Merge pull request #3 from NicolasConstant/topic_debug-signature-call

Topic debug signature call

.github/workflows/dotnet-core.yml

@@ -15,6 +15,8 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
+    - name: Launch Db for testing
+      run: docker run --name postgres -e POSTGRES_DB=mytestdb -e POSTGRES_PASSWORD=mysecretpassword -d -p 5432:5432 postgres
     - name: Setup .NET Core
       uses: actions/setup-dotnet@v1
       with:

src/BirdsiteLive.ActivityPub/Converters/ContextArrayConverter.cs

@@ -0,0 +1,39 @@
+using System;
+using System.Collections.Generic;
+using Newtonsoft.Json;
+
+namespace BirdsiteLive.ActivityPub.Converters
+{
+    public class ContextArrayConverter : JsonConverter
+    {
+        public override bool CanWrite { get { return false; } }
+        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
+        {
+            throw new NotImplementedException();
+        }
+
+        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
+        {
+            var result = new List<string>();
+
+            var list = serializer.Deserialize<List<object>>(reader);
+            foreach (var l in list)
+            {
+                if (l is string s)
+                    result.Add(s);
+                else
+                {
+                    var str = JsonConvert.SerializeObject(l);
+                    result.Add(str);
+                }
+            }
+
+            return result.ToArray();
+        }
+
+        public override bool CanConvert(Type objectType)
+        {
+            throw new NotImplementedException();
+        }
+    }
+}

src/BirdsiteLive.ActivityPub/Models/Actor.cs

@@ -1,7 +1,5 @@
-using System;
+using BirdsiteLive.ActivityPub.Converters;
-using System.Collections.Generic;
 using Newtonsoft.Json;
-using JsonConverter = Newtonsoft.Json.JsonConverter;
 
 namespace BirdsiteLive.ActivityPub
 {
@@ -22,37 +20,4 @@ namespace BirdsiteLive.ActivityPub
         public Image icon { get; set; }
         public Image image { get; set; }
     }
-
-    public class ContextArrayConverter : JsonConverter
-    {
-        public override bool CanWrite { get { return false; } }
-        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
-        {
-            throw new NotImplementedException();
-        }
-
-        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
-        {
-            var result = new List<string>();
-
-            var list = serializer.Deserialize<List<object>>(reader);
-            foreach (var l in list)
-            {
-                if (l is string s)
-                    result.Add(s);
-                else
-                {
-                    var str = JsonConvert.SerializeObject(l);
-                    result.Add(str);
-                }
-            }
-
-            return result.ToArray();
-        }
-
-        public override bool CanConvert(Type objectType)
-        {
-            throw new NotImplementedException();
-        }
-    }
 }

src/BirdsiteLive.ActivityPub/Models/Note.cs

@@ -1,10 +1,16 @@
 using System;
 using System.Collections.Generic;
+using BirdsiteLive.ActivityPub.Converters;
+using Newtonsoft.Json;
 
 namespace BirdsiteLive.ActivityPub
 {
     public class Note
     {
+        [JsonProperty("@context")]
+        [JsonConverter(typeof(ContextArrayConverter))]
+        public string[] context { get; set; } = new[] { "https://www.w3.org/ns/activitystreams" };
+
         public string id { get; set; }
         public string type { get; } = "Note";
         public string summary { get; set; }

src/BirdsiteLive.Domain/UserService.cs

@@ -10,6 +10,7 @@ using BirdsiteLive.Common.Settings;
 using BirdsiteLive.Cryptography;
 using BirdsiteLive.Twitter.Models;
 using Tweetinvi.Core.Exceptions;
+using Tweetinvi.Models;
 
 namespace BirdsiteLive.Domain
 {
@@ -17,6 +18,7 @@ namespace BirdsiteLive.Domain
     {
         Actor GetUser(TwitterUser twitterUser);
         Task<bool> FollowRequestedAsync(string signature, string method, string path, string queryString, Dictionary<string, string> requestHeaders, ActivityFollow activity);
+        Note GetStatus(TwitterUser user, ITweet tweet);
     }
 
     public class UserService : IUserService
@@ -65,6 +67,39 @@ namespace BirdsiteLive.Domain
             return user;
         }
 
