#!/usr/bin/env bash
# ── Sovran Hub External Backup Script ────────────────────────────
# Backs up Sovran_SystemsOS data to an external USB hard drive.
# Designed for the Hub web UI (no GUI dependencies).
#
# Your Sovran Pro already backs up your data automatically to its
# internal second drive (BTCEcoandBackup at /run/media/Second_Drive).
# This script creates an additional copy on an external USB drive —
# storing your data in a third location for maximum protection.
#
# Usage:
#   BACKUP_TARGET=/run/media/<user>/<drive> bash sovran-hub-backup.sh
#   (or run with no env var to auto-detect the first external USB drive)

set -euo pipefail

BACKUP_LOG="/var/log/sovran-hub-backup.log"
BACKUP_STATUS="/var/log/sovran-hub-backup.status"
MEDIA_ROOT="/run/media"
HUB_CONFIG_JSON="/var/lib/sovran-hub/config.json"
ROLE_STATE_NIX="/etc/nixos/role-state.nix"
SECOND_DRIVE_MOUNT="/run/media/Second_Drive"
SAFETY_MARGIN_BYTES=$((1024 * 1024 * 1024))

# ── Internal drive labels/paths to NEVER use as backup targets ───
INTERNAL_LABELS=("BTCEcoandBackup" "sovran_systemsos")
INTERNAL_MOUNTS=("$SECOND_DRIVE_MOUNT" "/boot/efi" "/")

FAILED_ALREADY=0
BACKUP_COMPLETE=0
LND_STOPPED=0
LND_UNITS_TO_RESTART=()

ARCHIVE_FILES=()
DB_DUMP_FILES=()
MANIFEST_EXCLUDES=()
LND_BACKUP_NOTES=()

# ── Logging helpers ──────────────────────────────────────────────

log() {
  local msg="[$(date '+%Y-%m-%d %H:%M:%S')] $*"
  echo "$msg" | tee -a "$BACKUP_LOG"
}

set_status() {
  echo "$1" > "$BACKUP_STATUS"
}

fail() {
  FAILED_ALREADY=1
  log "ERROR: $*"
  set_status "FAILED"
  exit 1
}

cleanup() {
  local rc=$?
  local restart_failed=0

  if [[ "$LND_STOPPED" -eq 1 ]]; then
    log "Restarting previously active LND-related services…"
    for (( idx=${#LND_UNITS_TO_RESTART[@]}-1 ; idx>=0 ; idx-- )); do
      local unit="${LND_UNITS_TO_RESTART[$idx]}"
      if systemctl start "$unit"; then
        log "Started $unit"
      else
        log "ERROR: Failed to start $unit"
        restart_failed=1
      fi
    done
    LND_STOPPED=0
  fi

  if [[ "$restart_failed" -eq 1 ]]; then
    rc=1
    FAILED_ALREADY=1
    set_status "FAILED"
  fi

  if [[ "$BACKUP_COMPLETE" -eq 1 && "$rc" -eq 0 ]]; then
    return
  fi

  if [[ "$FAILED_ALREADY" -eq 0 ]]; then
    log "ERROR: Backup terminated unexpectedly (exit code $rc)."
    set_status "FAILED"
  fi
}

trap cleanup EXIT
trap 'exit 1' INT TERM

require_cmd() {
  local cmd="$1"
  command -v "$cmd" >/dev/null 2>&1 || fail "Required command not found: $cmd"
}

# ── Check whether a mount point is an internal drive ────────────

is_internal() {
  local mnt="$1"
  for internal in "${INTERNAL_MOUNTS[@]}"; do
    if [[ "$mnt" == "$internal" || "$mnt" == "${internal}/"* ]]; then
      return 0
    fi
  done
  return 1
}

