Added ML (#29)

* added ML training on start (might be cached in future?) and ability to autoban

.env.example

@@ -15,3 +15,10 @@ USE_FAKE_TG_API=false
 CLEANUP_OLD_MESSAGES=true
 CLEANUP_INTERVAL_SEC=86400
 CLEANUP_OLD_LIMIT_SEC=259200
+ML_ENABLED=false
+ML_SEED=
+ML_SPAM_DELETION_ENABLED=false
+ML_TRAIN_BEFORE_DATE=2021-01-01
+ML_TRAINING_SET_FRACTION=0.2
+ML_SPAM_THRESHOLD=0.5
+ML_STOP_WORDS_IN_CHATS={"-123":["word1","word2"]}

src/VahterBanBot.Tests/ContainerTestBase.fs

@@ -4,6 +4,7 @@ open System
 open System.IO
 open System.Net.Http
 open System.Text
+open System.Threading.Tasks
 open DotNet.Testcontainers.Builders
 open DotNet.Testcontainers.Configurations
 open DotNet.Testcontainers.Containers
@@ -90,6 +91,14 @@ type VahterTestContainers() =
             .WithEnvironment("USE_FAKE_TG_API", "true")
             .WithEnvironment("USE_POLLING", "false")
             .WithEnvironment("DATABASE_URL", internalConnectionString)
+            .WithEnvironment("CLEANUP_OLD_MESSAGES", "false")
+            .WithEnvironment("ML_ENABLED", "true")
+            // seed data uses 2021-01-01 as a date for all messages
+            .WithEnvironment("ML_TRAIN_BEFORE_DATE", "2021-01-02T00:00:00Z")
+            .WithEnvironment("ML_SEED", "42")
+            .WithEnvironment("ML_SPAM_DELETION_ENABLED", "true")
+            .WithEnvironment("ML_SPAM_THRESHOLD", "1.0")
+            .WithEnvironment("ML_STOP_WORDS_IN_CHATS", """{"-42":["2"]}""")
             // .net 8.0 upgrade has a breaking change
             // https://learn.microsoft.com/en-us/dotnet/core/compatibility/containers/8.0/aspnet-port
             // Azure default port for containers is 80, se we need explicitly set it
@@ -124,10 +133,14 @@ type VahterTestContainers() =
                 failwith out
 
             // seed some test data
-            // inserting the only admin users we have
-            // TODO might be a script in test assembly
-            let! _ = dbContainer.ExecAsync([|"""INSERT INTO "user"(id, username, banned_by, banned_at, ban_reason) VALUES (34, 'vahter_1', NULL, NULL, NULL), (69, 'vahter_2', NULL, NULL, NULL);"""|])
-
+            let script = File.ReadAllText(CommonDirectoryPath.GetCallerFileDirectory().DirectoryPath + "/test_seed.sql")
+            let scriptFilePath = String.Join("/", String.Empty, "tmp", Guid.NewGuid().ToString("D"), Path.GetRandomFileName())
+            do! dbContainer.CopyAsync(Encoding.Default.GetBytes script, scriptFilePath, Unix.FileMode644)
+            let! scriptResult = dbContainer.ExecAsync [|"psql"; "--username"; "vahter_bot_ban_service"; "--dbname"; "vahter_bot_ban"; "--file"; scriptFilePath |]
+
+            if scriptResult.Stderr <> "" then
+                failwith scriptResult.Stderr
+
             // start the app container
             do! appContainer.StartAsync()
 
@@ -185,3 +198,18 @@ type VahterTestContainers() =
         let! count = conn.QuerySingleAsync<int>(sql, {| chatId = msg.Chat.Id; messageId = msg.MessageId |})
         return count > 0
     }
+
+    member _.MessageIsAutoBanned(msg: Message) = task {
+        use conn = new NpgsqlConnection(publicConnectionString)
+        //language=postgresql
+        let sql = "SELECT COUNT(*) FROM banned_by_bot WHERE banned_in_chat_id = @chatId AND message_id = @messageId"
+        let! count = conn.QuerySingleAsync<int>(sql, {| chatId = msg.Chat.Id; messageId = msg.MessageId |})
+        return count > 0
+    }
+
+// workaround to wait for ML to be ready
+type MlAwaitFixture() =
+    interface IAsyncLifetime with
+        member this.DisposeAsync() = Task.CompletedTask
+        // we assume 5 seconds is enough for model to train. Could be flaky
+        member this.InitializeAsync() = Task.Delay 5000

