go backend

.gitignore

@@ -1 +1,6 @@
+builder
+bin
+go.mod
+go.sum
 public/submit/*
+.env

Makefile

@@ -0,0 +1,26 @@
+BIN = builder
+SRC = main.go
+GOMODS = github.com/joho/godotenv
+
+all: ${BIN}
+
+${BIN}: ${SRC}
+	go build -o $@
+
+run: ${BIN}
+	@./$< &
+
+stop:
+	-@pkill -SIGTERM ${BIN} || true
+
+restart: stop run
+
+bootstrap:
+	go mod init ${BIN}
+	go get ${GOMODS}
+
+clean:
+	rm -f ${BIN}
+
+clean-mods:
+	rm -f go.*

main.go

@@ -0,0 +1,123 @@
+package main
+
+import (
+	"encoding/json"
+	"log"
+	"net/http"
+	"strings"
+	"os"
+	"fmt"
+	"os/signal"
+	"syscall"
+	"bytes"
+
+	"github.com/joho/godotenv"
+)
+
+var (
+	baseURL = "https://api-m.sandbox.paypal.com"
+)
+
+func init() {
+	if err := godotenv.Load() ; err != nil {
+		log.Fatalf("Error loading .env file: %v", err)
+	}
+}
+
+func main() {
+	// Handlers
+	http.HandleFunc("/api/orders", CreateOrder)
+	http.Handle("/", http.FileServer(http.Dir("./public")))
+
+	// Channel to listen for signals
+	stop := make(chan os.Signal, 1)
+	signal.Notify(stop, syscall.SIGINT, syscall.SIGTERM)
+
+	// Run the server in a goroutine so that it doesn't block
+	go func() {
+		log.Println("Starting server on :8080...")
+		if err := http.ListenAndServe(":8080", nil); err != nil {
+			log.Fatalf("Could not listen on :8080: %v\n", err)
+		}
+	}()
+
+	<-stop // Shutdown signal recieved
+	log.Println("Server shutdown gracefully.")
+}
+
+func Token() (string, error) {
+	// Create request
+	req, err := http.NewRequest("POST", baseURL+"/v1/oauth2/token", strings.NewReader(`grant_type=client_credentials`))
+	if err != nil {
+		return "", fmt.Errorf("Error creating request: %v", err)
+	}
+
+	// Make POST req, should return JSON with AccessToken
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	req.SetBasicAuth(os.Getenv("CLIENT_ID"), os.Getenv("CLIENT_SECRET"))
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return "", fmt.Errorf("Error sending request: %v", err)
+	}
+	defer resp.Body.Close()
+
+	// Decode response into result
+	var result struct {
+		AccessToken string `json:"access_token"`
+	}
+	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
+		return "", fmt.Errorf("Error decoding response: %v", err)
+	}
+
+	return result.AccessToken, nil
+}
+
+func CreateOrder(w http.ResponseWriter, r *http.Request) {
+	token, err := Token()
+	if err != nil {
+		http.Error(w, "Failed to get access token", http.StatusInternalServerError)
+		return
+	}
+
+	data := `{
+		"intent": "CAPTURE",
+		"purchase_units": [{
+			"amount": {
+				"currency_code": "USD",
+				"value": "20.00"
+			}
+		}],
+		"application_context": {
+			"shipping_preference": "NO_SHIPPING"
+		}
+	}`
+
+	req, err := http.NewRequest("POST", baseURL+"/v2/checkout/orders", bytes.NewBuffer([]byte(data)))
+	if err != nil {
+		http.Error(w, "Failed to create request", http.StatusInternalServerError)
+		return
+	}
+
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Authorization", "Bearer "+token)
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		http.Error(w, "Failed to send request", http.StatusInternalServerError)
+		return
+	}
+	defer resp.Body.Close()
+
+	var result map[string]interface{}
+	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
+		http.Error(w, "Failed to decode response", http.StatusInternalServerError)
+		return
+	}
+
+	if id, ok := result["id"].(string); ok {
+		json.NewEncoder(w).Encode(map[string]string{"id": id})
+		return
+	} else {
+		http.Error(w, "Order ID not found", http.StatusInternalServerError)
+		return
+	}
+}