+        public Note GetStatus(TwitterUser user, ITweet tweet)
+        {
+            var actor = GetUser(user);
+
+            var actorUrl = $"{_host}/users/{user.Acct}";
+            var noteId = $"{_host}/users/{user.Acct}/statuses/{tweet.Id}";
+            var noteUrl = $"{_host}/@{user.Acct}/{tweet.Id}";
+
+            var to = $"{actor}/followers";
+            var apPublic = "https://www.w3.org/ns/activitystreams#Public";
+
+            var note = new Note
+            {
+                id = $"{noteId}/activity",
+                
+                published = tweet.CreatedAt.ToString("s") + "Z",
+                url = noteUrl,
+                attributedTo = actorUrl,
+
+                //to = new [] {to},
+                //cc = new [] { apPublic },
+
+                to = new[] { apPublic },
+                cc = new[] { to },
+
+                sensitive = false,
+                content = $"<p>{tweet.Text}</p>",
+                attachment = new string[0],
+                tag = new string[0]
+            };
+            return note;
+        }
+
         public async Task<bool> FollowRequestedAsync(string signature, string method, string path, string queryString, Dictionary<string, string>  requestHeaders, ActivityFollow activity)
         {
             // Validate
@@ -91,7 +126,7 @@ namespace BirdsiteLive.Domain
             var result = await _activityPubService.PostDataAsync(acceptFollow, targetHost, activity.apObject);
             return result == HttpStatusCode.Accepted;
         }
-
+        
         private async Task<bool> ValidateSignature(string actor, string rawSig, string method, string path, string queryString, Dictionary<string, string> requestHeaders)
         {
             var signatures = rawSig.Split(',');

src/BirdsiteLive.Twitter/TwitterService.cs

@@ -3,12 +3,14 @@ using System.Threading.Tasks;
 using BirdsiteLive.Common.Settings;
 using BirdsiteLive.Twitter.Models;
 using Tweetinvi;
+using Tweetinvi.Models;
 
 namespace BirdsiteLive.Twitter
 {
     public interface ITwitterService
     {
         TwitterUser GetUser(string username);
+        ITweet GetTweet(long statusId);
     }
 
     public class TwitterService : ITwitterService
@@ -40,5 +42,12 @@ namespace BirdsiteLive.Twitter
                 ProfileBannerURL = user.ProfileBannerURL
             };
         }
+
+        public ITweet GetTweet(long statusId)
+        {
+            Auth.SetApplicationOnlyCredentials(_settings.ConsumerKey, _settings.ConsumerSecret, true);
+            var tweet = Tweet.GetTweet(statusId);
+            return tweet;
+        }
     }
 }

