# Source code for scrapy.pipelines.files

    """
    Files Pipeline

    See documentation in topics/media-pipeline.rst
    """
    import base64
    import functools
    import hashlib
    import logging
    import mimetypes
    import os
    import time
    from collections import defaultdict
    from contextlib import suppress
    from ftplib import FTP
    from io import BytesIO
    from os import PathLike
    from pathlib import Path
    from typing import DefaultDict, Optional, Set, Union
    from urllib.parse import urlparse

    from itemadapter import ItemAdapter
    from twisted.internet import defer, threads

    from scrapy.exceptions import IgnoreRequest, NotConfigured
    from scrapy.http import Request
    from scrapy.http.request import NO_CALLBACK
    from scrapy.pipelines.media import MediaPipeline
    from scrapy.settings import Settings
    from scrapy.utils.boto import is_botocore_available
    from scrapy.utils.datatypes import CaseInsensitiveDict
    from scrapy.utils.ftp import ftp_store_file
    from scrapy.utils.log import failure_to_exc_info
    from scrapy.utils.misc import md5sum
    from scrapy.utils.python import to_bytes
    from scrapy.utils.request import referer_str

    logger = logging.getLogger(__name__)

    def _to_string(path: Union[str, PathLike]) -> str:
        return str(path)  # convert a Path object to string

    class FileException(Exception):
        """General media error exception"""

    class FSFilesStore:
        def __init__(self, basedir: Union[str, PathLike]):
            basedir = _to_string(basedir)
            if "://" in basedir:
                basedir = basedir.split("://", 1)[1]
            self.basedir = basedir
            self._mkdir(Path(self.basedir))
            self.created_directories: DefaultDict[str, Set[str]] = defaultdict(set)

        def persist_file(
            self, path: Union[str, PathLike], buf, info, meta=None, headers=None
        ):
            absolute_path = self._get_filesystem_path(path)
            self._mkdir(absolute_path.parent, info)
            absolute_path.write_bytes(buf.getvalue())

        def stat_file(self, path: Union[str, PathLike], info):
            absolute_path = self._get_filesystem_path(path)
            try:
                last_modified = absolute_path.stat().st_mtime
            except os.error:
                return {}

            with absolute_path.open("rb") as f:
                checksum = md5sum(f)

            return {"last_modified": last_modified, "checksum": checksum}

        def _get_filesystem_path(self, path: Union[str, PathLike]) -> Path:
            path_comps = _to_string(path).split("/")
            return Path(self.basedir, *path_comps)

        def _mkdir(self, dirname: Path, domain: Optional[str] = None):
            seen = self.created_directories[domain] if domain else set()
            if str(dirname) not in seen:
                if not dirname.exists():
                    dirname.mkdir(parents=True)
                seen.add(str(dirname))

    class S3FilesStore:
        AWS_ACCESS_KEY_ID = None
        AWS_SECRET_ACCESS_KEY = None
        AWS_SESSION_TOKEN = None
        AWS_ENDPOINT_URL = None
        AWS_REGION_NAME = None
        AWS_USE_SSL = None
        AWS_VERIFY = None

        POLICY = "private"  # Overridden from settings.FILES_STORE_S3_ACL in FilesPipeline.from_settings
        HEADERS = {
            "Cache-Control": "max-age=172800",
        }

        def __init__(self, uri):
            if not is_botocore_available():
                raise NotConfigured("missing botocore library")
            import botocore.session

            session = botocore.session.get_session()
            self.s3_client = session.create_client(
                "s3",
                aws_access_key_id=self.AWS_ACCESS_KEY_ID,
                aws_secret_access_key=self.AWS_SECRET_ACCESS_KEY,
                aws_session_token=self.AWS_SESSION_TOKEN,
                endpoint_url=self.AWS_ENDPOINT_URL,
                region_name=self.AWS_REGION_NAME,
                use_ssl=self.AWS_USE_SSL,
                verify=self.AWS_VERIFY,
            )
            if not uri.startswith("s3://"):
                raise ValueError(f"Incorrect URI scheme in {uri}, expected 's3'")
            self.bucket, self.prefix = uri[5:].split("/", 1)

