Added the exact token count where the provider reports it (#989)

Co-authored-by: Thorsten Sommer <SommerEngineering@users.noreply.github.com>

app/Tests/Chat/ChatThreadReportedHistoryTests.cs

@@ -0,0 +1,184 @@
+using AIStudio.Chat;
+using AIStudio.Provider;
+
+namespace AIStudio.Tests.Chat;
+
+/// <summary>
+/// Checks when what a provider reported for a conversation still describes it.
+/// </summary>
+/// <remarks>
+/// A reported number is shown as exact, so a wrong one does more harm than no number at all: it
+/// tells a person that their chat fits while it does not. Every case below is one where the thread
+/// moved on after the report, and the estimate has to take over -- or one where it came back to
+/// exactly the state the report was taken in, and the report counts again.
+/// </remarks>
+[TestFixture]
+public sealed class ChatThreadReportedHistoryTests
+{
+    private static readonly DateTimeOffset START = new(2026, 9, 23, 10, 0, 0, TimeSpan.Zero);
+
+    private static readonly Model MODEL = new("model-a", null);
+
+    private static readonly Model OTHER_MODEL = new("model-b", null);
+
+    [Test]
+    public void TheReportOfTheLastAnswerCounts()
+    {
+        var thread = Thread(Question(1), Answer(2, promptTokens: 1200, blockCount: 2));
+
+        var history = thread.ReportedHistoryFor(MODEL);
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(history.IsKnown, Is.True);
+            Assert.That(history.PromptTokens, Is.EqualTo(1200));
+
+            //
+            // The answer comes along as text rather than as the provider's number for it, which
+            // would include the reasoning the next request never carries:
+            //
+            Assert.That(history.LastAnswer, Is.EqualTo("Answer 2"));
+        });
+    }
+
+    [Test]
+    public void AnAnswerWithoutTextAddsNothingToThePrompt()
+    {
+        //
+        // An answer which consists of reasoning only. It may be kept to be read, but without any
+        // text it is never sent, so what the provider counted is all the next request carries of
+        // the conversation so far.
+        //
+        var reasoningOnly = new ContentText { Text = string.Empty };
+        reasoningOnly.RecordReportedUsage(TokenUsage.Of(1200), MODEL.Id, 2);
+        var thread = Thread(Question(1), Block(ChatRole.AI, reasoningOnly, 2));
+
+        var history = thread.ReportedHistoryFor(MODEL);
+        Assert.Multiple(() =>
+        {
+            Assert.That(history.IsKnown, Is.True);
+            Assert.That(history.PromptTokens, Is.EqualTo(1200));
+            Assert.That(history.LastAnswer, Is.Empty);
+        });
+    }
+
+    [Test]
+    public void AMessageWhoseRequestFailedIsNotLeftOut()
+    {
+        //
+        // A request which was turned down leaves the question standing and removes the empty
+        // answer. The report before it knows nothing about that question -- which may well be the
+        // very message that made the chat too large.
+        //
+        var thread = Thread(Question(1), Answer(2, promptTokens: 1200, blockCount: 2), Question(3));
+
+        Assert.That(thread.ReportedHistoryFor(MODEL).IsKnown, Is.False);
+    }
+
+    [Test]
+    public void AnAnswerBeingWrittenDoesNotBorrowTheReportBeforeIt()
+    {
+        var streaming = Block(ChatRole.AI, new ContentText { Text = "Half an ans", IsStreaming = true }, 4);
+        var thread = Thread(Question(1), Answer(2, promptTokens: 1200, blockCount: 2), Question(3), streaming);
+
+        Assert.That(thread.ReportedHistoryFor(MODEL).IsKnown, Is.False);
+    }
+
+    [Test]
+    public void AnAnswerWithoutAReportDoesNotBorrowTheReportBeforeIt()
+    {
+        //