# ── Use lsblk to find the first genuine external USB drive ───────

find_external_drive() {
  local target=""

  while IFS=$'\t' read -r dev_type hotplug removable label mountpoint; do
    [[ "$dev_type" == "part" || "$dev_type" == "disk" ]] || continue
    [[ "$hotplug" == "1" || "$removable" == "1" ]] || continue
    [[ -n "$mountpoint" ]] || continue

    local skip=0
    for lbl in "${INTERNAL_LABELS[@]}"; do
      [[ "$label" == "$lbl" ]] && skip=1 && break
    done
    [[ "$skip" -eq 1 ]] && continue

    is_internal "$mountpoint" && continue

    if mountpoint -q "$mountpoint" 2>/dev/null; then
      target="$mountpoint"
      break
    fi
  done < <(lsblk -J -o NAME,LABEL,MOUNTPOINT,HOTPLUG,RM,TYPE 2>/dev/null | \
    python3 -c "
import sys, json

def flatten(devs):
    for d in devs:
        yield d
        for c in d.get('children', []):
            yield from flatten([c])

data = json.load(sys.stdin)
for d in flatten(data.get('blockdevices', [])):
    print('\\t'.join([
        d.get('type') or '',
        str(d.get('hotplug') or '0'),
        str(d.get('rm') or '0'),
        d.get('label') or '',
        d.get('mountpoint') or '',
    ]))
" 2>/dev/null || true)

  if [[ -z "$target" && -d "$MEDIA_ROOT" ]]; then
    while IFS= read -r -d '' mnt; do
      is_internal "$mnt" && continue
      if mountpoint -q "$mnt" 2>/dev/null; then
        target="$mnt"
        break
      fi
    done < <(find "$MEDIA_ROOT" -mindepth 2 -maxdepth 2 -type d -print0 2>/dev/null)
  fi

  echo "$target"
}

# ── Detect the configured system role ───────────────────────────

detect_role() {
  local role="server_plus_desktop"

  if [[ -f "$HUB_CONFIG_JSON" ]] && command -v python3 &>/dev/null; then
    local r
    r=$(python3 -c \
      "import json,sys; d=json.load(open(sys.argv[1])); print(d.get('role',''))" \
      "$HUB_CONFIG_JSON" 2>/dev/null || true)
    if [[ -n "$r" ]]; then
      echo "$r"
      return
    fi
  fi

  if [[ -f "$ROLE_STATE_NIX" ]]; then
    if grep -q 'roles\.desktop = lib\.mkDefault true' "$ROLE_STATE_NIX" 2>/dev/null; then
      role="desktop"
    elif grep -q 'roles\.node = lib\.mkDefault true' "$ROLE_STATE_NIX" 2>/dev/null; then
      role="node"
    fi
  fi

  echo "$role"
}

validate_target_mount() {
  local target="$1"
  [[ "$target" == "${MEDIA_ROOT}/"* ]] || fail "Target '$target' must be mounted under $MEDIA_ROOT."
  [[ -d "$target" ]] || fail "Target path '$target' does not exist."
  mountpoint -q "$target" || fail "Target path '$target' is not a mount point."

  local fstype=""
  fstype=$(findmnt -n -o FSTYPE -T "$target" 2>/dev/null || true)
  [[ -n "$fstype" ]] || fail "Could not determine filesystem type for '$target'."

  if [[ "$fstype" != "exfat" && "$fstype" != "fuseblk" ]]; then
    fail "Target '$target' must be exFAT (detected filesystem: $fstype)."
  fi

  if [[ "$fstype" == "fuseblk" ]]; then
    local src_dev blk_type
    src_dev=$(findmnt -n -o SOURCE -T "$target" 2>/dev/null || true)
    blk_type=""
    if [[ -n "$src_dev" ]]; then
      blk_type=$(lsblk -no FSTYPE "$src_dev" 2>/dev/null || true)
      [[ -z "$blk_type" ]] && blk_type=$(blkid -o value -s TYPE "$src_dev" 2>/dev/null || true)
    fi
    if [[ "$blk_type" != "exfat" && "$blk_type" != "fuseblk" ]]; then
      fail "Target '$target' is fuseblk but not identified as exFAT-compatible."
    fi
  fi

  local write_test
  write_test="$target/.sovran-write-test-$$"
  if ! ( : > "$write_test" && echo "ok" >> "$write_test" && rm -f "$write_test" ); then
    fail "Target '$target' is not writable."
  fi

  log "Verified backup target filesystem: $fstype"
}

has_unit() {
  systemctl cat "$1" >/dev/null 2>&1
}

is_unit_active() {
  systemctl is-active --quiet "$1"
}

estimate_path_bytes() {
  local path="$1"
  shift || true
  [[ -e "$path" ]] || {
    echo 0
    return
  }

  local size
  size=$(du -s -B1 -x "$@" "$path" 2>/dev/null | awk '{print $1}' || true)
  [[ -n "$size" ]] || size=0
  echo "$size"
}

