"""
Tests for TransactionService

Validates transaction service functionality, API interaction, and business logic.
"""
import pytest
from unittest.mock import AsyncMock, MagicMock, patch
from datetime import datetime

from services.transaction_service import TransactionService, transaction_service
from models.transaction import Transaction, RosterValidation
from exceptions import APIException


class TestTransactionService:
    """Test TransactionService functionality."""
    
    @pytest.fixture
    def service(self):
        """Create a fresh TransactionService instance for testing."""
        return TransactionService()
    
    @pytest.fixture
    def mock_transaction_data(self):
        """Create mock transaction data for testing."""
        return {
            'id': 27787,
            'week': 10,
            'season': 12,
            'moveid': 'Season-012-Week-10-19-13:04:41',
            'player': {
                'id': 12472,
                'name': 'Test Player',
                'wara': 2.47,
                'season': 12,
                'pos_1': 'LF'
            },
            'oldteam': {
                'id': 508,
                'abbrev': 'NYD',
                'sname': 'Diamonds',
                'lname': 'New York Diamonds',
                'season': 12
            },
            'newteam': {
                'id': 499,
                'abbrev': 'WV',
                'sname': 'Black Bears', 
                'lname': 'West Virginia Black Bears',
                'season': 12
            },
            'cancelled': False,
            'frozen': False
        }
    
    @pytest.fixture  
    def mock_api_response(self, mock_transaction_data):
        """Create mock API response with multiple transactions."""
        return {
            'count': 3,
            'transactions': [
                mock_transaction_data,
                {**mock_transaction_data, 'id': 27788, 'frozen': True},
                {**mock_transaction_data, 'id': 27789, 'cancelled': True}
            ]
        }
    
    @pytest.mark.asyncio
    async def test_service_initialization(self, service):
        """Test service initialization."""
        assert service.model_class == Transaction
        assert service.endpoint == 'transactions'
    
    @pytest.mark.asyncio
    async def test_get_team_transactions_basic(self, service, mock_api_response):
        """Test getting team transactions with basic parameters."""
        with patch.object(service, 'get_all_items', new_callable=AsyncMock) as mock_get:
            mock_get.return_value = [
                Transaction.from_api_data(tx) for tx in mock_api_response['transactions']
            ]
            
            result = await service.get_team_transactions('WV', 12)
            
            assert len(result) == 3
            assert all(isinstance(tx, Transaction) for tx in result)
            
            # Verify API call was made
            mock_get.assert_called_once()
    
    @pytest.mark.asyncio
    async def test_get_team_transactions_with_filters(self, service, mock_api_response):
        """Test getting team transactions with status filters."""
        with patch.object(service, 'get_all_items', new_callable=AsyncMock) as mock_get:
            mock_get.return_value = []
            
            await service.get_team_transactions(
                'WV', 12, 
                cancelled=True, 
                frozen=False,
                week_start=5,
                week_end=15
            )
            
            # Verify API call was made
            mock_get.assert_called_once()
    
    @pytest.mark.asyncio
    async def test_get_team_transactions_sorting(self, service, mock_transaction_data):
        """Test transaction sorting by week and moveid."""
        # Create transactions with different weeks and moveids
        transactions_data = [
            {**mock_transaction_data, 'id': 1, 'week': 10, 'moveid': 'Season-012-Week-10-19-13:04:41'},
            {**mock_transaction_data, 'id': 2, 'week': 8, 'moveid': 'Season-012-Week-08-12-10:30:15'},
            {**mock_transaction_data, 'id': 3, 'week': 10, 'moveid': 'Season-012-Week-10-15-09:22:33'},
        ]
        
        with patch.object(service, 'get_all_items', new_callable=AsyncMock) as mock_get:
            mock_get.return_value = [Transaction.from_api_data(tx) for tx in transactions_data]
            
            result = await service.get_team_transactions('WV', 12)
            
            # Verify sorting: week 8 first, then week 10 sorted by moveid
            assert result[0].week == 8
            assert result[1].week == 10
            assert result[2].week == 10
            assert result[1].moveid < result[2].moveid  # Alphabetical order
    
    @pytest.mark.asyncio
    async def test_get_pending_transactions(self, service):
        """Test getting pending transactions.

