add plugin: ai-prompt-template (#1019)

plugins/wasm-go/extensions/ai-prompt-template/main.go

@@ -0,0 +1,55 @@
+package main
+
+import (
+	"fmt"
+	"strings"
+
+	"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"
+	"github.com/tidwall/gjson"
+)
+
+func main() {
+	wrapper.SetCtx(
+		"ai-prompt-template",
+		wrapper.ParseConfigBy(parseConfig),
+		wrapper.ProcessRequestHeadersBy(onHttpRequestHeaders),
+		wrapper.ProcessRequestBodyBy(onHttpRequestBody),
+	)
+}
+
+type AIPromptTemplateConfig struct {
+	templates map[string]string
+}
+
+func parseConfig(json gjson.Result, config *AIPromptTemplateConfig, log wrapper.Log) error {
+	config.templates = make(map[string]string)
+	for _, v := range json.Get("templates").Array() {
+		config.templates[v.Get("name").String()] = v.Get("template").Raw
+		log.Info(v.Get("template").Raw)
+	}
+	return nil
+}
+
+func onHttpRequestHeaders(ctx wrapper.HttpContext, config AIPromptTemplateConfig, log wrapper.Log) types.Action {
+	templateEnable, _ := proxywasm.GetHttpRequestHeader("template-enable")
+	if templateEnable != "true" {
+		ctx.DontReadRequestBody()
+		return types.ActionContinue
+	}
+	proxywasm.RemoveHttpRequestHeader("content-length")
+	return types.ActionContinue
+}
+
+func onHttpRequestBody(ctx wrapper.HttpContext, config AIPromptTemplateConfig, body []byte, log wrapper.Log) types.Action {
+	if gjson.GetBytes(body, "template").Exists() && gjson.GetBytes(body, "properties").Exists() {
+		name := gjson.GetBytes(body, "template").String()
+		template := config.templates[name]
+		for key, value := range gjson.GetBytes(body, "properties").Map() {
+			template = strings.ReplaceAll(template, fmt.Sprintf("{{%s}}", key), value.String())
+		}
+		proxywasm.ReplaceHttpRequestBody([]byte(template))
+	}
+	return types.ActionContinue
+}