Generate ListChatCompletions with pagination

codegen/README.MD

@@ -0,0 +1,23 @@
+# Debugging the generator
+
+To configure VS Code for debugging the generator, specifically visitors, add the following to your `launch.json` in the root of the workspace
+
+```json
+{
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "Debug OpenAI Library Plugin",
+            "type": "coreclr",
+            "request": "launch",
+            "program": "dotnet",
+            "args": [
+                "${workspaceFolder}/codegen/dist/generator/Microsoft.TypeSpec.Generator.dll",
+                "${workspaceFolder}",
+                "-g",
+                "OpenAILibraryGenerator"
+            ],
+        }
+    ]
+}
+```

codegen/generator/src/OpenAILibraryGenerator.cs

@@ -38,6 +38,8 @@ protected override void Configure()
             AddVisitor(new ModelSerializationVisitor());
             AddVisitor(new ExperimentalAttributeVisitor());
             AddVisitor(new ModelDirectoryVisitor());
+            AddVisitor(new PaginationVisitor());
+            AddVisitor(new MetadataQueryParamVisitor());
         }
     }
 }

codegen/generator/src/Visitors/ExplicitConversionFromClientResultVisitor.cs

@@ -15,7 +15,8 @@ protected override MethodProvider VisitMethod(MethodProvider method)
         if (method.Signature.Modifiers.HasFlag(MethodSignatureModifiers.Explicit) &&
             method.Signature.Modifiers.HasFlag(MethodSignatureModifiers.Operator) &&
             method.Signature.Parameters.Count == 1 &&
-            method.Signature.Parameters[0].Type.Name == nameof(ClientResult))
+            method.Signature.Parameters[0].Type.Name == nameof(ClientResult) &&
+            !method.EnclosingType.DeclarationModifiers.HasFlag(TypeSignatureModifiers.Internal))
         {
             return null;
         }

