"""Contract tests for get_activity MCP tool."""

from pathlib import Path

import pytest

from xer_mcp.db import db


@pytest.fixture(autouse=True)
def setup_db():
    """Initialize and clear database for each test."""
    db.initialize()
    yield
    db.clear()


class TestGetActivityContract:
    """Contract tests verifying get_activity tool interface matches spec."""

    async def test_get_activity_returns_details(self, sample_xer_single_project: Path) -> None:
        """get_activity returns complete activity details."""
        from xer_mcp.tools.get_activity import get_activity
        from xer_mcp.tools.load_xer import load_xer

        await load_xer(file_path=str(sample_xer_single_project))

        result = await get_activity(activity_id="2002")

        assert result["task_id"] == "2002"
        assert result["task_code"] == "A1010"
        assert result["task_name"] == "Site Preparation"
        assert result["task_type"] == "TT_Task"
        assert "target_start_date" in result
        assert "target_end_date" in result
        assert "wbs_id" in result
        assert "predecessor_count" in result
        assert "successor_count" in result

    async def test_get_activity_includes_wbs_name(self, sample_xer_single_project: Path) -> None:
        """get_activity includes WBS name from lookup."""
        from xer_mcp.tools.get_activity import get_activity
        from xer_mcp.tools.load_xer import load_xer

        await load_xer(file_path=str(sample_xer_single_project))

        result = await get_activity(activity_id="2002")

        assert "wbs_name" in result

    async def test_get_activity_includes_relationship_counts(
        self, sample_xer_single_project: Path
    ) -> None:
        """get_activity includes predecessor and successor counts."""
        from xer_mcp.tools.get_activity import get_activity
        from xer_mcp.tools.load_xer import load_xer

        await load_xer(file_path=str(sample_xer_single_project))

        # A1010 (2002) has 1 predecessor (A1000) and 2 successors (A1020, A1030)
        result = await get_activity(activity_id="2002")

        assert result["predecessor_count"] == 1
        assert result["successor_count"] == 2

    async def test_get_activity_not_found_returns_error(
        self, sample_xer_single_project: Path
    ) -> None:
        """get_activity with invalid ID returns ACTIVITY_NOT_FOUND error."""
        from xer_mcp.tools.get_activity import get_activity
        from xer_mcp.tools.load_xer import load_xer

        await load_xer(file_path=str(sample_xer_single_project))

        result = await get_activity(activity_id="nonexistent")

        assert "error" in result
        assert result["error"]["code"] == "ACTIVITY_NOT_FOUND"

    async def test_get_activity_no_file_loaded_returns_error(self) -> None:
        """get_activity without loaded file returns NO_FILE_LOADED error."""
        from xer_mcp.server import set_file_loaded
        from xer_mcp.tools.get_activity import get_activity

        set_file_loaded(False)
        result = await get_activity(activity_id="2002")

        assert "error" in result
        assert result["error"]["code"] == "NO_FILE_LOADED"