"""Tests for credit service."""

import json
from unittest.mock import AsyncMock, patch

import pytest
from sqlmodel.ext.asyncio.session import AsyncSession

from app.models.credit_action import CreditActionType
from app.models.credit_transaction import CreditTransaction
from app.models.user import User
from app.services.credit import CreditService, InsufficientCreditsError


class TestCreditService:
    """Test credit service functionality."""

    @pytest.fixture
    def mock_db_session_factory(self):
        """Create a mock database session factory."""
        session = AsyncMock(spec=AsyncSession)
        return lambda: session

    @pytest.fixture
    def credit_service(self, mock_db_session_factory):
        """Create a credit service instance for testing."""
        return CreditService(mock_db_session_factory)

    @pytest.fixture
    def sample_user(self):
        """Create a sample user for testing."""
        return User(
            id=1,
            name="Test User",
            email="test@example.com",
            role="user",
            credits=10,
            plan_id=1,
        )

    @pytest.mark.asyncio
    async def test_check_credits_sufficient(self, credit_service, sample_user):
        """Test checking credits when user has sufficient credits."""
        mock_session = credit_service.db_session_factory()

        with patch("app.services.credit.UserRepository") as mock_repo_class:
            mock_repo = AsyncMock()
            mock_repo_class.return_value = mock_repo
            mock_repo.get_by_id.return_value = sample_user

            result = await credit_service.check_credits(1, CreditActionType.VLC_PLAY_SOUND)

            assert result is True
            mock_repo.get_by_id.assert_called_once_with(1)
            mock_session.close.assert_called_once()

    @pytest.mark.asyncio
    async def test_check_credits_insufficient(self, credit_service):
        """Test checking credits when user has insufficient credits."""
        mock_session = credit_service.db_session_factory()
        poor_user = User(
            id=1,
            name="Poor User",
            email="poor@example.com",
            role="user",
            credits=0,  # No credits
            plan_id=1,
        )

        with patch("app.services.credit.UserRepository") as mock_repo_class:
            mock_repo = AsyncMock()
            mock_repo_class.return_value = mock_repo
            mock_repo.get_by_id.return_value = poor_user

            result = await credit_service.check_credits(1, CreditActionType.VLC_PLAY_SOUND)

            assert result is False
            mock_session.close.assert_called_once()

    @pytest.mark.asyncio
    async def test_check_credits_user_not_found(self, credit_service):
        """Test checking credits when user is not found."""
        mock_session = credit_service.db_session_factory()

        with patch("app.services.credit.UserRepository") as mock_repo_class:
            mock_repo = AsyncMock()
            mock_repo_class.return_value = mock_repo
            mock_repo.get_by_id.return_value = None

            result = await credit_service.check_credits(999, CreditActionType.VLC_PLAY_SOUND)

            assert result is False
            mock_session.close.assert_called_once()

    @pytest.mark.asyncio
    async def test_validate_and_reserve_credits_success(self, credit_service, sample_user):
        """Test successful credit validation and reservation."""
        mock_session = credit_service.db_session_factory()

        with patch("app.services.credit.UserRepository") as mock_repo_class:
            mock_repo = AsyncMock()
            mock_repo_class.return_value = mock_repo
            mock_repo.get_by_id.return_value = sample_user

            user, action = await credit_service.validate_and_reserve_credits(
                1, CreditActionType.VLC_PLAY_SOUND,
            )

            assert user == sample_user
            assert action.action_type == CreditActionType.VLC_PLAY_SOUND
            assert action.cost == 1
            mock_session.close.assert_called_once()

    @pytest.mark.asyncio
    async def test_validate_and_reserve_credits_insufficient(self, credit_service):
        """Test credit validation with insufficient credits."""
        mock_session = credit_service.db_session_factory()
        poor_user = User(
            id=1,
            name="Poor User",
            email="poor@example.com",
            role="user",
            credits=0,
            plan_id=1,
        )

        with patch("app.services.credit.UserRepository") as mock_repo_class:
            mock_repo = AsyncMock()
            mock_repo_class.return_value = mock_repo
            mock_repo.get_by_id.return_value = poor_user

            with pytest.raises(InsufficientCreditsError) as exc_info:
                await credit_service.validate_and_reserve_credits(
                    1, CreditActionType.VLC_PLAY_SOUND,
                )

            assert exc_info.value.required == 1
            assert exc_info.value.available == 0
            mock_session.close.assert_called_once()

