feat: implement AI plugin calling interface with dedicated endpoints

pkg/server/ai_interface.go

@@ -0,0 +1,100 @@
+/*
+Copyright 2024 API Testing Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+	http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package server
+
+// AI Plugin Communication Interface Standards
+// AI plugins use the existing testing.Loader.Query(map[string]string) interface
+
+// Standard AI plugin communication methods
+const (
+	AIMethodGenerate     = "ai.generate"     // Generate content from prompt
+	AIMethodCapabilities = "ai.capabilities" // Get plugin capabilities
+)
+
+// AI Plugin Query Parameter Standards
+// AI plugins are called using loader.Query(query map[string]string) with these parameters:
+
+// For ai.generate:
+//   - "method": "ai.generate"
+//   - "model":  model identifier (e.g., "gpt-4", "claude")  
+//   - "prompt": the prompt or instruction
+//   - "config": optional JSON configuration string (e.g., `{"temperature": 0.7, "max_tokens": 1000}`)
+
+// For ai.capabilities:
+//   - "method": "ai.capabilities"
+
+// AI Plugin Response Standards
+// AI plugins return response through testing.DataResult.Pairs with these keys:
+
+// For successful ai.generate:
+//   - "content": the generated content
+//   - "meta":    optional JSON metadata string (model info, timing, etc.)
+//   - "success": "true"
+
+// For successful ai.capabilities:
+//   - "capabilities": JSON string containing plugin capabilities
+//   - "models":       JSON array of supported models (fallback if capabilities not available)
+//   - "features":     JSON array of supported features (fallback)
+//   - "description":  plugin description (fallback)
+//   - "version":      plugin version (fallback)
+//   - "success":      "true"
+
+// For errors:
+//   - "error":   error message
+//   - "success": "false"
+
+// Plugin Discovery
+// AI plugins are identified by having "ai" in their categories field:
+//   categories: ["ai"]
+
+// Usage Examples:
+//
+// Get AI plugins:
+//   stores, err := server.GetStores(ctx, &SimpleQuery{Kind: "ai"})
+//
+// Call AI plugin:
+//   loader, err := server.getLoaderByStoreName("my-ai-plugin")
+//   result, err := loader.Query(map[string]string{
+//       "method": "ai.generate",
+//       "model":  "gpt-4", 
+//       "prompt": "Hello world",
+//       "config": `{"temperature": 0.7}`,
+//   })
+//   content := result.Pairs["content"]
+
+// Documentation structures (for reference only, actual types are generated from proto)
+// See server.proto for the actual message definitions:
+//
+// AIRequest fields:
+//   - plugin_name: AI plugin name
+//   - model: Model identifier (e.g., "gpt-4", "claude")
+//   - prompt: The prompt or instruction
+//   - config: JSON configuration string (optional)
+//
+// AIResponse fields:
+//   - content: Generated content
+//   - meta: JSON metadata string (optional)
+//   - success: Whether the call succeeded
+//   - error: Error message if failed
+//
+// AICapabilitiesResponse fields:
+//   - models: Supported models
+//   - features: Supported features
+//   - description: Plugin description
+//   - version: Plugin version
+//   - success: Whether the call succeeded
+//   - error: Error message if failed