package uploader

import (
	"context"
	"errors"
	"fmt"
	"github.com/minio/minio-go/v7"
	"github.com/minio/minio-go/v7/pkg/credentials"
	"log"
	"os"
)

func UploadFile(bucketName, endpoint, fileName string) error {

	ctx := context.Background()
	accessKeyID, secretAccessKey, err := getCredentials()
	if err != nil {
		return (err)
	}
	client, err := createClient(accessKeyID, secretAccessKey, endpoint)
	if err != nil {
		return (err)
	}
	err = verifyBucket(client, ctx, bucketName)
	if err != nil {
		return err
	}
	absolutePath, basename, err := validateUploadFile(fileName)
	if err != nil {
		return err
	}

	_, err = client.FPutObject(ctx, bucketName, basename, absolutePath, minio.PutObjectOptions{})
	if err != nil {
		return err
	}

	log.Printf("upload of %s complete\n", basename)
	return nil
}

func validateUploadFile(fileName string) (string, string, error) {
	file, err := os.Stat(fileName)
	if err != nil {
		return "", "", err
	}

	if file.IsDir() {
		return "", "", errors.New("upload of directories is not supported")
	}

	return fileName, file.Name(), nil
}

func verifyBucket(client *minio.Client, ctx context.Context, bucketName string) error {
	exists, err := client.BucketExists(ctx, bucketName)
	if err != nil {
		return err
	}

	if !exists {
		return errors.New(fmt.Sprintf("bucket %s does not exist\n", bucketName))
	}

	return nil
}

func createClient(accessKeyID, secretAccessKey, endpoint string) (*minio.Client, error) {
	// Initialize minio client object.
	minioClient, err := minio.New(endpoint, &minio.Options{
		Creds:  credentials.NewStaticV4(accessKeyID, secretAccessKey, ""),
		Secure: true,
	})
	if err != nil {
		return nil, err
	}

	return minioClient, nil
}

func getCredentials() (string, string, error) {
	// get credentials from env vars
	keyName := os.Getenv("KEY_ID")
	if keyName == "" {
		return "", "", errors.New("missing or empty KEY_ID")
	}
	applicationKey := os.Getenv("APPLICATION_KEY")
	if applicationKey == "" {
		return "", "", errors.New("missing or empty APPLICATION_KEY")
	}
	return keyName, applicationKey, nil
}