# ── Initialise log file ──────────────────────────────────────────

: > "$BACKUP_LOG"
set_status "RUNNING"

log "=== Sovran_SystemsOS External Hub Backup ==="
log "Starting backup process…"

require_cmd tar
require_cmd sha256sum
require_cmd findmnt
require_cmd lsblk
require_cmd mountpoint
require_cmd df
require_cmd du
require_cmd awk
require_cmd sort
require_cmd find
require_cmd systemctl
require_cmd hostname
require_cmd date
require_cmd python3
require_cmd runuser

# ── Detect system role ───────────────────────────────────────────

ROLE="$(detect_role)"
case "$ROLE" in
  desktop)              ROLE_LABEL="Desktop Only" ;;
  node)                 ROLE_LABEL="Node (Bitcoin-only)" ;;
  server_plus_desktop)  ROLE_LABEL="Server + Desktop" ;;
  *)                    ROLE_LABEL="$ROLE" ;;
esac
log "Detected role: $ROLE_LABEL"

# ── Detect target drive ──────────────────────────────────────────

if [[ -n "${BACKUP_TARGET:-}" ]]; then
  TARGET="$BACKUP_TARGET"
  if is_internal "$TARGET"; then
    fail "Target '$TARGET' is an internal system drive and cannot be used for external backup."
  fi
  log "Using specified backup target: $TARGET"
else
  log "Auto-detecting external USB drives…"
  TARGET="$(find_external_drive)"
  if [[ -z "$TARGET" ]]; then
    fail "No external USB drive detected. Please plug in an exFAT-formatted USB drive and try again."
  fi
  log "Detected external drive: $TARGET"
fi

validate_target_mount "$TARGET"

# ── Plan role-aware source scope and exclusions ─────────────────

LND_AVAILABLE=0
if [[ "$ROLE" != "desktop" ]] && [[ -d /var/lib/lnd ]] && has_unit "lnd.service"; then
  LND_AVAILABLE=1
fi

if [[ "$ROLE" == "desktop" ]]; then
  MANIFEST_EXCLUDES+=("/etc/nix-bitcoin-secrets (not applicable for Desktop Only role)")
else
  MANIFEST_EXCLUDES+=("/etc/nix-bitcoin-secrets skipped when path absent")
fi

MANIFEST_EXCLUDES+=(
  "/run/media/Second_Drive (never traversed)"
  "/run/media/Second_Drive/BTCEcoandBackup/Bitcoin_Node (excluded; internal second-drive data)"
  "/run/media/Second_Drive/BTCEcoandBackup/Electrs_Data (excluded; internal second-drive data)"
  "/var/lib/bitcoind (excluded from manual backup)"
  "/var/lib/electrs (excluded from manual backup)"
  "/var/lib/*/log and /var/lib/*/logs"
  "/var/lib/*/cache and /var/lib/*/tmp"
  "/home/*/.cache and /home/*/.local/share/Trash"
)

if [[ "$ROLE" == "desktop" || "$LND_AVAILABLE" -eq 1 ]]; then
  MANIFEST_EXCLUDES+=("/var/lib/lnd from general /var/lib archive")
fi

# ── Estimate required free space ─────────────────────────────────

ETC_NIXOS_BYTES=$(estimate_path_bytes /etc/nixos)
HOME_BYTES=$(estimate_path_bytes /home --exclude='*/.cache' --exclude='*/.local/share/Trash' --exclude='*/Trash')
SECRETS_BYTES=0
if [[ "$ROLE" != "desktop" ]]; then
  SECRETS_BYTES=$(estimate_path_bytes /etc/nix-bitcoin-secrets)
fi

