from __future__ import annotations

import logging

logger = logging.getLogger(__name__)


def chunk_text(text: str, limit: int = 4000, mode: str = "markdown") -> list[str]:
    if len(text) <= limit:
        return [text]

    if mode == "markdown":
        return _chunk_markdown(text, limit)
    elif mode == "newline":
        return _chunk_by_newline(text, limit)
    return _chunk_by_length(text, limit)


def _chunk_markdown(text: str, limit: int) -> list[str]:
    chunks: list[str] = []
    remainder = text

    while len(remainder) > limit:
        cut = remainder.rfind("\n\n", 0, limit)
        if cut < limit // 2:
            cut = remainder.rfind("\n", 0, limit)
        if cut < limit // 4:
            cut = remainder.rfind(". ", 0, limit)
        if cut < 0:
            cut = limit

        chunk = remainder[: cut + 1].rstrip()
        chunks.append(chunk)
        remainder = remainder[cut + 1 :].lstrip()

    if remainder.strip():
        chunks.append(remainder.strip())

    return chunks


def _chunk_by_newline(text: str, limit: int) -> list[str]:
    chunks: list[str] = []
    current = ""
    for line in text.split("\n"):
        if len(current) + len(line) + 1 > limit and current:
            chunks.append(current.rstrip())
            current = line
        else:
            current = f"{current}\n{line}".strip()
    if current:
        chunks.append(current)
    return chunks


def _chunk_by_length(text: str, limit: int) -> list[str]:
    chunks: list[str] = []
    for i in range(0, len(text), limit):
        chunks.append(text[i : i + limit])
    return chunks