import asyncio
import logging
from collections.abc import Awaitable, Callable

logger = logging.getLogger(__name__)

MC_CHAT_MAX_CHARS = 256
CHUNK_PREFIX_OVERHEAD = 8
DELAY_BETWEEN_CHUNKS = 0.5


def split_for_minecraft(
    content: str,
    max_chars: int = MC_CHAT_MAX_CHARS,
    page_indicator: bool = True,
) -> list[str]:
    result: list[str] = []
    remaining = content

    while remaining:
        available = max_chars

        if len(remaining) <= available:
            result.append(remaining)
            break

        split_at = -1
        for sep in ("\n", "。", "！", "？", ". ", "! ", "? ", "，", ", ", " "):
            pos = remaining.rfind(sep, 0, available)
            if pos > available * 0.5:
                split_at = pos + len(sep)
                break

        if split_at == -1:
            split_at = available

        result.append(remaining[:split_at].rstrip())
        remaining = remaining[split_at:].lstrip()

    if page_indicator and len(result) > 1:
        total = len(result)
        result = [f"[{i + 1}/{total}] {chunk}" for i, chunk in enumerate(result)]

    return result


async def stream_block_minecraft(
    send_fn: Callable[[str], Awaitable[None]],
    content: str,
    chunk_delay: float = DELAY_BETWEEN_CHUNKS,
) -> None:
    chunks = split_for_minecraft(content)
    total = len(chunks)

    logger.info("Minecraft streaming: %d chars -> %d chunks", len(content), total)

    for i, chunk in enumerate(chunks):
        await send_fn(chunk)
        if i < total - 1:
            logger.debug("Chunk %d/%d sent, waiting %.1fs", i + 1, total, chunk_delay)
            await asyncio.sleep(chunk_delay)