+        // What an answer looks like whose provider reports nothing, or whose API is not read for a
+        // report yet: finished, but without a report of its own.
+        //
+        var withoutReport = Block(ChatRole.AI, new ContentText { Text = "Second answer" }, 4);
+        var thread = Thread(Question(1), Answer(2, promptTokens: 1200, blockCount: 2), Question(3), withoutReport);
+
+        Assert.That(thread.ReportedHistoryFor(MODEL).IsKnown, Is.False);
+    }
+
+    [Test]
+    public void DeletingAnEarlierMessageOutdatesTheReport()
+    {
+        //
+        // Deleting a large message to make room is exactly when somebody watches the number, and
+        // the deleted message is still inside what the provider reported.
+        //
+        var firstQuestion = Question(1);
+        var thread = Thread(firstQuestion, Answer(2, promptTokens: 1200, blockCount: 2), Question(3), Answer(4, promptTokens: 2600, blockCount: 4));
+
+        thread.Remove(firstQuestion.Content!);
+
+        Assert.That(thread.ReportedHistoryFor(MODEL).IsKnown, Is.False);
+    }
+
+    [Test]
+    public void AnotherModelOutdatesTheReport()
+    {
+        var thread = Thread(Question(1), Answer(2, promptTokens: 1200, blockCount: 2));
+
+        Assert.That(thread.ReportedHistoryFor(OTHER_MODEL).IsKnown, Is.False);
+    }
+
+    [Test]
+    public void EditingTheLastMessageBringsTheReportBeforeItBack()
+    {
+        var lastQuestion = Question(3);
+        var lastAnswer = Answer(4, promptTokens: 2600, blockCount: 4);
+        var thread = Thread(Question(1), Answer(2, promptTokens: 1200, blockCount: 2), lastQuestion, lastAnswer);
+
+        //
+        // What editing the last message does to the thread: the question goes back into the
+        // composer, and its answer goes with it.
+        //
+        thread.Remove(lastQuestion.Content!);
+        thread.Remove(lastAnswer.Content!);
+
+        var history = thread.ReportedHistoryFor(MODEL);
+        Assert.Multiple(() =>
+        {
+            Assert.That(history.IsKnown, Is.True, "The first answer is the last block again, with exactly the blocks it was reported for.");
+            Assert.That(history.PromptTokens, Is.EqualTo(1200));
+            Assert.That(history.LastAnswer, Is.EqualTo("Answer 2"));
+        });
+    }
+
+    [Test]
+    public void RollingBackToAnAnswerBringsItsReportBack()
+    {
+        var firstAnswer = Answer(2, promptTokens: 1200, blockCount: 2);
+        var thread = Thread(Question(1), firstAnswer, Question(3), Answer(4, promptTokens: 2600, blockCount: 4));
+
+        thread.RollBackTo(firstAnswer.Content!);
+
+        var history = thread.ReportedHistoryFor(MODEL);
+        Assert.Multiple(() =>
+        {
+            Assert.That(history.IsKnown, Is.True);
+            Assert.That(history.PromptTokens, Is.EqualTo(1200));
+            Assert.That(history.LastAnswer, Is.EqualTo("Answer 2"));
+        });
+    }
+
+    private static ChatThread Thread(params ContentBlock[] blocks) => new()
+    {
+        Blocks = [..blocks],
+    };
+
+    private static ContentBlock Question(int minute) => Block(ChatRole.USER, new ContentText { Text = $"Question {minute}" }, minute);
+
+    private static ContentBlock Answer(int minute, int promptTokens, int blockCount)
+    {
+        var answer = new ContentText { Text = $"Answer {minute}" };
+        answer.RecordReportedUsage(TokenUsage.Of(promptTokens), MODEL.Id, blockCount);
+        return Block(ChatRole.AI, answer, minute);
+    }
+
+    private static ContentBlock Block(ChatRole role, ContentText content, int minute) => new()
+    {
+        Time = START.AddMinutes(minute),
+        ContentType = ContentType.TEXT,
+        Content = content,
+        Role = role,
+    };
+}

