"""
Context manager — assembles the conversation history for a bot's prompt.
Ensures bots only see messages, never foreign system prompts.
Handles context summarization when enabled.
"""

import logging
from typing import TYPE_CHECKING

if TYPE_CHECKING:
    from fellowship.core.session import Session, BotConfig

logger = logging.getLogger(__name__)


class ContextManager:
    def __init__(self, session: "Session") -> None:
        self.session = session

    def build_context(self, bot: "BotConfig") -> list[dict]:
        """
        Return the conversation history formatted as LLM messages for the given bot.
        Uses shared_context or scoped_context based on session options.
        Skips any slots with content=None (reserved but not yet filled).
        """
        raise NotImplementedError

    def estimate_tokens(self, messages: list[dict]) -> int:
        """
        Estimate total token count for a list of messages.
        Used to check against max_context_tokens.
        """
        raise NotImplementedError

    async def summarize(self) -> None:
        """
        Summarize the older portion of history to reduce context size.
        Retains a recent tail of messages intact.
        Stores the summary in session state; future context builds use summary + tail.
        Full history list is preserved unchanged.
        """
        raise NotImplementedError