dgraph-client.go

package main

import (
	"context"
	"fmt"
	"log"
	"net/http"

	"github.com/dgraph-io/dgo/v210"
	"github.com/dgraph-io/dgo/v210/protos/api"
	"google.golang.org/grpc"
)

func client() *dgo.Dgraph {
	conn, err := grpc.Dial("localhost:9080", grpc.WithInsecure())
	if err != nil {
		log.Fatal(err)
	}
	dgraphClient := dgo.NewDgraphClient(api.NewDgraphClient(conn))
	return dgraphClient
}

func main() {
	http.HandleFunc("/", hi)
	http.HandleFunc("/api", doGET)
	http.HandleFunc("/api/create", doPOST)
	log.Println("Listening :8080")
	log.Fatal(http.ListenAndServe(":9999", nil))
}

func hi(w http.ResponseWriter, r *http.Request) {
	name := "Gustavo"
	fmt.Fprintf(w, "Hi, %s!", name)
}

func doGET(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/json")
	if r.Method != "GET" {
		w.WriteHeader(http.StatusMethodNotAllowed)
		w.Write([]byte(`{"message": "Method not allowed"}`))
		return
	}
	q := `{
		items(func: has(tweet)) {
			uid
			tweet
			tagged_with {
				uid 
			}
		}
	}`
	c := client()
	txn := c.NewReadOnlyTxn()
	resp, err := txn.Query(context.Background(), q)
	if err != nil {
		log.Fatal(err)
	}
	w.WriteHeader(http.StatusOK)
	w.Write(resp.GetJson())
}

func doPOST(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/json")
	if r.Method != "POST" {
		w.WriteHeader(http.StatusMethodNotAllowed)
		w.Write([]byte(`{"message": "Method not allowed"}`))
		return
	}
	w.WriteHeader(http.StatusCreated)
	w.Write([]byte(`{"data": "POST ok"}`))
}