# Copyright (c) Microsoft. All rights reserved.

import json
import tempfile
from dataclasses import dataclass
from datetime import datetime, timezone
from pathlib import Path
from typing import Any

import pytest

from agent_framework import (
    FileCheckpointStorage,
    InMemoryCheckpointStorage,
    WorkflowCheckpoint,
    WorkflowCheckpointException,
    WorkflowEvent,
)
from agent_framework._workflows._runner_context import WorkflowMessage


# Module-level dataclasses for pickle serialization in roundtrip tests
@dataclass
class _TestToolApprovalRequest:
    """Request data for tool approval in tests."""

    tool_name: str
    arguments: dict[str, Any]
    timestamp: datetime


@dataclass
class _TestExecutorState:
    """Executor state for tests."""

    counter: int
    history: list[str]


@dataclass
class _TestApprovalRequest:
    """Approval request data for tests."""

    action: str
    params: tuple[Any, ...]


@dataclass
class _TestCustomData:
    """Custom data for tests."""

    name: str
    value: int
    tags: list[str]


# region test WorkflowCheckpoint


def test_workflow_checkpoint_default_values():
    checkpoint = WorkflowCheckpoint(workflow_name="test-workflow", graph_signature_hash="test-hash")

    assert checkpoint.checkpoint_id != ""
    assert checkpoint.workflow_name == "test-workflow"
    assert checkpoint.graph_signature_hash == "test-hash"
    assert checkpoint.timestamp != ""
    assert checkpoint.messages == {}
    assert checkpoint.state == {}
    assert checkpoint.pending_request_info_events == {}
    assert checkpoint.iteration_count == 0
    assert checkpoint.metadata == {}
    assert checkpoint.version == "1.0"


def test_workflow_checkpoint_custom_values():
    custom_timestamp = datetime.now(timezone.utc).isoformat()
    checkpoint = WorkflowCheckpoint(
        checkpoint_id="test-checkpoint-123",
        workflow_name="test-workflow-456",
        graph_signature_hash="test-hash-456",
        timestamp=custom_timestamp,
        messages={"executor1": [{"data": "test"}]},  # type: ignore[arg-type]  # raw dict for serialization test
        pending_request_info_events={"req123": {"data": "test"}},  # type: ignore[arg-type]  # raw dict for serialization test
        state={"key": "value"},
        iteration_count=5,
        metadata={"test": True},
        version="2.0",
    )

    assert checkpoint.checkpoint_id == "test-checkpoint-123"
    assert checkpoint.workflow_name == "test-workflow-456"
    assert checkpoint.graph_signature_hash == "test-hash-456"
    assert checkpoint.timestamp == custom_timestamp
    assert checkpoint.messages == {"executor1": [{"data": "test"}]}
    assert checkpoint.state == {"key": "value"}
    assert checkpoint.pending_request_info_events == {"req123": {"data": "test"}}
    assert checkpoint.iteration_count == 5
    assert checkpoint.metadata == {"test": True}
    assert checkpoint.version == "2.0"


def test_workflow_checkpoint_to_dict():
    checkpoint = WorkflowCheckpoint(
        checkpoint_id="test-id",
        workflow_name="test-workflow",
        graph_signature_hash="test-hash",
        messages={"executor1": [{"data": "test"}]},  # type: ignore[arg-type]  # raw dict for serialization test
        state={"key": "value"},
        iteration_count=5,
    )

    result = checkpoint.to_dict()

    assert result["checkpoint_id"] == "test-id"
    assert result["workflow_name"] == "test-workflow"
    assert result["graph_signature_hash"] == "test-hash"
    assert result["messages"] == {"executor1": [{"data": "test"}]}
    assert result["state"] == {"key": "value"}
    assert result["iteration_count"] == 5


def test_workflow_checkpoint_previous_checkpoint_id():
    checkpoint = WorkflowCheckpoint(
        workflow_name="test-workflow",
        graph_signature_hash="test-hash",
        previous_checkpoint_id="previous-id-123",
    )

    assert checkpoint.previous_checkpoint_id == "previous-id-123"


# endregion

# region InMemoryCheckpointStorage


def test_checkpoint_storage_protocol_compliance():
    # This test ensures both implementations have all required methods
    memory_storage = InMemoryCheckpointStorage()

    with tempfile.TemporaryDirectory() as temp_dir:
        file_storage = FileCheckpointStorage(temp_dir)

        for storage in [memory_storage, file_storage]:
            # Test that all protocol methods exist and are callable
            assert hasattr(storage, "save")
            assert callable(storage.save)
            assert hasattr(storage, "load")
            assert callable(storage.load)
            assert hasattr(storage, "list_checkpoints")
            assert callable(storage.list_checkpoints)
            assert hasattr(storage, "delete")
            assert callable(storage.delete)
            assert hasattr(storage, "list_checkpoint_ids")
            assert callable(storage.list_checkpoint_ids)
            assert hasattr(storage, "get_latest")
            assert callable(storage.get_latest)


async def test_memory_checkpoint_storage_save_and_load():
    storage = InMemoryCheckpointStorage()
    checkpoint = WorkflowCheckpoint(
        workflow_name="test-workflow",
        graph_signature_hash="test-hash",
        messages={"executor1": [{"data": "hello"}]},  # type: ignore[arg-type]  # raw dict for serialization test
        pending_request_info_events={"req123": {"data": "test"}},  # type: ignore[arg-type]  # raw dict for serialization test
    )

    # Save checkpoint
    saved_id = await storage.save(checkpoint)
    assert saved_id == checkpoint.checkpoint_id

    # Load checkpoint
    loaded_checkpoint = await storage.load(checkpoint.checkpoint_id)
    assert loaded_checkpoint is not None
    assert loaded_checkpoint.checkpoint_id == checkpoint.checkpoint_id
    assert loaded_checkpoint.workflow_name == checkpoint.workflow_name
    assert loaded_checkpoint.graph_signature_hash == checkpoint.graph_signature_hash
    assert loaded_checkpoint.messages == checkpoint.messages
    assert loaded_checkpoint.pending_request_info_events == checkpoint.pending_request_info_events


async def test_memory_checkpoint_storage_load_nonexistent():
    storage = InMemoryCheckpointStorage()

    with pytest.raises(WorkflowCheckpointException):
        await storage.load("nonexistent-id")


async def test_memory_checkpoint_storage_list():
    storage = InMemoryCheckpointStorage()

    # Create checkpoints for different workflows
    checkpoint1 = WorkflowCheckpoint(workflow_name="workflow-1", graph_signature_hash="hash-1")
    checkpoint2 = WorkflowCheckpoint(workflow_name="workflow-1", graph_signature_hash="hash-2")
    checkpoint3 = WorkflowCheckpoint(workflow_name="workflow-2", graph_signature_hash="hash-3")

    await storage.save(checkpoint1)
    await storage.save(checkpoint2)
    await storage.save(checkpoint3)

    # Test list_ids for workflow-1
    workflow1_checkpoint_ids = await storage.list_checkpoint_ids(workflow_name="workflow-1")
    assert len(workflow1_checkpoint_ids) == 2
    assert checkpoint1.checkpoint_id in workflow1_checkpoint_ids
    assert checkpoint2.checkpoint_id in workflow1_checkpoint_ids