codegen/generator/src/Visitors/MetadataQueryParamVisitor.cs

@@ -0,0 +1,130 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using Microsoft.TypeSpec.Generator.ClientModel;
+using Microsoft.TypeSpec.Generator.Expressions;
+using Microsoft.TypeSpec.Generator.Primitives;
+using Microsoft.TypeSpec.Generator.Providers;
+using Microsoft.TypeSpec.Generator.Snippets;
+using Microsoft.TypeSpec.Generator.Statements;
+using static OpenAILibraryPlugin.Visitors.VisitorHelpers;
+
+namespace OpenAILibraryPlugin.Visitors;
+
+/// <summary>
+/// This visitor modifies GetRawPagesAsync methods to consider HasMore in addition to LastId when deciding whether to continue pagination.
+/// It also replaces specific parameters with an options type for pagination methods.
+/// </summary>
+public class MetadataQueryParamVisitor : ScmLibraryVisitor
+{
+
+    private static readonly string[] _chatParamsToReplace = ["after", "before", "limit", "order", "model", "metadata"];
+    private static readonly Dictionary<string, string> _paramReplacementMap = new()
+    {
+        { "after", "AfterId" },
+        { "before", "LastId" },
+        { "limit", "PageSizeLimit" },
+        { "order", "Order" },
+        { "model", "Model" },
+        { "metadata", "Metadata" }
+    };
+    private static readonly Dictionary<string, (string ReturnType, string OptionsType, string[] ParamsToReplace)> _optionsReplacements = new()
+    {
+        {
+            "GetChatCompletions",
+            ("ChatCompletion", "ChatCompletionCollectionOptions", _chatParamsToReplace)
+        },
+        {
+            "GetChatCompletionsAsync",
+            ("ChatCompletion", "ChatCompletionCollectionOptions", _chatParamsToReplace)
+        }
+    };
+
+    /// <summary>
+    /// Visits Create*Request methods to modify how metadata query parameters are handled.
+    /// It replaces the following statements:
+    /// <code>
+    /// List<object> list = new List<object>();
+	/// foreach (var @param in metadata)
+	/// {
+    ///     uri.AppendQuery($"metadata[{@param.Key}]", @param.Value, true);
+    ///     list.Add(@param.Key);
+    ///     list.Add(@param.Value);
+    /// }
+    /// uri.AppendQueryDelimited("metadata", list, ",", null, true);
+    /// </code>
+    /// with:
+    /// <code>
+    /// foreach (var @param in metadata)
+    /// {
+    ///    uri.AppendQuery($"metadata[{@param.Key}]", @param.Value, true);
+    /// }
+    /// </summary>
+    /// <param name="method"></param>
+    /// <returns></returns>
+    protected override MethodProvider? VisitMethod(MethodProvider method)
+    {
+        // Check if the method is one of the Create*Request methods and has a signature that takes a metadata parameter like IDictionary<string, string> metadata
+        if (method.Signature.Name.StartsWith("Create") && method.Signature.Name.EndsWith("Request") &&
+            method.Signature.Parameters.Any(p => p.Type.IsDictionary && p.Name == "metadata"))
+        {
+            ValueExpression? uri = null;
+            var statements = method.BodyStatements?.ToList() ?? new List<MethodBodyStatement>();
+            VisitExplodedMethodBodyStatements(
+                statements!,
+                statement =>
+                {
+                    // Check if the statement is an assignment to a variable named "uri"
+                    // Capture it if so
+                    if (statement is ExpressionStatement expressionStatement &&
+                       expressionStatement.Expression is AssignmentExpression assignmentExpression &&
+                       assignmentExpression.Variable is DeclarationExpression declarationExpression &&
+                       declarationExpression.Variable is VariableExpression variableExpression &&
+                       variableExpression.Declaration.RequestedName == "uri")
+                    {
+                        uri = variableExpression;
+                    }
+                    // Try to remove the unnecessary list declaration
+                    if (statement is ExpressionStatement expressionStatement2 &&
+                       expressionStatement2.Expression is AssignmentExpression assignmentExpression2 &&
+                       assignmentExpression2.Variable is DeclarationExpression declarationExpression2 &&
+                       declarationExpression2.Variable is VariableExpression variableExpression2 &&
+                       variableExpression2.Declaration.RequestedName == "list" &&
+                       variableExpression2.Type.IsCollection && variableExpression2.Type.IsGenericType)
+                    {
+                        // Remove the list declaration
+                        return new SingleLineCommentStatement("Plugin customization: remove unnecessary list declaration");
+                    }
+
+                    if (uri is not null &&
+                        statement is ForEachStatement foreachStatement &&
+                        foreachStatement.Enumerable is DictionaryExpression dictionaryExpression &&
+                        dictionaryExpression.Original is VariableExpression variable &&
+                        variable.Declaration.RequestedName == "metadata")
+                    {
+                        var formatString = new FormattableStringExpression("metadata[{0}]", [foreachStatement.ItemVariable.Property("Key")]);
+                        var appendQueryStatement = uri.Invoke("AppendQuery", [formatString, foreachStatement.ItemVariable.Property("Value"), Snippet.True]);
+                        foreachStatement.Body.Clear();
+                        foreachStatement.Body.Add(new SingleLineCommentStatement("Plugin customization: Properly handle metadata query parameters"));
+                        foreachStatement.Body.Add(appendQueryStatement.Terminate());
+                    }
+
+                    // Remove the call to AppendQueryDelimited for metadata
+                    if (statement is ExpressionStatement expressionStatement3 &&
+                        expressionStatement3.Expression is InvokeMethodExpression invokeMethodExpression &&
+                        invokeMethodExpression.MethodName == "AppendQueryDelimited" &&
+                        invokeMethodExpression.Arguments.Count == 5 &&
+                        invokeMethodExpression.Arguments[0].ToDisplayString() == "\"metadata\"")
+                    {
+                        return new SingleLineCommentStatement("Plugin customization: remove unnecessary AppendQueryDelimited for metadata");
+                    }
+                    return statement;
+                });
+
+            // Rebuild the method body with the modified statements
+            method.Update(bodyStatements: statements);
+        }
+
+        return base.VisitMethod(method);
+    }
+}