Feat: Add Deepl support for plugins/ai-proxy (#1147)

plugins/wasm-go/extensions/ai-proxy/provider/deepl.go

@@ -0,0 +1,176 @@
+package provider
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"time"
+
+	"github.com/alibaba/higress/plugins/wasm-go/extensions/ai-proxy/util"
+	"github.com/alibaba/higress/plugins/wasm-go/pkg/wrapper"
+	"github.com/higress-group/proxy-wasm-go-sdk/proxywasm"
+	"github.com/higress-group/proxy-wasm-go-sdk/proxywasm/types"
+)
+
+// deeplProvider is the provider for DeepL service.
+const (
+	deeplHostPro            = "api.deepl.com"
+	deeplHostFree           = "api-free.deepl.com"
+	deeplChatCompletionPath = "/v2/translate"
+)
+
+type deeplProviderInitializer struct {
+}
+
+type deeplProvider struct {
+	config       ProviderConfig
+	contextCache *contextCache
+}
+
+// spec reference: https://developers.deepl.com/docs/v/zh/api-reference/translate/openapi-spec-for-text-translation
+type deeplRequest struct {
+	// "Model" parameter is used to distinguish which service to use
+	Model              string   `json:"model,omitempty"`
+	Text               []string `json:"text"`
+	SourceLang         string   `json:"source_lang,omitempty"`
+	TargetLang         string   `json:"target_lang"`
+	Context            string   `json:"context,omitempty"`
+	SplitSentences     string   `json:"split_sentences,omitempty"`
+	PreserveFormatting bool     `json:"preserve_formatting,omitempty"`
+	Formality          string   `json:"formality,omitempty"`
+	GlossaryId         string   `json:"glossary_id,omitempty"`
+	TagHandling        string   `json:"tag_handling,omitempty"`
+	OutlineDetection   bool     `json:"outline_detection,omitempty"`
+	NonSplittingTags   []string `json:"non_splitting_tags,omitempty"`
+	SplittingTags      []string `json:"splitting_tags,omitempty"`
+	IgnoreTags         []string `json:"ignore_tags,omitempty"`
+}
+
+type deeplResponse struct {
+	Translations []deeplResponseTranslation `json:"translations,omitempty"`
+	Message      string                     `json:"message,omitempty"`
+}
+
+type deeplResponseTranslation struct {
+	DetectedSourceLanguage string `json:"detected_source_language"`
+	Text                   string `json:"text"`
+}
+
+func (d *deeplProviderInitializer) ValidateConfig(config ProviderConfig) error {
+	if config.targetLang == "" {
+		return errors.New("missing targetLang in deepl provider config")
+	}
+	return nil
+}
+
+func (d *deeplProviderInitializer) CreateProvider(config ProviderConfig) (Provider, error) {
+	return &deeplProvider{
+		config:       config,
+		contextCache: createContextCache(&config),
+	}, nil
+}
+
+func (d *deeplProvider) GetProviderType() string {
+	return providerTypeDeepl
+}
+
+func (d *deeplProvider) OnRequestHeaders(ctx wrapper.HttpContext, apiName ApiName, log wrapper.Log) (types.Action, error) {
+	if apiName != ApiNameChatCompletion {
+		return types.ActionContinue, errUnsupportedApiName
+	}
+	_ = util.OverwriteRequestPath(deeplChatCompletionPath)
+	_ = util.OverwriteRequestAuthorization("DeepL-Auth-Key " + d.config.GetRandomToken())
+	_ = proxywasm.RemoveHttpRequestHeader("Content-Length")
+	_ = proxywasm.RemoveHttpRequestHeader("Accept-Encoding")
+	return types.HeaderStopIteration, nil
+}
+
+func (d *deeplProvider) OnRequestBody(ctx wrapper.HttpContext, apiName ApiName, body []byte, log wrapper.Log) (types.Action, error) {
+	if apiName != ApiNameChatCompletion {
+		return types.ActionContinue, errUnsupportedApiName
+	}
+	if d.config.protocol == protocolOriginal {
+		request := &deeplRequest{}
+		if err := json.Unmarshal(body, request); err != nil {
+			return types.ActionContinue, fmt.Errorf("unable to unmarshal request: %v", err)
+		}
+		if err := d.overwriteRequestHost(request.Model); err != nil {
+			return types.ActionContinue, err
+		}
+		ctx.SetContext(ctxKeyFinalRequestModel, request.Model)
+		return types.ActionContinue, replaceJsonRequestBody(request, log)
+	} else {
+		originRequest := &chatCompletionRequest{}
+		if err := decodeChatCompletionRequest(body, originRequest); err != nil {
+			return types.ActionContinue, err
+		}
+		if err := d.overwriteRequestHost(originRequest.Model); err != nil {
+			return types.ActionContinue, err
+		}
+		ctx.SetContext(ctxKeyFinalRequestModel, originRequest.Model)
+		deeplRequest := &deeplRequest{
+			Text:       make([]string, 0),
+			TargetLang: d.config.targetLang,
+		}
+		for _, msg := range originRequest.Messages {
+			if msg.Role == roleSystem {
+				deeplRequest.Context = msg.Content
+			} else {
+				deeplRequest.Text = append(deeplRequest.Text, msg.Content)
+			}
+		}
+		return types.ActionContinue, replaceJsonRequestBody(deeplRequest, log)
+	}
+}
+
+func (d *deeplProvider) OnResponseHeaders(ctx wrapper.HttpContext, apiName ApiName, log wrapper.Log) (types.Action, error) {
+	_ = proxywasm.RemoveHttpResponseHeader("Content-Length")
+	return types.ActionContinue, nil
+}
+
+func (d *deeplProvider) OnResponseBody(ctx wrapper.HttpContext, apiName ApiName, body []byte, log wrapper.Log) (types.Action, error) {
+	deeplResponse := &deeplResponse{}
+	if err := json.Unmarshal(body, deeplResponse); err != nil {
+		return types.ActionContinue, fmt.Errorf("unable to unmarshal deepl response: %v", err)
+	}
+	response := d.responseDeepl2OpenAI(ctx, deeplResponse)
+	return types.ActionContinue, replaceJsonResponseBody(response, log)
+}
+
+func (d *deeplProvider) responseDeepl2OpenAI(ctx wrapper.HttpContext, deeplResponse *deeplResponse) *chatCompletionResponse {
+	var choices []chatCompletionChoice
+	// Fail
+	if deeplResponse.Message != "" {
+		choices = make([]chatCompletionChoice, 1)
+		choices[0] = chatCompletionChoice{
+			Message: &chatMessage{Role: roleAssistant, Content: deeplResponse.Message},
+			Index:   0,
+		}
+	} else {
+		// Success
+		choices = make([]chatCompletionChoice, len(deeplResponse.Translations))
+		for idx, t := range deeplResponse.Translations {
+			choices[idx] = chatCompletionChoice{
+				Index:   idx,
+				Message: &chatMessage{Role: roleAssistant, Content: t.Text, Name: t.DetectedSourceLanguage},
+			}
+		}
+	}
+	return &chatCompletionResponse{
+		Created: time.Now().UnixMilli() / 1000,
+		Object:  objectChatCompletion,
+		Choices: choices,
+		Model:   ctx.GetStringContext(ctxKeyFinalRequestModel, ""),
+	}
+}
+
+func (d *deeplProvider) overwriteRequestHost(model string) error {
+	if model == "Pro" {
+		_ = util.OverwriteRequestHost(deeplHostPro)
+	} else if model == "Free" {
+		_ = util.OverwriteRequestHost(deeplHostFree)
+	} else {
+		return errors.New(`deepl model should be "Free" or "Pro"`)
+	}
+	return nil
+}

