"""Unit tests for app.replay.transformer."""

from __future__ import annotations

import pytest

pytestmark = pytest.mark.unit


def _make_row(messages: list[dict], metadata: dict | None = None) -> dict:
    """Helper to build a checkpoint row with the given messages."""
    return {
        "thread_id": "thread-abc",
        "checkpoint_id": "cp-001",
        "checkpoint": {"channel_values": {"messages": messages}},
        "metadata": metadata or {},
    }


class TestTransformCheckpoints:
    def test_empty_rows_returns_empty_list(self) -> None:
        from app.replay.transformer import transform_checkpoints

        result = transform_checkpoints([])
        assert result == []

    def test_human_message_produces_user_message_step(self) -> None:
        from app.replay.models import StepType
        from app.replay.transformer import transform_checkpoints

        rows = [_make_row([{"type": "human", "content": "Hello, I need help"}])]
        steps = transform_checkpoints(rows)
        assert len(steps) == 1
        assert steps[0].type == StepType.user_message
        assert steps[0].content == "Hello, I need help"
        assert steps[0].step == 1

    def test_ai_message_with_content_produces_agent_response(self) -> None:
        from app.replay.models import StepType
        from app.replay.transformer import transform_checkpoints

        rows = [
            _make_row(
                [{"type": "ai", "content": "I can help you with that.", "tool_calls": []}],
                metadata={"writes": {"some_agent": "response"}},
            )
        ]
        steps = transform_checkpoints(rows)
        assert len(steps) == 1
        assert steps[0].type == StepType.agent_response
        assert steps[0].content == "I can help you with that."

    def test_ai_message_with_tool_calls_produces_tool_call_step(self) -> None:
        from app.replay.models import StepType
        from app.replay.transformer import transform_checkpoints

        rows = [
            _make_row(
                [
                    {
                        "type": "ai",
                        "content": "",
                        "tool_calls": [
                            {
                                "name": "get_order_status",
                                "args": {"order_id": "ORD-123"},
                                "id": "call_abc",
                            }
                        ],
                    }
                ]
            )
        ]
        steps = transform_checkpoints(rows)
        assert len(steps) == 1
        assert steps[0].type == StepType.tool_call
        assert steps[0].tool == "get_order_status"
        assert steps[0].params == {"order_id": "ORD-123"}

    def test_tool_message_produces_tool_result_step(self) -> None:
        from app.replay.models import StepType
        from app.replay.transformer import transform_checkpoints

        rows = [
            _make_row(
                [
                    {
                        "type": "tool",
                        "content": '{"status": "shipped"}',
                        "name": "get_order_status",
                    }
                ]
            )
        ]
        steps = transform_checkpoints(rows)
        assert len(steps) == 1
        assert steps[0].type == StepType.tool_result
        assert steps[0].tool == "get_order_status"

    def test_multiple_messages_sequential_steps(self) -> None:
        from app.replay.transformer import transform_checkpoints

        rows = [
            _make_row(
                [
                    {"type": "human", "content": "Help"},
                    {"type": "ai", "content": "Sure!", "tool_calls": []},
                ]
            )
        ]
        steps = transform_checkpoints(rows)
        assert len(steps) == 2
        assert steps[0].step == 1
        assert steps[1].step == 2

    def test_unknown_message_type_skipped(self) -> None:
        from app.replay.transformer import transform_checkpoints

        rows = [_make_row([{"type": "unknown_type", "content": "test"}])]
        steps = transform_checkpoints(rows)
        # Should not crash; unknown types may be skipped
        assert isinstance(steps, list)

    def test_row_missing_checkpoint_skipped(self) -> None:
        from app.replay.transformer import transform_checkpoints

        rows = [{"thread_id": "t1", "checkpoint_id": "cp1", "checkpoint": None, "metadata": {}}]
        steps = transform_checkpoints(rows)
        assert isinstance(steps, list)

    def test_row_missing_messages_key_skipped(self) -> None:
        from app.replay.transformer import transform_checkpoints

        rows = [{"thread_id": "t1", "checkpoint_id": "cp1", "checkpoint": {}, "metadata": {}}]
        steps = transform_checkpoints(rows)
        assert isinstance(steps, list)

    def test_multiple_rows_steps_are_continuous(self) -> None:
        from app.replay.transformer import transform_checkpoints

        rows = [
            _make_row([{"type": "human", "content": "Q1"}]),
            _make_row([{"type": "ai", "content": "A1", "tool_calls": []}]),
        ]
        steps = transform_checkpoints(rows)
        assert len(steps) == 2
        assert steps[0].step == 1
        assert steps[1].step == 2

    def test_timestamps_are_strings(self) -> None:
        from app.replay.transformer import transform_checkpoints

        rows = [_make_row([{"type": "human", "content": "Hi"}])]
        steps = transform_checkpoints(rows)
        assert isinstance(steps[0].timestamp, str)