package main

import (
	"encoding/json"
	"fmt"
	"log"
	"net/http"
	"runtime"

	"github.com/graphql-go/graphql"
)

func main() {
	runtime.GOMAXPROCS(runtime.NumCPU())

	// Schema
	fields := graphql.Fields{
		"hello": &graphql.Field{
			Type: graphql.String,
			Resolve: func(p graphql.ResolveParams) (interface{}, error) {
				return "world", nil
			},
		},
		"users": &graphql.Field{
			Type: graphql.NewList(graphql.NewObject(graphql.ObjectConfig{
				Name: "User",
				Fields: graphql.Fields{
					"id": &graphql.Field{
						Type: graphql.Int,
					},
					"name": &graphql.Field{
						Type: graphql.String,
					},
					"age": &graphql.Field{
						Type: graphql.Int,
					},
					"info": &graphql.Field{
						Type: graphql.String,
					},
					"price": &graphql.Field{
						Type: graphql.Float,
					},
				},
			})),
			Args: graphql.FieldConfigArgument{
				"id": &graphql.ArgumentConfig{
					Type: graphql.Int,
				},
			},
			Resolve: func(p graphql.ResolveParams) (interface{}, error) {
				fmt.Println("p.Args:", p.Args)
				return []interface{}{
					map[string]interface{}{
						"id":    1,
						"name":  "user1",
						"age":   10,
						"info":  "info",
						"price": 1.1,
					},
					map[string]interface{}{
						"id":    2,
						"name":  "user2",
						"age":   20,
						"info":  "info",
						"price": 2.2,
					},
				}, nil
			},
		},
	}
	rootQuery := graphql.ObjectConfig{Name: "RootQuery", Fields: fields}
	schemaConfig := graphql.SchemaConfig{Query: graphql.NewObject(rootQuery)}
	schema, err := graphql.NewSchema(schemaConfig)
	if err != nil {
		log.Fatalf("failed to create new schema, error: %v", err)
	}

	http.HandleFunc("/graphql", func(w http.ResponseWriter, r *http.Request) {
		query := r.URL.Query().Get("query")
		fmt.Println("query:", query)
		params := graphql.Params{Schema: schema, RequestString: query}
		result := graphql.Do(params)
		if len(result.Errors) > 0 {
			fmt.Printf("failed to execute graphql operation, errors: %+v", result.Errors)
			http.Error(w, result.Errors[0].Error(), 500)
			return
		}
		rJSON, _ := json.Marshal(result)
		fmt.Printf("%s \n", rJSON) // {"data":{"hello":"world"}}
		w.Write(rJSON)
	})

	http.ListenAndServe(":8080", nil)
}