using System;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Windows.Forms;
using HeuristicLab.Services.Optimization.Billing.Interfaces;
using HeuristicLab.Services.Optimization.Billing.Model;

namespace HeuristicLab.Services.Optimization.Billing.BillingEngine {
  public enum PlainTextInvoiceFormat {
    TXT,
    RTF,
    PDF
  }

  public class PlainTextInvoiceFormattingEngine : IInvoiceFormattingEngine {
    private const string defaultTemplatePath = @"BillingEngine\InvoiceTemplate.txt";
    private string template;
    private string invoiceText;
    private PlainTextInvoiceFormat invoiceFormat;
    private string invoiceOutputPath;

    public PlainTextInvoiceFormattingEngine()
      : this(defaultTemplatePath, PlainTextInvoiceFormat.RTF) {

    }

    public PlainTextInvoiceFormattingEngine(string templatePath, PlainTextInvoiceFormat format) {
      if (!File.Exists(templatePath)) {
        throw new FileNotFoundException("Cannot find template file", templatePath);
      }
      template = File.ReadAllText(templatePath);

      if (format == PlainTextInvoiceFormat.PDF) {
        throw new Exception("PDF invoice format is currently not supported");
      }
      invoiceFormat = format;
    }

    public string Generate(Invoice invoice) {
      invoiceText = string.Copy(template);

      invoiceText = invoiceText.Replace("{INVOICE_ID}", invoice.InvoiceId.ToString());

      invoiceText = invoiceText.Replace("{ORGANIZATION_NAME}", invoice.User.ContactInformation.OrganizationName);
      invoiceText = invoiceText.Replace("{FIRSTNAME}", invoice.User.ContactInformation.FirstName);
      invoiceText = invoiceText.Replace("{LASTNAME}", invoice.User.ContactInformation.LastName);
      invoiceText = invoiceText.Replace("{STREET}", invoice.User.ContactInformation.Street);
      invoiceText = invoiceText.Replace("{POSTAL_CODE}", invoice.User.ContactInformation.PostalCode);
      invoiceText = invoiceText.Replace("{CITY}", invoice.User.ContactInformation.City);

      invoiceText = invoiceText.Replace("{INVOICE_DATE}", invoice.InvoiceDate.ToString("dd.MM.yyyy"));
      invoiceText = invoiceText.Replace("{ORDER_ID}", invoice.OrderId.ToString());
      invoiceText = invoiceText.Replace("{USER_NAME}", invoice.User.Name);
      invoiceText = invoiceText.Replace("{PAYMENT_TERMS}", "2% 10, net 30 days");
      invoiceText = invoiceText.Replace("{PAYMENT_DUE}", invoice.Due.Date.ToString("dd.MM.yyyy"));

      int itemNo = invoice.InvoiceLines.Count;
      int first = invoiceText.IndexOf("#BEGIN");
      int last = invoiceText.LastIndexOf("#END");
      string orderLineTextTemplate = invoiceText.Substring(first, last + 6 - first);
      invoiceText = invoiceText.Remove(first, last + 6 - first);
      foreach (InvoiceLine invoiceLine in invoice.InvoiceLines.Reverse()) {
        string invoiceLineText = string.Copy(orderLineTextTemplate);

        invoiceLineText = invoiceLineText.Replace("{ITEM}", (itemNo).ToString().PadRight(5));
        itemNo--;
        invoiceLineText = invoiceLineText.Replace("{PRODUCT_NAME}", invoiceLine.Product.Name.PadRight(39));
        invoiceLineText = invoiceLineText.Replace("{QUANTITY}", invoiceLine.Quantity.ToString().PadRight(9));
        invoiceLineText = invoiceLineText.Replace("{PRODUCT_PRICE}", invoiceLine.ProductPrice.ToString("C2").PadLeft(10));
        double totalPrice = invoiceLine.Quantity * invoiceLine.ProductPrice;
        invoiceLineText = invoiceLineText.Replace("{PRODUCT_TOTAL}", totalPrice.ToString("C2").PadLeft(11));

        invoiceLineText = invoiceLineText.Remove(invoiceLineText.IndexOf("#BEGIN"), 7);
        invoiceLineText = invoiceLineText.Remove(invoiceLineText.IndexOf("#END"), 4);

        invoiceText = invoiceText.Insert(first, invoiceLineText);
      }

      invoiceText = invoiceText.Replace("{INVOICE_SUB_TOTAL}", string.Format("{0:C2}", invoice.Total - invoice.Tax).PadLeft(18));
      invoiceText = invoiceText.Replace("{INVOICE_TAX}", invoice.Tax.ToString("C2").PadLeft(12));
      invoiceText = invoiceText.Replace("{INVOICE_TOTAL}", invoice.Total.ToString("C2").PadLeft(14));

      if (invoiceFormat == PlainTextInvoiceFormat.RTF) {
        invoiceOutputPath = string.Format("{0}_{1}_{2}.rtf", invoice.InvoiceId, invoice.InvoiceDate.ToString("yyyMMdd"), "{CUSTOMER}");

        RichTextBox richTextBox = new RichTextBox();
        richTextBox.Text = invoiceText;
        richTextBox.SelectAll();
        richTextBox.SelectionFont = new Font("Consolas", 10, FontStyle.Regular);

        File.WriteAllText(invoiceOutputPath, richTextBox.Rtf);
      } else if (invoiceFormat == PlainTextInvoiceFormat.TXT) {
        invoiceOutputPath = string.Format("{0}_{1}_{2}.txt", invoice.InvoiceId, invoice.InvoiceDate.ToString("yyyMMdd"), "{CUSTOMER}");

        File.WriteAllText(invoiceOutputPath, invoiceText);
      } else if (invoiceFormat == PlainTextInvoiceFormat.PDF) {
        throw new Exception("PDF invoice format is currently not supported");
      }

      return invoiceOutputPath;
    }
  }
}