import io
import pytest
import hashlib
import copy

from collections import defaultdict
from mock import MagicMock, patch

from storage import StorageContext
from storage.swift import SwiftStorage, _EMPTY_SEGMENTS_KEY
from swiftclient.client import ClientException

base_args = {
  'context': StorageContext('nyc', None, None, None, None),
  'swift_container': 'container-name',
  'storage_path': '/basepath',
  'auth_url': 'https://auth.com',
  'swift_user': 'root',
  'swift_password': 'password',
}

class MockSwiftStorage(SwiftStorage):
  def __init__(self, *args, **kwargs):
    super(MockSwiftStorage, self).__init__(*args, **kwargs)
    self._connection = MagicMock()

  def _get_connection(self):
    return self._connection

class FakeSwiftStorage(SwiftStorage):
  def __init__(self, fail_checksum=False,connection=None, *args, **kwargs):
    super(FakeSwiftStorage, self).__init__(*args, **kwargs)
    self._connection = connection or FakeSwift(fail_checksum=fail_checksum,
                                               temp_url_key=kwargs.get('temp_url_key'))

  def _get_connection(self):
    return self._connection


class FakeSwift(object):
  def __init__(self, fail_checksum=False, temp_url_key=None):
    self.containers = defaultdict(dict)
    self.fail_checksum = fail_checksum
    self.temp_url_key = temp_url_key

  def get_auth(self):
    if self.temp_url_key == 'exception':
      raise ClientException('I failed!')
      
    return 'http://fake/swift', None

  def head_object(self, container, path):
    return self.containers.get(container, {}).get(path, {}).get('headers', None)

  def copy_object(self, container, path, target):
    pieces = target.split('/', 2)
    _, content = self.get_object(container, path)
    self.put_object(pieces[1], pieces[2], content)

  def get_container(self, container, prefix=None, full_listing=None):
    container_entries = self.containers[container]
    objs = []
    for path, data in list(container_entries.iteritems()):
      if not prefix or path.startswith(prefix):
        objs.append({
          'name': path,
          'bytes': len(data['content']),
        })
    return {}, objs

  def put_object(self, container, path, content, chunk_size=None, content_type=None, headers=None):
    if not isinstance(content, str):
      if hasattr(content, 'read'):
        content = content.read()
      else:
        content = ''.join(content)

    self.containers[container][path] = {
      'content': content,
      'chunk_size': chunk_size,
      'content_type': content_type,
      'headers': headers or {'is': True},
    }

    digest = hashlib.md5()
    digest.update(content)
    return digest.hexdigest() if not self.fail_checksum else 'invalid'

  def get_object(self, container, path, resp_chunk_size=None):
    data = self.containers[container].get(path, {})
    if 'X-Object-Manifest' in data['headers']:
      new_contents = []
      prefix = data['headers']['X-Object-Manifest']
      for key, value in self.containers[container].iteritems():
        if ('container-name/' + key).startswith(prefix):
          new_contents.append((key, value['content']))

      new_contents.sort(key=lambda value: value[0])

      data = dict(data)
      data['content'] = ''.join([nc[1] for nc in new_contents])
      return bool(data), data.get('content')

    return bool(data), data.get('content')

  def delete_object(self, container, path):
    self.containers[container].pop(path, None)


class FakeQueue(object):
  def __init__(self):
    self.items = []

  def get(self):
    if not self.items:
      return None

    return self.items.pop()

  def put(self, names, item, available_after=0):
    self.items.append({
      'names': names,
      'item': item,
      'available_after': available_after,
    })

def test_fixed_path_concat():
  swift = MockSwiftStorage(**base_args)
  swift.exists('object/path')
  swift._get_connection().head_object.assert_called_with('container-name', 'basepath/object/path')

def test_simple_path_concat():
  simple_concat_args = dict(base_args)
  simple_concat_args['simple_path_concat'] = True
  swift = MockSwiftStorage(**simple_concat_args)
  swift.exists('object/path')
  swift._get_connection().head_object.assert_called_with('container-name', 'basepathobject/path')

def test_delete_unknown_path():
  swift = SwiftStorage(**base_args)
  with pytest.raises(IOError):
    swift.remove('someunknownpath')

def test_simple_put_get():
  swift = FakeSwiftStorage(**base_args)
  assert not swift.exists('somepath')

  swift.put_content('somepath', 'hello world!')
  assert swift.exists('somepath')
  assert swift.get_content('somepath') == 'hello world!'

def test_stream_read_write():
  swift = FakeSwiftStorage(**base_args)
  assert not swift.exists('somepath')

  swift.stream_write('somepath', io.BytesIO('some content here'))
  assert swift.exists('somepath')
  assert swift.get_content('somepath') == 'some content here'
  assert ''.join(list(swift.stream_read('somepath'))) == 'some content here'

def test_stream_read_write_invalid_checksum():
  swift = FakeSwiftStorage(fail_checksum=True, **base_args)
  assert not swift.exists('somepath')

  with pytest.raises(IOError):
    swift.stream_write('somepath', io.BytesIO('some content here'))

def test_remove():
  swift = FakeSwiftStorage(**base_args)
  assert not swift.exists('somepath')

  swift.put_content('somepath', 'hello world!')
  assert swift.exists('somepath')