    # Test list for workflow-1 (returns objects)
    workflow1_checkpoints = await storage.list_checkpoints(workflow_name="workflow-1")
    assert len(workflow1_checkpoints) == 2
    assert all(isinstance(cp, WorkflowCheckpoint) for cp in workflow1_checkpoints)
    assert {cp.checkpoint_id for cp in workflow1_checkpoints} == {checkpoint1.checkpoint_id, checkpoint2.checkpoint_id}

    # Test list_ids for workflow-2
    workflow2_checkpoint_ids = await storage.list_checkpoint_ids(workflow_name="workflow-2")
    assert len(workflow2_checkpoint_ids) == 1
    assert checkpoint3.checkpoint_id in workflow2_checkpoint_ids

    # Test list for workflow-2 (returns objects)
    workflow2_checkpoints = await storage.list_checkpoints(workflow_name="workflow-2")
    assert len(workflow2_checkpoints) == 1
    assert workflow2_checkpoints[0].checkpoint_id == checkpoint3.checkpoint_id

    # Test list_ids for non-existent workflow
    empty_checkpoint_ids = await storage.list_checkpoint_ids(workflow_name="nonexistent-workflow")
    assert len(empty_checkpoint_ids) == 0

    # Test list for non-existent workflow
    empty_checkpoints = await storage.list_checkpoints(workflow_name="nonexistent-workflow")
    assert len(empty_checkpoints) == 0


async def test_memory_checkpoint_storage_delete():
    storage = InMemoryCheckpointStorage()
    checkpoint = WorkflowCheckpoint(workflow_name="test-workflow", graph_signature_hash="test-hash")

    # Save checkpoint
    await storage.save(checkpoint)
    assert await storage.load(checkpoint.checkpoint_id) is not None

    # Delete checkpoint
    result = await storage.delete(checkpoint.checkpoint_id)
    assert result is True

    # Verify deletion
    with pytest.raises(WorkflowCheckpointException):
        await storage.load(checkpoint.checkpoint_id)

    # Try to delete again
    result = await storage.delete(checkpoint.checkpoint_id)
    assert result is False


async def test_memory_checkpoint_storage_get_latest():
    import asyncio

    storage = InMemoryCheckpointStorage()

    # Create checkpoints with small delays to ensure different timestamps
    checkpoint1 = WorkflowCheckpoint(workflow_name="workflow-1", graph_signature_hash="hash-1")
    await asyncio.sleep(0.01)
    checkpoint2 = WorkflowCheckpoint(workflow_name="workflow-1", graph_signature_hash="hash-2")
    await asyncio.sleep(0.01)
    checkpoint3 = WorkflowCheckpoint(workflow_name="workflow-2", graph_signature_hash="hash-3")

    await storage.save(checkpoint1)
    await storage.save(checkpoint2)
    await storage.save(checkpoint3)

    # Test get_latest for workflow-1
    latest = await storage.get_latest(workflow_name="workflow-1")
    assert latest is not None
    assert latest.checkpoint_id == checkpoint2.checkpoint_id

    # Test get_latest for workflow-2
    latest2 = await storage.get_latest(workflow_name="workflow-2")
    assert latest2 is not None
    assert latest2.checkpoint_id == checkpoint3.checkpoint_id

    # Test get_latest for non-existent workflow
    latest_none = await storage.get_latest(workflow_name="nonexistent-workflow")
    assert latest_none is None


async def test_workflow_checkpoint_chaining_via_previous_checkpoint_id():
    """Test that consecutive checkpoints created by a workflow are properly chained via previous_checkpoint_id."""
    from typing_extensions import Never

    from agent_framework import WorkflowBuilder, WorkflowContext, handler
    from agent_framework._workflows._executor import Executor

    class StartExecutor(Executor):
        @handler
        async def run(self, message: str, ctx: WorkflowContext[str]) -> None:
            await ctx.send_message(message, target_id="middle")

    class MiddleExecutor(Executor):
        @handler
        async def process(self, message: str, ctx: WorkflowContext[str]) -> None:
            await ctx.send_message(message + "-processed", target_id="finish")

    class FinishExecutor(Executor):
        @handler
        async def finish(self, message: str, ctx: WorkflowContext[Never, str]) -> None:
            await ctx.yield_output(message + "-done")

    storage = InMemoryCheckpointStorage()

    start = StartExecutor(id="start")
    middle = MiddleExecutor(id="middle")
    finish = FinishExecutor(id="finish")

    workflow = (
        WorkflowBuilder(max_iterations=10, start_executor=start, checkpoint_storage=storage)
        .add_edge(start, middle)
        .add_edge(middle, finish)
        .build()
    )

    # Run workflow - this creates checkpoints at each superstep
    _ = [event async for event in workflow.run("hello", stream=True)]

    # Get all checkpoints sorted by timestamp
    checkpoints = sorted(await storage.list_checkpoints(workflow_name=workflow.name), key=lambda c: c.timestamp)

    # Should have multiple checkpoints (one initial + one per superstep)
    assert len(checkpoints) >= 2, f"Expected at least 2 checkpoints, got {len(checkpoints)}"

    # Verify chaining: first checkpoint has no previous
    assert checkpoints[0].previous_checkpoint_id is None

    # Subsequent checkpoints should chain to the previous one
    for i in range(1, len(checkpoints)):
        assert checkpoints[i].previous_checkpoint_id == checkpoints[i - 1].checkpoint_id, (
            f"Checkpoint {i} should chain to checkpoint {i - 1}"
        )


async def test_memory_checkpoint_storage_roundtrip_json_native_types():
    """Test that JSON-native types (str, int, float, bool, None) roundtrip correctly."""
    storage = InMemoryCheckpointStorage()

    checkpoint = WorkflowCheckpoint(
        workflow_name="test-workflow",
        graph_signature_hash="test-hash",
        state={
            "string": "hello world",
            "integer": 42,
            "negative_int": -100,
            "float": 3.14159,
            "negative_float": -2.71828,
            "bool_true": True,
            "bool_false": False,
            "null_value": None,
            "zero": 0,
            "empty_string": "",
        },
    )

    await storage.save(checkpoint)
    loaded = await storage.load(checkpoint.checkpoint_id)

    assert loaded.state == checkpoint.state


async def test_memory_checkpoint_storage_roundtrip_datetime():
    """Test that datetime objects roundtrip correctly."""
    storage = InMemoryCheckpointStorage()

    now = datetime.now(timezone.utc)
    specific_datetime = datetime(2025, 6, 15, 10, 30, 45, 123456, tzinfo=timezone.utc)

    checkpoint = WorkflowCheckpoint(
        workflow_name="test-workflow",
        graph_signature_hash="test-hash",
        state={
            "current_time": now,
            "specific_time": specific_datetime,
            "nested": {"created_at": now, "updated_at": specific_datetime},
        },
    )

    await storage.save(checkpoint)
    loaded = await storage.load(checkpoint.checkpoint_id)

