"""Registry lazy-loading performance tests (WP-0001 T06)."""

from __future__ import annotations

from pathlib import Path
from unittest.mock import patch

import pytest

from kaizen_agentic.installer import AgentInstaller, InstallationConfig
from kaizen_agentic.registry import AgentDefinition, AgentRegistry


def _write_agent(path: Path, name: str) -> None:
    path.write_text(
        f"""---
name: {name}
description: Agent {name}
category: testing
---

# {name}
""",
        encoding="utf-8",
    )


@pytest.fixture
def large_registry(tmp_path: Path) -> AgentRegistry:
    agents_dir = tmp_path / "agents"
    agents_dir.mkdir()
    for index in range(15):
        _write_agent(agents_dir / f"agent-agent-{index}.md", f"agent-{index}")
    _write_agent(agents_dir / "agent-tdd-workflow.md", "tdd-workflow")
    return AgentRegistry(agents_dir)


def test_registry_indexes_without_full_parse(large_registry: AgentRegistry):
    assert len(large_registry.agent_names()) == 16
    assert large_registry._agents == {}


def test_get_agent_loads_only_requested_agent(large_registry: AgentRegistry):
    with patch.object(
        AgentDefinition,
        "from_file",
        wraps=AgentDefinition.from_file,
    ) as mock_from_file:
        agent = large_registry.get_agent("tdd-workflow")

    assert agent is not None
    assert agent.name == "tdd-workflow"
    assert mock_from_file.call_count == 1


def test_install_single_agent_parses_minimal_subset(
    large_registry: AgentRegistry, tmp_path: Path
):
    installer = AgentInstaller(large_registry)
    project_dir = tmp_path / "project"

    with patch.object(
        AgentDefinition,
        "from_file",
        wraps=AgentDefinition.from_file,
    ) as mock_from_file:
        results = installer.install_agents(
            ["tdd-workflow"],
            InstallationConfig(
                target_dir=project_dir,
                create_backup=False,
                update_docs=False,
            ),
        )

    assert results["tdd-workflow"] == "INSTALLED"
    assert (project_dir / "agents" / "agent-tdd-workflow.md").exists()
    # resolve_dependencies loads only the target agent, not the full fleet
    assert mock_from_file.call_count == 1