  swift.remove('somepath')
  assert not swift.exists('somepath')

def test_copy_to():
  swift = FakeSwiftStorage(**base_args)

  modified_args = copy.deepcopy(base_args)
  modified_args['swift_container'] = 'another_container'

  another_swift = FakeSwiftStorage(connection=swift._connection, **modified_args)

  swift.put_content('somepath', 'some content here')
  swift.copy_to(another_swift, 'somepath')

  assert swift.exists('somepath')
  assert another_swift.exists('somepath')

  assert swift.get_content('somepath') == 'some content here'
  assert another_swift.get_content('somepath') == 'some content here'

def test_copy_to_different():
  swift = FakeSwiftStorage(**base_args)

  modified_args = copy.deepcopy(base_args)
  modified_args['swift_user'] = 'foobarbaz'
  modified_args['swift_container'] = 'another_container'

  another_swift = FakeSwiftStorage(**modified_args)

  swift.put_content('somepath', 'some content here')
  swift.copy_to(another_swift, 'somepath')

  assert swift.exists('somepath')
  assert another_swift.exists('somepath')

  assert swift.get_content('somepath') == 'some content here'
  assert another_swift.get_content('somepath') == 'some content here'

def test_checksum():
  swift = FakeSwiftStorage(**base_args)
  swift.put_content('somepath', 'hello world!')
  assert swift.get_checksum('somepath') is not None

@pytest.mark.parametrize('read_until_end', [
  (True,),
  (False,),
])
@pytest.mark.parametrize('max_chunk_size', [
  (10000000),
  (10),
  (5),
  (2),
  (1),
])
@pytest.mark.parametrize('chunks', [
  (['this', 'is', 'some', 'chunked', 'data', '']),
  (['this is a very large chunk of data', '']),
  (['h', 'e', 'l', 'l', 'o', '']),
])
def test_chunked_upload(chunks, max_chunk_size, read_until_end):
  swift = FakeSwiftStorage(**base_args)
  uuid, metadata = swift.initiate_chunked_upload()

  offset = 0

  with patch('storage.swift._MAXIMUM_SEGMENT_SIZE', max_chunk_size):
    for chunk in chunks:
      chunk_length = len(chunk) if not read_until_end else -1
      bytes_written, metadata, error = swift.stream_upload_chunk(uuid, offset, chunk_length,
                                                                 io.BytesIO(chunk), metadata)
      assert error is None
      assert len(chunk) == bytes_written
      offset += len(chunk)

    swift.complete_chunked_upload(uuid, 'somepath', metadata)
    assert swift.get_content('somepath') == ''.join(chunks)

    # Ensure each of the segments exist.
    for segment in metadata['segments']:
      assert swift.exists(segment.path)

    # Delete the file and ensure all of its segments were removed.
    swift.remove('somepath')
    assert not swift.exists('somepath')

    for segment in metadata['segments']:
      assert not swift.exists(segment.path)


def test_cancel_chunked_upload():
  chunk_cleanup_queue = FakeQueue()

  args = dict(base_args)
  args['context'] = StorageContext('nyc', None, chunk_cleanup_queue, None, None)

  swift = FakeSwiftStorage(**args)
  uuid, metadata = swift.initiate_chunked_upload()

  chunks = ['this', 'is', 'some', 'chunked', 'data', '']
  offset = 0
  for chunk in chunks:
    bytes_written, metadata, error = swift.stream_upload_chunk(uuid, offset, len(chunk),
                                                               io.BytesIO(chunk), metadata)
    assert error is None
    assert len(chunk) == bytes_written
    offset += len(chunk)

  swift.cancel_chunked_upload(uuid, metadata)

  found = chunk_cleanup_queue.get()
  assert found is not None


def test_empty_chunks_queued_for_deletion():
  chunk_cleanup_queue = FakeQueue()
  args = dict(base_args)
  args['context'] = StorageContext('nyc', None, chunk_cleanup_queue, None, None)

  swift = FakeSwiftStorage(**args)
  uuid, metadata = swift.initiate_chunked_upload()

  chunks = ['this', '', 'is', 'some', '', 'chunked', 'data', '']
  offset = 0
  for chunk in chunks:
    length = len(chunk)
    if length == 0:
      length = 1

    bytes_written, metadata, error = swift.stream_upload_chunk(uuid, offset, length,
                                                               io.BytesIO(chunk), metadata)
    assert error is None
    assert len(chunk) == bytes_written
    offset += len(chunk)

  swift.complete_chunked_upload(uuid, 'somepath', metadata)
  assert ''.join(chunks) == swift.get_content('somepath')

  # Check the chunk deletion queue and ensure we have the last chunk queued.
  found = chunk_cleanup_queue.get()
  assert found is not None

  found2 = chunk_cleanup_queue.get()
  assert found2 is None

@pytest.mark.parametrize('temp_url_key, expects_url', [
  (None, False),
  ('foobarbaz', True),
  ('exception', False),
])
def test_get_direct_download_url(temp_url_key, expects_url):
  swift = FakeSwiftStorage(temp_url_key=temp_url_key, **base_args)
  swift.put_content('somepath', 'hello world!')
  assert (swift.get_direct_download_url('somepath') is not None) == expects_url