VAR_LIB_BYTES=$(estimate_path_bytes /var/lib \
  --exclude='bitcoind' \
  --exclude='electrs' \
  --exclude='lnd' \
  --exclude='*/log' \
  --exclude='*/logs' \
  --exclude='*/cache' \
  --exclude='*/tmp')

LND_BYTES=0
if [[ "$LND_AVAILABLE" -eq 1 ]]; then
  LND_BYTES=$(estimate_path_bytes /var/lib/lnd)
fi

ESTIMATED_BYTES=$(( ETC_NIXOS_BYTES + HOME_BYTES + SECRETS_BYTES + VAR_LIB_BYTES + LND_BYTES ))
REQUIRED_BYTES=$(( ESTIMATED_BYTES + (ESTIMATED_BYTES / 5) + SAFETY_MARGIN_BYTES ))

FREE_BYTES=$(df -B1 --output=avail "$TARGET" | tail -1 | tr -d ' ')
FREE_GB=$(( FREE_BYTES / 1024 / 1024 / 1024 ))
REQUIRED_GB=$(( REQUIRED_BYTES / 1024 / 1024 / 1024 ))

log "Estimated backup size: $(( ESTIMATED_BYTES / 1024 / 1024 / 1024 )) GB"
log "Required free space (with safety margin): ${REQUIRED_GB} GB"
log "Free space on drive: ${FREE_GB} GB"

(( FREE_BYTES >= REQUIRED_BYTES )) || \
  fail "Not enough free space on drive (${FREE_GB} GB available, ${REQUIRED_GB} GB required)."

# ── Create timestamped backup directory ─────────────────────────

TIMESTAMP="$(date '+%Y%m%d_%H%M%S')"
BACKUP_DIR="${TARGET}/Sovran_SystemsOS_Backup/${TIMESTAMP}"
DB_DUMP_DIR="$BACKUP_DIR/database-dumps"
mkdir -p "$BACKUP_DIR" "$DB_DUMP_DIR"
log "Backup destination: $BACKUP_DIR"

create_tar_archive() {
  local archive_name="$1"
  shift
  local archive_path="$BACKUP_DIR/$archive_name"

  log "Creating $archive_name …"
  tar \
    --create \
    --file "$archive_path" \
    --numeric-owner \
    --acls \
    --xattrs \
    --sparse \
    --one-file-system \
    "$@"

  ARCHIVE_FILES+=("$archive_name")
  log "Created archive: $archive_name"
}

export_postgresql_dumps() {
  if ! command -v pg_dump >/dev/null 2>&1 || ! has_unit "postgresql.service"; then
    log "PostgreSQL tools/service not available — skipping PostgreSQL exports."
    return
  fi

  if ! is_unit_active "postgresql.service"; then
    log "PostgreSQL service is not active — skipping PostgreSQL exports."
    return
  fi

  log "Exporting PostgreSQL globals and databases…"
  local globals_file="$DB_DUMP_DIR/postgresql_globals.sql"
  runuser -u postgres -- pg_dumpall --globals-only > "$globals_file" || \
    fail "Failed to export PostgreSQL globals."
  DB_DUMP_FILES+=("database-dumps/postgresql_globals.sql")

  local dbs
  dbs=$(runuser -u postgres -- psql -Atqc "SELECT datname FROM pg_database WHERE datistemplate = false AND datallowconn AND datname <> 'postgres';" 2>/dev/null || true)

  if [[ -z "$dbs" ]]; then
    log "No non-template PostgreSQL application databases found."
    return
  fi

  while IFS= read -r db; do
    [[ -n "$db" ]] || continue
    local safe_db
    safe_db="$(echo "$db" | tr -c '[:alnum:]_.-' '_')"
    local out_file="$DB_DUMP_DIR/postgresql_${safe_db}.dump"
    runuser -u postgres -- pg_dump --format=custom --file "$out_file" "$db" || \
      fail "Failed to export PostgreSQL database '$db'."
    DB_DUMP_FILES+=("database-dumps/postgresql_${safe_db}.dump")
  done <<< "$dbs"
}

