from __future__ import annotations

import hashlib
import logging
from pathlib import Path
from typing import Any

logger = logging.getLogger(__name__)

CHUNK_SIZE = 10 * 1024 * 1024


class ChunkedMediaUploader:
    def __init__(self, api_client: Any = None):
        self._api_client = api_client

    def needs_chunked_upload(self, file_size: int, threshold: int = CHUNK_SIZE) -> bool:
        return file_size >= threshold

    async def upload_file_chunked(
        self, file_path: str, chat_type: str, target_id: str
    ) -> dict | None:
        path = Path(file_path)
        if not path.exists():
            return None

        data = path.read_bytes()
        file_hash = hashlib.sha256(data).hexdigest()[:16]

        parts = []
        offset = 0
        part_num = 1
        while offset < len(data):
            chunk = data[offset : offset + CHUNK_SIZE]
            chunk_hash = hashlib.sha256(chunk).hexdigest()[:8]
            parts.append(
                {
                    "part_num": part_num,
                    "data": chunk,
                    "hash": chunk_hash,
                }
            )
            offset += CHUNK_SIZE
            part_num += 1

        return {
            "file_hash": file_hash,
            "total_parts": len(parts),
            "file_size": len(data),
            "filename": path.name,
        }