GoLang menyediakan .js.gz secara bersyarat jika ada, jika tidak .js

package main

import (
    "fmt"
    "net/http"
    "strings"

    "github.com/aws/aws-sdk-go/aws"
    "github.com/aws/aws-sdk-go/aws/session"
    "github.com/aws/aws-sdk-go/service/s3"
)

func getFileFromS3(bucket, key string, w http.ResponseWriter, r *http.Request) error {
    sess, err := session.NewSession(&aws.Config{
        Region: aws.String("your-region"),
        // Add other necessary configurations
    })
    if err != nil {
        return err
    }

    client := s3.New(sess)

    // Check if gzipped version exists
    gzKey := key + ".gz"
    _, err = client.HeadObject(&s3.HeadObjectInput{
        Bucket: aws.String(bucket),
        Key:    aws.String(gzKey),
    })
    if err == nil {
        // Gzipped version exists, fetch and serve directly
        obj, err := client.GetObject(&s3.GetObjectInput{
            Bucket: aws.String(bucket),
            Key:    aws.String(gzKey),
        })
        if err != nil {
            return err
        }
        defer obj.Body.Close()

        // Set appropriate headers
        w.Header().Set("Content-Encoding", "gzip")
        w.Header().Set("Content-Type", "application/javascript") // Set the appropriate content type

        // Copy the gzipped content directly to the response
        _, err = fmt.Fprint(w, obj.Body)
        return err
    }

    // Gzipped version doesn't exist, fetch the regular version
    obj, err := client.GetObject(&s3.GetObjectInput{
        Bucket: aws.String(bucket),
        Key:    aws.String(key),
    })
    if err != nil {
        return err
    }
    defer obj.Body.Close()

    // Set appropriate headers
    w.Header().Set("Content-Type", "application/javascript") // Set the appropriate content type

    // Copy the regular content directly to the response
    _, err = fmt.Fprint(w, obj.Body)
    return err
}

func handler(w http.ResponseWriter, r *http.Request) {
    // Extract the file key from the request URL or any other way you have it
    fileKey := "your-file-key"

    // Set appropriate cache headers, handle CORS, etc.

    // Fetch the file from S3
    err := getFileFromS3("your-s3-bucket", fileKey, w, r)
    if err != nil {
        // Handle error, e.g., return a 404 or 500 response
        http.Error(w, "Internal Server Error", http.StatusInternalServerError)
        return
    }
}

func main() {
    http.HandleFunc("/your-endpoint", handler)
    http.ListenAndServe(":8080", nil)
}