import logging
from typing import Any

import pytest
from langchain_core.runnables import RunnableConfig
from pydantic import BaseModel

from langgraph.checkpoint.base import (
    Checkpoint,
    CheckpointMetadata,
    create_checkpoint,
    empty_checkpoint,
)
from langgraph.checkpoint.memory import InMemorySaver
from langgraph.checkpoint.serde.jsonplus import (
    JsonPlusSerializer,
    _warned_blocked_types,
    _warned_unregistered_types,
)


class MemoryPydantic(BaseModel):
    foo: str


@pytest.fixture(autouse=True)
def _reset_warned_types() -> None:
    # Warning dedup state is process-global; reset per-test so each case sees
    # a fresh slate and assertions about warning emission are stable.
    _warned_unregistered_types.clear()
    _warned_blocked_types.clear()


class TestMemorySaver:
    @pytest.fixture(autouse=True)
    def setup(self) -> None:
        self.memory_saver = InMemorySaver()

        # objects for test setup
        self.config_1: RunnableConfig = {
            "configurable": {
                "thread_id": "thread-1",
                "checkpoint_ns": "",
                "checkpoint_id": "1",
            }
        }
        self.config_2: RunnableConfig = {
            "configurable": {
                "thread_id": "thread-2",
                "checkpoint_ns": "",
                "checkpoint_id": "2",
            }
        }
        self.config_3: RunnableConfig = {
            "configurable": {
                "thread_id": "thread-2",
                "checkpoint_id": "2-inner",
                "checkpoint_ns": "inner",
            }
        }

        self.chkpnt_1: Checkpoint = empty_checkpoint()
        self.chkpnt_2: Checkpoint = create_checkpoint(self.chkpnt_1, {}, 1)
        self.chkpnt_3: Checkpoint = empty_checkpoint()

        self.metadata_1: CheckpointMetadata = {
            "source": "input",
            "step": 2,
            "writes": {},
            "score": 1,
        }
        self.metadata_2: CheckpointMetadata = {
            "source": "loop",
            "step": 1,
            "writes": {"foo": "bar"},
            "score": None,
        }
        self.metadata_3: CheckpointMetadata = {}

    def test_combined_metadata(self) -> None:
        config: RunnableConfig = {
            "configurable": {
                "thread_id": "thread-2",
                "checkpoint_ns": "",
                "__super_private_key": "super_private_value",
            },
            "metadata": {"run_id": "my_run_id"},
        }
        self.memory_saver.put(
            config, self.chkpnt_2, self.metadata_2, self.chkpnt_2["channel_versions"]
        )
        checkpoint = self.memory_saver.get_tuple(config)
        assert checkpoint is not None
        assert checkpoint.metadata == {
            **self.metadata_2,
            "run_id": "my_run_id",
        }

    async def test_search(self) -> None:
        # set up test
        # save checkpoints
        self.memory_saver.put(
            self.config_1,
            self.chkpnt_1,
            self.metadata_1,
            self.chkpnt_1["channel_versions"],
        )
        self.memory_saver.put(
            self.config_2,
            self.chkpnt_2,
            self.metadata_2,
            self.chkpnt_2["channel_versions"],
        )
        self.memory_saver.put(
            self.config_3,
            self.chkpnt_3,
            self.metadata_3,
            self.chkpnt_3["channel_versions"],
        )

        # call method / assertions
        query_1 = {"source": "input"}  # search by 1 key
        query_2 = {
            "step": 1,
            "writes": {"foo": "bar"},
        }  # search by multiple keys
        query_3: dict[str, Any] = {}  # search by no keys, return all checkpoints
        query_4 = {"source": "update", "step": 1}  # no match

        search_results_1 = list(self.memory_saver.list(None, filter=query_1))
        assert len(search_results_1) == 1
        assert search_results_1[0].metadata == self.metadata_1

        search_results_2 = list(self.memory_saver.list(None, filter=query_2))
        assert len(search_results_2) == 1
        assert search_results_2[0].metadata == self.metadata_2

        search_results_3 = list(self.memory_saver.list(None, filter=query_3))
        assert len(search_results_3) == 3

        search_results_4 = list(self.memory_saver.list(None, filter=query_4))
        assert len(search_results_4) == 0

