#!/usr/bin/env bash
set -euo pipefail

# Track temp files for cleanup
tmpfiles=()

cleanup() {
  for f in "${tmpfiles[@]}"; do
    [ -f "$f" ] && rm -f "$f"
  done
}
trap 'cleanup; exit 130' INT
trap 'cleanup' EXIT

mkdir -p channels

file="$1"
start_id="${2:-}"
skip=true

while read -r id; do
  # Skip logic
  if [ -n "$start_id" ] && $skip; then
    if [ "$id" = "$start_id" ]; then
      skip=false
    else
      continue
    fi
  fi

  playlist_id="UU${id:2}"

  outfile="channels/${id}.json"
  tmpfile="${outfile}.tmp.$$"

  if [ ! -f "$outfile" ]; then
    echo "Fetching $id..."
    tmpfiles+=("$tmpfile")

    if yt-dlp \
      -j \
      --flat-playlist \
      --lazy-playlist \
      --extractor-arg "youtubetab:approximate_date" \
      "https://www.youtube.com/playlist?list=$playlist_id" \
      > "$tmpfile"; then
      mv -f "$tmpfile" "$outfile"
      # remove from tracked list since it's now promoted
      tmpfiles=("${tmpfiles[@]/$tmpfile}")
    else
      echo "Failed to fetch $id" >&2
      rm -f "$tmpfile"
      tmpfiles=("${tmpfiles[@]/$tmpfile}")
    fi
  else
    echo "Skipping $id (already exists)" >&2
  fi
done < "$file"