src/BirdsiteLive.sln

@@ -17,11 +17,19 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Tests", "Tests", "{A32D3458
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "BirdsiteLive.Cryptography.Tests", "Tests\BirdsiteLive.Cryptography.Tests\BirdsiteLive.Cryptography.Tests.csproj", "{155D46A4-2D05-47F2-8FFC-0B7C412A7652}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "BirdsiteLive.Domain", "BirdsiteLive.Domain\BirdsiteLive.Domain.csproj", "{D48450EE-D8BD-4228-9864-043AC88F7EE0}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "BirdsiteLive.Domain", "BirdsiteLive.Domain\BirdsiteLive.Domain.csproj", "{D48450EE-D8BD-4228-9864-043AC88F7EE0}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "BirdsiteLive.ActivityPub", "BirdsiteLive.ActivityPub\BirdsiteLive.ActivityPub.csproj", "{7463E1E2-9736-4A46-8507-010BDD8ECFBB}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "BirdsiteLive.ActivityPub", "BirdsiteLive.ActivityPub\BirdsiteLive.ActivityPub.csproj", "{7463E1E2-9736-4A46-8507-010BDD8ECFBB}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "BirdsiteLive.ActivityPub.Tests", "Tests\BirdsiteLive.ActivityPub.Tests\BirdsiteLive.ActivityPub.Tests.csproj", "{1D713961-9926-41FF-8D6A-8A4B8D548484}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "BirdsiteLive.ActivityPub.Tests", "Tests\BirdsiteLive.ActivityPub.Tests\BirdsiteLive.ActivityPub.Tests.csproj", "{1D713961-9926-41FF-8D6A-8A4B8D548484}"
+EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "DataAccessLayers", "DataAccessLayers", "{CFAB3509-3931-42DB-AC97-4F91FC2D849C}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "BirdsiteLive.DAL", "DataAccessLayers\BirdsiteLive.DAL\BirdsiteLive.DAL.csproj", "{47058CAB-DC43-4DD1-8F68-D3D625332905}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "BirdsiteLive.DAL.Postgres", "DataAccessLayers\BirdsiteLive.DAL.Postgres\BirdsiteLive.DAL.Postgres.csproj", "{87E46519-BBF2-437C-8A5B-CF6CDE7CDAA6}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "BirdsiteLive.DAL.Postgres.Tests", "Tests\BirdsiteLive.DAL.Postgres.Tests\BirdsiteLive.DAL.Postgres.Tests.csproj", "{CD9489BF-69C8-4705-8774-81C45F4F8FE1}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -61,6 +69,18 @@ Global
 		{1D713961-9926-41FF-8D6A-8A4B8D548484}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{1D713961-9926-41FF-8D6A-8A4B8D548484}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{1D713961-9926-41FF-8D6A-8A4B8D548484}.Release|Any CPU.Build.0 = Release|Any CPU
+		{47058CAB-DC43-4DD1-8F68-D3D625332905}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{47058CAB-DC43-4DD1-8F68-D3D625332905}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{47058CAB-DC43-4DD1-8F68-D3D625332905}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{47058CAB-DC43-4DD1-8F68-D3D625332905}.Release|Any CPU.Build.0 = Release|Any CPU
+		{87E46519-BBF2-437C-8A5B-CF6CDE7CDAA6}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{87E46519-BBF2-437C-8A5B-CF6CDE7CDAA6}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{87E46519-BBF2-437C-8A5B-CF6CDE7CDAA6}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{87E46519-BBF2-437C-8A5B-CF6CDE7CDAA6}.Release|Any CPU.Build.0 = Release|Any CPU
+		{CD9489BF-69C8-4705-8774-81C45F4F8FE1}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{CD9489BF-69C8-4705-8774-81C45F4F8FE1}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{CD9489BF-69C8-4705-8774-81C45F4F8FE1}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{CD9489BF-69C8-4705-8774-81C45F4F8FE1}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -73,6 +93,9 @@ Global
 		{D48450EE-D8BD-4228-9864-043AC88F7EE0} = {4FEAD6BC-3C8E-451A-8CA1-FF1AF47D26CC}
 		{7463E1E2-9736-4A46-8507-010BDD8ECFBB} = {4FEAD6BC-3C8E-451A-8CA1-FF1AF47D26CC}
 		{1D713961-9926-41FF-8D6A-8A4B8D548484} = {A32D3458-09D0-4E0A-BA4B-8C411B816B94}
+		{47058CAB-DC43-4DD1-8F68-D3D625332905} = {CFAB3509-3931-42DB-AC97-4F91FC2D849C}
+		{87E46519-BBF2-437C-8A5B-CF6CDE7CDAA6} = {CFAB3509-3931-42DB-AC97-4F91FC2D849C}
+		{CD9489BF-69C8-4705-8774-81C45F4F8FE1} = {A32D3458-09D0-4E0A-BA4B-8C411B816B94}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {69E8DCAD-4C37-4010-858F-5F94E6FBABCE}

src/BirdsiteLive/Controllers/DebugingController.cs

@@ -13,14 +13,14 @@ using Newtonsoft.Json;
 
 namespace BirdsiteLive.Controllers
 {
-    public class DebugController : Controller
+    public class DebugingController : Controller
     {
         private readonly InstanceSettings _instanceSettings;
         private readonly ICryptoService _cryptoService;
         private readonly IActivityPubService _activityPubService;
 
