fix: handle large file downloads with progress tracking (fixes #2)

app.py

@@ -2,14 +2,22 @@
 import uuid
 import glob
 import json
+import re
 import subprocess
 import threading
+import logging
 from flask import Flask, request, jsonify, send_file, render_template
 
 app = Flask(__name__)
 DOWNLOAD_DIR = os.path.join(os.path.dirname(__file__), "downloads")
 os.makedirs(DOWNLOAD_DIR, exist_ok=True)
 
+logging.basicConfig(level=logging.INFO)
+logger = logging.getLogger(__name__)
+
+# Download timeout: 30 minutes (large files need more time)
+DOWNLOAD_TIMEOUT = 1800
+
 jobs = {}
 
 
@@ -19,6 +27,9 @@ def run_download(job_id, url, format_choice, format_id):
 
     cmd = ["yt-dlp", "--no-playlist", "-o", out_template]
 
+    # Enable progress tracking via newline-separated output
+    cmd += ["--newline", "--progress"]
+
     if format_choice == "audio":
         cmd += ["-x", "--audio-format", "mp3"]
     elif format_id:
@@ -29,10 +40,47 @@ def run_download(job_id, url, format_choice, format_id):
     cmd.append(url)
 
     try:
-        result = subprocess.run(cmd, capture_output=True, text=True, timeout=300)
-        if result.returncode != 0:
+        # Use Popen for real-time progress parsing
+        process = subprocess.Popen(
+            cmd,
+            stdout=subprocess.PIPE,
+            stderr=subprocess.STDOUT,
+            text=True,
+            bufsize=1,
+        )
+
+        progress_pattern = re.compile(r"\[download\]\s+Destination:|\[download\]\s+(\d+\.?\d*)%")
+        last_error_lines = []
+
+        for line in process.stdout:
+            line = line.strip()
+            if not line:
+                continue
+
+            # Track progress percentage
+            match = progress_pattern.search(line)
+            if match:
+                if match.group(1):
+                    try:
+                        pct = float(match.group(1))
+                        job["progress"] = min(pct, 100.0)
+                    except ValueError:
+                        pass
+
+            # Track error/warning lines for better error reporting
+            if line.startswith("ERROR:") or line.startswith("WARNING:"):
+                last_error_lines.append(line)
+                logger.warning(f"Job {job_id}: {line}")
+
+        process.wait(timeout=DOWNLOAD_TIMEOUT)
+
+        if process.returncode != 0:
             job["status"] = "error"
-            job["error"] = result.stderr.strip().split("\n")[-1]
+            # Use the most informative error line
+            if last_error_lines:
+                job["error"] = last_error_lines[-1].replace("ERROR: ", "")
+            else:
+                job["error"] = f"yt-dlp exited with code {process.returncode}"
             return
 
         files = glob.glob(os.path.join(DOWNLOAD_DIR, f"{job_id}.*"))
@@ -56,6 +104,7 @@ def run_download(job_id, url, format_choice, format_id):
                     pass
 
         job["status"] = "done"
+        job["progress"] = 100.0
         job["file"] = chosen
         ext = os.path.splitext(chosen)[1]
         title = job.get("title", "").strip()
@@ -65,12 +114,31 @@ def run_download(job_id, url, format_choice, format_id):
             job["filename"] = f"{safe_title}{ext}" if safe_title else os.path.basename(chosen)
         else:
             job["filename"] = os.path.basename(chosen)
+
+        # Report file size for user awareness
+        try:
+            file_size = os.path.getsize(chosen)
+            job["file_size_mb"] = round(file_size / (1024 * 1024), 2)
+        except OSError:
+            pass
+
     except subprocess.TimeoutExpired:
         job["status"] = "error"
-        job["error"] = "Download timed out (5 min limit)"
+        job["error"] = f"Download timed out ({DOWNLOAD_TIMEOUT // 60} min limit). Try a lower quality format for large files."
+        # Clean up partial file
+        try:
+            process.kill()
+        except Exception:
+            pass
+        for f in glob.glob(os.path.join(DOWNLOAD_DIR, f"{job_id}.*")):
+            try:
+                os.remove(f)
+            except OSError:
+                pass
     except Exception as e:
         job["status"] = "error"
         job["error"] = str(e)
+        logger.exception(f"Job {job_id} failed with unexpected error")
 
 
 @app.route("/")
@@ -154,6 +222,8 @@ def check_status(job_id):
         "status": job["status"],
         "error": job.get("error"),
         "filename": job.get("filename"),
+        "progress": job.get("progress"),
+        "file_size_mb": job.get("file_size_mb"),
     })
 
 

templates/index.html

@@ -270,6 +270,21 @@
     .card-status.done { color: var(--success); }
     .card-status.error { color: var(--error); }
 
+    .progress-bar-wrap {
+      width: 100%;
+      height: 4px;
+      background: var(--card-border);
+      border-radius: 2px;
+      margin-top: 6px;
+      overflow: hidden;
+    }
+    .progress-bar-fill {
+      height: 100%;
+      background: var(--accent);
+      border-radius: 2px;
+      transition: width 0.3s ease;
+    }
+
     .q-chip {
       padding: 4px 10px;
       border: 1.5px solid var(--card-border);
@@ -568,7 +583,12 @@ <h1>Re<em>Clip</em></h1>
       if (c.status === 'ready') {
         actionHtml = `<button class="card-dl-btn" onclick="dlCard(${idx})">Download</button>${qualityChips}`;
       } else if (c.status === 'downloading') {
-        actionHtml = `<span class="card-status downloading"><span class="spin"></span> Downloading...</span>`;
+        const pct = c.progress != null ? Math.round(c.progress) : null;
+        const pctText = pct != null ? `${pct}%` : '';
+        actionHtml = `<span class="card-status downloading"><span class="spin"></span> Downloading... ${pctText}</span>`;
+        if (pct != null) {
+          actionHtml += `<div class="progress-bar-wrap"><div class="progress-bar-fill" style="width:${pct}%"></div></div>`;
+        }
       } else if (c.status === 'done') {
         actionHtml = `<button class="card-dl-btn done" onclick="saveCard(${idx})">Save</button>
           <span class="card-status done">${esc(c.filename || '')}</span>`;
@@ -653,6 +673,9 @@ <h1>Re<em>Clip</em></h1>
             c.status = 'error';
             c.error = data.error;
             renderCard(idx);
+          } else if (data.status === 'downloading' && data.progress != null) {
+            c.progress = data.progress;
+            renderCard(idx);
           }
         } catch {
           clearInterval(iv);