"""Comprehensive tests for the core engine module.

Targets gaps not covered by individual module tests:
- engine/webhooks.py (dispatch, delivery logging, retries)
- engine/scorers/format.py (structure validation, length edge cases)
- engine/cache.py (additional edge cases)
- engine/adapters (adapter mock call patterns)
- engine/sweep.py (grid combo count verification)
- Cross-module integration tests
"""

import asyncio
import json
import math
import uuid
from typing import Any
from unittest.mock import AsyncMock, MagicMock, patch

import httpx
import pytest
from sqlalchemy import create_engine
from sqlalchemy.orm import Session

from engine.adapters.base import AdapterResponse, BaseAdapter
from engine.cache import ResponseCacheLayer, compute_config_hash
from engine.runner import EventBus, render_prompt, run_single
from engine.scorers.format import FormatScorer
from engine.scorers.keyword import KeywordScorer
from engine.sweep import (
    generate_grid_configs,
    generate_random_configs,
)
from engine.webhooks import (
    _log_delivery,
    deliver_webhook,
    deliver_webhook_async,
    dispatch_webhooks,
    dispatch_webhooks_async,
    get_active_webhooks,
)
from models import (
    Base,
    Experiment,
    ExperimentStatus,
    Project,
    ResponseCache,
    Run,
    RunStatus,
    Score,
    StageResult,
    User,
    WebhookConfig,
    WebhookDelivery,
)


# ---------------------------------------------------------------------------
# DB helpers
# ---------------------------------------------------------------------------


def _engine():
    engine = create_engine("sqlite:///:memory:")
    Base.metadata.create_all(engine)
    return engine


def _session(engine):
    return Session(engine)


def _make_webhook(db: Session, event_type: str = "run.completed", url: str = "https://example.com/hook", is_active: bool = True, headers: dict | None = None) -> WebhookConfig:
    wh = WebhookConfig(event_type=event_type, url=url, is_active=is_active, headers=headers)
    db.add(wh)
    db.commit()
    db.refresh(wh)
    return wh


class MockAdapter(BaseAdapter):
    def __init__(self, response_text: str = "mock response", tokens_in: int = 10, tokens_out: int = 5):
        self.response_text = response_text
        self.tokens_in = tokens_in
        self.tokens_out = tokens_out
        self.calls: list[tuple[str, str, dict]] = []

    async def complete(self, prompt: str, model: str, params: dict[str, Any]) -> AdapterResponse:
        self.calls.append((prompt, model, params))
        return AdapterResponse(
            text=self.response_text,
            tokens_in=self.tokens_in,
            tokens_out=self.tokens_out,
            latency_ms=42.0,
            model=model,
        )

    async def list_models(self) -> list[str]:
        return ["mock-model"]

    async def test_connection(self) -> bool:
        return True


# ===========================================================================
# Webhook engine tests — engine/webhooks.py
# ===========================================================================


class TestGetActiveWebhooks:
    def test_returns_matching_active(self):
        engine = _engine()
        with _session(engine) as db:
            _make_webhook(db, event_type="run.completed")
            _make_webhook(db, event_type="run.failed")
            _make_webhook(db, event_type="run.completed", is_active=False)

            results = get_active_webhooks(db, "run.completed")
            assert len(results) == 1
            assert results[0].event_type == "run.completed"
            assert results[0].is_active is True

    def test_returns_empty_when_no_match(self):
        engine = _engine()
        with _session(engine) as db:
            _make_webhook(db, event_type="run.failed")
            results = get_active_webhooks(db, "run.completed")
            assert results == []

    def test_returns_multiple_active(self):
        engine = _engine()
        with _session(engine) as db:
            _make_webhook(db, event_type="sweep.completed", url="https://a.com")
            _make_webhook(db, event_type="sweep.completed", url="https://b.com")
            results = get_active_webhooks(db, "sweep.completed")
            assert len(results) == 2


class TestLogDelivery:
    def test_creates_delivery_record(self):
        engine = _engine()
        with _session(engine) as db:
            wh = _make_webhook(db)
            delivery = _log_delivery(
                db,
                webhook_id=wh.id,
                event_type="run.completed",
                payload={"key": "value"},
                status_code=200,
                success=True,
                attempts=1,
            )
            assert delivery.id is not None
            assert delivery.webhook_id == wh.id
            assert delivery.success is True
            assert delivery.attempts == 1
            assert delivery.status_code == 200

