CAAvPsa8

1//ReSharper disable SwitchStatementMissingSomeCases
2
3using System;
4using System.Collections.Generic;
5using System.IO;
6using System.Linq;
7using System.Threading.Tasks;
8using HtmlAgilityPack;
9using SendGrid;
10using SendGrid.Helpers.Mail;
11using Trichoma.DataAccessLayer.Database;
12using Trichoma.DataAccessLayer.Database.Logs;
13using Trichoma.Emails.Interfaces;
14using Trichoma.Emails.Models;
15using Trichoma.Enumerations;
16using Trichoma.Messaging.Interfaces;
17
18namespace Trichoma.Messaging.Services
19{
20    public class EmailService : IEmailService
21    {
22        #region Properties & Constructor
23
24        private readonly TrichomaContext _db;
25
26        public EmailService(TrichomaContext context)
27        {
28            _db = context;
29        }
30
31        #endregion
32
33        #region Public Methods
34
35        /// <summary>
36        /// Method to send an email from Trichoma no reply
37        /// </summary>
38        /// <param name="toAddresses">List of addresses email must be sent to</param>
39        /// <param name="subject">Subject of the email</param>
40        /// <param name="body">HTML content of the email</param>
41        /// <param name="ccAddresses">List of cc addresses</param>
42        /// <param name="bccAddresses">List of bcc addresses</param>
43        /// <returns></returns>
44        public Task SendEmail(List<string> toAddresses, string subject, string body, List<string> ccAddresses = null, List<string> bccAddresses = null)
45        {
46#if DEBUG
47            toAddresses = new List<string>{"pierrephilip@dupreez.org.za"};
48#endif
49
50            //Get the API key from the DB
51            var apiKey = _db.Settings.First(s => s.Key == nameof(SettingKey.SendGridApiKey)).Value;
52            //Get the from address and name
53            var fromAddress = _db.Settings.First(s => s.Key == nameof(SettingKey.EmailFromAddress)).Value;
54            var fromName = _db.Settings.First(s => s.Key == nameof(SettingKey.EmailFromName)).Value;
55
56            //Convert the HTML email to plaintext
57            var plainText = HtmlToPlainText(body);
58
59            //Create a log event for the email
60            _db.EmailLogs.Add(new EmailLog
61            {
62                Recipients = string.Join(",", toAddresses),
63                CcRecipients = (ccAddresses == null) ? null : string.Join(",", ccAddresses),
64                BccRecipients = (bccAddresses == null) ? null : string.Join(",", bccAddresses),
65                Subject = subject,
66                BodyPlainText = plainText
67            });
68
69            //Save database changes
70            _db.SaveChanges();
71
72            //Create the SendGrid client to send the email
73            var client = new SendGridClient(apiKey);
74            //Set the from details
75            var from = new EmailAddress(fromAddress, fromName);
76
77            //Create variable to store message
78            var message = new SendGridMessage();
79
80            //Check the amount of recipients to decide what type of email to send
81            if (toAddresses.Count == 1)
82            {
83                //Build up the message
84                message = MailHelper.CreateSingleEmail(from, new EmailAddress(toAddresses.First()), subject, plainText,
85                    body);
86            }
87            else if (toAddresses.Count > 1)
88            {
89                //Build up list of recipients
90                var toList = new List<EmailAddress>();
91
92                //Loop through all the to addresses
93                foreach (var address in toAddresses)
94                    toList.Add(new EmailAddress(address));
95
96                //Build up the message
97                message = MailHelper.CreateSingleEmailToMultipleRecipients(from, toList, subject, plainText, body);
98            }
99
100            //Add the CC addresses to the mail
101            if (ccAddresses != null)
102                foreach (var address in ccAddresses)
103                    message.AddCc(new EmailAddress(address));
104
105            //Add BCC addresses
106            if (bccAddresses != null)
107                foreach (var address in bccAddresses)
108                    message.AddBcc(new EmailAddress(address));
109
110            return client.SendEmailAsync(message);
111        }
112
113        #endregion
114
115        #region Private & Helper Methods
116
117        /// <summary>
118        /// Converts HTML to plain text / strips tags.
119        /// </summary>
120        /// <param name="html">The HTML.</param>
121        /// <returns></returns>
122        private string HtmlToPlainText(string html)
123        {
124            //Build up a new html document
125            var doc = new HtmlDocument();
126            //Load the HTML into the document
127            doc.LoadHtml(html);
128
129            //Create a new string writer
130            var sw = new StringWriter();
131            //Convert the html to string
132            ConvertTo(doc.DocumentNode, sw);
133            //Flush the writer
134            sw.Flush();
135            return sw.ToString();
136        }
137
138        private void ConvertContentTo(HtmlNode node, TextWriter outText)
139        {
140            //Loop through each child node in the HtmlNode
141            //Convert each subnode to text
142            foreach (var subnode in node.ChildNodes)
143                ConvertTo(subnode, outText);
144        }
145
146        private void ConvertTo(HtmlNode node, TextWriter outText)
147        {
148            switch (node.NodeType)
149            {
150                case HtmlNodeType.Comment:
151                    // don't output comments
152                    break;
153
154                case HtmlNodeType.Document:
155                    ConvertContentTo(node, outText);
156                    break;
157
158                case HtmlNodeType.Text:
159                    // script and style must not be output
160                    string parentName = node.ParentNode.Name;
161                    if ((parentName == "script") || (parentName == "style"))
162                        break;
163
164                    // get text
165                    var html = ((HtmlTextNode)node).Text;
166
167                    // is it in fact a special closing node output as text?
168                    if (HtmlNode.IsOverlappedClosingElement(html))
169                        break;
170
171                    // check the text is meaningful and not a bunch of whitespaces
172                    if (html.Trim().Length > 0)
173                    {
174                        outText.Write(HtmlEntity.DeEntitize(html));
175                    }
176
177                    break;
178
179                case HtmlNodeType.Element:
180                    switch (node.Name)
181                    {
182                        case "p":
183                            // treat paragraphs as crlf
184                            outText.Write("\r\n");
185                            break;
186                        case "br":
187                            outText.Write("\r\n");
188                            break;
189                    }
190
191                    if (node.HasChildNodes)
192                    {
193                        ConvertContentTo(node, outText);
194                    }
195
196                    break;
197            }
198        }
199
200        #endregion
201    }
202}