#!/usr/bin/env bash
set -e

TARGET="$HOME/yt-download"
VENV="$TARGET/env"

# 1) Create project dir
mkdir -p "$TARGET"
cd "$TARGET"

# 2) Create venv if missing
if [ ! -d "$VENV" ]; then
  python3 -m venv env
fi

# 3) Activate venv
# shellcheck disable=SC1090
source "$VENV/bin/activate"

# 4) Install Python deps quietly
pip install --upgrade pip -q
pip install pytubefix tqdm -q

# 5) Check Homebrew
if ! command -v brew >/dev/null 2>&1; then
  cat <<EOF

🏗  Homebrew is required but not installed.
Please install it by running:

  /bin/bash -c "\$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

Then re-run this script.
EOF
  deactivate || true
  exit 1
fi

# 6) Install ffmpeg silently
if ! command -v ffmpeg >/dev/null 2>&1; then
  brew install ffmpeg >/dev/null 2>&1
fi

# 7) Write the Python downloader into downloader.py
cat > downloader.py << 'PYCODE'
#!/usr/bin/env python3
import os
import sys
import subprocess
import time
from urllib.parse import urlparse
from pytubefix import YouTube
from tqdm import tqdm

# ─── Unicode fractional bar setup ──────────────────────────────────────────────
BLOCKS     = ["","▏","▎","▍","▌","▋","▊","▉"]
FULL_BLOCK = "█"
BAR_LEN    = 30

def make_bar(ratio):
    total_eights = int(ratio * BAR_LEN * 8)
    full_chars   = total_eights // 8
    frac         = total_eights % 8
    bar = FULL_BLOCK*full_chars + (BLOCKS[frac] if frac else "")
    bar += " "*(BAR_LEN - full_chars - (1 if frac else 0))
    return bar

def progress_cb(label, start):
    def cb(stream, chunk, rem):
        total   = stream.filesize
        done    = total - rem
        now     = time.time()
        elapsed = now - start
        speed   = (done/(1024*1024))/max(elapsed,1e-6)
        eta     = (total-done)/(speed*1024*1024) if speed>0 else 0
        mb_done = done/(1024*1024)
        mb_tot  = total/(1024*1024)
        pct     = done/total
        bar     = make_bar(pct)
        line = (
            f"\r{label}: [{bar}] {int(pct*100):3d}% "
            f"{mb_done:5.1f}/{mb_tot:5.1f} MB  "
            f"{speed:6.2f} MB/s  "
            f"{int(eta):4d}s left  "
            f"{int(elapsed):4d}s elapsed"
        )
        sys.stdout.write(line)
        sys.stdout.flush()
    return cb

def download_stream(url, label, filters, order, temp_dir, fn):
    start = time.time()
    cb    = progress_cb(label, start)
    try:
        yt = YouTube(url, on_progress_callback=cb)
    except Exception:
        print("\nError: Video not found. Is it private? URLs are case-sensitive.", file=sys.stderr)
        sys.exit(1)
    stream = yt.streams.filter(**filters).order_by(order).desc().first()
    if not stream:
        print("\nError: Video not found. Is it private? URLs are case-sensitive.", file=sys.stderr)
        sys.exit(1)
    stream.download(output_path=temp_dir, filename=fn)
    print()

def main():
    url = sys.argv[1] if len(sys.argv)>1 else input("Input Video URL: ").strip()
    if not url:
        print("Error: Please enter a URL.", file=sys.stderr)
        sys.exit(1)
    parsed = urlparse(url)
    if not parsed.scheme or not parsed.netloc:
        print("Error: That's not a valid URL.", file=sys.stderr)
        sys.exit(1)
    if 'youtube.com' not in parsed.netloc and 'youtu.be' not in parsed.netloc:
        print("Error: That's not a YouTube URL.", file=sys.stderr)
        sys.exit(1)

    temp_dir  = os.path.expanduser("~/yt-download")
    final_dir = os.path.expanduser("~/Downloads")
    os.makedirs(temp_dir,  exist_ok=True)
    os.makedirs(final_dir, exist_ok=True)

    # Download video
    download_stream(
        url, "Video",
        {"progressive":False,"file_extension":"mp4","type":"video"},
        "resolution", temp_dir, "video_temp.mp4"
    )

    # Download audio
    download_stream(
        url, "Audio",
        {"only_audio":True,"file_extension":"mp4"},
        "abr", temp_dir, "audio_temp.mp4"
    )

    print("Creating")
    yt    = YouTube(url)
    title = yt.title.replace("/","_").replace("\\","_") + ".mp4"
    final = os.path.join(final_dir, title)
    subprocess.run([
        "ffmpeg","-y",
        "-i",os.path.join(temp_dir,"video_temp.mp4"),
        "-i",os.path.join(temp_dir,"audio_temp.mp4"),
        "-c","copy", final
    ], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)

    os.remove(os.path.join(temp_dir,"video_temp.mp4"))
    os.remove(os.path.join(temp_dir,"audio_temp.mp4"))

    print(f"\n✅ Download and merge complete!  Saved to: {final}")

if __name__=="__main__":
    main()
PYCODE

chmod +x downloader.py

# 8) Run downloader
./downloader.py "$@"

# 9) Deactivate venv
deactivate || true