    def test_logs_failure_with_error(self):
        engine = _engine()
        with _session(engine) as db:
            wh = _make_webhook(db)
            delivery = _log_delivery(
                db,
                webhook_id=wh.id,
                event_type="run.failed",
                payload={},
                status_code=500,
                success=False,
                attempts=3,
                error_message="Server error",
            )
            assert delivery.success is False
            assert delivery.error_message == "Server error"
            assert delivery.attempts == 3


class TestDeliverWebhook:
    def test_successful_delivery(self):
        engine = _engine()
        with _session(engine) as db:
            wh = _make_webhook(db, url="https://example.com/ok")
            mock_response = httpx.Response(200, request=httpx.Request("POST", "https://example.com/ok"))

            with patch("engine.webhooks.httpx.Client") as MockClient:
                client_instance = MagicMock()
                client_instance.post.return_value = mock_response
                client_instance.__enter__ = MagicMock(return_value=client_instance)
                client_instance.__exit__ = MagicMock(return_value=False)
                MockClient.return_value = client_instance

                result = deliver_webhook(db, wh, "run.completed", {"data": 1})

            assert result is True
            deliveries = db.query(WebhookDelivery).all()
            assert len(deliveries) == 1
            assert deliveries[0].success is True

    def test_failed_delivery_after_retries(self):
        engine = _engine()
        with _session(engine) as db:
            wh = _make_webhook(db, url="https://example.com/fail")
            mock_response = httpx.Response(
                500,
                request=httpx.Request("POST", "https://example.com/fail"),
                text="Internal error",
            )

            with patch("engine.webhooks.httpx.Client") as MockClient, \
                 patch("engine.webhooks.time.sleep"):
                client_instance = MagicMock()
                client_instance.post.return_value = mock_response
                client_instance.__enter__ = MagicMock(return_value=client_instance)
                client_instance.__exit__ = MagicMock(return_value=False)
                MockClient.return_value = client_instance

                result = deliver_webhook(db, wh, "run.completed", {"data": 1})

            assert result is False
            deliveries = db.query(WebhookDelivery).all()
            assert len(deliveries) == 1
            assert deliveries[0].success is False
            assert deliveries[0].attempts == 3

    def test_network_error_retries(self):
        engine = _engine()
        with _session(engine) as db:
            wh = _make_webhook(db, url="https://example.com/timeout")

            with patch("engine.webhooks.httpx.Client") as MockClient, \
                 patch("engine.webhooks.time.sleep"):
                client_instance = MagicMock()
                client_instance.post.side_effect = httpx.ConnectError("Connection refused")
                client_instance.__enter__ = MagicMock(return_value=client_instance)
                client_instance.__exit__ = MagicMock(return_value=False)
                MockClient.return_value = client_instance

                result = deliver_webhook(db, wh, "run.completed", {})

            assert result is False

    def test_custom_headers_included(self):
        engine = _engine()
        with _session(engine) as db:
            wh = _make_webhook(
                db,
                url="https://example.com/hook",
                headers={"X-Custom": "test-value"},
            )
            mock_response = httpx.Response(200, request=httpx.Request("POST", wh.url))

            with patch("engine.webhooks.httpx.Client") as MockClient:
                client_instance = MagicMock()
                client_instance.post.return_value = mock_response
                client_instance.__enter__ = MagicMock(return_value=client_instance)
                client_instance.__exit__ = MagicMock(return_value=False)
                MockClient.return_value = client_instance

                deliver_webhook(db, wh, "run.completed", {})

                call_args = client_instance.post.call_args
                headers_sent = call_args[1].get("headers") or call_args.kwargs.get("headers")
                assert headers_sent["X-Custom"] == "test-value"


class TestDeliverWebhookAsync:
    @pytest.mark.asyncio
    async def test_successful_async_delivery(self):
        engine = _engine()
        with _session(engine) as db:
            wh = _make_webhook(db, url="https://example.com/ok")
            mock_response = httpx.Response(200, request=httpx.Request("POST", wh.url))

            with patch("engine.webhooks.httpx.AsyncClient") as MockAsyncClient:
                client_instance = AsyncMock()
                client_instance.post.return_value = mock_response
                client_instance.__aenter__ = AsyncMock(return_value=client_instance)
                client_instance.__aexit__ = AsyncMock(return_value=False)
                MockAsyncClient.return_value = client_instance

                result = await deliver_webhook_async(db, wh, "run.completed", {"test": True})

            assert result is True

    @pytest.mark.asyncio
    async def test_failed_async_delivery(self):
        engine = _engine()
        with _session(engine) as db:
            wh = _make_webhook(db, url="https://example.com/fail")
            mock_response = httpx.Response(
                503,
                request=httpx.Request("POST", wh.url),
                text="Service unavailable",
            )

