namespace ConsoleApp1;

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using System;

using System.Linq;

using LanguageExt;

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// --- Domain Models ---

public record Product(string Name, decimal Price);

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public record Order(string OrderId, string CustomerName, Product[] Products);

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// --- Formatting Logic ---

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public delegate string FormatOrderDelegate(Order order);

public delegate string FormatOrdersDelegate(FormatOrderDelegate formatter, Order[] orders);

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// --- Formatters ---

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public static class InvoiceFormatters

{

    // Formatter for CSV format

    public static FormatOrderDelegate CsvFormatter = order =>

        $"{order.OrderId}, {order.CustomerName}, {string.Join(", ", order.Products.Select(p => $"{p.Name} ({p.Price:C})"))}";

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    // Formatter for JSON format

    public static FormatOrderDelegate JsonFormatter = order =>

        $"{{\"OrderId\": \"{order.OrderId}\", \"Customer\": \"{order.CustomerName}\", \"Products\": [{string.Join(", ", order.Products.Select(p => $"{{\"Name\": \"{p.Name}\", \"Price\": {p.Price}}}"))}]}}";

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    // Formatter for PDF format (simplified)

    public static FormatOrderDelegate PdfFormatter = order =>

        $"Invoice for Order ID: {order.OrderId}\nCustomer: {order.CustomerName}\nProducts:\n{string.Join("\n", order.Products.Select(p => $"- {p.Name}: {p.Price:C}"))}";

}

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// --- Invoice Generator ---

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public static class InvoiceGenerator

{

    // Function for generating an invoice (formats all orders)

    public static string GenerateInvoice(FormatOrderDelegate formatOrder, Order[] orders)

    {

        return string.Join("\n", orders.Select(formatOrder.Invoke));

    }

}

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// --- Program (Using Partial Function Application) ---

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public static class Program

{

    public static void Main()

    {

        // Example products

        Product[] products =

        [

            new Product("Laptop", 1200.00m),

            new Product("Mouse", 25.00m),

            new Product("Keyboard", 45.00m)

        ];

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        // Example orders

        Order[] orders =

        [

            new Order("ORD123", "John Doe", products),

            new Order("ORD124", "Jane Smith", products)

        ];

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        // Curried function to generate invoices in different formats

        var curriedGenerateInvoice = Prelude.curry<FormatOrderDelegate, Order[], string>(InvoiceGenerator.GenerateInvoice);

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        // Partially apply the curried function for different formats

        Func<Order[], string> generateCsvInvoice = curriedGenerateInvoice(InvoiceFormatters.CsvFormatter);

        Func<Order[], string> generateJsonInvoice = curriedGenerateInvoice(InvoiceFormatters.JsonFormatter);

        Func<Order[], string> generatePdfInvoice = curriedGenerateInvoice(InvoiceFormatters.PdfFormatter);

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        // Generate invoices

        string csvInvoice = generateCsvInvoice(orders);

        string jsonInvoice = generateJsonInvoice(orders);

        string pdfInvoice = generatePdfInvoice(orders);

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        // Output the invoices

        Console.WriteLine("CSV Invoice:");

        Console.WriteLine(csvInvoice);

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        Console.WriteLine("\nJSON Invoice:");

        Console.WriteLine(jsonInvoice);

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        Console.WriteLine("\nPDF Invoice:");

        Console.WriteLine(pdfInvoice);

    }

}

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