import hashlib
import json

from io import BytesIO

import pytest

from mock import patch

from app import docker_v2_signing_key

from data.registry_model.blobuploader import BlobUploadSettings, upload_blob
from data.registry_model.manifestbuilder import create_manifest_builder, lookup_manifest_builder
from data.registry_model.registry_pre_oci_model import PreOCIModel
from data.registry_model.registry_oci_model import OCIModel

from storage.distributedstorage import DistributedStorage
from storage.fakestorage import FakeStorage
from test.fixtures import *


@pytest.fixture(params=[PreOCIModel, OCIModel])
def registry_model(request, initialized_db):
  return request.param()


@pytest.fixture()
def fake_session():
  with patch('data.registry_model.manifestbuilder.session', {}):
    yield


@pytest.mark.parametrize('layers', [
  pytest.param([('someid', None, 'some data')], id='Single layer'),
  pytest.param([('parentid', None, 'some parent data'),
                ('someid', 'parentid', 'some data')],
               id='Multi layer'),
])
def test_build_manifest(layers, fake_session, registry_model):
  repository_ref = registry_model.lookup_repository('devtable', 'complex')
  storage = DistributedStorage({'local_us': FakeStorage(None)}, ['local_us'])
  settings = BlobUploadSettings('2M', 512 * 1024, 3600)
  app_config = {'TESTING': True}

  builder = create_manifest_builder(repository_ref, storage, docker_v2_signing_key)
  assert lookup_manifest_builder(repository_ref, 'anotherid', storage,
                                 docker_v2_signing_key) is None
  assert lookup_manifest_builder(repository_ref, builder.builder_id, storage,
                                 docker_v2_signing_key) is not None

  blobs_by_layer = {}
  for layer_id, parent_id, layer_bytes in layers:
    # Start a new layer.
    assert builder.start_layer(layer_id, json.dumps({'id': layer_id, 'parent': parent_id}),
                               'local_us', None, 60)

    checksum = hashlib.sha1(layer_bytes).hexdigest()

    # Assign it a blob.
    with upload_blob(repository_ref, storage, settings) as uploader:
      uploader.upload_chunk(app_config, BytesIO(layer_bytes))
      blob = uploader.commit_to_blob(app_config)
      blobs_by_layer[layer_id] = blob
      builder.assign_layer_blob(builder.lookup_layer(layer_id), blob, [checksum])

    # Validate the checksum.
    assert builder.validate_layer_checksum(builder.lookup_layer(layer_id), checksum)

  # Commit the manifest to a tag.
  tag = builder.commit_tag_and_manifest('somenewtag', builder.lookup_layer(layers[-1][0]))
  assert tag
  assert tag in builder.committed_tags

  # Mark the builder as done.
  builder.done()

  # Verify the legacy image for the tag.
  found = registry_model.get_repo_tag(repository_ref, 'somenewtag', include_legacy_image=True)
  assert found
  assert found.name == 'somenewtag'
  assert found.legacy_image.docker_image_id == layers[-1][0]

  # Verify the blob and manifest.
  manifest = registry_model.get_manifest_for_tag(found)
  assert manifest

  parsed = manifest.get_parsed_manifest()
  assert len(list(parsed.layers)) == len(layers)

  for index, (layer_id, parent_id, layer_bytes) in enumerate(layers):
    assert list(parsed.blob_digests)[index] == blobs_by_layer[layer_id].digest
    assert list(parsed.layers)[index].v1_metadata.image_id == layer_id
    assert list(parsed.layers)[index].v1_metadata.parent_image_id == parent_id

  assert parsed.leaf_layer_v1_image_id == layers[-1][0]


def test_build_manifest_missing_parent(fake_session, registry_model):
  storage = DistributedStorage({'local_us': FakeStorage(None)}, ['local_us'])
  repository_ref = registry_model.lookup_repository('devtable', 'complex')
  builder = create_manifest_builder(repository_ref, storage, docker_v2_signing_key)

  assert builder.start_layer('somelayer', json.dumps({'id': 'somelayer', 'parent': 'someparent'}),
                             'local_us', None, 60) is None