: dict[str, list[dict[str, Any]]] = {}

    def add(self, chat_guid: str, message: dict[str, Any]) -> None:
        if chat_guid not in self._history:
            self._history[chat_guid] = []
        self._history[chat_guid].append(
            {
                **message,
                "_recorded_at": time.monotonic(),
            }
        )
        self._trim(chat_guid)

    def get(self, chat_guid: str, limit: int = 50) -> list[dict[str, Any]]:
        messages = self._history.get(chat_guid, [])
        self._evict_expired(chat_guid)
        return messages[-limit:]

    def get_since(self, chat_guid: str, since_ts: float) -> list[dict[str, Any]]:
        messages = self._history.get(chat_guid, [])
        self._evict_expired(chat_guid)
        return [m for m in messages if m.get("_recorded_at", 0) >= since_ts]

    def _trim(self, chat_guid: str) -> None:
        messages = self._history.get(chat_guid, [])
        if len(messages) > self.MAX_MESSAGES:
            self._history[chat_guid] = messages[-self.MAX_MESSAGES :]

    def _evict_expired(self, chat_guid: str) -> None:
        messages = self._history.get(chat_guid, [])
        if not messages:
            return
        now = time.monotonic()
        self._history[chat_guid] = [m for m in messages if now - m.get("_recorded_at", now) < self.TTL_SECONDS]

    def clear(self, chat_guid: str) -> None:
        self._history.pop(chat_guid, None)