# tests/test_stock_service.py
import uuid

import pytest

from app.services.stock_service import StockService
from app.exceptions import (
    StockNotFoundException,
    InsufficientStockException,
    InvalidStockOperationException,
    StockValidationException,
    NegativeStockException,
    InvalidQuantityException,
    ValidationException,
)
from models.schemas.stock import StockAdd, StockCreate, StockUpdate
from models.database.marketplace_product import MarketplaceProduct
from models.database.stock import Stock


@pytest.mark.unit
@pytest.mark.stock
class TestStockService:
    def setup_method(self):
        self.service = StockService()

    def test_normalize_gtin_invalid(self):
        """Test GTIN normalization with invalid GTINs."""
        # Completely invalid values that should return None
        assert self.service._normalize_gtin("invalid") is None
        assert self.service._normalize_gtin("abcdef") is None
        assert self.service._normalize_gtin("") is None
        assert self.service._normalize_gtin(None) is None
        assert self.service._normalize_gtin("   ") is None  # Only whitespace
        assert self.service._normalize_gtin("!@#$%") is None  # Only special characters

        # Mixed invalid characters that become empty after filtering
        assert self.service._normalize_gtin("abc-def-ghi") is None  # No digits

    def test_normalize_gtin_valid(self):
        """Test GTIN normalization with valid GTINs."""
        # Test various valid GTIN formats - these should remain unchanged
        assert self.service._normalize_gtin("1234567890123") == "1234567890123"  # EAN-13
        assert self.service._normalize_gtin("123456789012") == "123456789012"  # UPC-A
        assert self.service._normalize_gtin("12345678") == "12345678"  # EAN-8
        assert self.service._normalize_gtin("12345678901234") == "12345678901234"  # GTIN-14

        # Test with decimal points (should be removed)
        assert self.service._normalize_gtin("1234567890123.0") == "1234567890123"

        # Test with whitespace (should be trimmed)
        assert self.service._normalize_gtin("  1234567890123  ") == "1234567890123"

        # Test short GTINs being padded
        assert self.service._normalize_gtin("123") == "0000000000123"  # Padded to EAN-13
        assert self.service._normalize_gtin("12345") == "0000000012345"  # Padded to EAN-13

        # Test long GTINs being truncated
        assert self.service._normalize_gtin("123456789012345") == "3456789012345"  # Truncated to 13

    def test_normalize_gtin_edge_cases(self):
        """Test GTIN normalization edge cases."""
        # Test numeric inputs
        assert self.service._normalize_gtin(1234567890123) == "1234567890123"
        assert self.service._normalize_gtin(123) == "0000000000123"

        # Test mixed valid/invalid characters
        assert self.service._normalize_gtin("123-456-789-012") == "123456789012"  # Dashes removed
        assert self.service._normalize_gtin("123 456 789 012") == "123456789012"  # Spaces removed
        assert self.service._normalize_gtin("ABC123456789012DEF") == "123456789012"  # Letters removed

    def test_set_stock_new_entry_success(self, db):
        """Test setting stock for a new GTIN/location combination successfully."""
        unique_id = str(uuid.uuid4())[:8]
        stock_data = StockCreate(
            gtin="1234567890123", location=f"WAREHOUSE_A_{unique_id}", quantity=100
        )

        result = self.service.set_stock(db, stock_data)

        assert result.gtin == "1234567890123"
        assert result.location.upper() == f"WAREHOUSE_A_{unique_id}".upper()
        assert result.quantity == 100

    def test_set_stock_existing_entry_success(self, db, test_stock):
        """Test setting stock for an existing GTIN/location combination successfully."""
        stock_data = StockCreate(
            gtin=test_stock.gtin,
            location=test_stock.location,  # Use exact same location as test_stock
            quantity=200,
        )

        result = self.service.set_stock(db, stock_data)

        assert result.gtin == test_stock.gtin
        assert result.location == test_stock.location
        assert result.quantity == 200  # Should replace the original quantity

    def test_set_stock_invalid_gtin_validation_error(self, db):
        """Test setting stock with invalid GTIN returns StockValidationException."""
        stock_data = StockCreate(
            gtin="invalid_gtin", location="WAREHOUSE_A", quantity=100
        )

        with pytest.raises(StockValidationException) as exc_info:
            self.service.set_stock(db, stock_data)

        assert exc_info.value.error_code == "STOCK_VALIDATION_FAILED"
        assert "Invalid GTIN format" in str(exc_info.value)
        assert exc_info.value.details.get("field") == "gtin"

    def test_set_stock_invalid_quantity_error(self, db):
        """Test setting stock with invalid quantity through service validation."""

