#!/bin/bash
#
# Restore the Bitcoin Signet chain from a full datadir backup (tar.gz).
# Use this to resume on the previous chain (e.g. height ~11535) after data loss.
#
# Prerequisite: a backup created with save-signet-datadir-backup.sh
#   (or: docker exec bitcoin-signet-instance tar czf /tmp/bitcoin-backup.tar.gz /root/.bitcoin/
#        docker cp bitcoin-signet-instance:/tmp/bitcoin-backup.tar.gz ./backups/)
#
# Usage: ./restore-signet-from-backup.sh <path-to-backup.tar.gz>
# Example: ./restore-signet-from-backup.sh backups/bitcoin-backup-20260124.tar.gz
#
# Author: 4NK Team
# Date: 2026-02-02

set -e

CONTAINER_NAME="bitcoin-signet-instance"
VOLUME_NAME="signet-bitcoin-data"
BACKUP_PATH="${1:?Usage: $0 <path-to-backup.tar.gz>}"

if [[ ! -f "$BACKUP_PATH" ]]; then
    echo "Error: Backup file not found: $BACKUP_PATH"
    exit 1
fi

BACKUP_PATH=$(realpath "$BACKUP_PATH")
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
cd "$SCRIPT_DIR"

echo "=== Restore Signet from backup ==="
echo "Backup: $BACKUP_PATH"
echo "Volume: $VOLUME_NAME"
echo ""

if docker ps -a --format "{{.Names}}" | grep -q "^${CONTAINER_NAME}$"; then
    echo "Stopping and removing current container..."
    sudo docker stop "$CONTAINER_NAME" 2>/dev/null || true
    sudo docker rm "$CONTAINER_NAME" 2>/dev/null || true
fi

echo "Creating volume $VOLUME_NAME if needed..."
sudo docker volume create "$VOLUME_NAME" 2>/dev/null || true

echo "Extracting backup into volume..."
# Archive may contain root/.bitcoin/... (from tar czf -C / root/.bitcoin) or .bitcoin/...
# Volume is mounted at /root/.bitcoin; extract to / then ensure content is under /root/.bitcoin
sudo docker run --rm \
    -v "$VOLUME_NAME":/restore_target \
    -v "$BACKUP_PATH":/backup.tar.gz:ro \
    debian:bookworm-slim \
    sh -c "cd / && tar xzf /backup.tar.gz && if [ -d /root/.bitcoin ] && [ -n \"\$(ls -A /root/.bitcoin 2>/dev/null)\" ]; then cp -a /root/.bitcoin/. /restore_target/; elif [ -d /.bitcoin ]; then cp -a /.bitcoin/. /restore_target/; else echo 'Unexpected archive layout' && exit 1; fi"

echo "Starting container with restored data..."
sudo docker run --env-file .env -d \
  --name "$CONTAINER_NAME" \
  -v "$VOLUME_NAME":/root/.bitcoin \
  -p 38332:38332 -p 38333:38333 \
  -p 28332:28332 -p 28333:28333 -p 28334:28334 \
  bitcoin-signet

echo ""
echo "Container started. Check height with:"
echo "  sudo docker exec $CONTAINER_NAME bitcoin-cli -datadir=\$(docker exec $CONTAINER_NAME printenv BITCOIN_DIR 2>/dev/null || echo /root/.bitcoin) getblockchaininfo"
echo ""