        def stat_file(self, path, info):
            def _onsuccess(boto_key):
                checksum = boto_key["ETag"].strip('"')
                last_modified = boto_key["LastModified"]
                modified_stamp = time.mktime(last_modified.timetuple())
                return {"checksum": checksum, "last_modified": modified_stamp}

            return self._get_boto_key(path).addCallback(_onsuccess)

        def _get_boto_key(self, path):
            key_name = f"{self.prefix}{path}"
            return threads.deferToThread(
                self.s3_client.head_object, Bucket=self.bucket, Key=key_name
            )

        def persist_file(self, path, buf, info, meta=None, headers=None):
            """Upload file to S3 storage"""
            key_name = f"{self.prefix}{path}"
            buf.seek(0)
            extra = self._headers_to_botocore_kwargs(self.HEADERS)
            if headers:
                extra.update(self._headers_to_botocore_kwargs(headers))
            return threads.deferToThread(
                self.s3_client.put_object,
                Bucket=self.bucket,
                Key=key_name,
                Body=buf,
                Metadata={k: str(v) for k, v in (meta or {}).items()},
                ACL=self.POLICY,
                **extra,
            )

        def _headers_to_botocore_kwargs(self, headers):
            """Convert headers to botocore keyword arguments."""
            # This is required while we need to support both boto and botocore.
            mapping = CaseInsensitiveDict(
                {
                    "Content-Type": "ContentType",
                    "Cache-Control": "CacheControl",
                    "Content-Disposition": "ContentDisposition",
                    "Content-Encoding": "ContentEncoding",
                    "Content-Language": "ContentLanguage",
                    "Content-Length": "ContentLength",
                    "Content-MD5": "ContentMD5",
                    "Expires": "Expires",
                    "X-Amz-Grant-Full-Control": "GrantFullControl",
                    "X-Amz-Grant-Read": "GrantRead",
                    "X-Amz-Grant-Read-ACP": "GrantReadACP",
                    "X-Amz-Grant-Write-ACP": "GrantWriteACP",
                    "X-Amz-Object-Lock-Legal-Hold": "ObjectLockLegalHoldStatus",
                    "X-Amz-Object-Lock-Mode": "ObjectLockMode",
                    "X-Amz-Object-Lock-Retain-Until-Date": "ObjectLockRetainUntilDate",
                    "X-Amz-Request-Payer": "RequestPayer",
                    "X-Amz-Server-Side-Encryption": "ServerSideEncryption",
                    "X-Amz-Server-Side-Encryption-Aws-Kms-Key-Id": "SSEKMSKeyId",
                    "X-Amz-Server-Side-Encryption-Context": "SSEKMSEncryptionContext",
                    "X-Amz-Server-Side-Encryption-Customer-Algorithm": "SSECustomerAlgorithm",
                    "X-Amz-Server-Side-Encryption-Customer-Key": "SSECustomerKey",
                    "X-Amz-Server-Side-Encryption-Customer-Key-Md5": "SSECustomerKeyMD5",
                    "X-Amz-Storage-Class": "StorageClass",
                    "X-Amz-Tagging": "Tagging",
                    "X-Amz-Website-Redirect-Location": "WebsiteRedirectLocation",
                }
            )
            extra = {}
            for key, value in headers.items():
                try:
                    kwarg = mapping[key]
                except KeyError:
                    raise TypeError(f'Header "{key}" is not supported by botocore')
                else:
                    extra[kwarg] = value
            return extra

    class GCSFilesStore:
        GCS_PROJECT_ID = None

        CACHE_CONTROL = "max-age=172800"

