# Copyright (c) 2026, AG2ai, Inc., AG2ai open-source projects maintainers and core contributors
#
# SPDX-License-Identifier: Apache-2.0

"""Tests for the shared event-serialization layer."""

import datetime
from dataclasses import dataclass
from enum import Enum
from uuid import UUID, uuid4

import pytest
from pydantic import BaseModel

from ag2.events import BaseEvent, BinaryInput, BinaryType, ModelMessage, ModelRequest, ToolCallEvent
from ag2.events._serialization import (
    deserialize_value,
    import_event_class,
    serialize_value,
)


class _Outer:
    """Container for a nested event class used by the import test."""

    class NestedEvent(BaseEvent):
        value: str


class TestImportEventClass:
    def test_resolves_module_level_event(self) -> None:
        cls = import_event_class(f"{ModelMessage.__module__}.{ModelMessage.__qualname__}")
        assert cls is ModelMessage

    def test_resolves_nested_event(self) -> None:
        qualname = f"{_Outer.NestedEvent.__module__}.{_Outer.NestedEvent.__qualname__}"
        cls = import_event_class(qualname)
        assert cls is _Outer.NestedEvent

    def test_returns_none_for_missing_dotted_path(self) -> None:
        assert import_event_class("nonexistent.module.FakeEvent") is None

    def test_returns_none_for_non_event_class(self) -> None:
        assert import_event_class("builtins.int") is None


def _round_trip(value: object) -> object:
    return deserialize_value(serialize_value(value))


class TestPrimitives:
    @pytest.mark.parametrize("value", [None, "hello", 42, 3.14, True, False])
    def test_primitive_round_trip(self, value: object) -> None:
        assert _round_trip(value) == value


class TestBytes:
    def test_bytes_round_trip(self) -> None:
        raw = b"\x12\x34\x00\x99\xff\xab"
        result = _round_trip(raw)
        assert result == raw
        assert isinstance(result, bytes)

    def test_bytearray_round_trip(self) -> None:
        raw = bytearray(b"\x01\x02\x03")
        # bytearray serializes as bytes — round-trip yields bytes (acceptable)
        result = _round_trip(raw)
        assert result == bytes(raw)

    def test_bytes_inside_dict(self) -> None:
        payload = {"signature": b"\x12\x34", "name": "weather"}
        assert _round_trip(payload) == payload

    def test_bytes_inside_list(self) -> None:
        payload = [b"\x01", b"\x02"]
        assert _round_trip(payload) == payload


class TestUUID:
    def test_uuid_round_trip(self) -> None:
        u = uuid4()
        result = _round_trip(u)
        assert result == u
        assert isinstance(result, UUID)


class _SamplePriority(Enum):
    LOW = 1
    HIGH = 2


class TestEnum:
    def test_str_enum_round_trip_preserves_identity(self) -> None:
        # str-enums compare equal to their value, so assert identity, not equality:
        # a degraded "image" string would pass `==` but fail `is` (see #3084).
        result = _round_trip(BinaryType.IMAGE)
        assert result is BinaryType.IMAGE

    def test_plain_enum_round_trip(self) -> None:
        result = _round_trip(_SamplePriority.HIGH)
        assert result is _SamplePriority.HIGH

    def test_enum_inside_dict(self) -> None:
        result = _round_trip({"kind": BinaryType.DOCUMENT})
        assert result["kind"] is BinaryType.DOCUMENT


@dataclass
class _SamplePoint:
    x: int
    y: int
    label: str = "origin"


class TestDataclass:
    def test_dataclass_round_trip(self) -> None:
        point = _SamplePoint(1, 2, "p")
        result = _round_trip(point)
        assert result == point
        assert isinstance(result, _SamplePoint)


class _SamplePydanticModel(BaseModel):
    name: str
    count: int
    payload: bytes | None = None


class TestPydantic:
    def test_pydantic_round_trip(self) -> None:
        model = _SamplePydanticModel(name="hello", count=3)
        result = _round_trip(model)
        assert result == model
        assert isinstance(result, _SamplePydanticModel)

    def test_pydantic_with_bytes_field_round_trip(self) -> None:
        """SDK objects (e.g. OpenAI ImageGenerationCall) embed bytes; pydantic mode='json' handles them."""
        model = _SamplePydanticModel(name="img", count=1, payload=b"\xff\xd8\xff")
        result = _round_trip(model)
        assert result == model


class TestUnknownTypePassthrough:
    """Unknown types pass through ``serialize_value`` unchanged.

    The wire-format boundary (e.g. ``json.dumps`` in the Redis serializer)
    is what surfaces a ``TypeError`` if the value can't be encoded — keeping
    ``serialize_value`` itself permissive preserves backwards compatibility
    for callers like ``BaseEvent.to_dict`` that pair it with their own
    JSON fallback (e.g. ``json.dumps(..., default=str)``).
    """

    def test_unknown_type_passes_through(self) -> None:
        when = datetime.datetime(2026, 4, 29)
        assert serialize_value(when) is when

    def test_unknown_type_inside_dict_passes_through(self) -> None:
        when = datetime.datetime(2026, 4, 29)
        assert serialize_value({"when": when}) == {"when": when}


class TestEventRoundTrip:
    def test_simple_event(self) -> None:
        event = ModelMessage("hello world")
        result = _round_trip(event)
        assert isinstance(result, ModelMessage)
        assert result.content == "hello world"

    def test_tool_call_event(self) -> None:
        event = ToolCallEvent(id="abc", name="search", arguments='{"q": "ag2"}')
        result = _round_trip(event)
        assert isinstance(result, ToolCallEvent)
        assert result.name == "search"
        assert result.arguments == '{"q": "ag2"}'

    def test_binary_input_kind_survives_round_trip(self) -> None:
        """``BinaryInput.kind`` must come back as the enum, not its string value (#3084)."""
        event = ModelRequest([BinaryInput(b"\x89PNG", media_type="image/png", kind=BinaryType.IMAGE)])
        result = _round_trip(event)
        assert isinstance(result, ModelRequest)
        part = result.parts[0]
        assert isinstance(part, BinaryInput)
        assert part.kind is BinaryType.IMAGE
        assert part.data == b"\x89PNG"