Go QR Code Integration

package main

import (
    "bytes"
    "encoding/json"
    "io"
    "net/http"
    "os"
)

type QRRequest struct {
    Data   string `json:"data"`
    Size   int    `json:"size"`
    Format string `json:"format"`
}

func GenerateQRCode(data string, size int) ([]byte, error) {
    apiKey := os.Getenv("QR_API_KEY")
    
    reqBody := QRRequest{
        Data:   data,
        Size:   size,
        Format: "png",
    }
    
    jsonBody, _ := json.Marshal(reqBody)
    
    req, _ := http.NewRequest("POST", 
        "https://www.qrcodeapi.io/api/generate",
        bytes.NewBuffer(jsonBody))
    
    req.Header.Set("Authorization", "Bearer "+apiKey)
    req.Header.Set("Content-Type", "application/json")
    
    client := &http.Client{}
    resp, err := client.Do(req)
    if err != nil {
        return nil, err
    }
    defer resp.Body.Close()
    
    return io.ReadAll(resp.Body)
}

func main() {
    qrCode, err := GenerateQRCode("https://example.com", 300)
    if err != nil {
        panic(err)
    }
    
    os.WriteFile("qrcode.png", qrCode, 0644)
}

func QRCodeHandler(w http.ResponseWriter, r *http.Request) {
    url := r.URL.Query().Get("url")
    if url == "" {
        http.Error(w, "url parameter required", http.StatusBadRequest)
        return
    }
    
    qrCode, err := GenerateQRCode(url, 300)
    if err != nil {
        http.Error(w, "Failed to generate QR code", http.StatusInternalServerError)
        return
    }
    
    w.Header().Set("Content-Type", "image/png")
    w.Write(qrCode)
}

func main() {
    http.HandleFunc("/qr", QRCodeHandler)
    http.ListenAndServe(":8080", nil)
}