Add ability to query the article index

cmd/calls/articles.go

@@ -1,6 +1,7 @@
 package calls
 
 import (
+	"encoding/json"
 	"fmt"
 	"log"
 	"net/http"
@@ -109,3 +110,21 @@ func ServeClicks(db *b.DB) http.HandlerFunc {
 		}
 	}
 }
+
+func QueryArticles(i *b.Index) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		result, err := i.Query(r.PathValue("query"))
+		if err != nil {
+			log.Println(err)
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+
+		w.Header().Set("Content-Type", "application/json")
+		if err := json.NewEncoder(w).Encode(result); err != nil {
+			log.Println(err)
+			http.Error(w, fmt.Sprintf("error encoding results to JSON: %v", err), http.StatusInternalServerError)
+			return
+		}
+	}
+}