         #region Ctor
-        public DebugController(InstanceSettings instanceSettings, ICryptoService cryptoService, IActivityPubService activityPubService)
+        public DebugingController(InstanceSettings instanceSettings, ICryptoService cryptoService, IActivityPubService activityPubService)
         {
             _instanceSettings = instanceSettings;
             _cryptoService = cryptoService;

src/BirdsiteLive/Controllers/UsersController.cs

@@ -33,18 +33,43 @@ namespace BirdsiteLive.Controllers
         {
             var user = _twitterService.GetUser(id);
             if (user == null) return NotFound();
-            
+
             var r = Request.Headers["Accept"].First();
             if (r.Contains("application/activity+json"))
             {
                 var apUser = _userService.GetUser(user);
                 var jsonApUser = JsonConvert.SerializeObject(apUser);
-                return Content(jsonApUser, "application/json");
+                return Content(jsonApUser, "application/activity+json; charset=utf-8");
             }
 
             return View(user);
         }
 
+        [Route("/@{id}/{statusId}")]
+        [Route("/users/{id}/statuses/{statusId}")]
+        public IActionResult Tweet(string id, string statusId)
+        {
+            var r = Request.Headers["Accept"].First();
+            if (r.Contains("application/activity+json"))
+            {
+                if (!long.TryParse(statusId, out var parsedStatusId))
+                    return NotFound();
+                
+                var tweet = _twitterService.GetTweet(parsedStatusId);
+                if(tweet == null)
+                    return NotFound();
+
+                var user = _twitterService.GetUser(id);
+                if (user == null) return NotFound();
+
+                var status = _userService.GetStatus(user, tweet);
+                var jsonApUser = JsonConvert.SerializeObject(status);
+                return Content(jsonApUser, "application/activity+json; charset=utf-8");
+            }
+
+            return View("Tweet", statusId);
+        }
+
         [Route("/users/{id}/inbox")]
         [HttpPost]
         public async Task<IActionResult> Inbox()
@@ -58,7 +83,7 @@ namespace BirdsiteLive.Controllers
 
                 switch (activity.type)
                 {
-                    case "Follow": 
+                    case "Follow":
                         var succeeded = await _userService.FollowRequestedAsync(r.Headers["Signature"].First(), r.Method, r.Path, r.QueryString.ToString(), RequestHeaders(r.Headers), activity as ActivityFollow);
                         if (succeeded) return Accepted();
                         else return Unauthorized();

src/BirdsiteLive/Properties/launchSettings.json

@@ -21,7 +21,7 @@
       "environmentVariables": {
         "ASPNETCORE_ENVIRONMENT": "Development"
       },
-      "applicationUrl": "https://localhost:5001;http://localhost:5000"
+      "applicationUrl": "http://localhost:5000"
     },
     "Docker": {
       "commandName": "Docker",

src/BirdsiteLive/Views/Debuging/Index.cshtml

@@ -0,0 +1,19 @@
+
+@{
+    ViewData["Title"] = "Index";
+}
+
+<h1>Debug</h1>
+
+<form asp-controller="Debug" asp-action="Follow" method="post">
+    <!-- Input and Submit elements -->
+
+    <button type="submit" value="Submit">Follow</button>
+</form>
+
+
+<form asp-controller="Debug" asp-action="PostNote" method="post">
+    <!-- Input and Submit elements -->
+
+    <button type="submit" value="Submit">Post Note</button>
+</form>