    assert loaded.state["current_time"] == now
    assert loaded.state["specific_time"] == specific_datetime
    assert loaded.state["nested"]["created_at"] == now
    assert loaded.state["nested"]["updated_at"] == specific_datetime


async def test_memory_checkpoint_storage_roundtrip_dataclass():
    """Test that dataclass objects roundtrip correctly."""
    storage = InMemoryCheckpointStorage()

    custom_obj = _TestCustomData(name="test", value=42, tags=["a", "b", "c"])

    checkpoint = WorkflowCheckpoint(
        workflow_name="test-workflow",
        graph_signature_hash="test-hash",
        state={
            "custom_data": custom_obj,
            "nested": {"inner_data": custom_obj},
        },
    )

    await storage.save(checkpoint)
    loaded = await storage.load(checkpoint.checkpoint_id)

    assert loaded.state["custom_data"] == custom_obj
    assert loaded.state["custom_data"].name == "test"
    assert loaded.state["custom_data"].value == 42
    assert loaded.state["custom_data"].tags == ["a", "b", "c"]
    assert loaded.state["nested"]["inner_data"] == custom_obj
    assert isinstance(loaded.state["custom_data"], _TestCustomData)


async def test_memory_checkpoint_storage_roundtrip_tuple_and_set():
    """Test that tuples and frozensets roundtrip correctly (type preserved in memory)."""
    storage = InMemoryCheckpointStorage()

    original_tuple = (1, "two", 3.0, None)
    original_frozenset = frozenset({1, 2, 3})

    checkpoint = WorkflowCheckpoint(
        workflow_name="test-workflow",
        graph_signature_hash="test-hash",
        state={
            "my_tuple": original_tuple,
            "my_frozenset": original_frozenset,
            "nested_tuple": {"inner": (10, 20, 30)},
        },
    )

    await storage.save(checkpoint)
    loaded = await storage.load(checkpoint.checkpoint_id)

    # In-memory storage preserves exact types (no JSON serialization)
    assert loaded.state["my_tuple"] == original_tuple
    assert isinstance(loaded.state["my_tuple"], tuple)
    assert loaded.state["my_frozenset"] == original_frozenset
    assert isinstance(loaded.state["my_frozenset"], frozenset)
    assert loaded.state["nested_tuple"]["inner"] == (10, 20, 30)
    assert isinstance(loaded.state["nested_tuple"]["inner"], tuple)


async def test_memory_checkpoint_storage_roundtrip_complex_nested_structures():
    """Test complex nested structures with mixed types roundtrip correctly."""
    storage = InMemoryCheckpointStorage()

    # Create complex nested structure mixing JSON-native and non-native types
    complex_state = {
        "level1": {
            "level2": {
                "level3": {
                    "deep_string": "hello",
                    "deep_int": 123,
                    "deep_datetime": datetime(2025, 1, 1, tzinfo=timezone.utc),
                    "deep_tuple": (1, 2, 3),
                }
            },
            "list_of_dicts": [
                {"a": 1, "b": datetime(2025, 2, 1, tzinfo=timezone.utc)},
                {"c": 2, "d": (4, 5, 6)},
            ],
        },
        "mixed_list": [
            "string",
            42,
            3.14,
            True,
            None,
            datetime(2025, 3, 1, tzinfo=timezone.utc),
            (7, 8, 9),
        ],
    }

    checkpoint = WorkflowCheckpoint(
        workflow_name="test-workflow",
        graph_signature_hash="test-hash",
        state=complex_state,
    )

    await storage.save(checkpoint)
    loaded = await storage.load(checkpoint.checkpoint_id)

    # Verify deep nested values
    assert loaded.state["level1"]["level2"]["level3"]["deep_string"] == "hello"
    assert loaded.state["level1"]["level2"]["level3"]["deep_int"] == 123
    assert loaded.state["level1"]["level2"]["level3"]["deep_datetime"] == datetime(2025, 1, 1, tzinfo=timezone.utc)
    assert loaded.state["level1"]["level2"]["level3"]["deep_tuple"] == (1, 2, 3)
    assert isinstance(loaded.state["level1"]["level2"]["level3"]["deep_tuple"], tuple)

    # Verify list of dicts
    assert loaded.state["level1"]["list_of_dicts"][0]["a"] == 1
    assert loaded.state["level1"]["list_of_dicts"][0]["b"] == datetime(2025, 2, 1, tzinfo=timezone.utc)
    assert loaded.state["level1"]["list_of_dicts"][1]["d"] == (4, 5, 6)
    assert isinstance(loaded.state["level1"]["list_of_dicts"][1]["d"], tuple)

    # Verify mixed list with correct types
    assert loaded.state["mixed_list"][0] == "string"
    assert loaded.state["mixed_list"][1] == 42
    assert loaded.state["mixed_list"][5] == datetime(2025, 3, 1, tzinfo=timezone.utc)
    assert loaded.state["mixed_list"][6] == (7, 8, 9)
    assert isinstance(loaded.state["mixed_list"][6], tuple)


async def test_memory_checkpoint_storage_roundtrip_messages_with_complex_data():
    """Test that messages dict with Message objects roundtrips correctly."""
    storage = InMemoryCheckpointStorage()

    msg1 = WorkflowMessage(
        data={"text": "hello", "timestamp": datetime(2025, 1, 1, tzinfo=timezone.utc)},
        source_id="source",
        target_id="target",
    )
    msg2 = WorkflowMessage(
        data=(1, 2, 3),
        source_id="s2",
        target_id=None,
    )
    msg3 = WorkflowMessage(
        data="simple string",
        source_id="s3",
        target_id="t3",
    )

    messages = {
        "executor1": [msg1, msg2],
        "executor2": [msg3],
    }

    checkpoint = WorkflowCheckpoint(
        workflow_name="test-workflow",
        graph_signature_hash="test-hash",
        messages=messages,
    )

    await storage.save(checkpoint)
    loaded = await storage.load(checkpoint.checkpoint_id)

    # Verify messages structure and types
    assert len(loaded.messages["executor1"]) == 2
    loaded_msg1 = loaded.messages["executor1"][0]
    loaded_msg2 = loaded.messages["executor1"][1]
    loaded_msg3 = loaded.messages["executor2"][0]

    # Verify Message type is preserved
    assert isinstance(loaded_msg1, WorkflowMessage)
    assert isinstance(loaded_msg2, WorkflowMessage)
    assert isinstance(loaded_msg3, WorkflowMessage)

    # Verify Message fields
    assert loaded_msg1.data["text"] == "hello"
    assert loaded_msg1.data["timestamp"] == datetime(2025, 1, 1, tzinfo=timezone.utc)
    assert loaded_msg1.source_id == "source"
    assert loaded_msg1.target_id == "target"

    assert loaded_msg2.data == (1, 2, 3)
    assert isinstance(loaded_msg2.data, tuple)
    assert loaded_msg2.source_id == "s2"
    assert loaded_msg2.target_id is None

    assert loaded_msg3.data == "simple string"
    assert loaded_msg3.source_id == "s3"
    assert loaded_msg3.target_id == "t3"


async def test_memory_checkpoint_storage_roundtrip_pending_request_info_events():
    """Test that pending_request_info_events with WorkflowEvent objects roundtrip correctly."""
    storage = InMemoryCheckpointStorage()

