from __future__ import annotations

import logging

from yuxi.channel.extensions.line.bot import LineBotClient

logger = logging.getLogger(__name__)

MAX_REPLY_MESSAGES = 5
MAX_PUSH_MESSAGES_PER_BATCH = 5


class LineDeliveryManager:

    async def deliver_messages(
        self,
        to: str,
        messages: list[dict],
        reply_token: str | None,
        token: str,
    ) -> bool:
        bot = LineBotClient(channel_access_token=token)

        if reply_token:
            try:
                reply_batch = messages[:MAX_REPLY_MESSAGES]
                ok = await bot.reply_message(reply_token, reply_batch)
                if ok:
                    remaining = messages[MAX_REPLY_MESSAGES:]
                    if remaining:
                        for batch in _batch_list(remaining, MAX_PUSH_MESSAGES_PER_BATCH):
                            await bot.push_message(to, batch)
                    return True
            except Exception:
                logger.exception("LINE reply_message failed, falling back to push")

        for batch in _batch_list(messages, MAX_PUSH_MESSAGES_PER_BATCH):
            ok = await bot.push_message(to, batch)
            if not ok:
                return False

        return True


def _batch_list(items: list, batch_size: int) -> list[list]:
    return [items[i: i + batch_size] for i in range(0, len(items), batch_size)]