app/Tests/Chat/ConversationPartsTests.cs

@@ -56,7 +56,8 @@ public sealed class ConversationPartsTests
         Assert.Multiple(() =>
         {
             Assert.That(parts.Texts, Is.EqualTo(new[] { "You are helpful.", "What is the capital of France?", "Paris." }));
-            Assert.That(parts.GrowingTexts, Is.EqualTo(new[] { "And of Italy?" }));
+            Assert.That(parts.DraftText, Is.EqualTo("And of Italy?"));
+            Assert.That(parts.GrowingTexts, Is.Empty, "The draft is a part of its own, and it stands nowhere else.");
         });
     }
 
@@ -77,7 +78,8 @@ public sealed class ConversationPartsTests
         Assert.Multiple(() =>
         {
             Assert.That(parts.Texts, Is.EqualTo(new[] { "A question." }));
-            Assert.That(parts.GrowingTexts, Is.EqualTo(new[] { "The answer so far", "a draft" }));
+            Assert.That(parts.GrowingTexts, Is.EqualTo(new[] { "The answer so far" }));
+            Assert.That(parts.DraftText, Is.EqualTo("a draft"));
         });
     }
 
@@ -135,7 +137,7 @@ public sealed class ConversationPartsTests
         Assert.Multiple(() =>
         {
             Assert.That(parts.Texts, Is.Empty);
-            Assert.That(parts.GrowingTexts, Is.EqualTo(new[] { "Hello" }));
+            Assert.That(parts.DraftText, Is.EqualTo("Hello"));
         });
     }
 
@@ -149,6 +151,7 @@ public sealed class ConversationPartsTests
         {
             Assert.That(parts.Texts, Is.Empty);
             Assert.That(parts.GrowingTexts, Is.Empty);
+            Assert.That(parts.DraftText, Is.Empty);
         });
     }
 
@@ -188,7 +191,11 @@ public sealed class ConversationPartsTests
 
         var parts = ConversationParts.Of(new() { Blocks = [block] }, string.Empty, "And this one.", [FileAttachment.FromPath(draft)], imagesAreSent: true, toolDefinitions: null);
 
-        Assert.That(parts.Documents.Select(document => document.FileName), Is.EqualTo(new[] { "older.txt", "draft.txt" }));
+        Assert.Multiple(() =>
+        {
+            Assert.That(parts.Documents.Select(document => document.FileName), Is.EqualTo(new[] { "older.txt" }));
+            Assert.That(parts.DraftDocuments.Select(document => document.FileName), Is.EqualTo(new[] { "draft.txt" }), "Both count, each in the part it belongs to.");
+        });
     }
 
     [Test]
@@ -201,7 +208,7 @@ public sealed class ConversationPartsTests
 
         var parts = ConversationParts.Of(null, string.Empty, "Here", [attachment], imagesAreSent: true, toolDefinitions: null);
 
-        Assert.That(parts.Documents, Is.Empty);
+        Assert.That(parts.DraftDocuments, Is.Empty);
     }
 
     [Test]
@@ -214,8 +221,29 @@ public sealed class ConversationPartsTests
 
         Assert.Multiple(() =>
         {
-            Assert.That(parts.Documents.Select(entry => entry.FileName), Is.EqualTo(new[] { "notes.txt" }));
+            Assert.That(parts.DraftDocuments.Select(entry => entry.FileName), Is.EqualTo(new[] { "notes.txt" }));
+            Assert.That(parts.DraftImages, Is.EqualTo(1));
+        });
+    }
+
+    [Test]
+    public void ImagesOfTheConversationAndOfTheDraftAreKeptApart()
+    {
+        //
+        // A provider which reported the conversation so far counted the pictures in it as well,
+        // but never the ones which are still waiting in the composer.
+        //
+        var sent = this.WriteFile("sent.png", "not really a png");
+        var waiting = this.WriteFile("waiting.png", "not really a png either");
+        var block = Block("Look at this.");
+        ((ContentText)block.Content!).FileAttachments.Add(FileAttachment.FromPath(sent));
+
+        var parts = ConversationParts.Of(new() { Blocks = [block] }, string.Empty, "And at this.", [FileAttachment.FromPath(waiting)], imagesAreSent: true, toolDefinitions: null);
+
+        Assert.Multiple(() =>
+        {
             Assert.That(parts.Images, Is.EqualTo(1));
+            Assert.That(parts.DraftImages, Is.EqualTo(1));
         });
     }
 
@@ -230,7 +258,7 @@ public sealed class ConversationPartsTests
 
         var parts = ConversationParts.Of(null, string.Empty, "Look", [FileAttachment.FromPath(image)], imagesAreSent: false, toolDefinitions: null);
 
-        Assert.That(parts.Images, Is.Zero);
+        Assert.That(parts.DraftImages, Is.Zero);
     }
 
     [Test]
@@ -250,7 +278,8 @@ public sealed class ConversationPartsTests
         Assert.Multiple(() =>
         {
             Assert.That(parts.Texts, Is.Empty);
-            Assert.That(parts.GrowingTexts, Is.EqualTo(new[] { "What the web search found.", "What the page said." }));
+            Assert.That(parts.ToolConversation, Is.EqualTo(new[] { "What the web search found.", "What the page said." }));
+            Assert.That(parts.GrowingTexts, Is.Empty, "The tool conversation is a part of its own, so that its share can be named.");
         });
     }
 