    # Create request_info events using the proper WorkflowEvent factory
    event1 = WorkflowEvent.request_info(
        request_id="req123",
        source_executor_id="executor1",
        request_data="What is your name?",
        response_type=str,
    )
    event2 = WorkflowEvent.request_info(
        request_id="req456",
        source_executor_id="executor2",
        request_data=_TestToolApprovalRequest(
            tool_name="search",
            arguments={"query": "test"},
            timestamp=datetime(2025, 1, 1, tzinfo=timezone.utc),
        ),
        response_type=bool,
    )

    pending_events = {
        "req123": event1,
        "req456": event2,
    }

    checkpoint = WorkflowCheckpoint(
        workflow_name="test-workflow",
        graph_signature_hash="test-hash",
        pending_request_info_events=pending_events,
    )

    await storage.save(checkpoint)
    loaded = await storage.load(checkpoint.checkpoint_id)

    # Verify WorkflowEvent type is preserved
    loaded_event1 = loaded.pending_request_info_events["req123"]
    loaded_event2 = loaded.pending_request_info_events["req456"]

    assert isinstance(loaded_event1, WorkflowEvent)
    assert isinstance(loaded_event2, WorkflowEvent)

    # Verify event1 fields
    assert loaded_event1.type == "request_info"
    assert loaded_event1.request_id == "req123"
    assert loaded_event1.source_executor_id == "executor1"
    assert loaded_event1.data == "What is your name?"
    assert loaded_event1.response_type is str

    # Verify event2 fields with complex data
    assert loaded_event2.type == "request_info"
    assert loaded_event2.request_id == "req456"
    assert loaded_event2.source_executor_id == "executor2"
    assert isinstance(loaded_event2.data, _TestToolApprovalRequest)
    assert loaded_event2.data.tool_name == "search"
    assert loaded_event2.data.arguments == {"query": "test"}
    assert loaded_event2.data.timestamp == datetime(2025, 1, 1, tzinfo=timezone.utc)
    assert loaded_event2.response_type is bool


async def test_memory_checkpoint_storage_roundtrip_full_checkpoint():
    """Test complete WorkflowCheckpoint roundtrip with all fields populated using proper types."""
    storage = InMemoryCheckpointStorage()

    # Create proper WorkflowMessage objects
    msg1 = WorkflowMessage(data="msg1", source_id="s", target_id="t")
    msg2 = WorkflowMessage(data=datetime(2025, 1, 1, tzinfo=timezone.utc), source_id="a", target_id="b")

    # Create proper WorkflowEvent for pending request
    pending_event = WorkflowEvent.request_info(
        request_id="req1",
        source_executor_id="exec1",
        request_data=_TestApprovalRequest(action="approve", params=(1, 2, 3)),
        response_type=bool,
    )

    checkpoint = WorkflowCheckpoint(
        checkpoint_id="full-test-checkpoint",
        workflow_name="comprehensive-test",
        graph_signature_hash="hash-abc123",
        previous_checkpoint_id="previous-checkpoint-id",
        timestamp=datetime(2025, 6, 15, 12, 0, 0, tzinfo=timezone.utc).isoformat(),
        messages={
            "exec1": [msg1],
            "exec2": [msg2],
        },
        state={
            "user_data": {"name": "test", "created": datetime(2025, 1, 1, tzinfo=timezone.utc)},
            "_executor_state": {
                "exec1": _TestExecutorState(counter=5, history=["a", "b", "c"]),
            },
        },
        pending_request_info_events={
            "req1": pending_event,
        },
        iteration_count=10,
        metadata={
            "superstep": 5,
            "started_at": datetime(2025, 6, 15, 11, 0, 0, tzinfo=timezone.utc),
        },
        version="1.0",
    )

    await storage.save(checkpoint)
    loaded = await storage.load(checkpoint.checkpoint_id)

    # Verify all scalar fields
    assert loaded.checkpoint_id == checkpoint.checkpoint_id
    assert loaded.workflow_name == checkpoint.workflow_name
    assert loaded.graph_signature_hash == checkpoint.graph_signature_hash
    assert loaded.previous_checkpoint_id == checkpoint.previous_checkpoint_id
    assert loaded.timestamp == checkpoint.timestamp
    assert loaded.iteration_count == checkpoint.iteration_count
    assert loaded.version == checkpoint.version

    # Verify complex nested state data
    assert loaded.state["user_data"]["created"] == datetime(2025, 1, 1, tzinfo=timezone.utc)
    assert loaded.state["_executor_state"]["exec1"].counter == 5
    assert loaded.state["_executor_state"]["exec1"].history == ["a", "b", "c"]
    assert isinstance(loaded.state["_executor_state"]["exec1"], _TestExecutorState)

    # Verify messages are proper Message objects
    loaded_msg1 = loaded.messages["exec1"][0]
    loaded_msg2 = loaded.messages["exec2"][0]
    assert isinstance(loaded_msg1, WorkflowMessage)
    assert isinstance(loaded_msg2, WorkflowMessage)
    assert loaded_msg1.data == "msg1"
    assert loaded_msg1.source_id == "s"
    assert loaded_msg2.data == datetime(2025, 1, 1, tzinfo=timezone.utc)

    # Verify pending events are proper WorkflowEvent objects
    loaded_event = loaded.pending_request_info_events["req1"]
    assert isinstance(loaded_event, WorkflowEvent)
    assert loaded_event.type == "request_info"
    assert loaded_event.request_id == "req1"
    assert isinstance(loaded_event.data, _TestApprovalRequest)
    assert loaded_event.data.params == (1, 2, 3)

    # Verify metadata
    assert loaded.metadata["superstep"] == 5
    assert loaded.metadata["started_at"] == datetime(2025, 6, 15, 11, 0, 0, tzinfo=timezone.utc)


async def test_memory_checkpoint_storage_roundtrip_bytes():
    """Test that bytes objects roundtrip correctly."""
    storage = InMemoryCheckpointStorage()

    binary_data = b"\x00\x01\x02\xff\xfe\xfd"
    unicode_bytes = "Hello 世界".encode()

    checkpoint = WorkflowCheckpoint(
        workflow_name="test-workflow",
        graph_signature_hash="test-hash",
        state={
            "binary_data": binary_data,
            "unicode_bytes": unicode_bytes,
            "nested": {"inner_bytes": binary_data},
        },
    )

    await storage.save(checkpoint)
    loaded = await storage.load(checkpoint.checkpoint_id)

    assert loaded.state["binary_data"] == binary_data
    assert loaded.state["unicode_bytes"] == unicode_bytes
    assert loaded.state["nested"]["inner_bytes"] == binary_data
    assert isinstance(loaded.state["binary_data"], bytes)


async def test_memory_checkpoint_storage_roundtrip_empty_collections():
    """Test that empty collections roundtrip correctly (types preserved in memory)."""
    storage = InMemoryCheckpointStorage()

    checkpoint = WorkflowCheckpoint(
        workflow_name="test-workflow",
        graph_signature_hash="test-hash",
        state={
            "empty_dict": {},
            "empty_list": [],
            "empty_tuple": (),
            "nested_empty": {"inner_dict": {}, "inner_list": []},
        },
        messages={},
        pending_request_info_events={},
    )

    await storage.save(checkpoint)
    loaded = await storage.load(checkpoint.checkpoint_id)

    assert loaded.state["empty_dict"] == {}
    assert loaded.state["empty_list"] == []
    # In-memory storage preserves exact types (no JSON serialization)
    assert loaded.state["empty_tuple"] == ()
    assert isinstance(loaded.state["empty_tuple"], tuple)
    assert loaded.state["nested_empty"]["inner_dict"] == {}
    assert loaded.messages == {}
    assert loaded.pending_request_info_events == {}