        The method first fetches the current week, then calls get_team_transactions
        with week_start set to the current week.
        """
        with patch.object(service, 'get_client', new_callable=AsyncMock) as mock_get_client:
            mock_client = AsyncMock()
            mock_client.get.return_value = {'week': 17}  # Simulate current week
            mock_get_client.return_value = mock_client

            with patch.object(service, 'get_team_transactions', new_callable=AsyncMock) as mock_get:
                mock_get.return_value = []

                await service.get_pending_transactions('WV', 12)

                mock_get.assert_called_once_with('WV', 12, cancelled=False, frozen=False, week_start=17)
    
    @pytest.mark.asyncio
    async def test_get_frozen_transactions(self, service):
        """Test getting frozen transactions.""" 
        with patch.object(service, 'get_team_transactions', new_callable=AsyncMock) as mock_get:
            mock_get.return_value = []
            
            await service.get_frozen_transactions('WV', 12)
            
            mock_get.assert_called_once_with('WV', 12, frozen=True)
    
    @pytest.mark.asyncio
    async def test_get_processed_transactions_success(self, service, mock_transaction_data):
        """Test getting processed transactions with current week lookup."""
        # Mock current week response
        current_response = {'week': 12}
        
        # Create test transactions with different statuses
        all_transactions = [
            Transaction.from_api_data({**mock_transaction_data, 'id': 1, 'cancelled': False, 'frozen': False}),  # pending
            Transaction.from_api_data({**mock_transaction_data, 'id': 2, 'cancelled': False, 'frozen': True}),   # frozen
            Transaction.from_api_data({**mock_transaction_data, 'id': 3, 'cancelled': True, 'frozen': False}),   # cancelled
            Transaction.from_api_data({**mock_transaction_data, 'id': 4, 'cancelled': False, 'frozen': False}),  # pending
        ]
        
        # Mock the service methods
        with patch.object(service, 'get_client', new_callable=AsyncMock) as mock_client:
            mock_api_client = AsyncMock()
            mock_api_client.get.return_value = current_response
            mock_client.return_value = mock_api_client
            
            with patch.object(service, 'get_team_transactions', new_callable=AsyncMock) as mock_get_team:
                mock_get_team.return_value = all_transactions
                
                result = await service.get_processed_transactions('WV', 12)
                
                # Should return empty list since all test transactions are either pending, frozen, or cancelled
                # (none are processed - not pending, not frozen, not cancelled)
                assert len(result) == 0
                
                # Verify current week API call
                mock_api_client.get.assert_called_once_with('current')
                
                # Verify team transactions call with week range
                mock_get_team.assert_called_once_with('WV', 12, week_start=8)  # 12 - 4 = 8
    
    @pytest.mark.asyncio
    async def test_get_processed_transactions_fallback(self, service):
        """Test processed transactions fallback when current week fails."""
        with patch.object(service, 'get_client', new_callable=AsyncMock) as mock_client:
            # Mock client to raise exception
            mock_client.side_effect = Exception("API Error")
            
            with patch.object(service, 'get_team_transactions', new_callable=AsyncMock) as mock_get_team:
                mock_get_team.return_value = []
                
                result = await service.get_processed_transactions('WV', 12)
                
                assert result == []
                # Verify fallback call without week range
                mock_get_team.assert_called_with('WV', 12)
    
    @pytest.mark.asyncio
    async def test_validate_transaction_success(self, service, mock_transaction_data):
        """Test successful transaction validation."""
        transaction = Transaction.from_api_data(mock_transaction_data)
        
        result = await service.validate_transaction(transaction)
        
        assert isinstance(result, RosterValidation)
        assert result.is_legal is True
        assert len(result.errors) == 0
    
    @pytest.mark.asyncio
    async def test_validate_transaction_no_moves(self, service, mock_transaction_data):
        """Test transaction validation with no moves (edge case)."""
        # For single-move transactions, this test simulates validation logic
        transaction = Transaction.from_api_data(mock_transaction_data)
        
        # Mock validation that would fail for complex business rules
        with patch.object(service, 'validate_transaction') as mock_validate:
            validation_result = RosterValidation(
                is_legal=False,
                errors=['Transaction validation failed']
            )
            mock_validate.return_value = validation_result
            
            result = await service.validate_transaction(transaction)
            
            assert result.is_legal is False
            assert 'Transaction validation failed' in result.errors
    
    @pytest.mark.skip(reason="Exception handling test needs refactoring for new patterns")
    @pytest.mark.asyncio
    async def test_validate_transaction_exception_handling(self, service, mock_transaction_data):
        """Test transaction validation exception handling."""
        pass
    
    @pytest.mark.asyncio
    async def test_cancel_transaction_success(self, service, mock_transaction_data):
        """Test successful transaction cancellation.