            with patch("engine.webhooks.httpx.AsyncClient") as MockAsyncClient, \
                 patch("asyncio.sleep", new_callable=AsyncMock):
                client_instance = AsyncMock()
                client_instance.post.return_value = mock_response
                client_instance.__aenter__ = AsyncMock(return_value=client_instance)
                client_instance.__aexit__ = AsyncMock(return_value=False)
                MockAsyncClient.return_value = client_instance

                result = await deliver_webhook_async(db, wh, "run.completed", {})

            assert result is False

    @pytest.mark.asyncio
    async def test_async_network_error(self):
        engine = _engine()
        with _session(engine) as db:
            wh = _make_webhook(db, url="https://example.com/err")

            with patch("engine.webhooks.httpx.AsyncClient") as MockAsyncClient, \
                 patch("asyncio.sleep", new_callable=AsyncMock):
                client_instance = AsyncMock()
                client_instance.post.side_effect = httpx.ConnectError("refused")
                client_instance.__aenter__ = AsyncMock(return_value=client_instance)
                client_instance.__aexit__ = AsyncMock(return_value=False)
                MockAsyncClient.return_value = client_instance

                result = await deliver_webhook_async(db, wh, "run.failed", {})

            assert result is False


class TestDispatchWebhooks:
    def test_dispatches_to_matching_webhooks(self):
        engine = _engine()
        with _session(engine) as db:
            _make_webhook(db, event_type="run.completed", url="https://a.com")
            _make_webhook(db, event_type="run.completed", url="https://b.com")
            mock_response = httpx.Response(200, request=httpx.Request("POST", "https://a.com"))

            with patch("engine.webhooks.httpx.Client") as MockClient:
                client_instance = MagicMock()
                client_instance.post.return_value = mock_response
                client_instance.__enter__ = MagicMock(return_value=client_instance)
                client_instance.__exit__ = MagicMock(return_value=False)
                MockClient.return_value = client_instance

                count = dispatch_webhooks(db, "run.completed", {"data": 1})

            assert count == 2

    def test_returns_zero_when_no_webhooks(self):
        engine = _engine()
        with _session(engine) as db:
            count = dispatch_webhooks(db, "nonexistent.event", {})
            assert count == 0


class TestDispatchWebhooksAsync:
    @pytest.mark.asyncio
    async def test_dispatches_async(self):
        engine = _engine()
        with _session(engine) as db:
            _make_webhook(db, event_type="sweep.completed", url="https://hook.com")
            mock_response = httpx.Response(200, request=httpx.Request("POST", "https://hook.com"))

            with patch("engine.webhooks.httpx.AsyncClient") as MockAsyncClient:
                client_instance = AsyncMock()
                client_instance.post.return_value = mock_response
                client_instance.__aenter__ = AsyncMock(return_value=client_instance)
                client_instance.__aexit__ = AsyncMock(return_value=False)
                MockAsyncClient.return_value = client_instance

                count = await dispatch_webhooks_async(db, "sweep.completed", {"info": "done"})

            assert count == 1

    @pytest.mark.asyncio
    async def test_returns_zero_when_none_match(self):
        engine = _engine()
        with _session(engine) as db:
            count = await dispatch_webhooks_async(db, "no.match", {})
            assert count == 0


# ===========================================================================
# Format scorer — structure / length edge cases
# ===========================================================================


class TestFormatScorerStructure:
    def test_valid_against_schema(self):
        schema = {
            "type": "object",
            "required": ["name", "age"],
            "properties": {
                "name": {"type": "string"},
                "age": {"type": "integer"},
            },
        }
        scorer = FormatScorer(format_type="structure", json_schema=schema)
        assert scorer.score(None, '{"name": "Alice", "age": 30}', {}) == 1.0

    def test_invalid_against_schema(self):
        schema = {
            "type": "object",
            "required": ["name", "age"],
        }
        scorer = FormatScorer(format_type="structure", json_schema=schema)
        assert scorer.score(None, '{"name": "Alice"}', {}) < 1.0

    def test_not_json(self):
        schema = {"type": "object"}
        scorer = FormatScorer(format_type="structure", json_schema=schema)
        assert scorer.score(None, "not json at all", {}) == 0.0

    def test_no_schema_returns_zero(self):
        scorer = FormatScorer(format_type="structure", json_schema=None)
        assert scorer.score(None, '{"anything": true}', {}) == 0.0

