higress/plugins/wasm-go/extensions/ai-search/engine/elasticsearch/elasticsearch.go

package elasticsearch

import (
	"errors"
	"fmt"
	"net/http"
	"strings"

	"github.com/alibaba/higress/plugins/wasm-go/pkg/wrapper"
	"github.com/tidwall/gjson"

	"github.com/alibaba/higress/plugins/wasm-go/extensions/ai-search/engine"
)

type ElasticsearchSearch struct {
	client             wrapper.HttpClient
	index              string
	contentField       string
	linkField          string
	titleField         string
	start              int
	count              int
	timeoutMillisecond uint32
}

func NewElasticsearchSearch(config *gjson.Result) (*ElasticsearchSearch, error) {
	engine := &ElasticsearchSearch{}
	serviceName := config.Get("serviceName").String()
	if serviceName == "" {
		return nil, errors.New("serviceName not found")
	}
	servicePort := config.Get("servicePort").Int()
	if servicePort == 0 {
		return nil, errors.New("servicePort not found")
	}
	engine.client = wrapper.NewClusterClient(wrapper.FQDNCluster{
		FQDN: serviceName,
		Port: servicePort,
	})
	engine.index = config.Get("index").String()
	if engine.index == "" {
		return nil, errors.New("index not found")
	}
	engine.contentField = config.Get("contentField").String()
	if engine.contentField == "" {
		return nil, errors.New("contentField not found")
	}
	engine.linkField = config.Get("linkField").String()
	if engine.linkField == "" {
		return nil, errors.New("linkField not found")
	}
	engine.titleField = config.Get("titleField").String()
	if engine.titleField == "" {
		return nil, errors.New("titleField not found")
	}
	engine.timeoutMillisecond = uint32(config.Get("timeoutMillisecond").Uint())
	if engine.timeoutMillisecond == 0 {
		engine.timeoutMillisecond = 5000
	}
	engine.start = int(config.Get("start").Uint())
	engine.count = int(config.Get("count").Uint())
	if engine.count == 0 {
		engine.count = 10
	}
	return engine, nil
}

func (e ElasticsearchSearch) NeedExectue(ctx engine.SearchContext) bool {
	return ctx.EngineType == "private"
}

func (e ElasticsearchSearch) Client() wrapper.HttpClient {
	return e.client
}

func (e ElasticsearchSearch) CallArgs(ctx engine.SearchContext) engine.CallArgs {
	searchBody := fmt.Sprintf(`{
		"query": {
			"match": {
				"%s": {
					"query": "%s",
					"operator": "AND"
				}
			}
		}
	}`, e.contentField, strings.Join(ctx.Querys, " "))

	return engine.CallArgs{
		Method: http.MethodPost,
		Url:    fmt.Sprintf("/%s/_search?from=%d&size=%d", e.index, e.start, e.count),
		Headers: [][2]string{
			{"Content-Type", "application/json"},
		},
		Body:               []byte(searchBody),
		TimeoutMillisecond: e.timeoutMillisecond,
	}
}

func (e ElasticsearchSearch) ParseResult(ctx engine.SearchContext, response []byte) []engine.SearchResult {
	jsonObj := gjson.ParseBytes(response)
	var results []engine.SearchResult
	for _, hit := range jsonObj.Get("hits.hits").Array() {
		source := hit.Get("_source")
		result := engine.SearchResult{
			Title:   source.Get(e.titleField).String(),
			Link:    source.Get(e.linkField).String(),
			Content: source.Get(e.contentField).String(),
		}
		if result.Valid() {
			results = append(results, result)
		}
	}
	return results
}