        # The bucket's default object ACL will be applied to the object.
        # Overridden from settings.FILES_STORE_GCS_ACL in FilesPipeline.from_settings.
        POLICY = None

        def __init__(self, uri):
            from google.cloud import storage

            client = storage.Client(project=self.GCS_PROJECT_ID)
            bucket, prefix = uri[5:].split("/", 1)
            self.bucket = client.bucket(bucket)
            self.prefix = prefix
            permissions = self.bucket.test_iam_permissions(
                ["storage.objects.get", "storage.objects.create"]
            )
            if "storage.objects.get" not in permissions:
                logger.warning(
                    "No 'storage.objects.get' permission for GSC bucket %(bucket)s. "
                    "Checking if files are up to date will be impossible. Files will be downloaded every time.",
                    {"bucket": bucket},
                )
            if "storage.objects.create" not in permissions:
                logger.error(
                    "No 'storage.objects.create' permission for GSC bucket %(bucket)s. Saving files will be impossible!",
                    {"bucket": bucket},
                )

        def stat_file(self, path, info):
            def _onsuccess(blob):
                if blob:
                    checksum = base64.b64decode(blob.md5_hash).hex()
                    last_modified = time.mktime(blob.updated.timetuple())
                    return {"checksum": checksum, "last_modified": last_modified}
                return {}

            blob_path = self._get_blob_path(path)
            return threads.deferToThread(self.bucket.get_blob, blob_path).addCallback(
                _onsuccess
            )

        def _get_content_type(self, headers):
            if headers and "Content-Type" in headers:
                return headers["Content-Type"]
            return "application/octet-stream"

        def _get_blob_path(self, path):
            return self.prefix + path

        def persist_file(self, path, buf, info, meta=None, headers=None):
            blob_path = self._get_blob_path(path)
            blob = self.bucket.blob(blob_path)
            blob.cache_control = self.CACHE_CONTROL
            blob.metadata = {k: str(v) for k, v in (meta or {}).items()}
            return threads.deferToThread(
                blob.upload_from_string,
                data=buf.getvalue(),
                content_type=self._get_content_type(headers),
                predefined_acl=self.POLICY,
            )

    class FTPFilesStore:
        FTP_USERNAME = None
        FTP_PASSWORD = None
        USE_ACTIVE_MODE = None

        def __init__(self, uri):
            if not uri.startswith("ftp://"):
                raise ValueError(f"Incorrect URI scheme in {uri}, expected 'ftp'")
            u = urlparse(uri)
            self.port = u.port
            self.host = u.hostname
            self.port = int(u.port or 21)
            self.username = u.username or self.FTP_USERNAME
            self.password = u.password or self.FTP_PASSWORD
            self.basedir = u.path.rstrip("/")

        def persist_file(self, path, buf, info, meta=None, headers=None):
            path = f"{self.basedir}/{path}"
            return threads.deferToThread(
                ftp_store_file,
                path=path,
                file=buf,
                host=self.host,
                port=self.port,
                username=self.username,
                password=self.password,
                use_active_mode=self.USE_ACTIVE_MODE,
            )

        def stat_file(self, path, info):
            def _stat_file(path):
                try:
                    ftp = FTP()
                    ftp.connect(self.host, self.port)
                    ftp.login(self.username, self.password)
                    if self.USE_ACTIVE_MODE:
                        ftp.set_pasv(False)
                    file_path = f"{self.basedir}/{path}"
                    last_modified = float(ftp.voidcmd(f"MDTM {file_path}")[4:].strip())
                    m = hashlib.md5()
                    ftp.retrbinary(f"RETR {file_path}", m.update)
                    return {"last_modified": last_modified, "checksum": m.hexdigest()}
                # The file doesn't exist
                except Exception:
                    return {}

            return threads.deferToThread(_stat_file, path)

    class FilesPipeline(MediaPipeline):
        """Abstract pipeline that implement the file downloading

        This pipeline tries to minimize network transfers and file processing,
        doing stat of the files and determining if file is new, up-to-date or
        expired.

        ``new`` files are those that pipeline never processed and needs to be
            downloaded from supplier site the first time.

        ``uptodate`` files are the ones that the pipeline processed and are still
            valid files.

        ``expired`` files are those that pipeline already processed but the last
            modification was made long time ago, so a reprocessing is recommended to
            refresh it in case of change.

