refactor: migrate MCP SDK to main repo (#3516)

plugins/wasm-go/pkg/mcp/utils/mcp_rpc.go

@@ -0,0 +1,117 @@
+// Copyright (c) 2022 Alibaba Group Holding Ltd.
+//
+// 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 utils
+
+import (
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+
+	"github.com/higress-group/wasm-go/pkg/wrapper"
+)
+
+func OnMCPResponseSuccess(ctx wrapper.HttpContext, result map[string]any, debugInfo string) {
+	OnJsonRpcResponseSuccess(ctx, result, debugInfo)
+	// TODO: support pub to redis when use POST + SSE
+}
+
+func OnMCPResponseError(ctx wrapper.HttpContext, err error, code int, debugInfo string) {
+	OnJsonRpcResponseError(ctx, err, code, debugInfo)
+	// TODO: support pub to redis when use POST + SSE
+}
+
+func OnMCPToolCallSuccess(ctx wrapper.HttpContext, content []map[string]any, debugInfo string) {
+	OnMCPResponseSuccess(ctx, map[string]any{
+		"content": content,
+		"isError": false,
+	}, debugInfo)
+}
+
+// OnMCPToolCallSuccessWithStructuredContent sends a successful MCP tool response with structured content
+// According to MCP spec, structuredContent is a field in tool results, not a capability
+func OnMCPToolCallSuccessWithStructuredContent(ctx wrapper.HttpContext, content []map[string]any, structuredContent json.RawMessage, debugInfo string) {
+	response := map[string]any{
+		"content": content,
+		"isError": false,
+	}
+	if structuredContent != nil && len(structuredContent) > 0 {
+		response["structuredContent"] = structuredContent
+	}
+	OnMCPResponseSuccess(ctx, response, debugInfo)
+}
+
+func OnMCPToolCallError(ctx wrapper.HttpContext, err error, debugInfo ...string) {
+	responseDebugInfo := fmt.Sprintf("mcp:tools/call:error(%s)", err)
+	if len(debugInfo) > 0 {
+		responseDebugInfo = debugInfo[0]
+	}
+	OnMCPResponseSuccess(ctx, map[string]any{
+		"content": []map[string]any{
+			{
+				"type": "text",
+				"text": err.Error(),
+			},
+		},
+		"isError": true,
+	}, responseDebugInfo)
+}
+
+func SendMCPToolTextResult(ctx wrapper.HttpContext, result string, debugInfo ...string) {
+	responseDebugInfo := "mcp:tools/call::result"
+	if len(debugInfo) > 0 {
+		responseDebugInfo = debugInfo[0]
+	}
+	OnMCPToolCallSuccess(ctx, []map[string]any{
+		{
+			"type": "text",
+			"text": result,
+		},
+	}, responseDebugInfo)
+}
+
+func SendMCPToolImageResult(ctx wrapper.HttpContext, image []byte, contentType string, debugInfo ...string) {
+	responseDebugInfo := "mcp:tools/call::result"
+	if len(debugInfo) > 0 {
+		responseDebugInfo = debugInfo[0]
+	}
+
+	content := []map[string]any{
+		{
+			"type":     "image",
+			"data":     base64.StdEncoding.EncodeToString(image),
+			"mimeType": contentType,
+		},
+	}
+
+	// Use traditional response format since no structured data is provided
+	OnMCPToolCallSuccess(ctx, content, responseDebugInfo)
+}
+
+// SendMCPToolTextResultWithStructuredContent sends a tool result with both text content and structured content
+// According to MCP spec, for backward compatibility, tools that return structured content
+// SHOULD also return the serialized JSON in a TextContent block
+func SendMCPToolTextResultWithStructuredContent(ctx wrapper.HttpContext, textResult string, structuredContent json.RawMessage, debugInfo ...string) {
+	responseDebugInfo := "mcp:tools/call::result"
+	if len(debugInfo) > 0 {
+		responseDebugInfo = debugInfo[0]
+	}
+	content := []map[string]any{
+		{
+			"type": "text",
+			"text": textResult,
+		},
+	}
+	OnMCPToolCallSuccessWithStructuredContent(ctx, content, structuredContent, responseDebugInfo)
+}