Add simple graphql function

graphql/client.go

@@ -0,0 +1,126 @@
+package graphql
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"os/user"
+	"regexp"
+)
+
+type graphQLResponse struct {
+	Data   interface{}
+	Errors []struct {
+		Message string
+	}
+}
+
+/*
+GraphQL usage
+
+type repoResponse struct {
+	repository struct {
+		createdAt string
+	}
+}
+
+query := `query {
+	repository(owner: "golang", name: "go") {
+		createdAt
+	}
+}`
+
+variables := map[string]string{}
+
+var resp repoResponse
+err := graphql(query, map[string]string{}, &resp)
+if err != nil {
+	panic(err)
+}
+
+fmt.Printf("%+v\n", resp)
+*/
+func GraphQL(query string, variables map[string]string, v interface{}) error {
+	url := "https://api.github.com/graphql"
+	reqBody, err := json.Marshal(map[string]interface{}{"query": query, "variables": variables})
+	if err != nil {
+		panic(err)
+	}
+
+	req, err := http.NewRequest("POST", url, bytes.NewBuffer(reqBody))
+	if err != nil {
+		panic(err)
+	}
+
+	req.Header.Set("Authorization", "token "+getToken())
+	req.Header.Set("Content-Type", "application/json; charset=utf-8")
+
+	client := &http.Client{}
+	resp, err := client.Do(req)
+	if err != nil {
+		panic(err)
+	}
+	defer resp.Body.Close()
+
+	return handleResponse(resp, v)
+}
+
+func handleResponse(resp *http.Response, v interface{}) error {
+	success := resp.StatusCode >= 200 && resp.StatusCode < 300
+	if success {
+		gr := &graphQLResponse{Data: v}
+		err := json.NewDecoder(resp.Body).Decode(gr)
+		if err != nil {
+			return err
+		}
+		if len(gr.Errors) > 0 {
+			errorMessages := gr.Errors[0].Message
+			for _, e := range gr.Errors[1:] {
+				errorMessages += ", " + e.Message
+			}
+			return fmt.Errorf("graphql error: '%s'", errorMessages)
+		}
+		return nil
+	}
+
+	return handleHTTPError(resp)
+}
+
+func handleHTTPError(resp *http.Response) error {
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return err
+	}
+
+	var message string
+	var parsedBody struct {
+		Message string `json:"message"`
+	}
+	err = json.Unmarshal(body, &parsedBody)
+	if err != nil {
+		message = string(body)
+	} else {
+		message = parsedBody.Message
+	}
+
+	return fmt.Errorf("http error, '%s' failed (%d): '%s'", resp.Request.URL, resp.StatusCode, message)
+}
+
+// THIS IS A BULLSHIT FUNCTION THAT SHOULD BE REMOVED
+func getToken() string {
+	usr, err := user.Current()
+	if err != nil {
+		panic(err)
+	}
+
+	content, err := ioutil.ReadFile(usr.HomeDir + "/.config/hub")
+	if err != nil {
+		panic(err)
+	}
+
+	r := regexp.MustCompile(`oauth_token: (\w+)`)
+	token := r.FindStringSubmatch(string(content))
+	return token[1]
+}