more services from Web API

src/Yavsc.Server/Services/EMailer.cs

@@ -0,0 +1,174 @@
+using System.Text;
+// // EMailer.cs
+// /*
+// paul  26/06/2018 12:18 20182018 6 26
+// */
+using Yavsc.Templates;
+using Microsoft.CodeAnalysis;
+using Microsoft.Extensions.Localization;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.Emit;
+
+using Yavsc.Models;
+using Yavsc.Services;
+using System.Reflection;
+using Yavsc.Abstract.Templates;
+using Microsoft.AspNetCore.Identity;
+using RazorEngine.Configuration;
+using Yavsc.Interface;
+using Microsoft.Extensions.Logging;
+
+namespace Yavsc.Lib
+{
+    public class EMailer
+    {
+        const string DefaultBaseClassName = "ATemplate";
+        const string DefaultBaseClass = nameof(UserOrientedTemplate);
+        ISet<string> Namespaces = new System.Collections.Generic.HashSet<string> {
+            "System",
+            "Yavsc.Templates" ,
+            "Yavsc.Models",
+            "Yavsc.Models.Identity"};
+
+        readonly IStringLocalizer<EMailer> stringLocalizer;
+        readonly ApplicationDbContext dbContext;
+
+        readonly ILogger logger;
+
+        public EMailer(ApplicationDbContext context, 
+                       IStringLocalizer<EMailer> localizer,
+                       ILoggerFactory loggerFactory)
+        {
+            stringLocalizer = localizer;
+
+            logger = loggerFactory.CreateLogger<EMailer>();
+
+
+            var templateServiceConfig = new TemplateServiceConfiguration()
+            {
+                BaseTemplateType = typeof(UserOrientedTemplate),
+                Language = RazorEngine.Language.CSharp,
+                Namespaces = Namespaces
+
+            };
+
+        }
+
+        public void SendMonthlyEmail(string templateCode, string baseclassName = DefaultBaseClassName)
+        {
+            string className = "Generated" + baseclassName;
+
+            string subtemp = stringLocalizer["MonthlySubjectTemplate"].Value;
+
+            logger.LogInformation($"Generating {subtemp}[{className}]");
+
+
+            var templateInfo = dbContext.MailingTemplate.FirstOrDefault(t => t.Id == templateCode);
+            var templatekey = RazorEngine.Engine.Razor.GetKey(templateInfo.Id);
+
+
+            logger.LogInformation($"Using code: {templateCode},  subject: {subtemp} ");
+            logger.LogInformation("And body:\n" + templateInfo.Body);
+            using (StringReader reader = new StringReader(templateInfo.Body))
+            {
+
+                // Generate code for the template
+                using (var rzcode = new MemoryStream())
+                {
+                    using (var writter = new StreamWriter(rzcode))
+                    {
+                        RazorEngine.Engine.Razor.Run(templatekey, writter);
+                        rzcode.Seek(0, SeekOrigin.Begin);
+
+                        SyntaxTree syntaxTree = CSharpSyntaxTree.ParseText(Encoding.Default.GetString(rzcode.ToArray()));
+
+
+                        logger.LogInformation("CSharp parsed");
+                        List<MetadataReference> references = new List<MetadataReference>();
+
+                        foreach (var type in new Type[] {
+                    typeof(object),
+                    typeof(Enumerable),
+                    typeof(IdentityUser),
+                    typeof(ApplicationUser),
+                    typeof(Template),
+                    typeof(UserOrientedTemplate),
+                    typeof(System.Threading.Tasks.TaskExtensions)
+                 })
+                        {
+                            var location = type.Assembly.Location;
+                            if (!string.IsNullOrWhiteSpace(location))
+                            {
+                                references.Add(
+                                    MetadataReference.CreateFromFile(location)
+                                );
+                                logger.LogInformation($"Assembly for {type.Name} found at {location}");
+                            }
+                            else logger.LogWarning($"Assembly Not found for {type.Name}");
+                        }
+
+                        logger.LogInformation("Compilation creation ...");
+
+                        var compilationOptions = new CSharpCompilationOptions(OutputKind.DynamicallyLinkedLibrary)
+                            .WithAllowUnsafe(true).WithOptimizationLevel(OptimizationLevel.Debug)
+                            .WithOutputKind(OutputKind.DynamicallyLinkedLibrary).WithPlatform(Platform.AnyCpu)
+                            .WithUsings("Yavsc.Templates")
+                            ;
+                        string assemblyName = "EMailSenderTemplate";
+                        CSharpCompilation compilation = CSharpCompilation.Create(
+                            assemblyName,
+                            syntaxTrees: new[] { syntaxTree },
+                            references: references,
+                            options: compilationOptions
+                            );
+
+                        using (var ms = new MemoryStream())
+                        {
+                            logger.LogInformation("Emitting result ...");
+                            EmitResult result = compilation.Emit(ms);
+                            foreach (Diagnostic diagnostic in result.Diagnostics.Where(diagnostic =>
+                                    diagnostic.Severity < DiagnosticSeverity.Error && !diagnostic.IsWarningAsError))
+                            {
+                                logger.LogWarning("{0}: {1}", diagnostic.Id, diagnostic.GetMessage());
+                                logger.LogWarning("{0}: {1}", diagnostic.Id, diagnostic.Location.GetLineSpan());
+                            }
+                            if (!result.Success)
+                            {
+
+                                IEnumerable<Diagnostic> failures = result.Diagnostics.Where(diagnostic =>
+                                    diagnostic.IsWarningAsError ||
+                                    diagnostic.Severity == DiagnosticSeverity.Error);
+                                foreach (Diagnostic diagnostic in failures)
+                                {
+                                    logger.LogCritical("{0}: {1}", diagnostic.Id, diagnostic.GetMessage());
+                                    logger.LogCritical("{0}: {1}", diagnostic.Id, diagnostic.Location.GetLineSpan());
+                                }
+                            }
+                            else
+                            {
+
+                                ms.Seek(0, SeekOrigin.Begin);
+                                Assembly assembly = Assembly.Load(ms.ToArray());
+
+                                Type type = assembly.GetType(Namespaces + "." + className);
+                                var generatedtemplate = (UserOrientedTemplate)Activator.CreateInstance(type);
+                                foreach (var user in dbContext.ApplicationUser.Where(
+                                    u => u.AllowMonthlyEmail
+                                ))
+                                {
+                                    logger.LogInformation("Generation for " + user.UserName);
+                                    generatedtemplate.Init();
+                                    generatedtemplate.User = user;
+                                    generatedtemplate.ExecuteAsync();
+                                    logger.LogInformation(generatedtemplate.GeneratedText);
+                                }
+
+                            }
+                        }
+                    }
+
+                }
+            }
+        }
+    }
+}