Initial commit carried over from private repo. This is V2.

code/MessengerApi/Handlers/UserSetupHandler.cs

@@ -0,0 +1,99 @@
+using MessengerApi.Configuration.Model;
+using MessengerApi.Contracts.Factories;
+using MessengerApi.Db;
+using MessengerApi.Models;
+using System.Text;
+
+namespace MessengerApi.Handlers
+{
+    // TODO: This needs to be redone, because at every run, it wipes users and creates new ones. This makes
+    // all existing DB messages unassignable.
+    public class UserSetupHandler
+    {
+        private readonly MessengerConfiguration configuration;
+        private readonly ILogger logger;
+        private readonly IDbContextFactory dbContextFactory;
+
+        public UserSetupHandler(
+            MessengerConfiguration configuration, 
+            ILogger logger,
+            IDbContextFactory dbContextFactory)
+        {
+            this.configuration = configuration;
+            this.logger = logger;
+            this.dbContextFactory = dbContextFactory;
+        }
+
+        public async Task UpdateFromFile(FileInfo file)
+        {
+            if(file.Exists)
+            {
+                var lines = await File.ReadAllLinesAsync(file.FullName, Encoding.UTF8);
+                var items = await this.ReadLines(lines);
+
+                await this.SynchronizeUsers(items);
+            }
+        }
+
+        private async Task<UserSetupItem[]> ReadLines(string[] lines)
+        {
+            var items = new List<UserSetupItem>();
+
+            foreach (var line in lines)
+            {
+                var values = line.Split(';', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
+                var item = new UserSetupItem
+                {
+                    UserName = values[0],
+                    ApiKey = values[1],
+                };
+
+                if(values.Length > 2)
+                {
+                    item.CanSendToUserNames = values[2].Split(',', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
+                }
+
+                items.Add(item);
+            }
+
+            if (items.GroupBy(x => x.UserName).Any(x => x.Count() > 1))
+            {
+                throw new InvalidOperationException("Usernames are not unique. One username per line.");
+            }
+            else if(items.GroupBy(x=>x.ApiKey).Any(x=>x.Count() > 1))
+            {
+                throw new InvalidOperationException("API keys are not unique. One API key per line.");
+            }
+
+            return items.ToArray();
+        }
+
+        private Task SynchronizeUsers(IEnumerable<UserSetupItem> users)
+        {
+            using var db = this.dbContextFactory.CreateDbContext();
+            db.RemoveRange(db.Users);
+            db.RemoveRange(db.UserRoutes);
+
+            var dbUsers = users.Select(x => new Db.Entities.User
+            {
+                Id = new Guid(),
+                Name = x.UserName,
+                ApiKey = Guid.Parse(x.ApiKey),
+                IsEnabled = true
+            });
+
+            var dbRoutes = users.SelectMany(x => x.CanSendToUserNames.Select(cs => new Db.Entities.UserRoute
+            {
+                Id = new Guid(),
+                From = dbUsers.Single(dbu => dbu.Name == x.UserName),
+                To = dbUsers.Single(dbu => dbu.Name == x.UserName)
+            }));
+
+            db.AddRange(dbUsers);
+            db.AddRange(dbRoutes);
+
+            db.SaveChanges();
+            return Task.CompletedTask;
+        }
+    }
+}