# Source code for scrapy.core.downloader.handlers.s3

    from __future__ import annotations

    from typing import TYPE_CHECKING

    from scrapy.core.downloader.handlers.base import BaseDownloadHandler
    from scrapy.core.downloader.handlers.http11 import HTTP11DownloadHandler
    from scrapy.exceptions import NotConfigured
    from scrapy.utils.boto import is_botocore_available
    from scrapy.utils.httpobj import urlparse_cached
    from scrapy.utils.misc import build_from_crawler

    if TYPE_CHECKING:
        from scrapy import Request
        from scrapy.crawler import Crawler
        from scrapy.http import Response

    class S3DownloadHandler(BaseDownloadHandler):
        lazy = True

        def __init__(self, crawler: Crawler):
            if not is_botocore_available():
                raise NotConfigured("missing botocore library")

            super().__init__(crawler)
            aws_access_key_id = crawler.settings["AWS_ACCESS_KEY_ID"]
            aws_secret_access_key = crawler.settings["AWS_SECRET_ACCESS_KEY"]
            aws_session_token = crawler.settings["AWS_SESSION_TOKEN"]
            self.anon = not aws_access_key_id and not aws_secret_access_key
            self._signer = None
            if not self.anon:
                import botocore.auth  # noqa: PLC0415
                import botocore.credentials  # noqa: PLC0415

                SignerCls = botocore.auth.AUTH_TYPE_MAPS["s3"]
                # botocore.auth.BaseSigner doesn't have an __init__() with args, only subclasses do
                self._signer = SignerCls(  # type: ignore[call-arg]
                    botocore.credentials.Credentials(
                        aws_access_key_id, aws_secret_access_key, aws_session_token
                    )
                )

            _http_handler = build_from_crawler(HTTP11DownloadHandler, crawler)
            self._download_http = _http_handler.download_request

        async def download_request(self, request: Request) -> Response:
            p = urlparse_cached(request)
            scheme = "https" if request.meta.get("is_secure") else "http"
            bucket = p.hostname
            path = p.path + "?" + p.query if p.query else p.path
            url = f"{scheme}://{bucket}.s3.amazonaws.com{path}"
            if self.anon:
                request = request.replace(url=url)
            else:
                import botocore.awsrequest  # noqa: PLC0415

                awsrequest = botocore.awsrequest.AWSRequest(
                    method=request.method,
                    url=f"{scheme}://s3.amazonaws.com/{bucket}{path}",
                    headers=request.headers.to_unicode_dict(),
                    data=request.body,
                )
                assert self._signer
                self._signer.add_auth(awsrequest)
                request = request.replace(url=url, headers=awsrequest.headers.items())
            return await self._download_http(request)