# Copyright (C) 2015-2020  The Software Heritage developers
# See the AUTHORS file at the top-level directory of this distribution
# License: GNU General Public License version 3, or any later version
# See top-level LICENSE file for more information

from swh.core.api import RPCClient
from swh.model import hashutil

from ..objstorage import DEFAULT_CHUNK_SIZE, DEFAULT_LIMIT
from ..exc import Error, ObjNotFoundError, ObjStorageAPIError


class RemoteObjStorage:
    """Proxy to a remote object storage.

    This class allows to connect to an object storage server via
    http protocol.

    Attributes:
        url (string): The url of the server to connect. Must end
            with a '/'
        session: The session to send requests.

    """

    def __init__(self, **kwargs):
        self._proxy = RPCClient(
            api_exception=ObjStorageAPIError,
            reraise_exceptions=[ObjNotFoundError, Error],
            **kwargs
        )

    def check_config(self, *, check_write):
        return self._proxy.post("check_config", {"check_write": check_write})

    def __contains__(self, obj_id):
        return self._proxy.post("content/contains", {"obj_id": obj_id})

    def add(self, content, obj_id=None, check_presence=True):
        return self._proxy.post(
            "content/add",
            {"content": content, "obj_id": obj_id, "check_presence": check_presence},
        )

    def add_batch(self, contents, check_presence=True):
        return self._proxy.post(
            "content/add/batch",
            {"contents": contents, "check_presence": check_presence,},
        )

    def restore(self, content, obj_id=None, *args, **kwargs):
        return self.add(content, obj_id, check_presence=False)

    def get(self, obj_id):
        return self._proxy.post("content/get", {"obj_id": obj_id})

    def get_batch(self, obj_ids):
        return self._proxy.post("content/get/batch", {"obj_ids": obj_ids})

    def check(self, obj_id):
        return self._proxy.post("content/check", {"obj_id": obj_id})

    def delete(self, obj_id):
        # deletion permission are checked server-side
        return self._proxy.post("content/delete", {"obj_id": obj_id})

    # Management methods

    def get_random(self, batch_size):
        return self._proxy.post("content/get/random", {"batch_size": batch_size})

    # Streaming methods

    def add_stream(self, content_iter, obj_id, check_presence=True):
        obj_id = hashutil.hash_to_hex(obj_id)
        return self._proxy.post_stream(
            "content/add_stream/{}".format(obj_id),
            params={"check_presence": check_presence},
            data=content_iter,
        )

    def get_stream(self, obj_id, chunk_size=DEFAULT_CHUNK_SIZE):
        obj_id = hashutil.hash_to_hex(obj_id)
        return self._proxy.get_stream(
            "content/get_stream/{}".format(obj_id), chunk_size=chunk_size
        )

    def __iter__(self):
        yield from self._proxy.get_stream("content")

    def list_content(self, last_obj_id=None, limit=DEFAULT_LIMIT):
        params = {"limit": limit}
        if last_obj_id:
            params["last_obj_id"] = hashutil.hash_to_hex(last_obj_id)
        yield from self._proxy.get_stream("content", params=params)