prs/prs.desktop/Utils/EmailUtils.cs

using InABox.Clients;
using InABox.Core;
using InABox.Reports;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Net.Mail;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Controls;
using System.Windows;
using System.Windows.Forms;
using System.Drawing;
using InABox.WPF;
using MessageBox = System.Windows.Forms.MessageBox;
using Comal.Classes;
using TextBox = System.Windows.Controls.TextBox;
using InABox.Wpf.Reports;

namespace PRSDesktop
{
    public class EmailUtils
    {   
        /// <summary>
         /// Creates and opens an email with the default email app - selected by the user.
         /// This method is for emails with a PDF attachment. Provide the file name and data.
         /// Optionally provide from, subject and body.
         /// If from is not provided, an attempt will be made to find the User's email address - if empty it will throw an error (cannot be empty)
         /// </summary>
         /// <param name="attachmentname"></param>
         /// <param name="attachmentdata"></param>
         /// <param name="from"></param>
         /// <param name="subject"></param>
         /// <param name="body"></param>
        public static void CreateEMLFile(string attachmentname, byte[] attachmentdata, string from = "", string subject = "", string body = "", string to = "")
        {
            var message = CreateMessage(from, subject, body, to);

            message = AddAttachment(message, attachmentname, attachmentdata);

            OpenEmail(message, attachmentname);
        }
        
        /// <summary>
        /// Creates and opens an email with the default email app - selected by the user.
        /// This method is for emails with multiple PDF attachments. Provide the a Dictionary of names and byte arrays
        /// Optionally provide from, subject and body.
        /// If from is not provided, an attempt will be made to find the User's email address - if empty it will throw an error (cannot be empty)
        /// </summary>
        /// <param name="attachmentname"></param>
        /// <param name="attachmentdata"></param>
        /// <param name="from"></param>
        /// <param name="subject"></param>
        /// <param name="body"></param>
        public static void CreateEMLFile(Dictionary<string,byte[]> attachments, string from = "", string subject = "", string body = "", string to = "")
        {
            var message = CreateMessage(from, subject, body, to);

            foreach (var key in attachments.Keys)
                AddAttachment(message, key, attachments[key]);

            OpenEmail(message);
        }

        /// <summary>
        /// Creates and opens an email with the default email app - selected by the user.
        /// This method is for emails with no attachments.
        /// Optionally provide from, subject and body.
        /// If from is not provided, an attempt will be made to find the User's email address - if empty it will throw an error (cannot be empty)
        /// </summary>
        /// <param name="from"></param>
        /// <param name="subject"></param>
        /// <param name="body"></param>

        public static void CreateEMLFile(string from = "", string subject = "", string body = "")
        {
            var message = CreateMessage(from, subject, body);

            OpenEmail(message, "Message from " + from);
        }

        private static void OpenEmail(MailMessage message, string name = null)
        {
            var filename = Path.Combine(
                Path.GetTempPath(), 
                Path.ChangeExtension(String.IsNullOrWhiteSpace(name) ? Guid.NewGuid().ToString() : name, ".eml")
            );

            using (var filestream = File.Open(filename, FileMode.Create))
            {
                var binaryWriter = new BinaryWriter(filestream);
                //Write the Unsent header to the file so the mail client knows this mail must be presented in "New message" mode
                binaryWriter.Write(Encoding.UTF8.GetBytes("X-Unsent: 1" + Environment.NewLine));

                var assembly = typeof(SmtpClient).Assembly;
                var mailWriterType = assembly.GetType("System.Net.Mail.MailWriter")!;

                // Get reflection info for MailWriter contructor
                var mailWriterConstructor =
                    mailWriterType.GetConstructor(BindingFlags.Instance | BindingFlags.NonPublic, null, new Type[] { typeof(Stream), typeof(bool) }, null)!;

                // Construct MailWriter object with our FileStream
                var mailWriter = mailWriterConstructor.Invoke(new object[] { filestream, true });

                // Get reflection info for Send() method on MailMessage
                var sendMethod = typeof(MailMessage).GetMethod("Send", BindingFlags.Instance | BindingFlags.NonPublic)!;

                sendMethod.Invoke(message, BindingFlags.Instance | BindingFlags.NonPublic, null, new[] { mailWriter, true, true }, null);

                // Finally get reflection info for Close() method on our MailWriter
                var closeMethod = mailWriter.GetType().GetMethod("Close", BindingFlags.Instance | BindingFlags.NonPublic)!;

                // Call close method
                closeMethod.Invoke(mailWriter, BindingFlags.Instance | BindingFlags.NonPublic, null, new object[] { }, null);
            }

