CRM Account Email Plugin

using System;
using Microsoft.Xrm.Sdk;

namespace UOP.Plugins.Account
{
    public class OnUpdateAccountEmail_CreateEmailChangeRequestCase : IPlugin
    {
        private const string PreImageAlias = "Pre";
        private const string PostImageAlias = "Post";

        public void Execute(IServiceProvider serviceProvider)
        {
            // Obtain the tracing service
            ITracingService tracingService = (ITracingService)serviceProvider.GetService(typeof(ITracingService));

            // Obtain the execution context from the service provider.
            IPluginExecutionContext context = (IPluginExecutionContext)serviceProvider.GetService(typeof(IPluginExecutionContext));
            if (context == null)
            {
                tracingService.Trace($"Error in plugin {nameof(OnUpdateAccountEmail_CreateEmailChangeRequestCase)} - Service context is null");
                throw new ArgumentNullException("context");
            }

            if (context.Depth > 1)
            {
                return;
            }

            // Obtain the organization service reference.
            IOrganizationServiceFactory serviceFactory = (IOrganizationServiceFactory)serviceProvider.GetService(typeof(IOrganizationServiceFactory));
            IOrganizationService service = serviceFactory.CreateOrganizationService(context.UserId);

            // The InputParameters collection contains all the data passed in the message request.
            if (context.InputParameters.Contains("Target") && context.InputParameters["Target"] is Entity)
            {
                // Obtain the target entity from the input parameters.
                Entity target = (Entity)context.InputParameters["Target"];
                try
                {
                    //If it's update get the latest data
                    if (context.MessageName.Equals("update", StringComparison.InvariantCultureIgnoreCase))
                    {
                        tracingService.Trace($"Attempting to retrieve account email.");

                        //Obtain the pre image and post image entities
                        Entity preImageEntity = (context.PreEntityImages != null && context.PreEntityImages.Contains(PreImageAlias)) ? context.PreEntityImages[PreImageAlias] : null;
                        Entity postImageEntity = (context.PostEntityImages != null && context.PostEntityImages.Contains(PostImageAlias)) ? context.PostEntityImages[PostImageAlias] : null;

                        if (preImageEntity == null || !preImageEntity.Attributes.Contains("emailaddress1") || preImageEntity.GetAttributeValue<string>("emailaddress1") == null)
                        {
                            throw new InvalidPluginExecutionException($"An error occurred in {nameof(OnUpdateAccountEmail_CreateEmailChangeRequestCase)} plugin. The preImage fields are empty!");
                        }
                        if (postImageEntity == null || !postImageEntity.Attributes.Contains("emailaddress1") || postImageEntity.GetAttributeValue<string>("emailaddress1") == null)
                        {
                            throw new InvalidPluginExecutionException($"An error occurred in {nameof(OnUpdateAccountEmail_CreateEmailChangeRequestCase)} plugin. The new value for Email field is null.");
                        }

                        string previousEmail = preImageEntity.GetAttributeValue<string>("emailaddress1");
                        string newEmail = postImageEntity.GetAttributeValue<string>("emailaddress1");

                        if (previousEmail == newEmail)
                        {
                            tracingService.Trace($"Newly entered Email is the same as the old one. Aborting plugin execution.");
                            return;
                        }

                        target["emailaddress1"] = previousEmail;
                        tracingService.Trace($"Email field value set to the previous one: {previousEmail}");
                        service.Update(target);

                        //Create case
                        Entity caseRecord = new Entity("incident");
                        tracingService.Trace($"Creating new case.");

                        //Setting case attributes
                        caseRecord["title"] = "Email Change Request";
                        tracingService.Trace($"Case Title set to Email Change Request");

                        caseRecord["new_previousemail"] = previousEmail;
                        tracingService.Trace($"Case Previous Email set to {previousEmail}");

                        caseRecord["new_newemail"] = newEmail;
                        tracingService.Trace($"Case New Email set to {newEmail}");

                        caseRecord["subjectid"] = new EntityReference("subject", Guid.Parse("1F5C140F-DA8D-E911-A97D-000D3A26C11D"));
                        tracingService.Trace($"Case Subject set to Email Change Request");

                        caseRecord.Attributes.Add("customerid", new EntityReference("account", target.Id));
                        tracingService.Trace($"Case connected with account id {target.Id}");

                        service.Create(caseRecord);
                        tracingService.Trace($"Case with id {caseRecord.Id} created ");
                    }
                }
                catch (Exception ex)
                {
                    tracingService.Trace($"An error occurred in {nameof(OnUpdateAccountEmail_CreateEmailChangeRequestCase)}. Exception details: {ex.Message}");
                    throw new InvalidPluginExecutionException(ex.Message);
                }
            }
        }
    }
}