        The cancel_transaction method uses get_client().patch() directly,
        returning a success message for bulk updates. We mock the client.patch()
        method to simulate successful cancellation.
        """
        with patch.object(service, 'get_client', new_callable=AsyncMock) as mock_get_client:
            mock_client = AsyncMock()
            # cancel_transaction expects a string response for success
            mock_client.patch.return_value = "Updated 1 transactions"
            mock_get_client.return_value = mock_client

            result = await service.cancel_transaction('27787')

            assert result is True
            mock_client.patch.assert_called_once()
            call_args = mock_client.patch.call_args
            assert call_args[0][0] == 'transactions'  # endpoint
            assert 'cancelled' in call_args[0][1]  # update_data contains 'cancelled'
            assert call_args[1]['object_id'] == '27787'  # transaction_id
    
    @pytest.mark.asyncio
    async def test_cancel_transaction_not_found(self, service):
        """Test cancelling non-existent transaction.

        When the API returns None (no response), cancel_transaction returns False.
        """
        with patch.object(service, 'get_client', new_callable=AsyncMock) as mock_get_client:
            mock_client = AsyncMock()
            mock_client.patch.return_value = None  # No response = failure
            mock_get_client.return_value = mock_client

            result = await service.cancel_transaction('99999')

            assert result is False
    
    @pytest.mark.asyncio
    async def test_cancel_transaction_not_pending(self, service, mock_transaction_data):
        """Test cancelling already processed transaction.

        The API handles validation - we just need to simulate a failure response.
        """
        with patch.object(service, 'get_client', new_callable=AsyncMock) as mock_get_client:
            mock_client = AsyncMock()
            mock_client.patch.return_value = None  # API returns None on failure
            mock_get_client.return_value = mock_client

            result = await service.cancel_transaction('27787')

            assert result is False
    
    @pytest.mark.asyncio
    async def test_cancel_transaction_exception_handling(self, service):
        """Test transaction cancellation exception handling.

        When the API call raises an exception, cancel_transaction catches it
        and returns False.
        """
        with patch.object(service, 'get_client', new_callable=AsyncMock) as mock_get_client:
            mock_client = AsyncMock()
            mock_client.patch.side_effect = Exception("Database error")
            mock_get_client.return_value = mock_client

            result = await service.cancel_transaction('27787')

            assert result is False
    
    @pytest.mark.asyncio
    async def test_get_contested_transactions(self, service, mock_transaction_data):
        """Test getting contested transactions."""
        # Create transactions where multiple teams want the same player
        contested_data = [
            {**mock_transaction_data, 'id': 1, 'newteam': {'id': 499, 'abbrev': 'WV', 'sname': 'Black Bears', 'lname': 'West Virginia Black Bears', 'season': 12}},
            {**mock_transaction_data, 'id': 2, 'newteam': {'id': 502, 'abbrev': 'LAA', 'sname': 'Angels', 'lname': 'Los Angeles Angels', 'season': 12}},  # Same player, different team
        ]
        
        with patch.object(service, 'get_all_items', new_callable=AsyncMock) as mock_get:
            mock_get.return_value = [Transaction.from_api_data(tx) for tx in contested_data]
            
            result = await service.get_contested_transactions(12, 10)
            
            # Should return both transactions since they're for the same player
            assert len(result) == 2
            
            # Verify API call was made
            mock_get.assert_called_once()
            # Note: This test might need adjustment based on actual contested transaction logic
    
    @pytest.mark.asyncio
    async def test_api_exception_handling(self, service):
        """Test API exception handling in service methods."""
        with patch.object(service, 'get_all_items', new_callable=AsyncMock) as mock_get:
            mock_get.side_effect = APIException("API unavailable")
            
            with pytest.raises(APIException):
                await service.get_team_transactions('WV', 12)
    
    def test_global_service_instance(self):
        """Test that global service instance is properly initialized."""
        assert isinstance(transaction_service, TransactionService)
        assert transaction_service.model_class == Transaction
        assert transaction_service.endpoint == 'transactions'


class TestTransactionServiceIntegration:
    """Integration tests for TransactionService with real-like scenarios."""
    