        # Test the service validation directly instead of going through Pydantic schema
        # This bypasses the Pydantic validation to test service layer validation

        # Create a mock stock data object that bypasses Pydantic validation
        class MockStockData:
            def __init__(self, gtin, location, quantity):
                self.gtin = gtin
                self.location = location
                self.quantity = quantity

        mock_stock_data = MockStockData("1234567890123", "WAREHOUSE_A", -10)

        # Test the internal validation method directly
        with pytest.raises(InvalidQuantityException) as exc_info:
            self.service._validate_quantity(-10, allow_zero=True)

        assert exc_info.value.error_code == "INVALID_QUANTITY"
        assert "Quantity cannot be negative" in str(exc_info.value)
        assert exc_info.value.details.get("quantity") == -10

    def test_add_stock_new_entry_success(self, db):
        """Test adding stock for a new GTIN/location combination successfully."""
        unique_id = str(uuid.uuid4())[:8]
        stock_data = StockAdd(
            gtin="1234567890123", location=f"WAREHOUSE_B_{unique_id}", quantity=50
        )

        result = self.service.add_stock(db, stock_data)

        assert result.gtin == "1234567890123"
        assert result.location.upper() == f"WAREHOUSE_B_{unique_id}".upper()
        assert result.quantity == 50

    def test_add_stock_existing_entry_success(self, db, test_stock):
        """Test adding stock to an existing GTIN/location combination successfully."""
        original_quantity = test_stock.quantity
        stock_data = StockAdd(
            gtin=test_stock.gtin,
            location=test_stock.location,  # Use exact same location as test_stock
            quantity=25,
        )

        result = self.service.add_stock(db, stock_data)

        assert result.gtin == test_stock.gtin
        assert result.location == test_stock.location
        assert result.quantity == original_quantity + 25

    def test_add_stock_invalid_gtin_validation_error(self, db):
        """Test adding stock with invalid GTIN returns StockValidationException."""
        stock_data = StockAdd(gtin="invalid_gtin", location="WAREHOUSE_A", quantity=50)

        with pytest.raises(StockValidationException) as exc_info:
            self.service.add_stock(db, stock_data)

        assert exc_info.value.error_code == "STOCK_VALIDATION_FAILED"
        assert "Invalid GTIN format" in str(exc_info.value)

    def test_add_stock_invalid_quantity_error(self, db):
        """Test adding stock with invalid quantity through service validation."""
        # Test zero quantity which should fail for add_stock (doesn't allow zero)
        # This tests the service validation: allow_zero=False for add operations
        with pytest.raises(InvalidQuantityException) as exc_info:
            self.service._validate_quantity(0, allow_zero=False)

        assert exc_info.value.error_code == "INVALID_QUANTITY"
        assert "Quantity must be positive" in str(exc_info.value)


    def test_remove_stock_success(self, db, test_stock):
        """Test removing stock successfully."""
        original_quantity = test_stock.quantity
        remove_quantity = min(10, original_quantity)  # Ensure we don't remove more than available

        stock_data = StockAdd(
            gtin=test_stock.gtin,
            location=test_stock.location,  # Use exact same location as test_stock
            quantity=remove_quantity,
        )

        result = self.service.remove_stock(db, stock_data)

        assert result.gtin == test_stock.gtin
        assert result.location == test_stock.location
        assert result.quantity == original_quantity - remove_quantity

    def test_remove_stock_insufficient_stock_error(self, db, test_stock):
        """Test removing more stock than available returns InsufficientStockException."""
        stock_data = StockAdd(
            gtin=test_stock.gtin,
            location=test_stock.location,  # Use exact same location as test_stock
            quantity=test_stock.quantity + 10,  # More than available
        )