src/BirdsiteLive/Views/Home/Index.cshtml

@@ -10,6 +10,6 @@
 
     @if (HtmlHelperExtensions.IsDebug())
     {
-        <a class="nav-link text-dark" asp-area="" asp-controller="Debug" asp-action="Index">Debug</a>
+        <a class="nav-link text-dark" asp-area="" asp-controller="Debuging" asp-action="Index">Debug</a>
     }
 </div>

src/BirdsiteLive/Views/Users/Tweet.cshtml

@@ -0,0 +1,8 @@
+@{
+    ViewData["Title"] = "Tweet";
+}
+
+<div align="center">
+    <blockquote class="twitter-tweet"><p lang="en" dir="ltr">Embedded tweet <a href="https://twitter.com/TwitterSupport/status/@ViewData.Model">Tweet</a></blockquote>
+    <script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>
+</div>

src/DataAccessLayers/BirdsiteLive.DAL.Postgres/BirdsiteLive.DAL.Postgres.csproj

@@ -0,0 +1,16 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>netstandard2.0</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Dapper" Version="2.0.35" />
+    <PackageReference Include="Npgsql" Version="4.1.3.1" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\BirdsiteLive.DAL\BirdsiteLive.DAL.csproj" />
+  </ItemGroup>
+
+</Project>

src/DataAccessLayers/BirdsiteLive.DAL.Postgres/DataAccessLayers/Base/PostgresBase.cs

@@ -0,0 +1,25 @@
+using BirdsiteLive.DAL.Postgres.Settings;
+using Npgsql;
+
+namespace BirdsiteLive.DAL.Postgres.DataAccessLayers.Base
+{
+    public class PostgresBase
+    {
+        protected readonly PostgresSettings _settings;
+
+        #region Ctor
+        protected PostgresBase(PostgresSettings settings)
+        {
+            _settings = settings;
+        }
+        #endregion
+
+        protected NpgsqlConnection Connection
+        {
+            get
+            {
+                return new NpgsqlConnection(_settings.ConnString);
+            }
+        }
+    }
+}

src/DataAccessLayers/BirdsiteLive.DAL.Postgres/DataAccessLayers/DbInitializerPostgresDal.cs