        """

        MEDIA_NAME = "file"
        EXPIRES = 90
        STORE_SCHEMES = {
            "": FSFilesStore,
            "file": FSFilesStore,
            "s3": S3FilesStore,
            "gs": GCSFilesStore,
            "ftp": FTPFilesStore,
        }
        DEFAULT_FILES_URLS_FIELD = "file_urls"
        DEFAULT_FILES_RESULT_FIELD = "files"

        def __init__(self, store_uri, download_func=None, settings=None):
            store_uri = _to_string(store_uri)
            if not store_uri:
                raise NotConfigured

            if isinstance(settings, dict) or settings is None:
                settings = Settings(settings)
            cls_name = "FilesPipeline"
            self.store = self._get_store(store_uri)
            resolve = functools.partial(
                self._key_for_pipe, base_class_name=cls_name, settings=settings
            )
            self.expires = settings.getint(resolve("FILES_EXPIRES"), self.EXPIRES)
            if not hasattr(self, "FILES_URLS_FIELD"):
                self.FILES_URLS_FIELD = self.DEFAULT_FILES_URLS_FIELD
            if not hasattr(self, "FILES_RESULT_FIELD"):
                self.FILES_RESULT_FIELD = self.DEFAULT_FILES_RESULT_FIELD
            self.files_urls_field = settings.get(
                resolve("FILES_URLS_FIELD"), self.FILES_URLS_FIELD
            )
            self.files_result_field = settings.get(
                resolve("FILES_RESULT_FIELD"), self.FILES_RESULT_FIELD
            )

            super().__init__(download_func=download_func, settings=settings)

        @classmethod
        def from_settings(cls, settings):
            s3store = cls.STORE_SCHEMES["s3"]
            s3store.AWS_ACCESS_KEY_ID = settings["AWS_ACCESS_KEY_ID"]
            s3store.AWS_SECRET_ACCESS_KEY = settings["AWS_SECRET_ACCESS_KEY"]
            s3store.AWS_SESSION_TOKEN = settings["AWS_SESSION_TOKEN"]
            s3store.AWS_ENDPOINT_URL = settings["AWS_ENDPOINT_URL"]
            s3store.AWS_REGION_NAME = settings["AWS_REGION_NAME"]
            s3store.AWS_USE_SSL = settings["AWS_USE_SSL"]
            s3store.AWS_VERIFY = settings["AWS_VERIFY"]
            s3store.POLICY = settings["FILES_STORE_S3_ACL"]

            gcs_store = cls.STORE_SCHEMES["gs"]
            gcs_store.GCS_PROJECT_ID = settings["GCS_PROJECT_ID"]
            gcs_store.POLICY = settings["FILES_STORE_GCS_ACL"] or None

            ftp_store = cls.STORE_SCHEMES["ftp"]
            ftp_store.FTP_USERNAME = settings["FTP_USER"]
            ftp_store.FTP_PASSWORD = settings["FTP_PASSWORD"]
            ftp_store.USE_ACTIVE_MODE = settings.getbool("FEED_STORAGE_FTP_ACTIVE")

            store_uri = settings["FILES_STORE"]
            return cls(store_uri, settings=settings)

        def _get_store(self, uri: str):
            if Path(uri).is_absolute():  # to support win32 paths like: C:\\some\dir
                scheme = "file"
            else:
                scheme = urlparse(uri).scheme
            store_cls = self.STORE_SCHEMES[scheme]
            return store_cls(uri)

        def media_to_download(self, request, info, *, item=None):
            def _onsuccess(result):
                if not result:
                    return  # returning None force download

                last_modified = result.get("last_modified", None)
                if not last_modified:
                    return  # returning None force download

                age_seconds = time.time() - last_modified
                age_days = age_seconds / 60 / 60 / 24
                if age_days > self.expires:
                    return  # returning None force download

                referer = referer_str(request)
                logger.debug(
                    "File (uptodate): Downloaded %(medianame)s from %(request)s "
                    "referred in <%(referer)s>",
                    {"medianame": self.MEDIA_NAME, "request": request, "referer": referer},
                    extra={"spider": info.spider},
                )
                self.inc_stats(info.spider, "uptodate")

                checksum = result.get("checksum", None)
                return {
                    "url": request.url,
                    "path": path,
                    "checksum": checksum,
                    "status": "uptodate",
                }

