#!/bin/bash

INPUT_DIR="${1:-.}"
OUTPUT_DIR="${2:-.}"

if [ -z "$1" ]; then
  echo "Usage: $0 <input_dir> [output_dir]"
  echo "Concatenates all .tar.gz parts and extracts them"
  exit 1
fi

PREFIX=""
for f in "${INPUT_DIR}"/**.tar.gz; do
  if [ -f "$f" ]; then
    BASE=$(basename "$f")
    # Убираем числовой суффикс для определения префикса
    PREFIX=$(echo "$BASE" | sed -E 's/\.[0-9]+$//')
    if [ -n "$PREFIX" ]; then
      break
    fi
  fi
done

COMBINED="/tmp/${PREFIX}_combined.tar.gz"

echo "Combining parts into ${COMBINED}..."
# Собираем в правильном порядке: сначала базовый файл (без суффикса), затем части по порядку
cat "${INPUT_DIR}/${PREFIX}" > "$COMBINED" 2>/dev/null
for f in $(ls -v "${INPUT_DIR}/${PREFIX}".* 2>/dev/null); do
  BASE=$(basename "$f")
  if [[ "$BASE" =~ \.[0-9]+$ ]]; then
    echo "Appending ${BASE}..."
    cat "$f" >> "$COMBINED"
  fi
done

echo "Extracting ${COMBINED} to ${OUTPUT_DIR}..."
tar -xzf "$COMBINED" -C "$OUTPUT_DIR"

if [ $? -eq 0 ]; then
  echo "Extraction complete."
  rm -f "$COMBINED"
else
  echo "Extraction failed. Combined file kept at ${COMBINED}"
  exit 1
fi