@@ -0,0 +1,150 @@
+using System;
+using System.Data;
+using System.Linq;
+using System.Runtime.CompilerServices;
+using System.Threading.Tasks;
+using System.Xml;
+using BirdsiteLive.DAL.Contracts;
+using BirdsiteLive.DAL.Postgres.DataAccessLayers.Base;
+using BirdsiteLive.DAL.Postgres.Settings;
+using BirdsiteLive.DAL.Postgres.Tools;
+using Dapper;
+using Npgsql;
+
+namespace BirdsiteLive.DAL.Postgres.DataAccessLayers
+{
+    internal class DbVersion
+    {
+        public string Type { get; set; }
+        public int Major { get; set; }
+        public int Minor { get; set; }
+    }
+
+    public class DbInitializerPostgresDal : PostgresBase, IDbInitializerDal
+    {
+        private readonly PostgresTools _tools;
+        private readonly Version _currentVersion = new Version(1,0);
+        private const string DbVersionType = "db-version";
+
+        #region Ctor
+        public DbInitializerPostgresDal(PostgresSettings settings, PostgresTools tools) : base(settings)
+        {
+            _tools = tools;
+        }
+        #endregion
+        
+        public async Task<Version> GetCurrentDbVersionAsync()
+        {
+            var query = $"SELECT * FROM {_settings.DbVersionTableName} WHERE type = @type";
+
+            try
+            {
+                using (var dbConnection = Connection)
+                {
+                    dbConnection.Open();
+
+                    var result = (await dbConnection.QueryAsync<DbVersion>(query, new { type = DbVersionType })).FirstOrDefault();
+
+                    if (result == default)
+                        return null;
+
+                    return new Version(result.Major, result.Minor);
+                }
+            }
+            catch (PostgresException e)
+            {
+                if (e.Message.Contains("42P01"))
+                    return null;
+
+                throw;
+            }
+        }
+
+        public Version GetMandatoryDbVersion()
+        {
+            return _currentVersion;
+        }
+
+        public Tuple<Version, Version>[] GetMigrationPatterns()
+        {
+            return new Tuple<Version, Version>[0];
+        }
+
+        public Task MigrateDbAsync(Version from, Version to)
+        {
+            throw new NotImplementedException();
+        }
+
+        public async Task InitDbAsync()
+        {
+            // Create version table 
+            var createVersion = $@"CREATE TABLE {_settings.DbVersionTableName}
+		    (
+                type VARCHAR(128) PRIMARY KEY,
+
+                major SMALLINT NOT NULL,
+                minor SMALLINT NOT NULL
+		    );";
+            await _tools.ExecuteRequestAsync(createVersion);
+
+            // Create Twitter User table
+            var createTwitter = $@"CREATE TABLE {_settings.TwitterUserTableName}
+		    (
+                id SERIAL PRIMARY KEY,
+                acct VARCHAR(20) UNIQUE, 
+
+                lastTweetPostedId BIGINT,
+                lastTweetSynchronizedForAllFollowersId BIGINT
+		    );";
+            await _tools.ExecuteRequestAsync(createTwitter);
+
+            // Create Followers table
+            var createFollowers = $@"CREATE TABLE {_settings.FollowersTableName}
+		    (
+                id SERIAL PRIMARY KEY,
+                
+                followings INTEGER[],
+                followingsSyncStatus JSONB,
+
+                acct VARCHAR(20) UNIQUE, 
+                host VARCHAR(20)
+		    );";
+            await _tools.ExecuteRequestAsync(createFollowers);
+
+            // Create Cached Tweet table 
+            var createCachedTweets = $@"CREATE TABLE {_settings.CachedTweetsTableName}
+		    (
+                id BIGINT PRIMARY KEY,
+                twitterUserId INTEGER,
+                data JSONB
+		    );";
+            await _tools.ExecuteRequestAsync(createCachedTweets);
+
+            // Insert version to db
+            using (var dbConnection = Connection)
+            {
+                dbConnection.Open();
+
+                await dbConnection.ExecuteAsync(
+                    $"INSERT INTO {_settings.DbVersionTableName} (type,major,minor) VALUES(@type,@major,@minor)",
+                    new { type = DbVersionType, major = _currentVersion.Major, minor = _currentVersion.Minor });
+            }
+        }
+
+        public async Task DeleteAllAsync()
+        {
+            var dropsRequests = new[]
+            {
+                $@"DROP TABLE {_settings.DbVersionTableName};",
+                $@"DROP TABLE {_settings.TwitterUserTableName};",
+                $@"DROP TABLE {_settings.FollowersTableName};",
+                $@"DROP TABLE {_settings.CachedTweetsTableName};"
+            };
+
+            foreach (var r in dropsRequests)
+            {
+                await _tools.ExecuteRequestAsync(r);
+            }
+        }
+    }
+}

src/DataAccessLayers/BirdsiteLive.DAL.Postgres/DataAccessLayers/FollowersPostgresDal.cs

@@ -0,0 +1,9 @@
+using BirdsiteLive.DAL.Contracts;
+
+namespace BirdsiteLive.DAL.Postgres.DataAccessLayers
+{
+    public class FollowersPostgresDal : IFollowersDal
+    {
+        
+    }
+}

src/DataAccessLayers/BirdsiteLive.DAL.Postgres/DataAccessLayers/TwitterUserPostgresDal.cs