# endregion

# region FileCheckpointStorage


async def test_file_checkpoint_storage_save_and_load():
    with tempfile.TemporaryDirectory() as temp_dir:
        storage = FileCheckpointStorage(temp_dir)
        checkpoint = WorkflowCheckpoint(
            workflow_name="test-workflow",
            graph_signature_hash="test-hash",
            messages={"executor1": [{"data": "hello", "source_id": "test", "target_id": None}]},  # type: ignore[arg-type]  # raw dict for serialization test
            state={"key": "value"},
            pending_request_info_events={"req123": {"data": "test"}},  # type: ignore[arg-type]  # raw dict for serialization test
        )

        # Save checkpoint
        saved_id = await storage.save(checkpoint)
        assert saved_id == checkpoint.checkpoint_id

        # Verify file was created
        file_path = Path(temp_dir) / f"{checkpoint.checkpoint_id}.json"
        assert file_path.exists()

        # Load checkpoint
        loaded_checkpoint = await storage.load(checkpoint.checkpoint_id)
        assert loaded_checkpoint is not None
        assert loaded_checkpoint.checkpoint_id == checkpoint.checkpoint_id
        assert loaded_checkpoint.workflow_name == checkpoint.workflow_name
        assert loaded_checkpoint.graph_signature_hash == checkpoint.graph_signature_hash
        assert loaded_checkpoint.messages == checkpoint.messages
        assert loaded_checkpoint.state == checkpoint.state
        assert loaded_checkpoint.pending_request_info_events == checkpoint.pending_request_info_events


async def test_file_checkpoint_storage_load_nonexistent():
    with tempfile.TemporaryDirectory() as temp_dir:
        storage = FileCheckpointStorage(temp_dir)

        with pytest.raises(WorkflowCheckpointException):
            await storage.load("nonexistent-id")


async def test_file_checkpoint_storage_list():
    with tempfile.TemporaryDirectory() as temp_dir:
        storage = FileCheckpointStorage(temp_dir)

        # Create checkpoints for different workflows
        checkpoint1 = WorkflowCheckpoint(workflow_name="workflow-1", graph_signature_hash="hash-1")
        checkpoint2 = WorkflowCheckpoint(workflow_name="workflow-1", graph_signature_hash="hash-2")
        checkpoint3 = WorkflowCheckpoint(workflow_name="workflow-2", graph_signature_hash="hash-3")

        await storage.save(checkpoint1)
        await storage.save(checkpoint2)
        await storage.save(checkpoint3)

        # Test list_ids for workflow-1
        workflow1_checkpoint_ids = await storage.list_checkpoint_ids(workflow_name="workflow-1")
        assert len(workflow1_checkpoint_ids) == 2
        assert checkpoint1.checkpoint_id in workflow1_checkpoint_ids
        assert checkpoint2.checkpoint_id in workflow1_checkpoint_ids

        # Test list for workflow-1 (returns objects)
        workflow1_checkpoints = await storage.list_checkpoints(workflow_name="workflow-1")
        assert len(workflow1_checkpoints) == 2
        assert all(isinstance(cp, WorkflowCheckpoint) for cp in workflow1_checkpoints)
        checkpoint_ids = {cp.checkpoint_id for cp in workflow1_checkpoints}
        assert checkpoint_ids == {checkpoint1.checkpoint_id, checkpoint2.checkpoint_id}

        # Test list_ids for workflow-2
        workflow2_checkpoint_ids = await storage.list_checkpoint_ids(workflow_name="workflow-2")
        assert len(workflow2_checkpoint_ids) == 1
        assert checkpoint3.checkpoint_id in workflow2_checkpoint_ids

        # Test list for workflow-2 (returns objects)
        workflow2_checkpoints = await storage.list_checkpoints(workflow_name="workflow-2")
        assert len(workflow2_checkpoints) == 1
        assert workflow2_checkpoints[0].checkpoint_id == checkpoint3.checkpoint_id


async def test_file_checkpoint_storage_delete():
    with tempfile.TemporaryDirectory() as temp_dir:
        storage = FileCheckpointStorage(temp_dir)
        checkpoint = WorkflowCheckpoint(workflow_name="test-workflow", graph_signature_hash="test-hash")

        # Save checkpoint
        await storage.save(checkpoint)
        file_path = Path(temp_dir) / f"{checkpoint.checkpoint_id}.json"
        assert file_path.exists()

        # Delete checkpoint
        result = await storage.delete(checkpoint.checkpoint_id)
        assert result is True
        assert not file_path.exists()

        # Try to delete again
        result = await storage.delete(checkpoint.checkpoint_id)
        assert result is False


async def test_file_checkpoint_storage_directory_creation():
    with tempfile.TemporaryDirectory() as temp_dir:
        nested_path = Path(temp_dir) / "nested" / "checkpoint" / "storage"
        storage = FileCheckpointStorage(nested_path)

        # Directory should be created
        assert nested_path.exists()
        assert nested_path.is_dir()

        # Should be able to save checkpoints
        checkpoint = WorkflowCheckpoint(workflow_name="test-workflow", graph_signature_hash="test-hash")
        await storage.save(checkpoint)

        file_path = nested_path / f"{checkpoint.checkpoint_id}.json"
        assert file_path.exists()


async def test_file_checkpoint_storage_corrupted_file():
    with tempfile.TemporaryDirectory() as temp_dir:
        storage = FileCheckpointStorage(temp_dir)

        # Create a corrupted JSON file
        corrupted_file = Path(temp_dir) / "corrupted.json"
        with open(corrupted_file, "w") as f:  # noqa: ASYNC230
            f.write("{ invalid json }")

        # list should handle the corrupted file gracefully
        checkpoints = await storage.list_checkpoints(workflow_name="any-workflow")
        assert checkpoints == []


async def test_file_checkpoint_storage_json_serialization():
    with tempfile.TemporaryDirectory() as temp_dir:
        storage = FileCheckpointStorage(temp_dir)

        # Create checkpoint with complex nested data
        checkpoint = WorkflowCheckpoint(
            workflow_name="test-workflow",
            graph_signature_hash="test-hash",
            messages={"executor1": [{"data": {"nested": {"value": 42}}, "source_id": "test", "target_id": None}]},  # type: ignore[arg-type]  # raw dict for serialization test
            state={"list": [1, 2, 3], "dict": {"a": "b", "c": {"d": "e"}}, "bool": True, "null": None},
            pending_request_info_events={"req123": {"data": "test"}},  # type: ignore[arg-type]  # raw dict for serialization test
        )

