"""Integration test — ground-truth evaluation end-to-end with real similarity metrics."""
from __future__ import annotations

import asyncio
import json

import pytest
from unittest.mock import AsyncMock

from prometheus.application.ground_truth_evaluator import GroundTruthEvaluator
from prometheus.domain.entities import GroundTruthExample, Prompt
from prometheus.domain.ports import LLMPort
from prometheus.infrastructure.dataset_loader import FileDatasetLoader
from prometheus.infrastructure.similarity import (
    BleuSimilarity,
    CosineSimilarity,
    ExactMatchSimilarity,
    RougeLSimilarity,
    create_similarity_adapter,
)


def _make_dataset(items: list[tuple[str, str]]) -> list[GroundTruthExample]:
    return [
        GroundTruthExample(input_text=inp, expected_output=exp, id=i)
        for i, (inp, exp) in enumerate(items)
    ]


@pytest.fixture
def qa_dataset():
    return _make_dataset([
        ("What is the capital of France?", "Paris"),
        ("What is 2+2?", "4"),
        ("What color is the sky?", "blue"),
    ])


@pytest.fixture
def prompt():
    return Prompt(text="Answer the following question concisely.")


@pytest.fixture
def mock_executor():
    """Returns responses that partially match the ground truth."""
    port = AsyncMock(spec=LLMPort)
    port.execute.side_effect = [
        "Paris is the capital of France.",
        "The answer is 4.",
        "The sky is blue.",
    ]
    return port


class TestGroundTruthIntegrationWithExactMatch:
    @pytest.mark.asyncio
    async def test_exact_match_on_qa(self, mock_executor, qa_dataset, prompt):
        evaluator = GroundTruthEvaluator(
            executor=mock_executor,
            similarity=ExactMatchSimilarity(),
        )
        result = await evaluator.evaluate(prompt, qa_dataset)
        # None of the outputs are exact matches with expected outputs
        assert all(s == 0.0 for s in result.scores)

    @pytest.mark.asyncio
    async def test_exact_match_with_exact_outputs(self, qa_dataset, prompt):
        exact_executor = AsyncMock(spec=LLMPort)
        exact_executor.execute.side_effect = ["Paris", "4", "blue"]
        evaluator = GroundTruthEvaluator(
            executor=exact_executor,
            similarity=ExactMatchSimilarity(),
        )
        result = await evaluator.evaluate(prompt, qa_dataset)
        assert all(s == 1.0 for s in result.scores)


class TestGroundTruthIntegrationWithBleu:
    @pytest.mark.asyncio
    async def test_bleu_scores_partial_match(self, mock_executor, qa_dataset, prompt):
        evaluator = GroundTruthEvaluator(
            executor=mock_executor,
            similarity=BleuSimilarity(),
        )
        result = await evaluator.evaluate(prompt, qa_dataset)
        assert all(0.0 < s < 1.0 for s in result.scores)
        assert result.mean_score > 0.0

    @pytest.mark.asyncio
    async def test_bleu_perfect_match(self, qa_dataset, prompt):
        perfect_executor = AsyncMock(spec=LLMPort)
        perfect_executor.execute.side_effect = ["Paris", "4", "blue"]
        evaluator = GroundTruthEvaluator(
            executor=perfect_executor,
            similarity=BleuSimilarity(),
        )
        result = await evaluator.evaluate(prompt, qa_dataset)
        assert all(s > 0.0 for s in result.scores)


class TestGroundTruthIntegrationWithRouge:
    @pytest.mark.asyncio
    async def test_rouge_l_scores(self, mock_executor, qa_dataset, prompt):
        evaluator = GroundTruthEvaluator(
            executor=mock_executor,
            similarity=RougeLSimilarity(),
        )
        result = await evaluator.evaluate(prompt, qa_dataset)
        assert all(s > 0.0 for s in result.scores)


class TestGroundTruthIntegrationWithCosine:
    @pytest.mark.asyncio
    async def test_cosine_scores(self, mock_executor, qa_dataset, prompt):
        evaluator = GroundTruthEvaluator(
            executor=mock_executor,
            similarity=CosineSimilarity(),
        )
        result = await evaluator.evaluate(prompt, qa_dataset)
        assert all(s > 0.0 for s in result.scores)


class TestDatasetLoaderIntegration:
    @pytest.mark.asyncio
    async def test_load_csv_and_evaluate(self, tmp_path, prompt):
        csv_file = tmp_path / "eval.csv"
        csv_file.write_text("input,expected_output\nWhat is 2+2?,4\nWhat color is grass?,green\n")

        loader = FileDatasetLoader()
        dataset = loader.load(str(csv_file))
        assert len(dataset) == 2

        executor = AsyncMock(spec=LLMPort)
        executor.execute.side_effect = ["4", "green"]

        evaluator = GroundTruthEvaluator(
            executor=executor,
            similarity=ExactMatchSimilarity(),
        )
        result = await evaluator.evaluate(prompt, dataset)
        assert all(s == 1.0 for s in result.scores)

    @pytest.mark.asyncio
    async def test_load_json_and_evaluate(self, tmp_path, prompt):
        json_file = tmp_path / "eval.json"
        data = [
            {"input": "What is 2+2?", "expected_output": "4"},
            {"input": "What color is grass?", "expected_output": "green"},
        ]
        json_file.write_text(json.dumps(data))

        loader = FileDatasetLoader()
        dataset = loader.load(str(json_file))
        assert len(dataset) == 2

        executor = AsyncMock(spec=LLMPort)
        executor.execute.side_effect = ["4", "not green"]

        evaluator = GroundTruthEvaluator(
            executor=executor,
            similarity=create_similarity_adapter("bleu"),
        )
        result = await evaluator.evaluate(prompt, dataset)
        # First item should score well, second poorly
        assert result.scores[0] > result.scores[1]


class TestMetricComparison:
    """Compare different metrics on the same outputs to ensure they behave differently."""

    @pytest.mark.asyncio
    async def test_metrics_give_different_scores(self, qa_dataset, prompt):
        results = {}
        for metric_name, metric_cls in [
            ("exact", ExactMatchSimilarity),
            ("bleu", BleuSimilarity),
            ("rouge_l", RougeLSimilarity),
            ("cosine", CosineSimilarity),
        ]:
            executor = AsyncMock(spec=LLMPort)
            executor.execute.side_effect = [
                "Paris is the capital of France.",
                "The answer is 4.",
                "The sky is blue.",
            ]
            evaluator = GroundTruthEvaluator(
                executor=executor,
                similarity=metric_cls(),
            )
            result = await evaluator.evaluate(prompt, qa_dataset)
            results[metric_name] = result.mean_score

        # Exact match should be 0 (no exact matches)
        assert results["exact"] == 0.0
        # All other metrics should give partial credit
        assert results["bleu"] > 0.0
        assert results["rouge_l"] > 0.0
        assert results["cosine"] > 0.0