add search validate+explain (#31)

pkg/es/search.go

@@ -18,6 +18,7 @@ package es
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	"log"
 	"log/slog"
@@ -28,8 +29,10 @@ import (
 	"github.com/alecthomas/repr"
 	"github.com/elastic/go-elasticsearch/v9/typedapi/core/search"
 	"github.com/elastic/go-elasticsearch/v9/typedapi/esdsl"
+	"github.com/elastic/go-elasticsearch/v9/typedapi/indices/validatequery"
 	"github.com/elastic/go-elasticsearch/v9/typedapi/types"
 	"github.com/elastic/go-elasticsearch/v9/typedapi/types/enums/sortorder"
+	"github.com/tidwall/gjson"
 )
 
 const (
@@ -43,8 +46,11 @@ Execute an ES search.
 	additional filters can be given as -F key=value
 */
 func Search(conf *cfg.Config, queries []string) error {
-	searchEs := conf.DefaultCluster.ES.Search().
-		Index(conf.Index)
+	if conf.Validate {
+		return validateSearch(conf, queries)
+	}
+
+	searchEs := conf.DefaultCluster.ES.Search().Index(conf.Index)
 
 	queryCaster, err := prepareQuery(conf, queries)
 	if err != nil {
@@ -57,9 +63,11 @@ func Search(conf *cfg.Config, queries []string) error {
 
 	searchEs = addSort(conf, searchEs)
 
-	switch conf.Tail {
-	case true:
+	switch {
+	case conf.Tail:
 		return searchTail(conf, searchEs)
+	case conf.Explain:
+		return explainSearch(conf, searchEs)
 	default:
 		if conf.To > MAXPAGE {
 			return searchPit(conf, req)
@@ -69,6 +77,79 @@ func Search(conf *cfg.Config, queries []string) error {
 	}
 }
 
+func explainSearch(conf *cfg.Config, search *search.Search) error {
+	res, err := search.
+		Explain(true).
+		Size(1). // one's enough for explain
+		Do(context.Background())
+	if err != nil {
+		return fmt.Errorf("failed to call explain search (esdsl): %s", esErrorString(err))
+	}
+
+	raw, err := json.Marshal(res)
+	if err != nil {
+		return fmt.Errorf("failed to marshal explain result: %s", err)
+	}
+
+	if conf.Debug {
+		repr.Println(res)
+		value := gjson.Get(string(raw), "hits.hits.0._explanation")
+		fmt.Println(value.String())
+	}
+
+	if len(res.Hits.Hits) > 0 {
+		ex := res.Hits.Hits[0].Explanation_
+		fmt.Println(ex.Description)
+		fmt.Println(ex.Value)
+
+		// recurse into explanation details (it's a tree)
+		for _, ex := range ex.Details {
+			explain(&ex, "  ")
+		}
+	}
+
+	return nil
+}
+
+func explain(res *types.ExplanationDetail, indent string) {
+	fmt.Println(indent + "- " + res.Description)
+	for _, ex := range res.Details {
+		fmt.Println(indent + "  - " + ex.Description)
+		fmt.Println(indent + fmt.Sprintf("    score: %f", res.Value))
+
+		explain(&ex, indent+"  ")
+	}
+}
+
+func validateSearch(conf *cfg.Config, queries []string) error {
+	validate := conf.DefaultCluster.ES.Indices.ValidateQuery()
+
+	queryCaster, err := prepareQuery(conf, queries)
+	if err != nil {
+		return err
+	}
+
+	req := &validatequery.Request{Query: queryCaster}
+
+	validate.Request(req)
+
+	res, err := validate.
+		Do(context.Background())
+	if err != nil {
+		return fmt.Errorf("failed to validate search (esdsl): %s", esErrorString(err))
+	}
+
+	slog.Debug("ES result", "search", res)
+
+	if res.Valid {
+		fmt.Println(printer.Colorize(conf, "green", "valid"))
+	} else {
+		fmt.Println(printer.Colorize(conf, "red", "invalid"))
+	}
+
+	return nil
+}
+
 func Debug(conf *cfg.Config) error {
 	res, err := conf.DefaultCluster.ES.Search().
 		Index(conf.Index).