        # Save and load
        await storage.save(checkpoint)
        loaded = await storage.load(checkpoint.checkpoint_id)

        assert loaded is not None
        assert loaded.messages == checkpoint.messages
        assert loaded.state == checkpoint.state

        # Verify the JSON file is properly formatted
        file_path = Path(temp_dir) / f"{checkpoint.checkpoint_id}.json"
        with open(file_path) as f:  # noqa: ASYNC230
            data = json.load(f)

        assert data["messages"]["executor1"][0]["data"]["nested"]["value"] == 42
        assert data["state"]["list"] == [1, 2, 3]
        assert data["state"]["bool"] is True
        assert data["state"]["null"] is None
        assert data["pending_request_info_events"]["req123"]["data"] == "test"


async def test_file_checkpoint_storage_get_latest():
    import asyncio

    with tempfile.TemporaryDirectory() as temp_dir:
        storage = FileCheckpointStorage(temp_dir)

        # Create checkpoints with small delays to ensure different timestamps
        checkpoint1 = WorkflowCheckpoint(workflow_name="workflow-1", graph_signature_hash="hash-1")
        await asyncio.sleep(0.01)
        checkpoint2 = WorkflowCheckpoint(workflow_name="workflow-1", graph_signature_hash="hash-2")
        await asyncio.sleep(0.01)
        checkpoint3 = WorkflowCheckpoint(workflow_name="workflow-2", graph_signature_hash="hash-3")

        await storage.save(checkpoint1)
        await storage.save(checkpoint2)
        await storage.save(checkpoint3)

        # Test get_latest for workflow-1
        latest = await storage.get_latest(workflow_name="workflow-1")
        assert latest is not None
        assert latest.checkpoint_id == checkpoint2.checkpoint_id

        # Test get_latest for workflow-2
        latest2 = await storage.get_latest(workflow_name="workflow-2")
        assert latest2 is not None
        assert latest2.checkpoint_id == checkpoint3.checkpoint_id

        # Test get_latest for non-existent workflow
        latest_none = await storage.get_latest(workflow_name="nonexistent-workflow")
        assert latest_none is None


async def test_file_checkpoint_storage_list_ids_corrupted_file():
    with tempfile.TemporaryDirectory() as temp_dir:
        storage = FileCheckpointStorage(temp_dir)

        # Create a valid checkpoint first
        checkpoint = WorkflowCheckpoint(workflow_name="test-workflow", graph_signature_hash="test-hash")
        await storage.save(checkpoint)

        # Create a corrupted JSON file
        corrupted_file = Path(temp_dir) / "corrupted.json"
        with open(corrupted_file, "w") as f:  # noqa: ASYNC230
            f.write("{ invalid json }")

        # list_ids should handle the corrupted file gracefully
        checkpoint_ids = await storage.list_checkpoint_ids(workflow_name="test-workflow")
        assert len(checkpoint_ids) == 1
        assert checkpoint.checkpoint_id in checkpoint_ids


async def test_file_checkpoint_storage_list_ids_empty():
    with tempfile.TemporaryDirectory() as temp_dir:
        storage = FileCheckpointStorage(temp_dir)

        # Test list_ids on empty storage
        checkpoint_ids = await storage.list_checkpoint_ids(workflow_name="any-workflow")
        assert checkpoint_ids == []


async def test_file_checkpoint_storage_roundtrip_json_native_types():
    """Test that JSON-native types (str, int, float, bool, None) roundtrip correctly."""
    with tempfile.TemporaryDirectory() as temp_dir:
        storage = FileCheckpointStorage(temp_dir)

        checkpoint = WorkflowCheckpoint(
            workflow_name="test-workflow",
            graph_signature_hash="test-hash",
            state={
                "string": "hello world",
                "integer": 42,
                "negative_int": -100,
                "float": 3.14159,
                "negative_float": -2.71828,
                "bool_true": True,
                "bool_false": False,
                "null_value": None,
                "zero": 0,
                "empty_string": "",
            },
        )

        await storage.save(checkpoint)
        loaded = await storage.load(checkpoint.checkpoint_id)

        assert loaded.state == checkpoint.state


async def test_file_checkpoint_storage_roundtrip_datetime():
    """Test that datetime objects roundtrip correctly via pickle encoding."""
    with tempfile.TemporaryDirectory() as temp_dir:
        storage = FileCheckpointStorage(temp_dir)

        now = datetime.now(timezone.utc)
        specific_datetime = datetime(2025, 6, 15, 10, 30, 45, 123456, tzinfo=timezone.utc)

        checkpoint = WorkflowCheckpoint(
            workflow_name="test-workflow",
            graph_signature_hash="test-hash",
            state={
                "current_time": now,
                "specific_time": specific_datetime,
                "nested": {"created_at": now, "updated_at": specific_datetime},
            },
        )

        await storage.save(checkpoint)
        loaded = await storage.load(checkpoint.checkpoint_id)

        assert loaded.state["current_time"] == now
        assert loaded.state["specific_time"] == specific_datetime
        assert loaded.state["nested"]["created_at"] == now
        assert loaded.state["nested"]["updated_at"] == specific_datetime


async def test_file_checkpoint_storage_roundtrip_dataclass():
    """Test that dataclass objects roundtrip correctly via pickle encoding."""
    with tempfile.TemporaryDirectory() as temp_dir:
        storage = FileCheckpointStorage(
            temp_dir,
            allowed_checkpoint_types=["tests.workflow.test_checkpoint:_TestCustomData"],
        )

        custom_obj = _TestCustomData(name="test", value=42, tags=["a", "b", "c"])

        checkpoint = WorkflowCheckpoint(
            workflow_name="test-workflow",
            graph_signature_hash="test-hash",
            state={
                "custom_data": custom_obj,
                "nested": {"inner_data": custom_obj},
            },
        )

        await storage.save(checkpoint)
        loaded = await storage.load(checkpoint.checkpoint_id)

        assert loaded.state["custom_data"] == custom_obj
        assert loaded.state["custom_data"].name == "test"
        assert loaded.state["custom_data"].value == 42
        assert loaded.state["custom_data"].tags == ["a", "b", "c"]
        assert loaded.state["nested"]["inner_data"] == custom_obj
        assert isinstance(loaded.state["custom_data"], _TestCustomData)


async def test_file_checkpoint_storage_roundtrip_tuple_and_set():
    """Test tuple/frozenset encoding behavior.

