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

THREAD_ID="${THREAD_ID:-1455993943471820842}"
OUT_DIR="${OUT_DIR:-$PWD/thread}"
HTML="$OUT_DIR/export.html"
URLS="$OUT_DIR/urls.txt"   # aria2c input file: one URL per line

# Token from env, otherwise prompt (input hidden)
if [[ -z "${DISCORD_TOKEN:-}" ]]; then
  read -rsp "Discord token: " DISCORD_TOKEN
  echo
fi

mkdir -p "$OUT_DIR"

# 1. Export the thread to HTML
docker run --rm --user "$(id -u):$(id -g)" \
  -v "$OUT_DIR:/out" \
  tyrrrz/discordchatexporter:stable export \
  -t "$DISCORD_TOKEN" -c "$THREAD_ID" -f HtmlDark -o /out/export.html

unset DISCORD_TOKEN

# 2. Find base64 strings starting with "https://", then decode them
grep -oP 'aHR0cHM6Ly[89][A-Za-z0-9+/_-]*' "$HTML" \
  | sort -u \
  | while read -r s; do
      s=$(printf '%s' "$s" | tr '_-' '/+' | tr -d '=')
      while (( ${#s} % 4 )); do s="$s="; done
      printf '%s' "$s" | base64 -d 2>/dev/null | tr -d '\r\n' || true
      echo
    done \
  | grep -E '^https://[[:graph:]]+$' \
  | awk '!seen[$0]++' > "$URLS"

echo "Found $(wc -l < "$URLS") URLs -> $URLS"
echo "Download with: aria2c -i \"$URLS\" -d \"$OUT_DIR/downloads\""