import base64
import datetime
import json
from collections import defaultdict

import cloudpickle
import marshmallow
import pendulum
import pytest

import prefect
from prefect.engine import state
from prefect.engine.result import NoResult, Result, SafeResult
from prefect.engine.result_handlers import JSONResultHandler, ResultHandler
from prefect.serialization.state import StateSchema

all_states = sorted(
    set(
        cls
        for cls in state.__dict__.values()
        if isinstance(cls, type)
        and issubclass(cls, state.State)
        and cls not in (state.State, state._MetaState)
    ),
    key=lambda c: c.__name__,
)


def complex_states():
    res1 = SafeResult(1, result_handler=JSONResultHandler())
    res2 = SafeResult({"z": 2}, result_handler=JSONResultHandler())
    res3 = SafeResult(dict(x=1, y={"z": 2}), result_handler=JSONResultHandler())
    naive_dt = datetime.datetime(2020, 1, 1)
    utc_dt = pendulum.datetime(2020, 1, 1)
    complex_result = {"x": res1, "y": res2}
    cached_state = state.Cached(
        cached_inputs=complex_result,
        result=res3,
        cached_parameters={"x": 1, "y": {"z": 2}},
        cached_result_expiration=utc_dt,
    )
    cached_state_naive = state.Cached(
        cached_inputs=complex_result,
        result=res3,
        cached_parameters={"x": 1, "y": {"z": 2}},
        cached_result_expiration=naive_dt,
    )
    running_tags = state.Running()
    running_tags.context = dict(tags=["1", "2", "3"])
    test_states = [
        state.Looped(loop_count=45),
        state.Pending(cached_inputs=complex_result),
        state.Paused(cached_inputs=complex_result),
        state.Retrying(start_time=utc_dt, run_count=3),
        state.Retrying(start_time=naive_dt, run_count=3),
        state.Scheduled(start_time=utc_dt),
        state.Scheduled(start_time=naive_dt),
        state.Resume(start_time=utc_dt),
        state.Resume(start_time=naive_dt),
        running_tags,
        state.Submitted(state=state.Retrying(start_time=utc_dt, run_count=2)),
        state.Submitted(state=state.Resume(start_time=utc_dt)),
        state.Queued(state=state.Pending()),
        state.Queued(state=state.Pending(), start_time=utc_dt),
        state.Queued(state=state.Retrying(start_time=utc_dt, run_count=2)),
        cached_state,
        cached_state_naive,
        state.TimedOut(cached_inputs=complex_result),
    ]
    return test_states


def test_all_states_have_serialization_schemas_in_stateschema():
    """
    Tests that all State subclasses in prefect.engine.states have corresponding schemas
    in prefect.serialization.state
    """
    assert set(s.__name__ for s in all_states) == set(StateSchema.type_schemas.keys())


def test_all_states_have_deserialization_schemas_in_stateschema():
    """
    Tests that all State subclasses in prefect.engine.states have corresponding schemas
    in prefect.serialization.state with that state assigned as the object class
    so it will be recreated at deserialization
    """
    assert set(all_states) == set(
        s.Meta.object_class for s in StateSchema.type_schemas.values()
    )


@pytest.mark.parametrize("cls", [s for s in all_states if s is not state.Mapped])
def test_serialize_state_with_un_handled_result(cls):
    serialized = StateSchema().dump(cls(message="message", result=1))
    assert isinstance(serialized, dict)
    assert serialized["type"] == cls.__name__
    assert serialized["message"] == "message"
    assert serialized["_result"]["type"] == "NoResultType"
    assert serialized["__version__"] == prefect.__version__


@pytest.mark.parametrize("cls", [s for s in all_states if s is not state.Mapped])
def test_serialize_state_with_no_result(cls):
    state = cls(message="message")
    serialized = StateSchema().dump(state)
    assert isinstance(serialized, dict)
    assert serialized["type"] == cls.__name__
    assert serialized["message"] == "message"
    assert serialized["_result"]["type"] == "NoResultType"
    assert serialized["__version__"] == prefect.__version__


@pytest.mark.parametrize("cls", [s for s in all_states if s is not state.Mapped])
def test_serialize_state_with_handled_result(cls):
    res = Result(value=1, result_handler=JSONResultHandler())
    res.store_safe_value()
    state = cls(message="message", result=res)
    serialized = StateSchema().dump(state)
    assert isinstance(serialized, dict)
    assert serialized["type"] == cls.__name__
    assert serialized["message"] == "message"
    assert serialized["_result"]["type"] == "SafeResult"
    assert serialized["_result"]["value"] == "1"
    assert serialized["__version__"] == prefect.__version__


@pytest.mark.parametrize("cls", [s for s in all_states if s is not state.Mapped])
def test_serialize_state_with_safe_result(cls):
    res = SafeResult(value="1", result_handler=JSONResultHandler())
    state = cls(message="message", result=res)
    serialized = StateSchema().dump(state)
    assert isinstance(serialized, dict)
    assert serialized["type"] == cls.__name__
    assert serialized["message"] == "message"
    assert serialized["_result"]["type"] == "SafeResult"
    assert serialized["_result"]["value"] == "1"
    assert serialized["__version__"] == prefect.__version__