    @pytest.mark.asyncio
    async def test_validate_and_reserve_credits_user_not_found(self, credit_service):
        """Test credit validation when user is not found."""
        mock_session = credit_service.db_session_factory()

        with patch("app.services.credit.UserRepository") as mock_repo_class:
            mock_repo = AsyncMock()
            mock_repo_class.return_value = mock_repo
            mock_repo.get_by_id.return_value = None

            with pytest.raises(ValueError, match="User 999 not found"):
                await credit_service.validate_and_reserve_credits(
                    999, CreditActionType.VLC_PLAY_SOUND,
                )

            mock_session.close.assert_called_once()

    @pytest.mark.asyncio
    async def test_deduct_credits_success(self, credit_service, sample_user):
        """Test successful credit deduction."""
        mock_session = credit_service.db_session_factory()

        with patch("app.services.credit.UserRepository") as mock_repo_class, \
             patch("app.services.credit.socket_manager") as mock_socket_manager:
            mock_repo = AsyncMock()
            mock_repo_class.return_value = mock_repo
            mock_repo.get_by_id.return_value = sample_user
            mock_socket_manager.send_to_user = AsyncMock()

            transaction = await credit_service.deduct_credits(
                1, CreditActionType.VLC_PLAY_SOUND, success=True, metadata={"test": "data"},
            )

            # Verify user credits were updated
            mock_repo.update.assert_called_once_with(sample_user, {"credits": 9})

            # Verify transaction was created
            mock_session.add.assert_called_once()
            mock_session.commit.assert_called_once()

            # Verify socket event was emitted
            mock_socket_manager.send_to_user.assert_called_once_with(
                "1", "user_credits_changed", {
                    "user_id": "1",
                    "credits_before": 10,
                    "credits_after": 9,
                    "credits_deducted": 1,
                    "action_type": "vlc_play_sound",
                    "success": True,
                },
            )

            # Check transaction details
            added_transaction = mock_session.add.call_args[0][0]
            assert isinstance(added_transaction, CreditTransaction)
            assert added_transaction.user_id == 1
            assert added_transaction.action_type == "vlc_play_sound"
            assert added_transaction.amount == -1
            assert added_transaction.balance_before == 10
            assert added_transaction.balance_after == 9
            assert added_transaction.success is True
            assert json.loads(added_transaction.metadata_json) == {"test": "data"}

    @pytest.mark.asyncio
    async def test_deduct_credits_failed_action_requires_success(self, credit_service, sample_user):
        """Test credit deduction when action failed but requires success."""
        mock_session = credit_service.db_session_factory()

        with patch("app.services.credit.UserRepository") as mock_repo_class, \
             patch("app.services.credit.socket_manager") as mock_socket_manager:
            mock_repo = AsyncMock()
            mock_repo_class.return_value = mock_repo
            mock_repo.get_by_id.return_value = sample_user
            mock_socket_manager.send_to_user = AsyncMock()

            transaction = await credit_service.deduct_credits(
                1, CreditActionType.VLC_PLAY_SOUND, success=False,  # Action failed
            )

            # Verify user credits were NOT updated (action requires success)
            mock_repo.update.assert_not_called()

            # Verify transaction was still created for auditing
            mock_session.add.assert_called_once()
            mock_session.commit.assert_called_once()

            # Verify no socket event was emitted since no credits were actually deducted
            mock_socket_manager.send_to_user.assert_not_called()

            # Check transaction details
            added_transaction = mock_session.add.call_args[0][0]
            assert added_transaction.amount == 0  # No deduction for failed action
            assert added_transaction.balance_before == 10
            assert added_transaction.balance_after == 10  # No change
            assert added_transaction.success is False