            // Open the file with the default associated application registered on the local machine
            Process.Start(new ProcessStartInfo(filename) { UseShellExecute = true });
        }

        private static MailMessage CreateMessage(string from, string subject, string body, string to = "")
        {
            if (string.IsNullOrWhiteSpace(to))
                to = "example@outlook.com.au";
            if (string.IsNullOrWhiteSpace(from))
                from = GetAddressFromUser();
            if (string.IsNullOrWhiteSpace(subject))
                subject = "Enter subject";
            if (string.IsNullOrWhiteSpace(body))
                body = "Enter message";
            var message = new MailMessage(from, to, subject, body);
            message.IsBodyHtml = false;

            return message;
        }

        private static string GetAddressFromUser()
        {
            CoreTable table = new Client<User>().Query(new Filter<User>(x => x.ID).IsEqualTo(ClientFactory.UserGuid)
                , new Columns<User>(x => x.EmailAddress));
            User user = table.Rows.FirstOrDefault().ToObject<User>();

            if (!string.IsNullOrWhiteSpace(user.EmailAddress))
                return user.EmailAddress;
            else
                MessageBox.Show("Current User Email Address is blank - please fill in (Human Resources -> User Accounts -> Choose your User -> Email Settings -> Email Address", "Error");

            return "";

        }

        private static MailMessage AddAttachment(MailMessage message, string attachmentname, byte[] attachmentdata)
        {
            var attachment = Path.Combine(
                Path.GetTempPath(), 
                String.IsNullOrWhiteSpace(Path.GetExtension(attachmentname)) 
                    ? Path.ChangeExtension(attachmentname, ".pdf") 
                    : attachmentname 
            );
            File.WriteAllBytes(attachment, attachmentdata);

            message.Attachments.Add(new Attachment(attachment));

            return message;
        }

        public static IEnumerable<ReportExportDefinition> CreateTemplateDefinitions(DataModel model)
        {
            var templates = new Client<DataModelTemplate>().Query(new Filter<DataModelTemplate>(x => x.Model).IsEqualTo(model.Name)
                .And(x => x.Visible).IsEqualTo(true));

            if (templates.Rows.Any())
            {
                List<ReportExportDefinition> list = new List<ReportExportDefinition>();
                foreach (CoreRow row in templates.Rows)
                {
                    Action<DataModel, byte[]> action = new Action<DataModel, byte[]>((model, data) =>
                    {
                        DoEmailAction(model, data, row.Get<DataModelTemplate, string>(x => x.Name));
                    });
                    list.Add(
                        new ReportExportDefinition(
                            "Email Report",
                            ImageUtils.CreatePreviewWindowButtonContent(row.Get<DataModelTemplate, string>(x => x.Name),PRSDesktop.Resources.emailreport), 
                            ReportExportType.PDF, 
                            action));
                }
                return list;
            }
            else
                return new List<ReportExportDefinition>() 
                { 
                    new ReportExportDefinition(
                        "Email Report",
                        ImageUtils.CreatePreviewWindowButtonContent("Email",PRSDesktop.Resources.emailreport), 
                        ReportExportType.PDF,
                            DoEmailReport)
                };
        }

        private static void DoEmailAction(DataModel model, byte[] data, string templateName)
        {
            var template = new Client<DataModelTemplate>().Query(new Filter<DataModelTemplate>(x => x.Name).IsEqualTo(templateName)).Rows.FirstOrDefault();

            ParseTemplateAndCreateEmail(template, model, data);
        }

        private static void ParseTemplateAndCreateEmail(CoreRow row, DataModel model, byte[] data)
        {
            var to = DataModelUtils.ParseTemplate(model, row.Get<DataModelTemplate, string>(x => x.To)).Replace("\n", "").Replace("\r", "");
            var Subject = DataModelUtils.ParseTemplate(model, row.Get<DataModelTemplate, string>(x => x.Subject)).Replace("\n", "").Replace("\r", "");
            var attachmentName = DataModelUtils.ParseTemplate(model, row.Get<DataModelTemplate, string>(x => x.AttachmentName)).Replace("\n", "").Replace("\r", "");
            var body = DataModelUtils.ParseTemplate(model, row.Get<DataModelTemplate, string>(x => x.Template));

            if (string.IsNullOrWhiteSpace(attachmentName))
                attachmentName = model.Name;
            EmailUtils.CreateEMLFile(attachmentName, data, App.EmployeeEmail, Subject, body, to);
        }

        public static void DoEmailReport(DataModel model, byte[] data)
        {
            string attachmentName = DetermineName(model);
            EmailUtils.CreateEMLFile(attachmentName, data, App.EmployeeEmail, "Emailing report for " + attachmentName);
        }

        private static string DetermineName(DataModel model)
        {
            string title = model.Name;
            if (model.HasTable<Requisition>())
            {
                CoreTable table = model.GetTable<Requisition>();
                title = title + " - " + table.Rows.FirstOrDefault().Get<Requisition, string>(x => x.Title);
            }
            else if (model.HasTable<PurchaseOrder>())
            {
                title = "Purchase Order ";
                CoreTable table = model.GetTable<PurchaseOrder>();
                if (table.Rows.Count == 1)
                    title += table.Rows.FirstOrDefault().Get<PurchaseOrder, string>(x => x.PONumber);
                else if (table.Rows.Count > 1)
                {
                    foreach (CoreRow row in table.Rows)
                    {
                        title = title + row.Get<PurchaseOrder, string>(x => x.PONumber) + ", ";
                    }
                    title = title.Substring(0, title.Length - 2);
                }
            }

            return title;
        }

    }
}