    Tuples, sets, and frozensets are pickled to preserve their type through
    the encode/decode roundtrip.
    """
    with tempfile.TemporaryDirectory() as temp_dir:
        storage = FileCheckpointStorage(temp_dir)

        original_tuple = (1, "two", 3.0, None)
        original_frozenset = frozenset({1, 2, 3})

        checkpoint = WorkflowCheckpoint(
            workflow_name="test-workflow",
            graph_signature_hash="test-hash",
            state={
                "my_tuple": original_tuple,
                "my_frozenset": original_frozenset,
                "nested_tuple": {"inner": (10, 20, 30)},
            },
        )

        await storage.save(checkpoint)
        loaded = await storage.load(checkpoint.checkpoint_id)

        # Tuples preserve their type through roundtrip
        assert loaded.state["my_tuple"] == original_tuple
        assert isinstance(loaded.state["my_tuple"], tuple)

        # Frozensets are pickled and preserve their type
        assert loaded.state["my_frozenset"] == original_frozenset
        assert isinstance(loaded.state["my_frozenset"], frozenset)

        # Nested tuples also preserve their type
        assert loaded.state["nested_tuple"]["inner"] == (10, 20, 30)
        assert isinstance(loaded.state["nested_tuple"]["inner"], tuple)


async def test_file_checkpoint_storage_roundtrip_complex_nested_structures():
    """Test complex nested structures with mixed types roundtrip correctly."""
    with tempfile.TemporaryDirectory() as temp_dir:
        storage = FileCheckpointStorage(temp_dir)

        # Create complex nested structure mixing JSON-native and non-native types
        complex_state = {
            "level1": {
                "level2": {
                    "level3": {
                        "deep_string": "hello",
                        "deep_int": 123,
                        "deep_datetime": datetime(2025, 1, 1, tzinfo=timezone.utc),
                        "deep_tuple": (1, 2, 3),
                    }
                },
                "list_of_dicts": [
                    {"a": 1, "b": datetime(2025, 2, 1, tzinfo=timezone.utc)},
                    {"c": 2, "d": (4, 5, 6)},
                ],
            },
            "mixed_list": [
                "string",
                42,
                3.14,
                True,
                None,
                datetime(2025, 3, 1, tzinfo=timezone.utc),
                (7, 8, 9),
            ],
        }

        checkpoint = WorkflowCheckpoint(
            workflow_name="test-workflow",
            graph_signature_hash="test-hash",
            state=complex_state,
        )

        await storage.save(checkpoint)
        loaded = await storage.load(checkpoint.checkpoint_id)

        # Verify deep nested values
        assert loaded.state["level1"]["level2"]["level3"]["deep_string"] == "hello"
        assert loaded.state["level1"]["level2"]["level3"]["deep_int"] == 123
        assert loaded.state["level1"]["level2"]["level3"]["deep_datetime"] == datetime(2025, 1, 1, tzinfo=timezone.utc)
        # Tuples preserve their type through roundtrip
        assert loaded.state["level1"]["level2"]["level3"]["deep_tuple"] == (1, 2, 3)

        # Verify list of dicts
        assert loaded.state["level1"]["list_of_dicts"][0]["a"] == 1
        assert loaded.state["level1"]["list_of_dicts"][0]["b"] == datetime(2025, 2, 1, tzinfo=timezone.utc)
        # Tuples preserve their type through roundtrip
        assert loaded.state["level1"]["list_of_dicts"][1]["d"] == (4, 5, 6)

        # Verify mixed list with correct types
        assert loaded.state["mixed_list"][0] == "string"
        assert loaded.state["mixed_list"][1] == 42
        assert loaded.state["mixed_list"][5] == datetime(2025, 3, 1, tzinfo=timezone.utc)
        # Tuples preserve their type through roundtrip
        assert loaded.state["mixed_list"][6] == (7, 8, 9)
        assert isinstance(loaded.state["mixed_list"][6], tuple)


async def test_file_checkpoint_storage_roundtrip_messages_with_complex_data():
    """Test that messages dict with Message objects roundtrips correctly."""
    with tempfile.TemporaryDirectory() as temp_dir:
        storage = FileCheckpointStorage(temp_dir)

        msg1 = WorkflowMessage(
            data={"text": "hello", "timestamp": datetime(2025, 1, 1, tzinfo=timezone.utc)},
            source_id="source",
            target_id="target",
        )
        msg2 = WorkflowMessage(
            data=(1, 2, 3),
            source_id="s2",
            target_id=None,
        )
        msg3 = WorkflowMessage(
            data="simple string",
            source_id="s3",
            target_id="t3",
        )

        messages = {
            "executor1": [msg1, msg2],
            "executor2": [msg3],
        }

        checkpoint = WorkflowCheckpoint(
            workflow_name="test-workflow",
            graph_signature_hash="test-hash",
            messages=messages,
        )

        await storage.save(checkpoint)
        loaded = await storage.load(checkpoint.checkpoint_id)

        # Verify messages structure and types
        assert len(loaded.messages["executor1"]) == 2
        loaded_msg1 = loaded.messages["executor1"][0]
        loaded_msg2 = loaded.messages["executor1"][1]
        loaded_msg3 = loaded.messages["executor2"][0]

        # Verify WorkflowMessage type is preserved
        assert isinstance(loaded_msg1, WorkflowMessage)
        assert isinstance(loaded_msg2, WorkflowMessage)
        assert isinstance(loaded_msg3, WorkflowMessage)

        # Verify WorkflowMessage fields
        assert loaded_msg1.data["text"] == "hello"
        assert loaded_msg1.data["timestamp"] == datetime(2025, 1, 1, tzinfo=timezone.utc)
        assert loaded_msg1.source_id == "source"
        assert loaded_msg1.target_id == "target"

        assert loaded_msg2.data == (1, 2, 3)
        assert isinstance(loaded_msg2.data, tuple)
        assert loaded_msg2.source_id == "s2"
        assert loaded_msg2.target_id is None

        assert loaded_msg3.data == "simple string"
        assert loaded_msg3.source_id == "s3"
        assert loaded_msg3.target_id == "t3"


async def test_file_checkpoint_storage_roundtrip_pending_request_info_events():
    """Test that pending_request_info_events with WorkflowEvent objects roundtrip correctly."""
    with tempfile.TemporaryDirectory() as temp_dir:
        storage = FileCheckpointStorage(
            temp_dir,
            allowed_checkpoint_types=["tests.workflow.test_checkpoint:_TestToolApprovalRequest"],
        )

        # Create request_info events using the proper WorkflowEvent factory
        event1 = WorkflowEvent.request_info(
            request_id="req123",
            source_executor_id="executor1",
            request_data="What is your name?",
            response_type=str,
        )
        event2 = WorkflowEvent.request_info(
            request_id="req456",
            source_executor_id="executor2",
            request_data=_TestToolApprovalRequest(
                tool_name="search",
                arguments={"query": "test"},
                timestamp=datetime(2025, 1, 1, tzinfo=timezone.utc),
            ),
            response_type=bool,
        )

        pending_events = {
            "req123": event1,
            "req456": event2,
        }

        checkpoint = WorkflowCheckpoint(
            workflow_name="test-workflow",
            graph_signature_hash="test-hash",
            pending_request_info_events=pending_events,
        )

        await storage.save(checkpoint)
        loaded = await storage.load(checkpoint.checkpoint_id)

        # Verify WorkflowEvent type is preserved
        loaded_event1 = loaded.pending_request_info_events["req123"]
        loaded_event2 = loaded.pending_request_info_events["req456"]

        assert isinstance(loaded_event1, WorkflowEvent)
        assert isinstance(loaded_event2, WorkflowEvent)