    @pytest.mark.asyncio
    async def test_deduct_credits_insufficient(self, credit_service):
        """Test credit deduction with insufficient credits."""
        mock_session = credit_service.db_session_factory()
        poor_user = User(
            id=1,
            name="Poor User",
            email="poor@example.com",
            role="user",
            credits=0,
            plan_id=1,
        )

        with patch("app.services.credit.UserRepository") as mock_repo_class, \
             patch("app.services.credit.socket_manager") as mock_socket_manager:
            mock_repo = AsyncMock()
            mock_repo_class.return_value = mock_repo
            mock_repo.get_by_id.return_value = poor_user
            mock_socket_manager.send_to_user = AsyncMock()

            with pytest.raises(InsufficientCreditsError):
                await credit_service.deduct_credits(
                    1, CreditActionType.VLC_PLAY_SOUND, success=True,
                )

            # Verify no socket event was emitted since credits could not be deducted
            mock_socket_manager.send_to_user.assert_not_called()

            mock_session.rollback.assert_called_once()
            mock_session.close.assert_called_once()

    @pytest.mark.asyncio
    async def test_add_credits(self, credit_service, sample_user):
        """Test adding credits to user account."""
        mock_session = credit_service.db_session_factory()

        with patch("app.services.credit.UserRepository") as mock_repo_class, \
             patch("app.services.credit.socket_manager") as mock_socket_manager:
            mock_repo = AsyncMock()
            mock_repo_class.return_value = mock_repo
            mock_repo.get_by_id.return_value = sample_user
            mock_socket_manager.send_to_user = AsyncMock()

            transaction = await credit_service.add_credits(
                1, 5, "Bonus credits", {"reason": "signup"},
            )

            # Verify user credits were updated
            mock_repo.update.assert_called_once_with(sample_user, {"credits": 15})

            # Verify transaction was created
            mock_session.add.assert_called_once()
            mock_session.commit.assert_called_once()

            # Verify socket event was emitted
            mock_socket_manager.send_to_user.assert_called_once_with(
                "1", "user_credits_changed", {
                    "user_id": "1",
                    "credits_before": 10,
                    "credits_after": 15,
                    "credits_added": 5,
                    "description": "Bonus credits",
                    "success": True,
                },
            )

            # Check transaction details
            added_transaction = mock_session.add.call_args[0][0]
            assert added_transaction.amount == 5
            assert added_transaction.balance_before == 10
            assert added_transaction.balance_after == 15
            assert added_transaction.description == "Bonus credits"

    @pytest.mark.asyncio
    async def test_add_credits_invalid_amount(self, credit_service):
        """Test adding invalid amount of credits."""
        with pytest.raises(ValueError, match="Amount must be positive"):
            await credit_service.add_credits(1, 0, "Invalid")

        with pytest.raises(ValueError, match="Amount must be positive"):
            await credit_service.add_credits(1, -5, "Invalid")

    @pytest.mark.asyncio
    async def test_get_user_balance(self, credit_service, sample_user):
        """Test getting user credit balance."""
        mock_session = credit_service.db_session_factory()

        with patch("app.services.credit.UserRepository") as mock_repo_class:
            mock_repo = AsyncMock()
            mock_repo_class.return_value = mock_repo
            mock_repo.get_by_id.return_value = sample_user

            balance = await credit_service.get_user_balance(1)

            assert balance == 10
            mock_session.close.assert_called_once()

    @pytest.mark.asyncio
    async def test_get_user_balance_user_not_found(self, credit_service):
        """Test getting balance for non-existent user."""
        mock_session = credit_service.db_session_factory()

        with patch("app.services.credit.UserRepository") as mock_repo_class:
            mock_repo = AsyncMock()
            mock_repo_class.return_value = mock_repo
            mock_repo.get_by_id.return_value = None

            with pytest.raises(ValueError, match="User 999 not found"):
                await credit_service.get_user_balance(999)

            mock_session.close.assert_called_once()


class TestInsufficientCreditsError:
    """Test InsufficientCreditsError exception."""

    def test_insufficient_credits_error_creation(self):
        """Test creating InsufficientCreditsError."""
        error = InsufficientCreditsError(5, 2)
        assert error.required == 5
        assert error.available == 2
        assert str(error) == "Insufficient credits: 5 required, 2 available"