export_mariadb_dumps() {
  local dump_cmd=""
  local query_cmd=""
  local mariadb_unit=""

  if command -v mariadb-dump >/dev/null 2>&1; then
    dump_cmd="mariadb-dump"
  elif command -v mysqldump >/dev/null 2>&1; then
    dump_cmd="mysqldump"
  fi

  if command -v mariadb >/dev/null 2>&1; then
    query_cmd="mariadb"
  elif command -v mysql >/dev/null 2>&1; then
    query_cmd="mysql"
  fi

  if [[ -z "$dump_cmd" || -z "$query_cmd" ]]; then
    log "MariaDB dump/query tools not available — skipping MariaDB exports."
    return
  fi

  if has_unit "mariadb.service" && is_unit_active "mariadb.service"; then
    mariadb_unit="mariadb.service"
  elif has_unit "mysql.service" && is_unit_active "mysql.service"; then
    mariadb_unit="mysql.service"
  else
    log "MariaDB service is not active — skipping MariaDB exports."
    return
  fi

  log "Exporting MariaDB databases from ${mariadb_unit}…"

  local dbs
  dbs=$($query_cmd -N -e "SHOW DATABASES" 2>/dev/null || true)
  if [[ -z "$dbs" ]]; then
    log "No MariaDB databases found."
    return
  fi

  while IFS= read -r db; do
    [[ -n "$db" ]] || continue
    case "$db" in
      information_schema|performance_schema|mysql|sys) continue ;;
    esac

    local safe_db out_file
    safe_db="$(echo "$db" | tr -c '[:alnum:]_.-' '_')"
    out_file="$DB_DUMP_DIR/mariadb_${safe_db}.sql"

    $dump_cmd --single-transaction --quick --routines --events --triggers "$db" > "$out_file" || \
      fail "Failed to export MariaDB database '$db'."

    DB_DUMP_FILES+=("database-dumps/mariadb_${safe_db}.sql")
  done <<< "$dbs"
}

export_lnd_scb_if_possible() {
  [[ "$LND_AVAILABLE" -eq 1 ]] || return

  local scb_file="$BACKUP_DIR/lnd-static-channel-backup.scb"
  local attempts=(
    "lncli exportchanbackup --all --output_file $scb_file"
    "lncli -n mainnet exportchanbackup --all --output_file $scb_file"
    "runuser -u lnd -- lncli exportchanbackup --all --output_file $scb_file"
    "runuser -u lnd -- lncli -n mainnet exportchanbackup --all --output_file $scb_file"
  )

  if ! command -v lncli >/dev/null 2>&1; then
    log "lncli not available — skipping Static Channel Backup export."
    LND_BACKUP_NOTES+=("Static Channel Backup skipped (lncli unavailable)")
    return
  fi

  if ! is_unit_active "lnd.service"; then
    log "LND service is not active — skipping Static Channel Backup export."
    LND_BACKUP_NOTES+=("Static Channel Backup skipped (lnd.service inactive)")
    return
  fi

  log "Exporting LND Static Channel Backup…"
  local attempt
  for attempt in "${attempts[@]}"; do
    if eval "$attempt" >/dev/null 2>&1; then
      DB_DUMP_FILES+=("lnd-static-channel-backup.scb")
      LND_BACKUP_NOTES+=("Static Channel Backup exported via lncli")
      log "LND Static Channel Backup exported."
      return
    fi
  done

  log "WARNING: Unable to export LND Static Channel Backup with available lncli invocations."
  LND_BACKUP_NOTES+=("Static Channel Backup export failed (no compatible lncli invocation succeeded)")
}

capture_active_lnd_dependents() {
  [[ "$LND_AVAILABLE" -eq 1 ]] || return

  LND_UNITS_TO_RESTART=()
  local raw_units=""
  raw_units=$(systemctl show lnd.service -p RequiredBy -p WantedBy --value 2>/dev/null | tr ' ' '\n' | grep '\.service$' | sort -u || true)