        # search by config (defaults to checkpoints across all namespaces)
        search_results_5 = list(
            self.memory_saver.list({"configurable": {"thread_id": "thread-2"}})
        )
        assert len(search_results_5) == 2
        assert {
            search_results_5[0].config["configurable"]["checkpoint_ns"],
            search_results_5[1].config["configurable"]["checkpoint_ns"],
        } == {"", "inner"}

        # TODO: test before and limit params

    async def test_asearch(self) -> None:
        # set up test
        # save checkpoints
        self.memory_saver.put(
            self.config_1,
            self.chkpnt_1,
            self.metadata_1,
            self.chkpnt_1["channel_versions"],
        )
        self.memory_saver.put(
            self.config_2,
            self.chkpnt_2,
            self.metadata_2,
            self.chkpnt_2["channel_versions"],
        )
        self.memory_saver.put(
            self.config_3,
            self.chkpnt_3,
            self.metadata_3,
            self.chkpnt_3["channel_versions"],
        )

        # call method / assertions
        query_1 = {"source": "input"}  # search by 1 key
        query_2 = {
            "step": 1,
            "writes": {"foo": "bar"},
        }  # search by multiple keys
        query_3: dict[str, Any] = {}  # search by no keys, return all checkpoints
        query_4 = {"source": "update", "step": 1}  # no match

        search_results_1 = [
            c async for c in self.memory_saver.alist(None, filter=query_1)
        ]
        assert len(search_results_1) == 1
        assert search_results_1[0].metadata == self.metadata_1

        search_results_2 = [
            c async for c in self.memory_saver.alist(None, filter=query_2)
        ]
        assert len(search_results_2) == 1
        assert search_results_2[0].metadata == self.metadata_2

        search_results_3 = [
            c async for c in self.memory_saver.alist(None, filter=query_3)
        ]
        assert len(search_results_3) == 3

        search_results_4 = [
            c async for c in self.memory_saver.alist(None, filter=query_4)
        ]
        assert len(search_results_4) == 0


async def test_memory_saver() -> None:
    from langgraph.checkpoint.memory import InMemorySaver

    memory_saver = InMemorySaver()
    assert isinstance(memory_saver, InMemorySaver)

    async with memory_saver as async_memory_saver:
        assert async_memory_saver is memory_saver

    with memory_saver as sync_memory_saver:
        assert sync_memory_saver is memory_saver


def test_memory_saver_warns_on_unregistered_msgpack(
    caplog: pytest.LogCaptureFixture,
) -> None:
    serde = JsonPlusSerializer()
    memory_saver = InMemorySaver(serde=serde)
    obj = MemoryPydantic(foo="bar")

    checkpoint = empty_checkpoint()
    checkpoint["channel_values"] = {"foo": obj}
    checkpoint["channel_versions"] = {"foo": 1}

    config: RunnableConfig = {
        "configurable": {"thread_id": "thread-1", "checkpoint_ns": ""}
    }

    caplog.set_level(logging.WARNING, logger="langgraph.checkpoint.serde.jsonplus")
    new_config = memory_saver.put(config, checkpoint, {}, {"foo": 1})
    result = memory_saver.get_tuple(new_config)

    assert result is not None
    assert "unregistered type" in caplog.text.lower()
    assert result.checkpoint["channel_values"]["foo"] == obj


def test_memory_saver_allowlist_silences_warning(
    caplog: pytest.LogCaptureFixture,
) -> None:
    serde = JsonPlusSerializer(
        allowed_msgpack_modules=[("tests.test_memory", "MemoryPydantic")]
    )
    memory_saver = InMemorySaver(serde=serde)
    obj = MemoryPydantic(foo="bar")

    checkpoint = empty_checkpoint()
    checkpoint["channel_values"] = {"foo": obj}
    checkpoint["channel_versions"] = {"foo": 1}

    config: RunnableConfig = {
        "configurable": {"thread_id": "thread-1", "checkpoint_ns": ""}
    }

    caplog.set_level(logging.WARNING, logger="langgraph.checkpoint.serde.jsonplus")
    new_config = memory_saver.put(config, checkpoint, {}, {"foo": 1})
    result = memory_saver.get_tuple(new_config)

    assert result is not None
    assert "unregistered type" not in caplog.text.lower()
    assert result.checkpoint["channel_values"]["foo"] == obj


def test_memory_saver_strict_blocks_unregistered(
    caplog: pytest.LogCaptureFixture,
) -> None:
    serde = JsonPlusSerializer(allowed_msgpack_modules=None)
    memory_saver = InMemorySaver(serde=serde)
    obj = MemoryPydantic(foo="bar")

