add google search (#242)

* add google search

* fix git ignore

* Charge 1c for search queries

google/handler/google.go

@@ -0,0 +1,53 @@
+package handler
+
+import (
+	"context"
+	"strings"
+
+	"github.com/micro/micro/v3/service/errors"
+	"github.com/micro/micro/v3/service/logger"
+	pb "github.com/micro/services/google/proto"
+	"google.golang.org/api/customsearch/v1"
+	"google.golang.org/api/option"
+)
+
+type Google struct {
+	Client *customsearch.Service
+	CxId string
+}
+
+func New(apiKey, cxId string) *Google {
+	ctx := context.TODO()
+	cs, _ := customsearch.NewService(ctx, option.WithAPIKey(apiKey))
+
+	return &Google{
+		Client: cs,
+		CxId: cxId,
+	}
+}
+
+func (g *Google) Search(ctx context.Context, req *pb.SearchRequest, rsp *pb.SearchResponse) error {
+	if len(req.Query) == 0 {
+		return errors.BadRequest("google.search", "missing query")
+	}
+
+	resp, err := g.Client.Cse.List().Cx(g.CxId).Q(req.Query).Num(10).Do()
+	if err != nil {
+		logger.Errorf("failed to search google for %v: %v", req.Query, err)
+		return errors.InternalServerError("google.search", "Failed to search for "+req.Query)
+	}
+
+	for _, item := range resp.Items {
+		kind := strings.Split(item.Kind, "#")[1]
+		rsp.Results = append(rsp.Results, &pb.SearchResult{
+			Id:         item.CacheId,
+			Kind:       kind,
+			Title:      item.Title,
+			Url:        item.Link,
+			DisplayUrl: item.DisplayLink,
+			Snippet:    item.Snippet,
+		})
+	}
+
+	return nil
+}