        # Verify event1 fields
        assert loaded_event1.type == "request_info"
        assert loaded_event1.request_id == "req123"
        assert loaded_event1.source_executor_id == "executor1"
        assert loaded_event1.data == "What is your name?"
        assert loaded_event1.response_type is str

        # Verify event2 fields with complex data
        assert loaded_event2.type == "request_info"
        assert loaded_event2.request_id == "req456"
        assert loaded_event2.source_executor_id == "executor2"
        assert isinstance(loaded_event2.data, _TestToolApprovalRequest)
        assert loaded_event2.data.tool_name == "search"
        assert loaded_event2.data.arguments == {"query": "test"}
        assert loaded_event2.data.timestamp == datetime(2025, 1, 1, tzinfo=timezone.utc)
        assert loaded_event2.response_type is bool


async def test_file_checkpoint_storage_roundtrip_full_checkpoint():
    """Test complete WorkflowCheckpoint roundtrip with all fields populated using proper types."""
    with tempfile.TemporaryDirectory() as temp_dir:
        storage = FileCheckpointStorage(
            temp_dir,
            allowed_checkpoint_types=[
                "tests.workflow.test_checkpoint:_TestApprovalRequest",
                "tests.workflow.test_checkpoint:_TestExecutorState",
            ],
        )

        # Create proper WorkflowMessage objects
        msg1 = WorkflowMessage(data="msg1", source_id="s", target_id="t")
        msg2 = WorkflowMessage(data=datetime(2025, 1, 1, tzinfo=timezone.utc), source_id="a", target_id="b")

        # Create proper WorkflowEvent for pending request
        pending_event = WorkflowEvent.request_info(
            request_id="req1",
            source_executor_id="exec1",
            request_data=_TestApprovalRequest(action="approve", params=(1, 2, 3)),
            response_type=bool,
        )

        checkpoint = WorkflowCheckpoint(
            checkpoint_id="full-test-checkpoint",
            workflow_name="comprehensive-test",
            graph_signature_hash="hash-abc123",
            previous_checkpoint_id="previous-checkpoint-id",
            timestamp=datetime(2025, 6, 15, 12, 0, 0, tzinfo=timezone.utc).isoformat(),
            messages={
                "exec1": [msg1],
                "exec2": [msg2],
            },
            state={
                "user_data": {"name": "test", "created": datetime(2025, 1, 1, tzinfo=timezone.utc)},
                "_executor_state": {
                    "exec1": _TestExecutorState(counter=5, history=["a", "b", "c"]),
                },
            },
            pending_request_info_events={
                "req1": pending_event,
            },
            iteration_count=10,
            metadata={
                "superstep": 5,
                "started_at": datetime(2025, 6, 15, 11, 0, 0, tzinfo=timezone.utc),
            },
            version="1.0",
        )

        await storage.save(checkpoint)
        loaded = await storage.load(checkpoint.checkpoint_id)

        # Verify all scalar fields
        assert loaded.checkpoint_id == checkpoint.checkpoint_id
        assert loaded.workflow_name == checkpoint.workflow_name
        assert loaded.graph_signature_hash == checkpoint.graph_signature_hash
        assert loaded.previous_checkpoint_id == checkpoint.previous_checkpoint_id
        assert loaded.timestamp == checkpoint.timestamp
        assert loaded.iteration_count == checkpoint.iteration_count
        assert loaded.version == checkpoint.version

        # Verify complex nested state data
        assert loaded.state["user_data"]["created"] == datetime(2025, 1, 1, tzinfo=timezone.utc)
        assert loaded.state["_executor_state"]["exec1"].counter == 5
        assert loaded.state["_executor_state"]["exec1"].history == ["a", "b", "c"]
        assert isinstance(loaded.state["_executor_state"]["exec1"], _TestExecutorState)

        # Verify messages are proper Message objects
        loaded_msg1 = loaded.messages["exec1"][0]
        loaded_msg2 = loaded.messages["exec2"][0]
        assert isinstance(loaded_msg1, WorkflowMessage)
        assert isinstance(loaded_msg2, WorkflowMessage)
        assert loaded_msg1.data == "msg1"
        assert loaded_msg1.source_id == "s"
        assert loaded_msg2.data == datetime(2025, 1, 1, tzinfo=timezone.utc)

        # Verify pending events are proper WorkflowEvent objects
        loaded_event = loaded.pending_request_info_events["req1"]
        assert isinstance(loaded_event, WorkflowEvent)
        assert loaded_event.type == "request_info"
        assert loaded_event.request_id == "req1"
        assert isinstance(loaded_event.data, _TestApprovalRequest)
        assert loaded_event.data.params == (1, 2, 3)

        # Verify metadata
        assert loaded.metadata["superstep"] == 5
        assert loaded.metadata["started_at"] == datetime(2025, 6, 15, 11, 0, 0, tzinfo=timezone.utc)


async def test_file_checkpoint_storage_roundtrip_bytes():
    """Test that bytes objects roundtrip correctly via pickle encoding."""
    with tempfile.TemporaryDirectory() as temp_dir:
        storage = FileCheckpointStorage(temp_dir)

        binary_data = b"\x00\x01\x02\xff\xfe\xfd"
        unicode_bytes = "Hello 世界".encode()

        checkpoint = WorkflowCheckpoint(
            workflow_name="test-workflow",
            graph_signature_hash="test-hash",
            state={
                "binary_data": binary_data,
                "unicode_bytes": unicode_bytes,
                "nested": {"inner_bytes": binary_data},
            },
        )

        await storage.save(checkpoint)
        loaded = await storage.load(checkpoint.checkpoint_id)

        assert loaded.state["binary_data"] == binary_data
        assert loaded.state["unicode_bytes"] == unicode_bytes
        assert loaded.state["nested"]["inner_bytes"] == binary_data
        assert isinstance(loaded.state["binary_data"], bytes)


async def test_file_checkpoint_storage_roundtrip_empty_collections():
    """Test that empty collections roundtrip correctly."""
    with tempfile.TemporaryDirectory() as temp_dir:
        storage = FileCheckpointStorage(temp_dir)

        checkpoint = WorkflowCheckpoint(
            workflow_name="test-workflow",
            graph_signature_hash="test-hash",
            state={
                "empty_dict": {},
                "empty_list": [],
                "empty_tuple": (),
                "nested_empty": {"inner_dict": {}, "inner_list": []},
            },
            messages={},
            pending_request_info_events={},
        )

        await storage.save(checkpoint)
        loaded = await storage.load(checkpoint.checkpoint_id)

        assert loaded.state["empty_dict"] == {}
        assert loaded.state["empty_list"] == []
        # Empty tuples preserve their type through roundtrip
        assert loaded.state["empty_tuple"] == ()
        assert isinstance(loaded.state["empty_tuple"], tuple)
        assert loaded.state["nested_empty"]["inner_dict"] == {}
        assert loaded.messages == {}
        assert loaded.pending_request_info_events == {}


# endregion