  while IFS= read -r unit; do
    [[ -n "$unit" ]] || continue
    if is_unit_active "$unit"; then
      LND_UNITS_TO_RESTART+=("$unit")
    fi
  done <<< "$raw_units"

  if is_unit_active "lnd.service"; then
    LND_UNITS_TO_RESTART+=("lnd.service")
  fi
}

stop_lnd_stack_if_needed() {
  [[ "$LND_AVAILABLE" -eq 1 ]] || return

  capture_active_lnd_dependents

  if [[ "${#LND_UNITS_TO_RESTART[@]}" -eq 0 ]]; then
    log "No active LND-related services needed stopping."
    return
  fi

  log "Stopping active services that depend on LND for clean /var/lib/lnd archive…"

  local unit
  for unit in "${LND_UNITS_TO_RESTART[@]}"; do
    if [[ "$unit" == "lnd.service" ]]; then
      continue
    fi
    systemctl stop "$unit" || fail "Failed to stop dependent service: $unit"
    log "Stopped $unit"
  done

  if printf '%s\n' "${LND_UNITS_TO_RESTART[@]}" | grep -qx 'lnd.service'; then
    systemctl stop lnd.service || fail "Failed to stop lnd.service"
    log "Stopped lnd.service"
  fi

  LND_STOPPED=1
}

# ── Stage 1/5: NixOS configuration ──────────────────────────────

log ""
log "── Stage 1/5: NixOS configuration (/etc/nixos) ──────────────"
if [[ -d /etc/nixos ]]; then
  create_tar_archive "etc-nixos.tar" -C / etc/nixos
  log "Stage 1 complete."
else
  log "WARNING: /etc/nixos not found — skipping."
fi

# ── Stage 2/5: Secrets ──────────────────────────────────────────

log ""
log "── Stage 2/5: Secrets (/etc/nix-bitcoin-secrets) ───────────"
if [[ "$ROLE" == "desktop" ]]; then
  log "Skipping /etc/nix-bitcoin-secrets — not applicable for Desktop Only role."
elif [[ -e /etc/nix-bitcoin-secrets ]]; then
  create_tar_archive "etc-nix-bitcoin-secrets.tar" -C / etc/nix-bitcoin-secrets
else
  log "(not found: /etc/nix-bitcoin-secrets — skipping)"
fi
log "Stage 2 complete."

# ── Stage 3/5: Home directory ───────────────────────────────────

log ""
log "── Stage 3/5: Home directory (/home) ───────────────────────"
if [[ -d /home ]]; then
  create_tar_archive "home.tar" \
    -C / \
    --exclude='home/*/.cache' \
    --exclude='home/*/.local/share/Trash' \
    --exclude='home/*/Trash' \
    home
  log "Stage 3 complete."
else
  log "WARNING: /home not found — skipping."
fi

# ── Stage 4/5: Database exports + LND artifacts ────────────────

log ""
log "── Stage 4/5: Database and LND consistency exports ─────────"
export_postgresql_dumps
export_mariadb_dumps
export_lnd_scb_if_possible

if [[ "$LND_AVAILABLE" -eq 1 ]]; then
  stop_lnd_stack_if_needed
  create_tar_archive "var-lib-lnd-clean.tar" -C / var/lib/lnd
  LND_BACKUP_NOTES+=("Created clean raw /var/lib/lnd archive after controlled service stop")
fi

log "Stage 4 complete."