@@ -0,0 +1,9 @@
+using BirdsiteLive.DAL.Contracts;
+
+namespace BirdsiteLive.DAL.Postgres.DataAccessLayers
+{
+    public class TwitterUserPostgresDal : ITwitterUserDal
+    {
+        
+    }
+}

src/DataAccessLayers/BirdsiteLive.DAL.Postgres/Settings/PostgresSettings.cs

@@ -0,0 +1,12 @@
+namespace BirdsiteLive.DAL.Postgres.Settings
+{
+    public class PostgresSettings
+    {
+        public string ConnString { get; set; }
+
+        public string DbVersionTableName { get; set; } = "db-version";
+        public string TwitterUserTableName { get; set; } = "twitter-users";
+        public string FollowersTableName { get; set; } = "followers";
+        public string CachedTweetsTableName { get; set; } = "cached-tweets";
+    }
+}

src/DataAccessLayers/BirdsiteLive.DAL.Postgres/Tools/PostgresTools.cs

@@ -0,0 +1,36 @@
+using System;
+using System.Threading.Tasks;
+using BirdsiteLive.DAL.Postgres.Settings;
+using Npgsql;
+
+namespace BirdsiteLive.DAL.Postgres.Tools
+{
+    public class PostgresTools
+    {
+        private readonly PostgresSettings _settings;
+
+        #region Ctor
+        public PostgresTools(PostgresSettings settings)
+        {
+            _settings = settings;
+        }
+        #endregion
+
+        public async Task ExecuteRequestAsync(string request)
+        {
+            try
+            {
+                using (var conn = new NpgsqlConnection(_settings.ConnString))
+                using (var cmd = new NpgsqlCommand(request, conn))
+                {
+                    await conn.OpenAsync();
+                    await cmd.ExecuteNonQueryAsync();
+                }
+            }
+            catch (Exception e)
+            {
+                Console.WriteLine(e);
+            }
+        }
+    }
+}

src/DataAccessLayers/BirdsiteLive.DAL/BirdsiteLive.DAL.csproj

@@ -0,0 +1,7 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>netstandard2.0</TargetFramework>
+  </PropertyGroup>
+
+</Project>

src/DataAccessLayers/BirdsiteLive.DAL/Contracts/IDbInitializerDal.cs

@@ -0,0 +1,15 @@
+using System;
+using System.Reflection;
+using System.Threading.Tasks;
+
+namespace BirdsiteLive.DAL.Contracts
+{
+    public interface IDbInitializerDal
+    { 
+        Task<Version> GetCurrentDbVersionAsync();
+        Version GetMandatoryDbVersion();
+        Tuple<Version, Version>[] GetMigrationPatterns();
+        Task MigrateDbAsync(Version from, Version to);
+        Task InitDbAsync();
+    }
+}

src/DataAccessLayers/BirdsiteLive.DAL/Contracts/IFollowersDal.cs

@@ -0,0 +1,7 @@
+namespace BirdsiteLive.DAL.Contracts
+{
+    public interface IFollowersDal
+    {
+        
+    }
+}

src/DataAccessLayers/BirdsiteLive.DAL/Contracts/ITwitterUserDal.cs

@@ -0,0 +1,7 @@
+namespace BirdsiteLive.DAL.Contracts
+{
+    public interface ITwitterUserDal
+    {
+        
+    }
+}

src/DataAccessLayers/BirdsiteLive.DAL/Models/CachedTweet.cs

@@ -0,0 +1,10 @@
+namespace BirdsiteLive.DAL.Models
+{
+    public class CachedTweet
+    {
+        public long Id { get; set; }
+        public long TwitterUserId { get; set; }
+        
+        public string TweetData { get; set; } 
+    }
+}

src/DataAccessLayers/BirdsiteLive.DAL/Models/Follower.cs

@@ -0,0 +1,13 @@
+namespace BirdsiteLive.DAL.Models
+{
+    public class Follower
+    {
+        public int Id { get; set; }
+        public int FollowingAccountId { get; set; }
+        
+        public string Acct { get; set; }
+        public string Host { get; set; }
+        
+        public long LastTweetSynchronizedId { get; set; }
+    }
+}

src/DataAccessLayers/BirdsiteLive.DAL/Models/SyncTwitterUser.cs

@@ -0,0 +1,11 @@
+namespace BirdsiteLive.DAL.Models
+{
+    public class SyncTwitterUser
+    {
+        public int Id { get; set; }
+        public string Acct { get; set; }
+
+        public long LastTweetPostedId { get; set; }
+        public long LastTweetSynchronizedForAllFollowersId { get; set; }
+    }
+}