@pytest.mark.parametrize("cls", all_states)
def test_serialize_state_with_context(cls):
    with prefect.context(task_tags=set(["foo", "bar"])):
        s = cls(message="hi")
    serialized = StateSchema().dump(s)
    assert isinstance(serialized, dict)
    assert serialized["type"] == cls.__name__
    assert serialized["message"] == "hi"
    assert serialized["__version__"] == prefect.__version__
    assert isinstance(serialized["context"], dict)
    assert set(serialized["context"]["tags"]) == set(["foo", "bar"])

    deserialized = StateSchema().load(serialized)
    assert isinstance(deserialized, cls)
    assert set(deserialized.context["tags"]) == set(["foo", "bar"])


def test_serialize_scheduled_state_with_context():
    with prefect.context(task_run_count=42):
        s = state.Scheduled(message="hi")

    serialized = StateSchema().dump(s)
    assert isinstance(serialized, dict)
    assert serialized["type"] == "Scheduled"
    assert serialized["message"] == "hi"
    assert serialized["__version__"] == prefect.__version__
    assert serialized["context"] == dict(task_run_count=42)

    deserialized = StateSchema().load(serialized)
    assert deserialized.is_scheduled()
    assert deserialized.context == dict(task_run_count=42)


def test_serialize_state_with_context_allows_for_diverse_values():
    s = state.Running(message="hi")
    s.context = dict(tags=["foo", "bar"], info=dict(x=42), baz="99")
    serialized = StateSchema().dump(s)
    assert isinstance(serialized, dict)
    assert serialized["type"] == "Running"
    assert serialized["message"] == "hi"
    assert serialized["__version__"] == prefect.__version__
    assert serialized["context"] == s.context

    deserialized = StateSchema().load(serialized)
    assert deserialized.is_running()
    assert deserialized.context == s.context


def test_serialize_mapped():
    s = state.Success(message="1", result=1)
    f = state.Failed(message="2", result=2)
    serialized = StateSchema().dump(state.Mapped(message="message", map_states=[s, f]))
    assert isinstance(serialized, dict)
    assert serialized["type"] == "Mapped"
    assert serialized["message"] == "message"
    assert "_result" not in serialized
    assert "map_states" not in serialized
    assert serialized["n_map_states"] == 2
    assert serialized["__version__"] == prefect.__version__


@pytest.mark.parametrize("cls", [s for s in all_states if s is not state.Mapped])
def test_deserialize_state(cls):
    s = cls(message="message")
    serialized = StateSchema().dump(s)
    deserialized = StateSchema().load(serialized)
    assert isinstance(deserialized, cls)
    assert deserialized == s


@pytest.mark.parametrize("cls", [s for s in all_states if s is not state.Mapped])
def test_deserialize_state_with_safe_result(cls):
    s = cls(message="message")
    serialized = StateSchema().dump(s)
    deserialized = StateSchema().load(serialized)
    assert isinstance(deserialized, cls)
    assert deserialized == s


def test_deserialize_mapped():
    s = state.Success(message="1", result=1)
    f = state.Failed(message="2", result=2)
    serialized = StateSchema().dump(state.Mapped(message="message", map_states=[s, f]))
    deserialized = StateSchema().load(serialized)
    assert isinstance(deserialized, state.Mapped)
    assert len(deserialized.map_states) == 2
    assert deserialized.map_states == [None, None]
    assert deserialized._result == NoResult


@pytest.mark.parametrize("cls", all_states)
def test_deserialize_state_from_only_type(cls):
    serialized = dict(type=cls.__name__)
    new_state = StateSchema().load(serialized)
    assert isinstance(new_state, cls)
    assert new_state.message is None
    assert new_state._result == NoResult


def test_deserialize_state_without_type_fails():
    with pytest.raises(marshmallow.exceptions.ValidationError):
        StateSchema().load({})


def test_deserialize_state_with_unknown_type_fails():
    with pytest.raises(marshmallow.exceptions.ValidationError):
        StateSchema().load({"type": "FakeState"})


@pytest.mark.parametrize("state", complex_states())
def test_complex_state_attributes_are_handled(state):
    serialized = StateSchema().dump(state)
    deserialized = StateSchema().load(serialized)
    assert state == deserialized


def test_result_must_be_valid_json():
    res = SafeResult({"x": {"y": {"z": 1}}}, result_handler=JSONResultHandler())
    s = state.Success(result=res)
    serialized = StateSchema().dump(s)
    assert serialized["_result"]["value"] == s.result


def test_result_raises_error_on_dump_if_not_valid_json():
    res = SafeResult({"x": {"y": {"z": lambda: 1}}}, result_handler=JSONResultHandler())
    s = state.Success(result=res)
    with pytest.raises(marshmallow.exceptions.ValidationError):
        StateSchema().dump(s)


def test_deserialize_json_with_context():
    deserialized = StateSchema().load(
        {"type": "Running", "context": {"boo": ["a", "b", "c"]}}
    )
    assert type(deserialized) is state.Running
    assert deserialized.is_running()
    assert deserialized.message is None
    assert deserialized.context == dict(boo=["a", "b", "c"])
    assert deserialized._result == NoResult


def test_deserialize_json_without_version():
    deserialized = StateSchema().load({"type": "Running", "message": "test"})
    assert type(deserialized) is state.Running
    assert deserialized.is_running()
    assert deserialized.message == "test"
    assert deserialized.context == dict()
    assert deserialized._result == NoResult


def test_deserialize_handles_unknown_fields():
    """ensure that deserialization can happen even if a newer version of prefect created unknown fields"""
    deserialized = StateSchema().load(
        {
            "type": "Success",
            "success_message_that_definitely_wont_exist_on_a_real_state!": 1,
        }
    )

    assert deserialized.is_successful()