            path = self.file_path(request, info=info, item=item)
            dfd = defer.maybeDeferred(self.store.stat_file, path, info)
            dfd.addCallbacks(_onsuccess, lambda _: None)
            dfd.addErrback(
                lambda f: logger.error(
                    self.__class__.__name__ + ".store.stat_file",
                    exc_info=failure_to_exc_info(f),
                    extra={"spider": info.spider},
                )
            )
            return dfd

        def media_failed(self, failure, request, info):
            if not isinstance(failure.value, IgnoreRequest):
                referer = referer_str(request)
                logger.warning(
                    "File (unknown-error): Error downloading %(medianame)s from "
                    "%(request)s referred in <%(referer)s>: %(exception)s",
                    {
                        "medianame": self.MEDIA_NAME,
                        "request": request,
                        "referer": referer,
                        "exception": failure.value,
                    },
                    extra={"spider": info.spider},
                )

            raise FileException

        def media_downloaded(self, response, request, info, *, item=None):
            referer = referer_str(request)

            if response.status != 200:
                logger.warning(
                    "File (code: %(status)s): Error downloading file from "
                    "%(request)s referred in <%(referer)s>",
                    {"status": response.status, "request": request, "referer": referer},
                    extra={"spider": info.spider},
                )
                raise FileException("download-error")

            if not response.body:
                logger.warning(
                    "File (empty-content): Empty file from %(request)s referred "
                    "in <%(referer)s>: no-content",
                    {"request": request, "referer": referer},
                    extra={"spider": info.spider},
                )
                raise FileException("empty-content")

            status = "cached" if "cached" in response.flags else "downloaded"
            logger.debug(
                "File (%(status)s): Downloaded file from %(request)s referred in "
                "<%(referer)s>",
                {"status": status, "request": request, "referer": referer},
                extra={"spider": info.spider},
            )
            self.inc_stats(info.spider, status)

            try:
                path = self.file_path(request, response=response, info=info, item=item)
                checksum = self.file_downloaded(response, request, info, item=item)
            except FileException as exc:
                logger.warning(
                    "File (error): Error processing file from %(request)s "
                    "referred in <%(referer)s>: %(errormsg)s",
                    {"request": request, "referer": referer, "errormsg": str(exc)},
                    extra={"spider": info.spider},
                    exc_info=True,
                )
                raise
            except Exception as exc:
                logger.error(
                    "File (unknown-error): Error processing file from %(request)s "
                    "referred in <%(referer)s>",
                    {"request": request, "referer": referer},
                    exc_info=True,
                    extra={"spider": info.spider},
                )
                raise FileException(str(exc))

            return {
                "url": request.url,
                "path": path,
                "checksum": checksum,
                "status": status,
            }

        def inc_stats(self, spider, status):
            spider.crawler.stats.inc_value("file_count", spider=spider)
            spider.crawler.stats.inc_value(f"file_status_count/{status}", spider=spider)

        # Overridable Interface

        def get_media_requests(self, item, info):
            urls = ItemAdapter(item).get(self.files_urls_field, [])
            return [Request(u, callback=NO_CALLBACK) for u in urls]

        def file_downloaded(self, response, request, info, *, item=None):
            path = self.file_path(request, response=response, info=info, item=item)
            buf = BytesIO(response.body)
            checksum = md5sum(buf)
            buf.seek(0)
            self.store.persist_file(path, buf, info)
            return checksum

        def item_completed(self, results, item, info):
            with suppress(KeyError):
                ItemAdapter(item)[self.files_result_field] = [x for ok, x in results if ok]
            return item

        def file_path(self, request, response=None, info=None, *, item=None):
            media_guid = hashlib.sha1(to_bytes(request.url)).hexdigest()
            media_ext = Path(request.url).suffix
            # Handles empty and wild extensions by trying to guess the
            # mime type then extension or default to empty string otherwise
            if media_ext not in mimetypes.types_map:
                media_ext = ""
                media_type = mimetypes.guess_type(request.url)[0]
                if media_type:
                    media_ext = mimetypes.guess_extension(media_type)
            return f"full/{media_guid}{media_ext}"