        with pytest.raises(InsufficientStockException) as exc_info:
            self.service.remove_stock(db, stock_data)

        assert exc_info.value.error_code == "INSUFFICIENT_STOCK"
        assert exc_info.value.details["gtin"] == test_stock.gtin
        assert exc_info.value.details["location"] == test_stock.location
        assert exc_info.value.details["requested_quantity"] == test_stock.quantity + 10
        assert exc_info.value.details["available_quantity"] == test_stock.quantity

    def test_remove_stock_nonexistent_entry_not_found(self, db):
        """Test removing stock from non-existent GTIN/location returns StockNotFoundException."""
        unique_id = str(uuid.uuid4())[:8]
        stock_data = StockAdd(
            gtin="9999999999999", location=f"NONEXISTENT_{unique_id}", quantity=10
        )

        with pytest.raises(StockNotFoundException) as exc_info:
            self.service.remove_stock(db, stock_data)

        assert exc_info.value.error_code == "STOCK_NOT_FOUND"
        assert "9999999999999" in str(exc_info.value)
        assert exc_info.value.details["resource_type"] == "Stock"

    def test_remove_stock_invalid_gtin_validation_error(self, db):
        """Test removing stock with invalid GTIN returns StockValidationException."""
        stock_data = StockAdd(gtin="invalid_gtin", location="WAREHOUSE_A", quantity=10)

        with pytest.raises(StockValidationException) as exc_info:
            self.service.remove_stock(db, stock_data)

        assert exc_info.value.error_code == "STOCK_VALIDATION_FAILED"
        assert "Invalid GTIN format" in str(exc_info.value)

    def test_remove_stock_negative_result_error(self, db, test_stock):
        """Test removing stock that would result in negative quantity returns NegativeStockException."""
        # This is handled by InsufficientStockException, but test the logic
        stock_data = StockAdd(
            gtin=test_stock.gtin,
            location=test_stock.location,
            quantity=test_stock.quantity + 1,  # One more than available
        )

        with pytest.raises(InsufficientStockException) as exc_info:
            self.service.remove_stock(db, stock_data)

        # The service prevents negative stock through InsufficientStockException
        assert exc_info.value.error_code == "INSUFFICIENT_STOCK"

    def test_get_stock_by_gtin_success(self, db, test_stock, test_marketplace_product):
        """Test getting stock summary by GTIN successfully."""
        result = self.service.get_stock_by_gtin(db, test_stock.gtin)

        assert result.gtin == test_stock.gtin
        assert result.total_quantity == test_stock.quantity
        assert len(result.locations) == 1
        assert result.locations[0].location == test_stock.location
        assert result.locations[0].quantity == test_stock.quantity
        assert result.product_title == test_marketplace_product.title

    def test_get_stock_by_gtin_multiple_locations_success(self, db, test_marketplace_product):
        """Test getting stock summary with multiple locations successfully."""
        unique_gtin = test_marketplace_product.gtin
        unique_id = str(uuid.uuid4())[:8]

        # Create multiple stock entries for the same GTIN with unique locations
        stock1 = Stock(gtin=unique_gtin, location=f"WAREHOUSE_A_{unique_id}", quantity=50)
        stock2 = Stock(gtin=unique_gtin, location=f"WAREHOUSE_B_{unique_id}", quantity=30)

        db.add(stock1)
        db.add(stock2)
        db.commit()

        result = self.service.get_stock_by_gtin(db, unique_gtin)

        assert result.gtin == unique_gtin
        assert result.total_quantity == 80
        assert len(result.locations) == 2

    def test_get_stock_by_gtin_not_found_error(self, db):
        """Test getting stock for non-existent GTIN returns StockNotFoundException."""
        with pytest.raises(StockNotFoundException) as exc_info:
            self.service.get_stock_by_gtin(db, "9999999999999")

        assert exc_info.value.error_code == "STOCK_NOT_FOUND"
        assert "9999999999999" in str(exc_info.value)
        assert exc_info.value.details["resource_type"] == "Stock"

    def test_get_stock_by_gtin_invalid_gtin_validation_error(self, db):
        """Test getting stock with invalid GTIN returns StockValidationException."""
        with pytest.raises(StockValidationException) as exc_info:
            self.service.get_stock_by_gtin(db, "invalid_gtin")