src/DataAccessLayers/BirdsiteLive.DAL/Tools/RandomGenerator.cs

@@ -0,0 +1,18 @@
+using System;
+using System.Linq;
+
+namespace BirdsiteLive.DAL.Tools
+{
+    public static class RandomGenerator
+    {
+        private static readonly Random Random = new Random();
+
+        public static string GetString(int length)
+        {
+            const string chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
+            return new string(Enumerable.Repeat(chars, length)
+                .Select(s => s[Random.Next(s.Length)]).ToArray());
+        }
+
+    }
+}

src/Tests/BirdsiteLive.DAL.Postgres.Tests/BirdsiteLive.DAL.Postgres.Tests.csproj

@@ -0,0 +1,20 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
+
+    <IsPackable>false</IsPackable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.5.0" />
+    <PackageReference Include="MSTest.TestAdapter" Version="2.1.0" />
+    <PackageReference Include="MSTest.TestFramework" Version="2.1.0" />
+    <PackageReference Include="coverlet.collector" Version="1.2.0" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\DataAccessLayers\BirdsiteLive.DAL.Postgres\BirdsiteLive.DAL.Postgres.csproj" />
+  </ItemGroup>
+
+</Project>

src/Tests/BirdsiteLive.DAL.Postgres.Tests/DataAccessLayers/DbInitializerPostgresDalTests.cs

@@ -0,0 +1,68 @@
+using System;
+using System.Threading.Tasks;
+using BirdsiteLive.DAL.Postgres.DataAccessLayers;
+using BirdsiteLive.DAL.Postgres.Settings;
+using BirdsiteLive.DAL.Postgres.Tools;
+using BirdsiteLive.DAL.Tools;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+namespace BirdsiteLive.DAL.Postgres.Tests.DataAccessLayers
+{
+    [TestClass]
+    public class DbInitializerPostgresDalTests
+    {
+        private readonly PostgresSettings _settings;
+        private readonly PostgresTools _tools;
+
+        #region Ctor
+        public DbInitializerPostgresDalTests()
+        {
+            _settings = new PostgresSettings
+            {
+                ConnString = "Host=127.0.0.1;Username=postgres;Password=mysecretpassword;Database=mytestdb",
+                DbVersionTableName = "DbVersionTableName" + RandomGenerator.GetString(4),
+                CachedTweetsTableName = "CachedTweetsTableName" + RandomGenerator.GetString(4),
+                FollowersTableName = "FollowersTableName" + RandomGenerator.GetString(4),
+                TwitterUserTableName = "TwitterUserTableName" + RandomGenerator.GetString(4),
+            };
+            _tools = new PostgresTools(_settings);
+        }
+        #endregion
+
+        [TestCleanup]
+        public async Task CleanUp()
+        {
+            var dal = new DbInitializerPostgresDal(_settings, _tools);
+            try
+            {
+                await dal.DeleteAllAsync();
+            }
+            catch (Exception e)
+            {
+                Console.WriteLine(e);
+            }
+        }
+
+        [TestMethod]
+        public async Task GetCurrentDbVersionAsync_UninitializedDb()
+        {
+            var dal = new DbInitializerPostgresDal(_settings, _tools);
+            
+            var current = await dal.GetCurrentDbVersionAsync();
+            Assert.IsNull(current);
+        }
+
+        [TestMethod]
+        public async Task InitDbAsync()
+        {
+            var dal = new DbInitializerPostgresDal(_settings, _tools);
+
+            await dal.InitDbAsync();
+            var current = await dal.GetCurrentDbVersionAsync();
+            var mandatory = dal.GetMandatoryDbVersion();
+            Assert.IsNotNull(current);
+            Assert.AreEqual(mandatory.Minor, current.Minor);
+            Assert.AreEqual(mandatory.Major, current.Major);
+        }
+    }
+}