    def test_basic_schema_check_fallback(self):
        """Test the _basic_schema_check path when jsonschema is unavailable."""
        schema = {
            "type": "object",
            "required": ["a", "b", "c"],
        }
        scorer = FormatScorer(format_type="structure", json_schema=schema)
        # Simulate missing jsonschema library
        with patch.dict("sys.modules", {"jsonschema": None}):
            with patch("builtins.__import__", side_effect=lambda name, *a, **k: (_ for _ in ()).throw(ImportError) if name == "jsonschema" else __builtins__.__import__(name, *a, **k)):
                result = scorer._basic_schema_check({"a": 1, "b": 2}, schema)
        # 2 of 3 required fields → 2/3
        assert result == pytest.approx(2 / 3)

    def test_basic_schema_check_type_mismatch(self):
        scorer = FormatScorer(format_type="structure")
        result = scorer._basic_schema_check("not a dict", {"type": "object"})
        assert result == 0.0

    def test_basic_schema_check_array_type(self):
        scorer = FormatScorer(format_type="structure")
        result = scorer._basic_schema_check([1, 2], {"type": "array"})
        assert result == 1.0

    def test_basic_schema_check_no_type(self):
        scorer = FormatScorer(format_type="structure")
        result = scorer._basic_schema_check("anything", {})
        assert result == 1.0


class TestFormatScorerLengthEdgeCases:
    def test_over_max_score_decays(self):
        scorer = FormatScorer(format_type="length", max_tokens=10)
        # 20 tokens = 2x max, should return 0.0
        output = " ".join(["word"] * 20)
        assert scorer.score(None, output, {}) == 0.0

    def test_at_max_boundary(self):
        scorer = FormatScorer(format_type="length", max_tokens=5)
        output = " ".join(["word"] * 5)
        assert scorer.score(None, output, {}) == 1.0

    def test_under_min_proportional(self):
        scorer = FormatScorer(format_type="length", min_tokens=10)
        output = " ".join(["word"] * 5)
        score = scorer.score(None, output, {})
        assert score == pytest.approx(0.5)

    def test_zero_min_tokens(self):
        scorer = FormatScorer(format_type="length", min_tokens=0, max_tokens=100)
        assert scorer.score(None, "", {}) == 1.0


# ===========================================================================
# Cache — additional edge cases
# ===========================================================================


class TestCacheEdgeCases:
    def test_hash_with_nested_params(self):
        h1 = compute_config_hash("p", "m", {"nested": {"a": 1, "b": [2, 3]}})
        h2 = compute_config_hash("p", "m", {"nested": {"b": [2, 3], "a": 1}})
        assert h1 == h2

    def test_hash_with_special_characters(self):
        h = compute_config_hash("Hello 世界! 🌍", "model-ñ", {"key": "value with \"quotes\""})
        assert len(h) == 64

    def test_hash_with_numeric_input_data(self):
        h1 = compute_config_hash("p", "m", {}, input_data=42)
        h2 = compute_config_hash("p", "m", {}, input_data=42)
        assert h1 == h2

    def test_cache_put_with_none_fields(self):
        engine = _engine()
        with _session(engine) as db:
            cache = ResponseCacheLayer()
            cache.put(db, "a" * 64, response="resp", model="m")
            result = cache.get(db, "a" * 64)
            assert result.tokens_in is None
            assert result.tokens_out is None
            assert result.latency_ms is None

    def test_independent_hit_tracking(self):
        """Two cache instances track hits independently."""
        engine = _engine()
        with _session(engine) as db:
            cache1 = ResponseCacheLayer()
            cache2 = ResponseCacheLayer()
            h = "b" * 64
            cache1.put(db, h, response="r", model="m")

            cache1.get(db, h)  # hit on cache1
            cache2.get(db, h)  # hit on cache2

            stats1 = cache1.cache_stats(db)
            stats2 = cache2.cache_stats(db)
            assert stats1.hit_rate == 1.0
            assert stats2.hit_rate == 1.0


# ===========================================================================
# Adapter mock call tracking
# ===========================================================================


class TestAdapterMockCallTracking:
    @pytest.mark.asyncio
    async def test_adapter_records_all_calls(self):
        adapter = MockAdapter()
        await adapter.complete("prompt1", "model-a", {"temp": 0.5})
        await adapter.complete("prompt2", "model-b", {"temp": 0.9})

        assert len(adapter.calls) == 2
        assert adapter.calls[0] == ("prompt1", "model-a", {"temp": 0.5})
        assert adapter.calls[1] == ("prompt2", "model-b", {"temp": 0.9})

    @pytest.mark.asyncio
    async def test_adapter_returns_correct_model(self):
        adapter = MockAdapter(response_text="hello")
        resp = await adapter.complete("test", "specific-model", {})
        assert resp.model == "specific-model"
        assert resp.text == "hello"