        assert exc_info.value.error_code == "STOCK_VALIDATION_FAILED"
        assert "Invalid GTIN format" in str(exc_info.value)

    def test_get_total_stock_success(self, db, test_stock, test_marketplace_product):
        """Test getting total stock for a GTIN successfully."""
        result = self.service.get_total_stock(db, test_stock.gtin)

        assert result["gtin"] == test_stock.gtin
        assert result["total_quantity"] == test_stock.quantity
        assert result["product_title"] == test_marketplace_product.title
        assert result["locations_count"] == 1

    def test_get_total_stock_invalid_gtin_validation_error(self, db):
        """Test getting total stock with invalid GTIN returns StockValidationException."""
        with pytest.raises(StockValidationException) as exc_info:
            self.service.get_total_stock(db, "invalid_gtin")

        assert exc_info.value.error_code == "STOCK_VALIDATION_FAILED"
        assert "Invalid GTIN format" in str(exc_info.value)

    def test_get_total_stock_not_found_error(self, db):
        """Test getting total stock for non-existent GTIN returns StockNotFoundException."""
        with pytest.raises(StockNotFoundException) as exc_info:
            self.service.get_total_stock(db, "9999999999999")

        assert exc_info.value.error_code == "STOCK_NOT_FOUND"

    def test_get_all_stock_no_filters_success(self, db, test_stock):
        """Test getting all stock without filters successfully."""
        result = self.service.get_all_stock(db)

        assert len(result) >= 1
        assert any(stock.gtin == test_stock.gtin for stock in result)

    def test_get_all_stock_with_location_filter_success(self, db, test_stock):
        """Test getting all stock with location filter successfully."""
        result = self.service.get_all_stock(db, location=test_stock.location)

        assert len(result) >= 1
        # Check that all returned stocks match the filter (case insensitive)
        for stock in result:
            assert test_stock.location.upper() in stock.location.upper()

    def test_get_all_stock_with_gtin_filter_success(self, db, test_stock):
        """Test getting all stock with GTIN filter successfully."""
        result = self.service.get_all_stock(db, gtin=test_stock.gtin)

        assert len(result) >= 1
        assert all(stock.gtin == test_stock.gtin for stock in result)

    def test_get_all_stock_with_pagination_success(self, db):
        """Test getting all stock with pagination successfully."""
        unique_prefix = str(uuid.uuid4())[:8]

        # Create multiple stock entries with unique GTINs and locations
        for i in range(5):
            stock = Stock(
                gtin=f"1234567890{i:03d}",  # Creates valid 13-digit GTINs
                location=f"WAREHOUSE_{unique_prefix}_{i}",
                quantity=10,
            )
            db.add(stock)
        db.commit()

        result = self.service.get_all_stock(db, skip=2, limit=2)

        assert len(result) <= 2  # Should be at most 2, might be less if other records exist

    def test_update_stock_success(self, db, test_stock):
        """Test updating stock quantity successfully."""
        stock_update = StockUpdate(quantity=150)

        result = self.service.update_stock(db, test_stock.id, stock_update)

        assert result.id == test_stock.id
        assert result.quantity == 150

    def test_update_stock_not_found_error(self, db):
        """Test updating non-existent stock entry returns StockNotFoundException."""
        stock_update = StockUpdate(quantity=150)

        with pytest.raises(StockNotFoundException) as exc_info:
            self.service.update_stock(db, 99999, stock_update)

        assert exc_info.value.error_code == "STOCK_NOT_FOUND"
        assert "99999" in str(exc_info.value)

    def test_update_stock_invalid_quantity_error(self, db, test_stock):
        """Test updating stock with invalid quantity returns InvalidQuantityException."""
        stock_update = StockUpdate(quantity=-10)

        with pytest.raises(InvalidQuantityException) as exc_info:
            self.service.update_stock(db, test_stock.id, stock_update)

        assert exc_info.value.error_code == "INVALID_QUANTITY"
        assert "Quantity cannot be negative" in str(exc_info.value)

    def test_delete_stock_success(self, db, test_stock):
        """Test deleting stock entry successfully."""
        stock_id = test_stock.id