plugins/wasm-go/extensions/ai-proxy/provider/provider.go

@@ -35,6 +35,7 @@ const (
 	providerTypeCloudflare = "cloudflare"
 	providerTypeSpark      = "spark"
 	providerTypeGemini     = "gemini"
+	providerTypeDeepl      = "deepl"
 
 	protocolOpenAI   = "openai"
 	protocolOriginal = "original"
@@ -88,6 +89,7 @@ var (
 		providerTypeCloudflare: &cloudflareProviderInitializer{},
 		providerTypeSpark:      &sparkProviderInitializer{},
 		providerTypeGemini:     &geminiProviderInitializer{},
+		providerTypeDeepl:      &deeplProviderInitializer{},
 	}
 )
 
@@ -176,6 +178,9 @@ type ProviderConfig struct {
 	// @Title zh-CN Gemini AI内容过滤和安全级别设定
 	// @Description zh-CN 仅适用于 Gemini AI 服务。参考：https://ai.google.dev/gemini-api/docs/safety-settings
 	geminiSafetySetting map[string]string `required:"false" yaml:"geminiSafetySetting" json:"geminiSafetySetting"`
+	// @Title zh-CN 翻译服务需指定的目标语种
+	// @Description zh-CN 翻译结果的语种，目前仅适用于DeepL服务。
+	targetLang string `required:"false" yaml:"targetLang" json:"targetLang"`
 }
 
 func (c *ProviderConfig) FromJson(json gjson.Result) {
@@ -223,6 +228,7 @@ func (c *ProviderConfig) FromJson(json gjson.Result) {
 			c.geminiSafetySetting[k] = v.String()
 		}
 	}
+	c.targetLang = json.Get("targetLang").String()
 }
 
 func (c *ProviderConfig) Validate() error {