// package shopify calls the Shopify GraphQL Apu Endpoint
// This package rquires the follwing ENV vars to be set:
//
// SHOPIFY_GRAPHQL_ENDPOINT
// SHOPIFY_TOKEN
package shopify

import (
	"bytes"
	"io/ioutil"
	"net/http"
	"strconv"
	"time"
	"os"

	"github.com/m3tam3re/errors"
	"github.com/valyala/fastjson"
)

var endpoint = os.Getenv("SHOPIFY_GRAPHQL_ENDPOINT")

func StartRequest(body []byte) (*http.Response, error) {
	path := ""
	const op errors.Op = "func: startRequest"

	client := http.Client{
		Timeout: time.Second * 120,
	}
	req, err := http.NewRequest("POST", endpoint, bytes.NewBuffer(body))
	if err != nil {
		return nil, errors.E(errors.Internal, op, path, err, "error building request")
	}
	req.Header.Add("X-Shopify-Access-Token",os.Getenv("SHOPIFY_TOKEN"))
	req.Header.Add("Content-Type", "application/graphql")
	resp, err := client.Do(req)
	if err != nil {
		return nil, errors.E(errors.Internal, op, path, err, "error executing request")
	}
	return resp, nil
}

func GetItemPrice(sku string) (float32, error) {
	qu := `{
  inventoryItems(first:1, query:"sku:` + sku + `") {
    edges{
      node{
        sku
        variant {
          price
          compareAtPrice
        }
      }
    }
  }
}`
	resp, err := StartRequest([]byte(qu))
	defer resp.Body.Close()
	body, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		//TODO handle error
	}
	p := fastjson.GetString(body, "data", "inventoryItems", "edges", "0", "node", "variant", "price")
	cp := fastjson.GetString(body, "data", "inventoryItems", "edges", "0", "node", "variant", "compareAtPrice")
      
	var finalPrice string
	if cp != "" {
		finalPrice = cp
	} else {
		finalPrice = p
	}
	
	price, err:= strconv.ParseFloat(finalPrice, 32)
	if err != nil {
		//TODO handle error
	}
	return float32(price), nil
}