"""Integration test configurations."""

import os
import random
from collections.abc import Iterator
from hashlib import md5
from io import BytesIO
from pathlib import Path

import pytest
import torch
from dotenv import load_dotenv
from PIL import Image

from model.src.models import VisualCommunicationModel
from shared.datastore import Datastore

env_var_map = {
    'MINIO_BUCKET_NAME': 'test-bucket',
    'MINIO_OBJECT_NAME': '46KXJMFIAPVLM0TKRFZR5YPPTVJ6PJNX',
}


@pytest.fixture(scope='session', autouse=True)
def populate_env(
    request: pytest.FixtureRequest,
) -> None:
    """Populate environment with variables used for testing."""
    # read env-file for local testing
    load_dotenv(
        dotenv_path=Path(__file__).parent.parent.parent.parent.parent / 'server.env',
    )
    # update env
    for key, val in env_var_map.items():
        os.environ[key] = val

    # ensure cleanup
    def cleanup_env():
        for key in env_var_map:
            _ = os.environ.pop(key, default=None)

    request.addfinalizer(cleanup_env)


@pytest.fixture(scope='session')
def datastore(
    populate_env,
) -> Iterator[Datastore]:
    # prepare arguments
    minio_bucket_name = str(os.getenv('MINIO_BUCKET_NAME'))
    # connect to minio
    datastore_client = Datastore()
    datastore_client.connect()
    assert datastore_client._client is not None
    # ensure bucket exists
    if not datastore_client._client.bucket_exists(bucket_name=minio_bucket_name):
        datastore_client._client.make_bucket(bucket_name=minio_bucket_name)
    # expose client
    yield datastore_client
    # remove objects left behind by tests
    for obj in datastore_client._client.list_objects(
        bucket_name=minio_bucket_name,
        recursive=True,
    ):
        datastore_client._client.remove_object(
            bucket_name=obj.bucket_name,
            object_name=obj.object_name,
        )
    # remove bucket
    datastore_client._client.remove_bucket(bucket_name=minio_bucket_name)
    assert not datastore_client._client.bucket_exists(bucket_name=minio_bucket_name)
    # disconnect from minio
    datastore_client.close()


@pytest.fixture
def data() -> Iterator[bytes]:
    # generate random data
    num_bytes = 2**21  # 2 MB
    data = random.randbytes(n=num_bytes)
    # expose data
    yield data


@pytest.fixture
def data_in_minio(
    datastore: Datastore,
    data: bytes,
) -> Iterator[tuple[BytesIO, str, str]]:
    assert datastore._client is not None
    # prepare arguments
    minio_bucket_name = str(os.getenv('MINIO_BUCKET_NAME'))
    minio_object_name = str(os.getenv('MINIO_OBJECT_NAME'))
    # convert data
    buffer = BytesIO(data)
    # prepare for saving
    num_bytes = len(buffer.getvalue())
    buffer.seek(0)
    # send data to bucket
    datastore._client.put_object(
        bucket_name=minio_bucket_name,
        object_name=minio_object_name,
        length=num_bytes,
        data=buffer,
    )
    # expose data
    yield buffer, minio_bucket_name, minio_object_name
    # clean up
    datastore._client.remove_object(
        bucket_name=minio_bucket_name,
        object_name=minio_object_name,
    )


@pytest.fixture
def image() -> Iterator[Image.Image]:
    # generate image
    image = Image.new(mode='RGB', size=(480, 480))
    # expose image
    yield image


@pytest.fixture
def image_in_minio(
    datastore: Datastore,
    image: Image.Image,
) -> Iterator[tuple[Image.Image, str]]:
    assert datastore._client is not None
    # prepare arguments
    minio_bucket_name = str(os.getenv('MINIO_BUCKET_NAME'))
    # save data to buffer
    buffer = BytesIO()
    image.save(buffer, 'png')
    # get md5 of buffer
    checksum = md5(buffer.getbuffer()).hexdigest()
    # build object path
    object_path = f'images/{checksum}'
    # prepare for saving
    num_bytes = len(buffer.getvalue())
    buffer.seek(0)
    # send data to bucket
    datastore._client.put_object(
        bucket_name=minio_bucket_name,
        object_name=object_path,
        length=num_bytes,
        data=buffer,
    )
    # expose image and object name
    yield image, checksum
    # cleanup
    datastore._client.remove_object(
        bucket_name=minio_bucket_name,
        object_name=object_path,
    )


@pytest.fixture
def model() -> Iterator[torch.nn.Module]:
    # generate model
    model = VisualCommunicationModel().to('cpu')
    # expose model
    yield model


@pytest.fixture
def model_in_minio(
    datastore: Datastore,
    model: torch.nn.Module,
) -> Iterator[tuple[torch.nn.Module, str]]:
    assert datastore._client is not None
    # prepare arguments
    minio_bucket_name = str(os.getenv('MINIO_BUCKET_NAME'))
    # save data to buffer
    buffer = BytesIO()
    torch.save(model.state_dict(), buffer)
    # get md5 of image
    checksum = md5(buffer.getbuffer()).hexdigest()
    # build object path
    object_path = f'models/{checksum}'
    # prepare for saving
    num_bytes = len(buffer.getvalue())
    buffer.seek(0)
    # send data to bucket
    datastore._client.put_object(
        bucket_name=minio_bucket_name,
        object_name=object_path,
        length=num_bytes,
        data=buffer,
    )
    # expose model and object name
    yield model, checksum
    # cleanup
    datastore._client.remove_object(
        bucket_name=minio_bucket_name,
        object_name=object_path,
    )