    @pytest.mark.asyncio
    async def test_adapter_token_counts(self):
        adapter = MockAdapter(tokens_in=100, tokens_out=50)
        resp = await adapter.complete("test", "m", {})
        assert resp.tokens_in == 100
        assert resp.tokens_out == 50


# ===========================================================================
# Grid sweep — combo count verification
# ===========================================================================


class TestGridComboVerification:
    def test_single_param_3_values(self):
        configs = generate_grid_configs(
            {"prompt": "test", "params": {}},
            {"params.temperature": [0.1, 0.5, 0.9]},
        )
        assert len(configs) == 3

    def test_cartesian_product_2x3(self):
        configs = generate_grid_configs(
            {"prompt": "test", "model": "m", "params": {}},
            {
                "model": ["gpt-4", "claude"],
                "params.temperature": [0.1, 0.5, 0.9],
            },
        )
        assert len(configs) == 6  # 2 × 3

    def test_cartesian_product_2x2x3(self):
        configs = generate_grid_configs(
            {"prompt": "test", "model": "m", "params": {}},
            {
                "model": ["a", "b"],
                "params.temperature": [0.1, 0.9],
                "params.top_p": [0.5, 0.7, 1.0],
            },
        )
        assert len(configs) == 12  # 2 × 2 × 3

    def test_all_combos_are_unique(self):
        configs = generate_grid_configs(
            {"prompt": "test", "params": {}},
            {
                "params.temperature": [0.1, 0.5, 0.9],
                "params.top_p": [0.5, 1.0],
            },
        )
        serialized = [json.dumps(c, sort_keys=True) for c in configs]
        assert len(set(serialized)) == len(serialized)

    def test_random_respects_ranges_for_all_samples(self):
        configs = generate_random_configs(
            {"prompt": "test", "params": {}},
            {
                "params.temperature": {"min": 0.0, "max": 1.0},
                "params.top_p": {"min": 0.5, "max": 1.0},
            },
            n_trials=100,
        )
        for c in configs:
            assert 0.0 <= c["params"]["temperature"] <= 1.0
            assert 0.5 <= c["params"]["top_p"] <= 1.0


# ===========================================================================
# Scorer integration with known inputs
# ===========================================================================


class TestScorerKnownInputs:
    def test_keyword_all_present(self):
        scorer = KeywordScorer(required_present=["python", "fast", "simple"])
        score = scorer.score(None, "Python is fast and simple to learn", {})
        assert score == 1.0

    def test_keyword_partial_match(self):
        scorer = KeywordScorer(required_present=["python", "fast", "simple"])
        score = scorer.score(None, "Python is a great language", {})
        assert score == pytest.approx(1 / 3)

    def test_keyword_absent_violation(self):
        scorer = KeywordScorer(required_absent=["error", "bug"])
        score = scorer.score(None, "There was an error in the code", {})
        assert score < 1.0

    def test_keyword_absent_clean(self):
        scorer = KeywordScorer(required_absent=["error", "bug"])
        score = scorer.score(None, "The code works perfectly", {})
        assert score == 1.0

    def test_format_json_valid(self):
        scorer = FormatScorer(format_type="json")
        assert scorer.score(None, '{"key": "value", "number": 42}', {}) == 1.0

    def test_format_json_invalid(self):
        scorer = FormatScorer(format_type="json")
        assert scorer.score(None, "not json", {}) == 0.0

    def test_format_markdown_headers_only(self):
        scorer = FormatScorer(format_type="markdown")
        assert scorer.score(None, "# Title\nSome text", {}) == 0.5

    def test_format_markdown_full(self):
        scorer = FormatScorer(format_type="markdown")
        text = "# Title\n\n- Item 1\n- Item 2\n"
        assert scorer.score(None, text, {}) == 1.0


# ===========================================================================
# EventBus tests
# ===========================================================================


class TestEventBus:
    def test_publish_and_listen(self):
        bus = EventBus()
        events = []
        bus.add_listener(lambda e: events.append(e))
        bus.publish({"type": "test", "data": 42})
        assert len(events) == 1
        assert events[0]["data"] == 42

    def test_multiple_listeners(self):
        bus = EventBus()
        events1, events2 = [], []
        bus.add_listener(lambda e: events1.append(e))
        bus.add_listener(lambda e: events2.append(e))
        bus.publish({"type": "test"})
        assert len(events1) == 1
        assert len(events2) == 1

    def test_no_listeners_no_error(self):
        bus = EventBus()
        bus.publish({"type": "test"})  # Should not raise