using SampleWebApi.Models;

namespace SampleWebApi.Data;

public static class DataSeeder
{
    private static readonly Random _random = new Random();
    private static readonly string[] _categories = { "Electronics", "Books", "Clothing", "Home & Garden", "Sports", "Toys", "Food & Beverage" };
    private static readonly string[] _productAdjectives = { "Premium", "Essential", "Professional", "Deluxe", "Standard", "Advanced", "Basic" };
    private static readonly string[] _productNouns = { "Widget", "Gadget", "Tool", "Device", "Kit", "Set", "Pack", "Bundle" };

    public static async Task SeedAsync(SampleDbContext context)
    {
        // Check if data already exists
        if (context.Products.Any())
        {
            return;
        }

        // Create customers
        var customers = GenerateCustomers(1000);
        await context.Customers.AddRangeAsync(customers);
        await context.SaveChangesAsync();

        // Create products
        var products = GenerateProducts(10000);
        await context.Products.AddRangeAsync(products);
        await context.SaveChangesAsync();

        // Create orders with items
        var orders = GenerateOrders(customers, products, 50000);
        await context.Orders.AddRangeAsync(orders);
        await context.SaveChangesAsync();
    }

    private static List<Customer> GenerateCustomers(int count)
    {
        var customers = new List<Customer>();
        
        for (int i = 1; i <= count; i++)
        {
            customers.Add(new Customer
            {
                Id = $"CUST{i:D6}",
                Name = $"Customer {i}",
                Email = $"customer{i}@example.com",
                RegisteredAt = DateTime.UtcNow.AddDays(-_random.Next(1, 730))
            });
        }

        return customers;
    }

    private static List<Product> GenerateProducts(int count)
    {
        var products = new List<Product>();
        
        for (int i = 1; i <= count; i++)
        {
            var category = _categories[_random.Next(_categories.Length)];
            var adjective = _productAdjectives[_random.Next(_productAdjectives.Length)];
            var noun = _productNouns[_random.Next(_productNouns.Length)];
            
            products.Add(new Product
            {
                Id = i,
                Name = $"{adjective} {noun} {i}",
                Description = $"High-quality {adjective.ToLower()} {noun.ToLower()} for {category.ToLower()} enthusiasts",
                Category = category,
                Price = (decimal)(_random.NextDouble() * 990 + 10), // $10 to $1000
                StockQuantity = _random.Next(0, 1000),
                CreatedAt = DateTime.UtcNow.AddDays(-_random.Next(1, 365)),
                UpdatedAt = DateTime.UtcNow.AddDays(-_random.Next(0, 30))
            });
        }

        return products;
    }

    private static List<Order> GenerateOrders(List<Customer> customers, List<Product> products, int count)
    {
        var orders = new List<Order>();
        
        for (int i = 1; i <= count; i++)
        {
            var customer = customers[_random.Next(customers.Count)];
            var orderDate = DateTime.UtcNow.AddDays(-_random.Next(0, 365));
            var itemCount = _random.Next(1, 10);
            var orderItems = new List<OrderItem>();
            decimal totalAmount = 0;

            // Add random products to the order
            var selectedProducts = products
                .OrderBy(x => _random.Next())
                .Take(itemCount)
                .ToList();

            foreach (var product in selectedProducts)
            {
                var quantity = _random.Next(1, 5);
                var itemTotal = product.Price * quantity;
                totalAmount += itemTotal;

                orderItems.Add(new OrderItem
                {
                    ProductId = product.Id,
                    Quantity = quantity,
                    UnitPrice = product.Price,
                    TotalPrice = itemTotal
                });
            }

            orders.Add(new Order
            {
                Id = i,
                CustomerId = customer.Id,
                OrderDate = orderDate,
                TotalAmount = totalAmount,
                Status = GetRandomOrderStatus(orderDate),
                Items = orderItems
            });
        }

        return orders;
    }

    private static string GetRandomOrderStatus(DateTime orderDate)
    {
        var daysSinceOrder = (DateTime.UtcNow - orderDate).Days;
        
        if (daysSinceOrder < 1)
            return "Pending";
        else if (daysSinceOrder < 3)
            return _random.Next(2) == 0 ? "Processing" : "Pending";
        else if (daysSinceOrder < 7)
            return _random.Next(3) == 0 ? "Shipped" : "Processing";
        else
            return _random.Next(10) == 0 ? "Cancelled" : "Delivered";
    }
}