    @pytest.mark.asyncio
    async def test_full_transaction_workflow(self):
        """Test complete transaction workflow simulation."""
        service = TransactionService()
        
        # Mock data for a complete workflow
        mock_data = {
            'id': 27787,
            'week': 10,
            'season': 12,
            'moveid': 'Season-012-Week-10-19-13:04:41',
            'player': {
                'id': 12472,
                'name': 'Test Player',
                'wara': 2.47,
                'season': 12,
                'pos_1': 'LF'
            },
            'oldteam': {
                'id': 508,
                'abbrev': 'NYD',
                'sname': 'Diamonds',
                'lname': 'New York Diamonds',
                'season': 12
            },
            'newteam': {
                'id': 499,
                'abbrev': 'WV',
                'sname': 'Black Bears',
                'lname': 'West Virginia Black Bears',
                'season': 12
            },
            'cancelled': False,
            'frozen': False
        }
        
        # Mock the full workflow properly
        transaction = Transaction.from_api_data(mock_data)

        # Mock get_pending_transactions to return our test transaction
        with patch.object(service, 'get_pending_transactions', new_callable=AsyncMock) as mock_get_pending:
            mock_get_pending.return_value = [transaction]

            # Mock cancel_transaction
            with patch.object(service, 'get_client', new_callable=AsyncMock) as mock_get_client:
                mock_client = AsyncMock()
                mock_client.patch.return_value = "Updated 1 transactions"
                mock_get_client.return_value = mock_client

                # Test workflow: get pending -> validate -> cancel
                pending = await service.get_pending_transactions('WV', 12)
                assert len(pending) == 1

                validation = await service.validate_transaction(pending[0])
                assert validation.is_legal is True

                cancelled = await service.cancel_transaction(str(pending[0].id))
                assert cancelled is True
    
    @pytest.mark.asyncio
    async def test_performance_with_large_dataset(self):
        """Test service performance with large transaction dataset."""
        service = TransactionService()
        
        # Create 100 mock transactions
        large_dataset = []
        for i in range(100):
            tx_data = {
                'id': i,
                'week': (i % 18) + 1,  # Weeks 1-18
                'season': 12,
                'moveid': f'Season-012-Week-{(i % 18) + 1:02d}-{i}',
                'player': {
                    'id': i + 1000,
                    'name': f'Player {i}',
                    'wara': round(1.0 + (i % 50) * 0.1, 2),
                    'season': 12,
                    'pos_1': 'LF'
                },
                'oldteam': {
                    'id': 508,
                    'abbrev': 'NYD',
                    'sname': 'Diamonds',
                    'lname': 'New York Diamonds',
                    'season': 12
                },
                'newteam': {
                    'id': 499,
                    'abbrev': 'WV',
                    'sname': 'Black Bears',
                    'lname': 'West Virginia Black Bears',
                    'season': 12
                },
                'cancelled': i % 10 == 0,  # Every 10th transaction is cancelled
                'frozen': i % 7 == 0       # Every 7th transaction is frozen
            }
            large_dataset.append(Transaction.from_api_data(tx_data))
        
        with patch.object(service, 'get_all_items', new_callable=AsyncMock) as mock_get:
            mock_get.return_value = large_dataset
            
            # Test that service handles large datasets efficiently
            import time
            start_time = time.time()
            
            result = await service.get_team_transactions('WV', 12)
            
            end_time = time.time()
            processing_time = end_time - start_time
            
            assert len(result) == 100
            assert processing_time < 1.0  # Should process quickly
            
            # Verify sorting worked correctly
            for i in range(len(result) - 1):
                assert result[i].week <= result[i + 1].week