conversation: add echo implement (#3549)

Signed-off-by: Loong <[email protected]>

conversation/echo/echo.go

@@ -0,0 +1,75 @@
+/*
+Copyright 2024 The Dapr 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 echo
+
+import (
+	"context"
+	"reflect"
+
+	"github.com/dapr/components-contrib/conversation"
+	"github.com/dapr/components-contrib/metadata"
+	"github.com/dapr/kit/logger"
+	kmeta "github.com/dapr/kit/metadata"
+)
+
+// Echo implement is only for test.
+type Echo struct {
+	model  string
+	logger logger.Logger
+}
+
+func NewEcho(logger logger.Logger) conversation.Conversation {
+	e := &Echo{
+		logger: logger,
+	}
+
+	return e
+}
+
+func (e *Echo) Init(ctx context.Context, meta conversation.Metadata) error {
+	r := &conversation.ConversationRequest{}
+	err := kmeta.DecodeMetadata(meta.Properties, &r)
+	if err != nil {
+		return err
+	}
+
+	e.model = r.Model
+
+	return nil
+}
+
+func (e *Echo) GetComponentMetadata() (metadataInfo metadata.MetadataMap) {
+	metadataStruct := conversation.ConversationRequest{}
+	metadata.GetMetadataInfoFromStructType(reflect.TypeOf(metadataStruct), &metadataInfo, metadata.StateStoreType)
+	return
+}
+
+// Converse returns inputs directly.
+func (e *Echo) Converse(ctx context.Context, r *conversation.ConversationRequest) (res *conversation.ConversationResponse, err error) {
+	outputs := make([]conversation.ConversationResult, 0, len(r.Inputs))
+
+	for _, input := range r.Inputs {
+		outputs = append(outputs, conversation.ConversationResult{
+			Result:     input,
+			Parameters: r.Parameters,
+		})
+	}
+
+	res = &conversation.ConversationResponse{
+		Outputs: outputs,
+	}
+
+	return res, nil
+}