Implement DownloadFile function for S3 client and update VideoHandler to use it

Author: Prateet-Github

cmd/worker/main.go

@@ -19,6 +19,7 @@ func main() {
 	s3Client := s3.NewClient(cfg)
 	videoHandler := handlers.NewVideoHandler(
 		s3Client,
+		cfg,
 	)
 
 	mux := asynq.NewServeMux()

internal/handlers/video.go

@@ -5,20 +5,28 @@ import (
 	"encoding/json"
 	"log"
 
+	"github.com/Prateet-Github/worker-go/internal/config"
 	"github.com/Prateet-Github/worker-go/internal/queue"
-	"github.com/aws/aws-sdk-go-v2/service/s3"
+	"github.com/Prateet-Github/worker-go/internal/s3"
+
+	"path/filepath"
+
+	awss3 "github.com/aws/aws-sdk-go-v2/service/s3"
 	"github.com/hibiken/asynq"
 )
 
 type VideoHandler struct {
-	s3Client *s3.Client
+	s3Client *awss3.Client
+	cfg      *config.Config
 }
 
 func NewVideoHandler(
-	s3Client *s3.Client,
+	s3Client *awss3.Client,
+	cfg *config.Config,
 ) *VideoHandler {
 	return &VideoHandler{
 		s3Client: s3Client,
+		cfg:      cfg,
 	}
 }
 
@@ -33,6 +41,24 @@ func (h *VideoHandler) ProcessVideo(
 		return err
 	}
 
+	localPath := filepath.Join(
+		"temp",
+		payload.VideoID+".mp4",
+	)
+
+	err := s3.DownloadFile(
+		h.s3Client,
+		h.cfg.S3RawBucket,
+		payload.S3Key,
+		localPath,
+	)
+
+	if err != nil {
+		return err
+	}
+
+	log.Println("Download completed:", localPath)
+
 	log.Println("Processing video...")
 	log.Println("Video ID:", payload.VideoID)
 	log.Println("S3 Key:", payload.S3Key)

internal/s3/download.go

@@ -0,0 +1,74 @@
+package s3
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+
+	awss3 "github.com/aws/aws-sdk-go-v2/service/s3"
+)
+
+func DownloadFile(
+	client *awss3.Client,
+	bucket string,
+	key string,
+	outputPath string,
+) error {
+
+	fmt.Printf("Downloading: %s\n", key)
+	fmt.Printf("Saving to: %s\n", outputPath)
+
+	resp, err := client.GetObject(
+		context.Background(),
+		&awss3.GetObjectInput{
+			Bucket: &bucket,
+			Key:    &key,
+		},
+	)
+
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+
+	if err := os.MkdirAll(
+		filepath.Dir(outputPath),
+		0755,
+	); err != nil {
+		return err
+	}
+
+	file, err := os.Create(outputPath)
+
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	if _, err := io.Copy(file, resp.Body); err != nil {
+		_ = os.Remove(outputPath)
+		return err
+	}
+
+	info, err := file.Stat()
+
+	if err != nil {
+		_ = os.Remove(outputPath)
+		return err
+	}
+
+	if info.Size() == 0 {
+		_ = os.Remove(outputPath)
+		return fmt.Errorf("downloaded file is empty")
+	}
+
+	fmt.Printf(
+		"Downloaded: %s -> %s\n",
+		key,
+		outputPath,
+	)
+
+	return nil
+}