        result = self.service.delete_stock(db, stock_id)

        assert result is True

        # Verify the stock is actually deleted
        deleted_stock = db.query(Stock).filter(Stock.id == stock_id).first()
        assert deleted_stock is None

    def test_delete_stock_not_found_error(self, db):
        """Test deleting non-existent stock entry returns StockNotFoundException."""
        with pytest.raises(StockNotFoundException) as exc_info:
            self.service.delete_stock(db, 99999)

        assert exc_info.value.error_code == "STOCK_NOT_FOUND"
        assert "99999" in str(exc_info.value)

    def test_get_low_stock_items_success(self, db, test_stock, test_marketplace_product):
        """Test getting low stock items successfully."""
        # Set stock to a low value
        test_stock.quantity = 5
        db.commit()

        result = self.service.get_low_stock_items(db, threshold=10)

        assert len(result) >= 1
        low_stock_item = next((item for item in result if item["gtin"] == test_stock.gtin), None)
        assert low_stock_item is not None
        assert low_stock_item["current_quantity"] == 5
        assert low_stock_item["location"] == test_stock.location
        assert low_stock_item["product_title"] == test_marketplace_product.title

    def test_get_low_stock_items_invalid_threshold_error(self, db):
        """Test getting low stock items with invalid threshold returns InvalidQuantityException."""
        with pytest.raises(InvalidQuantityException) as exc_info:
            self.service.get_low_stock_items(db, threshold=-5)

        assert exc_info.value.error_code == "INVALID_QUANTITY"
        assert "Threshold must be non-negative" in str(exc_info.value)

    def test_get_stock_summary_by_location_success(self, db, test_stock):
        """Test getting stock summary by location successfully."""
        result = self.service.get_stock_summary_by_location(db, test_stock.location)

        assert result["location"] == test_stock.location.upper()  # Service normalizes to uppercase
        assert result["total_items"] >= 1
        assert result["total_quantity"] >= test_stock.quantity
        assert result["unique_gtins"] >= 1

    def test_get_stock_summary_by_location_empty_result(self, db):
        """Test getting stock summary for location with no stock."""
        unique_id = str(uuid.uuid4())[:8]
        result = self.service.get_stock_summary_by_location(db, f"EMPTY_LOCATION_{unique_id}")

        assert result["total_items"] == 0
        assert result["total_quantity"] == 0
        assert result["unique_gtins"] == 0

    def test_validate_quantity_edge_cases(self, db):
        """Test quantity validation with edge cases."""
        # Test zero quantity with allow_zero=True (should succeed)
        stock_data = StockCreate(gtin="1234567890123", location="WAREHOUSE_A", quantity=0)
        result = self.service.set_stock(db, stock_data)
        assert result.quantity == 0

        # Test zero quantity with add_stock (should fail - doesn't allow zero)
        stock_data_add = StockAdd(gtin="1234567890123", location="WAREHOUSE_B", quantity=0)
        with pytest.raises(InvalidQuantityException):
            self.service.add_stock(db, stock_data_add)

    def test_exception_structure_consistency(self, db):
        """Test that all exceptions follow the consistent LetzShopException structure."""
        # Test with a known error case
        with pytest.raises(StockNotFoundException) as exc_info:
            self.service.get_stock_by_gtin(db, "9999999999999")

        exception = exc_info.value

        # Verify exception structure matches LetzShopException.to_dict()
        assert hasattr(exception, 'error_code')
        assert hasattr(exception, 'message')
        assert hasattr(exception, 'status_code')
        assert hasattr(exception, 'details')

        assert isinstance(exception.error_code, str)
        assert isinstance(exception.message, str)
        assert isinstance(exception.status_code, int)
        assert isinstance(exception.details, dict)


@pytest.fixture
def test_product_with_stock(db, test_stock):
    """Create a test product that corresponds to the test stock."""
    product = MarketplaceProduct(
        marketplace_product_id="STOCK_TEST_001",
        title="Stock Test MarketplaceProduct",
        gtin=test_stock.gtin,
        price="29.99",
        brand="TestBrand",
        marketplace="Letzshop",
    )
    db.add(product)
    db.commit()
    db.refresh(product)
    return product