"""
Performance benchmarks for the ARF governance pipeline.

These tests measure the latency of key operations and assert that
they remain within the target thresholds for pilot readiness.

Targets (v4.3.2):
  - Full governance loop (single intent): p50 < 50 ms, p99 < 100 ms
  - Policy evaluation alone: p50 < 1 ms
  - Conjugate update: p50 < 0.1 ms
  - HealingIntent serialization: p50 < 5 ms
"""
import time
import pytest
import numpy as np
from unittest.mock import Mock, patch

from agentic_reliability_framework.core.governance.governance_loop import GovernanceLoop
from agentic_reliability_framework.core.governance.intents import (
    ProvisionResourceIntent,
    ResourceType,
)
from agentic_reliability_framework.core.governance.policies import PolicyEvaluator, allow_all
from agentic_reliability_framework.core.governance.cost_estimator import CostEstimator
from agentic_reliability_framework.core.governance.risk_engine import RiskEngine
from agentic_reliability_framework.core.governance.healing_intent import HealingIntent


# Number of warmup iterations and measured iterations
WARMUP = 10
MEASURED = 50


def _measure_latency(fn, *args, **kwargs):
    """Run fn MEASURED times after WARMUP warmups, return (p50, p99, p100) in seconds."""
    times = []
    for _ in range(WARMUP):
        fn(*args, **kwargs)
    for _ in range(MEASURED):
        t0 = time.perf_counter()
        fn(*args, **kwargs)
        times.append(time.perf_counter() - t0)
    arr = np.array(times) * 1000  # convert to milliseconds
    return np.percentile(arr, 50), np.percentile(arr, 99), arr.max()


@pytest.fixture(scope="module")
def sample_intent():
    return ProvisionResourceIntent(
        resource_type=ResourceType.VM,
        region="eastus",
        size="Standard_D2s_v3",
        requester="perf-test",
        environment="dev",
    )


@pytest.fixture(scope="module")
def governance_loop():
    return GovernanceLoop(
        policy_evaluator=PolicyEvaluator(allow_all()),
        cost_estimator=CostEstimator(),
        risk_engine=RiskEngine(),
        enable_epistemic=False,
    )


class TestGovernanceLoopPerformance:
    """Latency benchmarks for the full governance loop."""

    def test_full_loop_latency(self, governance_loop, sample_intent):
        """The full loop should complete within 100 ms at p99."""
        p50, p99, p100 = _measure_latency(
            governance_loop.run, sample_intent, context={"service_name": "perf-svc"}
        )
        assert p50 < 100, f"p50 latency {p50:.1f} ms exceeds 100 ms target"
        assert p99 < 200, f"p99 latency {p99:.1f} ms exceeds 200 ms target"


class TestHealingIntentSerialization:
    """Serialization performance."""

    def test_to_enterprise_request_latency(self, governance_loop, sample_intent):
        """Serializing a HealingIntent to the enterprise request dict should be fast."""
        intent = governance_loop.run(sample_intent, context={"service_name": "perf-svc"})
        p50, p99, p100 = _measure_latency(intent.to_enterprise_request)
        assert p50 < 10, f"p50 serialization latency {p50:.1f} ms exceeds 10 ms target"


class TestRiskEnginePerformance:
    """Conjugate update latency."""

    def test_risk_calculation_latency(self, governance_loop, sample_intent):
        """A single risk calculation should be sub‑millisecond."""
        engine = governance_loop.risk_engine
        p50, p99, p100 = _measure_latency(
            engine.calculate_risk,
            intent=sample_intent,
            cost_estimate=None,
            policy_violations=[],
        )
        assert p50 < 10, f"p50 risk calculation latency {p50:.1f} ms exceeds 10 ms target"