package handler

import (
	"fmt"
	"os"

	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/aws/session"
	"github.com/aws/aws-sdk-go/service/s3"
	"github.com/aws/aws-sdk-go/service/s3/s3manager"
)

const DefaultAwsRegion = "eu-west-1"

var (
	s3Session  *session.Session
	s3Client   *s3.S3
	s3Uploader *s3manager.Uploader
)

func init() {
	var err error
	s3Session, err = session.NewSession(&aws.Config{Region: aws.String(DefaultAwsRegion)})
	if err != nil {
		panic(err)
	}

	s3Client = s3.New(s3Session)
	s3Uploader = s3manager.NewUploader(s3Session)
}

type S3Handler struct {
	Bucket string
	ACL    string
}

func NewS3Handler(bucket string, acl string) *S3Handler {
	return &S3Handler{
		Bucket: bucket,
		ACL:    acl,
	}
}

func (h *S3Handler) AssetAdded(a Asset) error {
	f, err := os.Open(a.Path)
	if err != nil {
		return err
	}
	defer f.Close()

	result, err := s3Uploader.Upload(&s3manager.UploadInput{
		Key:    aws.String(a.Key),
		Bucket: aws.String(h.Bucket),
		ACL:    aws.String(h.ACL),
		Body:   f,
	})
	if err != nil {
		return err
	}

	fmt.Println("Uploaded", a.Path, "to", result.Location)

	return nil
}

func (h *S3Handler) AssetRemoved(a Asset) error {
	// TODO consider cleaning up assets every ~60 seconds?
	// https://github.com/aws/aws-sdk-go/blob/v1.33.4/service/s3/s3manager/batch.go#L255
	_, err := s3Client.DeleteObject(&s3.DeleteObjectInput{
		Key:    aws.String(a.Key),
		Bucket: aws.String(h.Bucket),
	})

	fmt.Println("Deleted", a.Key)

	if err != nil {
		return err
	}

	return nil
}