"""Tests for project-scoped metrics storage (ADR-004)."""

from __future__ import annotations

import json
from datetime import datetime, timedelta, timezone
from pathlib import Path

import pytest

from kaizen_agentic.metrics import MetricsStore, DEFAULT_RETENTION_DAYS


def _old_timestamp(days: int) -> str:
    dt = datetime.now(timezone.utc) - timedelta(days=days)
    return dt.strftime("%Y-%m-%dT%H:%M:%SZ")


@pytest.fixture
def project_dir(tmp_path: Path) -> Path:
    root = tmp_path / "demo-project"
    root.mkdir()
    return root


class TestMetricsStore:
    def test_scaffold_creates_directory_and_empty_executions(self, project_dir: Path):
        store = MetricsStore(project_dir, "tdd-workflow")
        path = store.scaffold()

        assert path == project_dir / ".kaizen" / "metrics" / "tdd-workflow"
        assert store.executions_path.exists()
        assert store.executions_path.read_text() == ""

    def test_append_and_read_executions(self, project_dir: Path):
        store = MetricsStore(project_dir, "tdd-workflow")

        assert store.append({"success": True, "quality_score": 0.9}) is True
        assert store.append({"success": False, "execution_time_s": 12.5}) is True

        records = store.read_executions()
        assert len(records) == 2
        assert records[0]["agent"] == "tdd-workflow"
        assert records[0]["success"] is True
        assert "timestamp" in records[0]

    def test_idempotency_key_rejects_duplicate(self, project_dir: Path):
        store = MetricsStore(project_dir, "coach")

        assert store.append({"success": True}, idempotency_key="sess-1") is True
        assert store.append({"success": True}, idempotency_key="sess-1") is False
        assert len(store.read_executions()) == 1

    def test_write_summary_regenerates_summary_json(self, project_dir: Path):
        store = MetricsStore(project_dir, "tdd-workflow")
        store.append({"success": True, "quality_score": 0.8, "execution_time_s": 10})
        store.append({"success": True, "quality_score": 1.0, "execution_time_s": 20})

        summary = store.write_summary()

        assert summary["execution_count"] == 2
        assert summary["success_rate"] == 1.0
        assert summary["avg_quality_score"] == 0.9
        assert summary["avg_execution_time_s"] == 15.0
        assert store.summary_path.exists()
        on_disk = json.loads(store.summary_path.read_text())
        assert on_disk["execution_count"] == 2

    def test_prune_removes_expired_records(self, project_dir: Path):
        store = MetricsStore(project_dir, "tdd-workflow", retention_days=30)
        store.scaffold()

        old = {
            "timestamp": _old_timestamp(45),
            "agent": "tdd-workflow",
            "success": False,
        }
        recent = {
            "timestamp": _old_timestamp(1),
            "agent": "tdd-workflow",
            "success": True,
            "quality_score": 0.7,
        }
        with store.executions_path.open("w", encoding="utf-8") as handle:
            handle.write(json.dumps(old) + "\n")
            handle.write(json.dumps(recent) + "\n")

        removed = store.prune()

        assert removed == 1
        records = store.read_executions()
        assert len(records) == 1
        assert records[0]["success"] is True
        summary = store.read_summary()
        assert summary is not None
        assert summary["execution_count"] == 1

    def test_list_agents_with_metrics(self, project_dir: Path):
        MetricsStore(project_dir, "tdd-workflow").scaffold()
        MetricsStore(project_dir, "coach").append({"success": True})

        agents = MetricsStore.list_agents(project_dir)

        assert agents == ["coach", "tdd-workflow"]

    def test_default_retention_matches_adr(self):
        assert DEFAULT_RETENTION_DAYS == 180