@@ -267,7 +296,7 @@ public sealed class ConversationPartsTests
 
         var parts = ConversationParts.Of(new() { Blocks = [running] }, string.Empty, string.Empty, null, imagesAreSent: true, toolDefinitions: null);
 
-        Assert.That(parts.GrowingTexts, Is.EqualTo(new[] { "The same page.", "The same page." }));
+        Assert.That(parts.ToolConversation, Is.EqualTo(new[] { "The same page.", "The same page." }));
     }
 
     [Test]
@@ -288,7 +317,7 @@ public sealed class ConversationPartsTests
         Assert.Multiple(() =>
         {
             Assert.That(parts.Texts, Is.EqualTo(new[] { "Here is what I found." }));
-            Assert.That(parts.GrowingTexts, Is.Empty);
+            Assert.That(parts.ToolConversation, Is.Empty);
         });
     }
 

app/Tests/Chat/ConversationTokensTests.cs

@@ -25,7 +25,7 @@ public sealed class ConversationTokensTests
         var counted = new ConversationTokens
         {
             IsKnown = true,
-            UncountedImages = images,
+            Images = images,
             ImageLimits = new ImageLimits(null, allowed),
         };
 
@@ -42,7 +42,7 @@ public sealed class ConversationTokensTests
         var counted = new ConversationTokens
         {
             IsKnown = true,
-            UncountedImages = 500,
+            Images = 500,
             ImageLimits = ImageLimits.UNKNOWN,
         };
 
@@ -60,7 +60,7 @@ public sealed class ConversationTokensTests
         var counted = new ConversationTokens
         {
             IsKnown = true,
-            UncountedImages = 20,
+            Images = 20,
             ImageLimits = new ImageLimits(8, 100),
         };
 
@@ -77,7 +77,7 @@ public sealed class ConversationTokensTests
         var counted = new ConversationTokens
         {
             IsKnown = true,
-            UncountedImages = 0,
+            Images = 0,
             ImageLimits = new ImageLimits(null, 0),
         };
 
@@ -93,4 +93,64 @@ public sealed class ConversationTokensTests
         //
         Assert.That(ConversationTokens.UNAVAILABLE.TooManyImages, Is.False);
     }
+
+    [Test]
+    public void PicturesAProviderCountedAreNotCalledUncounted()
+    {
+        //
+        // What the provider reported for the conversation so far includes its pictures, however
+        // it charges them. Only those still waiting in the composer are left for nobody to count.
+        //
+        var reported = new ConversationTokens
+        {
+            IsKnown = true,
+            HistoryIsReported = true,
+            Images = 3,
+            DraftImages = 1,
+        };
+
+        var estimated = reported with { HistoryIsReported = false };
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(reported.UncountedImages, Is.EqualTo(1), "The provider counted the two which were sent.");
+            Assert.That(estimated.UncountedImages, Is.EqualTo(3), "Without a report, nobody counted any of them.");
+        });
+    }
+
+    [Test]
+    public void TooManyPicturesStaysTooManyWhenTheProviderCountedThem()
+    {
+        //
+        // The limit is on how many pictures travel, not on what they cost. A provider which has
+        // counted them still refuses the request which carries one too many.
+        //
+        var counted = new ConversationTokens
+        {
+            IsKnown = true,
+            HistoryIsReported = true,
+            Images = 10,
+            ImageLimits = new ImageLimits(8, null),
+        };
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(counted.UncountedImages, Is.Zero);
+            Assert.That(counted.TooManyImages, Is.True);
+        });
+    }
+
+    [Test]
+    public void TheWholeNumberIsTheConversationAndTheDraft()
+    {
+        var counted = new ConversationTokens
+        {
+            IsKnown = true,
+            HistoryTokens = 12_400,
+            ToolTokens = 9_000,
+            DraftTokens = 340,
+        };
+
+        Assert.That(counted.Tokens, Is.EqualTo(12_740), "The tools' share is part of the conversation, not added on top of it.");
+    }
 }

app/Tests/Chat/TokenAmountTests.cs

@@ -51,4 +51,4 @@ public sealed class TokenAmountTests
         //
         Assert.That(TokenAmount.Format(tokens, GERMAN), Is.EqualTo(wanted));
     }
-}
+}