    checkpoint = empty_checkpoint()
    checkpoint["channel_values"] = {"foo": obj}
    checkpoint["channel_versions"] = {"foo": 1}

    config: RunnableConfig = {
        "configurable": {"thread_id": "thread-1", "checkpoint_ns": ""}
    }

    caplog.set_level(logging.WARNING, logger="langgraph.checkpoint.serde.jsonplus")
    new_config = memory_saver.put(config, checkpoint, {}, {"foo": 1})
    result = memory_saver.get_tuple(new_config)

    assert result is not None
    assert "blocked" in caplog.text.lower()
    expected = obj.model_dump() if hasattr(obj, "model_dump") else obj.dict()
    assert result.checkpoint["channel_values"]["foo"] == expected


def test_memory_saver_with_allowlist_proxy_isolated() -> None:
    serde = JsonPlusSerializer(allowed_msgpack_modules=None)
    memory_saver = InMemorySaver(serde=serde)
    proxy = memory_saver.with_allowlist([("tests.test_memory", "MemoryPydantic")])

    obj = MemoryPydantic(foo="bar")

    checkpoint = empty_checkpoint()
    checkpoint["channel_values"] = {"foo": obj}
    checkpoint["channel_versions"] = {"foo": 1}

    config: RunnableConfig = {
        "configurable": {"thread_id": "thread-1", "checkpoint_ns": ""}
    }

    new_config = proxy.put(config, checkpoint, {}, {"foo": 1})

    proxied = proxy.get_tuple(new_config)
    assert proxied is not None
    assert proxied.checkpoint["channel_values"]["foo"] == obj

    direct = memory_saver.get_tuple(new_config)
    assert direct is not None
    expected = obj.model_dump() if hasattr(obj, "model_dump") else obj.dict()
    assert direct.checkpoint["channel_values"]["foo"] == expected


class TestInMemorySaverDeltaChannel:
    def test_load_blobs_returns_sentinel_for_delta_channel(self) -> None:
        """_load_blobs returns DeltaChannelSentinel for delta channels (reconstruction deferred)."""
        from langgraph.checkpoint.base import (
            DeltaChannelSentinel,
            empty_checkpoint,
        )

        saver = InMemorySaver()
        serde = JsonPlusSerializer()

        thread_id, ns, channel = "t1", "", "messages"
        v1 = "00000000000000000000000000000001.0000000000000000"

        sentinel = DeltaChannelSentinel()
        saver.blobs[(thread_id, ns, channel, v1)] = serde.dumps_typed(sentinel)

        cp1 = empty_checkpoint()
        cp1["id"] = "cp1"
        cp1["channel_versions"][channel] = v1
        saver.storage[thread_id][ns] = {
            "cp1": (serde.dumps_typed(cp1), serde.dumps_typed({}), None),
        }

        result = saver._load_blobs(thread_id, ns, {channel: v1})
        assert channel in result
        assert isinstance(result[channel], DeltaChannelSentinel)

    def test_get_channel_writes_collects_writes(self) -> None:
        """get_channel_writes collects per-step writes oldest→newest."""
        from langgraph.checkpoint.base import empty_checkpoint

        saver = InMemorySaver()
        serde = JsonPlusSerializer()

        thread_id, ns, channel = "t1", "", "messages"

        cp1 = empty_checkpoint()
        cp1["id"] = "cp1"
        cp2 = empty_checkpoint()
        cp2["id"] = "cp2"
        saver.storage[thread_id][ns] = {
            "cp1": (serde.dumps_typed(cp1), serde.dumps_typed({}), None),
            "cp2": (serde.dumps_typed(cp2), serde.dumps_typed({}), "cp1"),
        }
        # cp1 has a write for channel
        saver.writes[(thread_id, ns, "cp1")][("task1", 0)] = (
            "task1",
            channel,
            serde.dumps_typed({"content": "hi"}),
            "",
        )
        # cp2 has a write for channel
        saver.writes[(thread_id, ns, "cp2")][("task2", 0)] = (
            "task2",
            channel,
            serde.dumps_typed({"content": "bye"}),
            "",
        )

        config: RunnableConfig = {
            "configurable": {
                "thread_id": thread_id,
                "checkpoint_ns": ns,
                "checkpoint_id": "cp2",
            }
        }
        result = saver.get_channel_writes(config, channel)
        assert result == [{"content": "hi"}, {"content": "bye"}]