# ── Stage 5/5: System data ──────────────────────────────────────

log ""
log "── Stage 5/5: System data (/var/lib) ───────────────────────"
if [[ -d /var/lib ]]; then
  VAR_LIB_EXCLUDES=(
    --exclude='var/lib/bitcoind'
    --exclude='var/lib/electrs'
    --exclude='var/lib/*/log'
    --exclude='var/lib/*/logs'
    --exclude='var/lib/*/cache'
    --exclude='var/lib/*/tmp'
  )

  if [[ "$ROLE" == "desktop" || "$LND_AVAILABLE" -eq 1 ]]; then
    VAR_LIB_EXCLUDES+=(--exclude='var/lib/lnd')
  fi

  create_tar_archive "var-lib.tar" -C / "${VAR_LIB_EXCLUDES[@]}" var/lib
  log "Stage 5 complete."
else
  log "WARNING: /var/lib not found — skipping."
fi

# ── Generate manifest ────────────────────────────────────────────

log ""
log "Generating BACKUP_MANIFEST.txt …"
MANIFEST_FILE="$BACKUP_DIR/BACKUP_MANIFEST.txt"
CHECKSUM_FILE="$BACKUP_DIR/SHA256SUMS.txt"

{
  echo "Sovran_SystemsOS Backup Manifest"
  echo "Generated: $(date -u '+%Y-%m-%dT%H:%M:%SZ')"
  echo "Timestamp: $TIMESTAMP"
  echo "Hostname:  $(hostname)"
  echo "Role:      $ROLE_LABEL"
  echo "Target:    $TARGET"
  echo ""
  echo "Source paths included:"
  echo "- /etc/nixos"
  echo "- /home"
  if [[ "$ROLE" != "desktop" ]]; then
    echo "- /etc/nix-bitcoin-secrets (when present)"
  fi
  echo "- /var/lib"
  echo ""
  echo "Exclusions:"
  for ex in "${MANIFEST_EXCLUDES[@]}"; do
    echo "- $ex"
  done
  echo ""
  echo "Archives:"
  for archive in "${ARCHIVE_FILES[@]}"; do
    echo "- $archive"
  done
  echo ""
  echo "Database and LND exports:"
  if [[ "${#DB_DUMP_FILES[@]}" -eq 0 && "${#LND_BACKUP_NOTES[@]}" -eq 0 ]]; then
    echo "- none"
  else
    for dump in "${DB_DUMP_FILES[@]}"; do
      echo "- $dump"
    done
    for note in "${LND_BACKUP_NOTES[@]}"; do
      echo "- $note"
    done
  fi
  echo ""
  echo "Restore guidance:"
  echo "- Verify artifacts: cd <backup_dir> && sha256sum -c SHA256SUMS.txt"
  echo "- Extract a tar archive: sudo tar --acls --xattrs --numeric-owner -xpf <archive>.tar -C /"
  echo "- PostgreSQL globals: sudo -u postgres psql -f database-dumps/postgresql_globals.sql"
  echo "- PostgreSQL DB dump: sudo -u postgres pg_restore --create --clean --if-exists -d postgres database-dumps/postgresql_<db>.dump"
  echo "- MariaDB DB dump: mariadb <db_name> < database-dumps/mariadb_<db>.sql"
  echo "- LND SCB: keep lnd-static-channel-backup.scb with wallet seed for channel recovery procedures"
  echo ""
  echo "Important note: Bitcoin blockchain and Electrs index data are intentionally excluded"
  echo "from manual external backup because they already live on the internal second drive"
  echo "(/run/media/Second_Drive) and are reconstructable/internal-backup data."
  echo ""
  echo "Artifact listing:"
  find "$BACKUP_DIR" -mindepth 1 -maxdepth 2 -type f | sort
} > "$MANIFEST_FILE"

ARCHIVE_FILES+=("BACKUP_MANIFEST.txt")

# ── Generate checksums for all backup artifacts ─────────────────

log "Generating SHA-256 checksums …"
(
  cd "$BACKUP_DIR"
  while IFS= read -r -d '' file; do
    sha256sum "$file"
  done < <(find . -mindepth 1 -maxdepth 2 -type f ! -name 'SHA256SUMS.txt' -print0 | sort -z)
) > "$CHECKSUM_FILE"

log "Manifest written to $MANIFEST_FILE"
log "Checksums written to $CHECKSUM_FILE"

# ── Done ─────────────────────────────────────────────────────────

log ""
log "All Finished! Your data is now backed up to a third location."
log "Please eject the drive safely before removing it from your Sovran Pro."

BACKUP_COMPLETE=1
set_status "SUCCESS"