"""Contract tests for list_milestones 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 TestListMilestonesContract:
    """Contract tests verifying list_milestones tool interface."""

    async def test_list_milestones_returns_milestone_activities(
        self, sample_xer_single_project: Path
    ) -> None:
        """list_milestones returns only milestone type activities."""
        from xer_mcp.tools.list_milestones import list_milestones
        from xer_mcp.tools.load_xer import load_xer

        await load_xer(file_path=str(sample_xer_single_project))

        result = await list_milestones()

        assert "milestones" in result
        assert len(result["milestones"]) == 2

    async def test_list_milestones_includes_expected_fields(
        self, sample_xer_single_project: Path
    ) -> None:
        """list_milestones returns milestones with required fields."""
        from xer_mcp.tools.list_milestones import list_milestones
        from xer_mcp.tools.load_xer import load_xer

        await load_xer(file_path=str(sample_xer_single_project))

        result = await list_milestones()

        milestone = result["milestones"][0]
        assert "task_id" in milestone
        assert "task_code" in milestone
        assert "task_name" in milestone
        assert "target_start_date" in milestone
        assert "target_end_date" in milestone

    async def test_list_milestones_returns_correct_activities(
        self, sample_xer_single_project: Path
    ) -> None:
        """list_milestones returns the expected milestone activities."""
        from xer_mcp.tools.list_milestones import list_milestones
        from xer_mcp.tools.load_xer import load_xer

        await load_xer(file_path=str(sample_xer_single_project))

        result = await list_milestones()

        milestone_names = [m["task_name"] for m in result["milestones"]]
        assert "Project Start" in milestone_names
        assert "Project Complete" in milestone_names

    async def test_list_milestones_empty_when_no_milestones(self, sample_xer_empty: Path) -> None:
        """list_milestones returns empty list when no milestones exist."""
        from xer_mcp.tools.list_milestones import list_milestones
        from xer_mcp.tools.load_xer import load_xer

        await load_xer(file_path=str(sample_xer_empty))

        result = await list_milestones()

        assert "milestones" in result
        assert len(result["milestones"]) == 0

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

        set_file_loaded(False)
        result = await list_milestones()

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