src/VahterBanBot.Tests/MLBanTests.fs

@@ -0,0 +1,59 @@
+module VahterBanBot.Tests.MLBanTests
+
+open System.Net
+open System.Threading.Tasks
+open VahterBanBot.Tests.ContainerTestBase
+open VahterBanBot.Tests.TgMessageUtils
+open Xunit
+open Xunit.Extensions.AssemblyFixture
+
+type MLBanTests(fixture: VahterTestContainers, _unused: MlAwaitFixture) =
+
+    [<Fact>]
+    let ``Message IS autobanned if it looks like a spam`` () = task {
+        // record a message, where 2 is in a training set as spam word
+        // ChatsToMonitor[0] doesn't have stopwords
+        let msgUpdate = Tg.quickMsg(chat = fixture.ChatsToMonitor[0], text = "2")
+        let! _ = fixture.SendMessage msgUpdate
+
+        // assert that the message got auto banned
+        let! msgBanned = fixture.MessageIsAutoBanned msgUpdate.Message
+        Assert.True msgBanned
+    }
+
+    [<Fact>]
+    let ``Message is NOT autobanned if it has a stopword in specific chat`` () = task {
+        // record a message, where 2 is in a training set as spam word
+        // ChatsToMonitor[1] does have a stopword 2
+        let msgUpdate = Tg.quickMsg(chat = fixture.ChatsToMonitor[1], text = "2")
+        let! _ = fixture.SendMessage msgUpdate
+
+        // assert that the message got auto banned
+        let! msgBanned = fixture.MessageIsAutoBanned msgUpdate.Message
+        Assert.False msgBanned
+    }
+
+    [<Fact>]
+    let ``Message is NOT autobanned if it is a known false-positive spam`` () = task {
+        // record a message, where 3 is in a training set as spam word
+        let msgUpdate = Tg.quickMsg(chat = fixture.ChatsToMonitor[0], text = "a")
+        let! _ = fixture.SendMessage msgUpdate
+
+        // assert that the message got auto banned
+        let! msgBanned = fixture.MessageIsAutoBanned msgUpdate.Message
+        Assert.False msgBanned
+    }
+
+    [<Fact>]
+    let ``Message IS autobanned if it is a known false-negative spam`` () = task {
+        // record a message, where 3 is in a training set as false negative spam word
+        let msgUpdate = Tg.quickMsg(chat = fixture.ChatsToMonitor[0], text = "3")
+        let! _ = fixture.SendMessage msgUpdate
+
+        // assert that the message got auto banned
+        let! msgBanned = fixture.MessageIsAutoBanned msgUpdate.Message
+        Assert.True msgBanned
+    }
+
+    interface IAssemblyFixture<VahterTestContainers>
+    interface IClassFixture<MlAwaitFixture>

src/VahterBanBot.Tests/TgMessageUtils.fs

@@ -5,7 +5,7 @@ open System.Threading
 open Telegram.Bot.Types
 
 type Tg() =
-    static let mutable i = 0L
+    static let mutable i = 1L // higher than the data in the test_seed.sql
     static let nextInt64() = Interlocked.Increment &i
     static let next() = nextInt64() |> int
     static member user (?id: int64, ?username: string, ?firstName: string) =

src/VahterBanBot.Tests/VahterBanBot.Tests.fsproj

@@ -9,10 +9,14 @@
     </PropertyGroup>
 
     <ItemGroup>
+        <Content Include="test_seed.sql">
+            <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+        </Content>
         <Compile Include="TgMessageUtils.fs" />
         <Compile Include="ContainerTestBase.fs" />
         <Compile Include="BaseTests.fs" />
         <Compile Include="MessageTests.fs" />
+        <Compile Include="MLBanTests.fs" />
         <Compile Include="BanTests.fs" />
         <Compile Include="PingTests.fs" />
         <Compile Include="Program.fs"/>