pass download status to discord

app/main.go

@@ -28,6 +28,7 @@ type DownloadResult struct {
 
 // startAsyncDownload initiates a download in a goroutine and handles progress updates
 func startAsyncDownload(s *discordgo.Session, i *discordgo.InteractionCreate, url, audioFormat, outputDir string) {
+	progressChan := make(chan ProgressUpdate, 1)
 	resultChan := make(chan DownloadResult, 1)
 
 	// Start download in goroutine
@@ -47,7 +48,7 @@ func startAsyncDownload(s *discordgo.Session, i *discordgo.InteractionCreate, ur
 		}()
 
 		// Call downloadVideo (it panics on error instead of returning error)
-		downloadVideo(outputDir, url, DownloadOptions{EmbedThumbnail: true, IncludeSubtitles: true})
+		downloadVideo(outputDir, url, DownloadOptions{EmbedThumbnail: true, IncludeSubtitles: true}, progressChan)
 
 		// If we reach here, download was successful
 		resultChan <- DownloadResult{
@@ -59,7 +60,7 @@ func startAsyncDownload(s *discordgo.Session, i *discordgo.InteractionCreate, ur
 		}
 	}()
 
-	// Handle results asynchronously
+	// Handle progress and results asynchronously
 	go func() {
 		// First update the original ephemeral message with "Processing..."
 		_, err := s.InteractionResponseEdit(i.Interaction, &discordgo.WebhookEdit{
@@ -69,31 +70,49 @@ func startAsyncDownload(s *discordgo.Session, i *discordgo.InteractionCreate, ur
 			log.Printf("Error updating interaction: %v", err)
 		}
 
-		result := <-resultChan
-
-		if result.Success {
-			// Update ephemeral message with completion status
-			_, err = s.InteractionResponseEdit(i.Interaction, &discordgo.WebhookEdit{
-				Content: ptr("✅ Download completed successfully!\nURL: " + result.URL + "\nAudio: " + result.Format),
-			})
-			if err != nil {
-				log.Printf("Error updating interaction: %v", err)
-			}
-
-			// Send non-ephemeral completion message
-			_, err = s.FollowupMessageCreate(i.Interaction, false, &discordgo.WebhookParams{
-				Content: "📥 Video downloaded: " + result.URL,
-			})
-			if err != nil {
-				log.Printf("Error sending public completion message: %v", err)
-			}
-		} else {
-			// Update ephemeral message with error
-			_, err = s.InteractionResponseEdit(i.Interaction, &discordgo.WebhookEdit{
-				Content: ptr("❌ Download failed: " + result.Message + "\nURL: " + result.URL + "\nAudio: " + result.Format),
-			})
-			if err != nil {
-				log.Printf("Error updating interaction: %v", err)
+		for {
+			select {
+			case prog, ok := <-progressChan:
+				if !ok {
+					progressChan = nil
+					continue
+				}
+				// Update message w/ phase and real time progress
+				phaseEmoji := "⏬"
+				if prog.Phase == "post-processing" {
+					phaseEmoji = "⚙️"
+				}
+				content := fmt.Sprintf("%s %s\n%s @ %s [eta: %s]\n📄 %s",
+					phaseEmoji,
+					prog.Phase,
+					prog.Status,
+					prog.Percent,
+					prog.ETA,
+					prog.Filename)
+				_, err := s.InteractionResponseEdit(i.Interaction, &discordgo.WebhookEdit{
+					Content: ptr(content),
+				})
+				if err != nil {
+					log.Printf("Error updating progress: %v", err)
+				}
+			case result := <-resultChan:
+				// Handle completion
+				if result.Success {
+					_, err = s.FollowupMessageCreate(i.Interaction, false, &discordgo.WebhookParams{
+						Content: "📥 Video downloaded: " + result.URL,
+					})
+					if err != nil {
+						log.Printf("Error updating interaction: %v", err)
+					}
+				} else {
+					_, err = s.InteractionResponseEdit(i.Interaction, &discordgo.WebhookEdit{
+						Content: ptr("❌ Download failed: " + result.Message),
+					})
+					if err != nil {
+						log.Printf("Error updating interaction: %v", err)
+					}
+				}
+				return
 			}
 		}
 	}()

app/ytdlp.go

@@ -2,7 +2,6 @@ package main
 
 import (
 	"context"
-	"fmt"
 	"time"
 
 	"github.com/lrstanley/go-ytdlp"
@@ -13,19 +12,45 @@ type DownloadOptions struct {
 	IncludeSubtitles bool
 }
 
-func downloadVideo(out_dir, url string, opts DownloadOptions) {
+type ProgressUpdate struct {
+	Status   ytdlp.ProgressStatus
+	Percent  string
+	ETA      time.Duration
+	Filename string
+	Phase    string
+}
+
+func downloadVideo(out_dir, url string, opts DownloadOptions, progressChan chan<- ProgressUpdate) {
+	defer close(progressChan)
+
+	var lastPhase string
+
 	dl := ytdlp.New().
 		SetWorkDir(out_dir).
 		FormatSort("res,ext:mp4:m4a").
 		RecodeVideo("mp4").
 		ProgressFunc(100*time.Millisecond, func(prog ytdlp.ProgressUpdate) {
-			fmt.Printf(
-				"%s @ %s [eta: %s] :: %s\n",
-				prog.Status,
-				prog.PercentString(),
-				prog.ETA(),
-				prog.Filename,
-			)
+			// Detect phase transition -- differentiate "downloading" as the main download
+			// and "post processing" when the file name changes, preventing it from appearing "reset"
+			phase := "downloading"
+			if prog.Status == ytdlp.ProgressStatusDownloading && prog.Percent() == 0.0 {
+				// If we already had progress, it's likely post-processing
+				if lastPhase == "downloading" {
+					phase = "post-processing"
+				}
+			} else if prog.Status != ytdlp.ProgressStatusDownloading {
+				phase = "post-processing"
+			}
+
+			lastPhase = phase
+
+			progressChan <- ProgressUpdate{
+				Status:   prog.Status,
+				Percent:  prog.PercentString(),
+				ETA:      prog.ETA(),
+				Filename: prog.Filename,
+				Phase:    phase,
+			}
 		}).
 		Output("%(title)s.%(ext)s")