#!/usr/bin/env bash
# restic backup: Synology SFTP (when reachable) + Backblaze B2 (always)
set -euo pipefail

source "$HOME/.credentials"

LOG_DIR="$HOME/.local/log/restic"
mkdir -p "$LOG_DIR"
LOG="$LOG_DIR/$(date +%Y-%m-%d).log"

EXCLUDES=(
  --exclude-file="$HOME/.config/restic/excludes"
  --exclude-caches
)

run_backup() {
  local repo="$1"
  local label="$2"

  echo "--- $label backup ---" | tee -a "$LOG"

  restic -r "$repo" backup ~ "${EXCLUDES[@]}" \
    --one-file-system \
    --tag "$(hostname)" 2>&1 | tee -a "$LOG"

  restic -r "$repo" forget \
    --keep-daily 7 \
    --keep-weekly 4 \
    --keep-monthly 6 \
    --prune 2>&1 | tee -a "$LOG"
}

run_and_notify() {
  local repo="$1"
  local label="$2"
  local machine="$3"
  local destination="$4"

  set +e
  run_backup "$repo" "$label"
  local exit_code=$?
  set -e

  local status="failure"
  [[ $exit_code -eq 0 ]] && status="success"

  local snap
  snap=$(grep -oE 'snapshot [a-f0-9]+' "$LOG" 2>/dev/null | tail -1 | awk '{print $2}')

  notify_backup.rb \
    --machine "$machine" \
    --destination "$destination" \
    --status "$status" \
    ${snap:+--snapshot "$snap"} \
    --log-path "$LOG" \
    --notes "$(tail -10 "$LOG")" || true

  return $exit_code
}

echo "=== Backup started $(date) ===" | tee -a "$LOG"

# Synology: attempt only if reachable (SSH key auth, 30s timeout for HDD spin-up)
if ssh -o ConnectTimeout=30 -o BatchMode=yes synology 'ls /volume1/backup > /dev/null 2>&1' 2>/dev/null; then
  run_and_notify "sftp:${SYNOLOGY_HOST}:${SYNOLOGY_PATH}" "Synology" "desktop" "synology"
else
  echo "Synology unreachable — skipping SFTP backup" | tee -a "$LOG"
  notify_backup.rb \
    --machine desktop \
    --destination synology \
    --status skipped \
    --log-path "$LOG" \
    --notes "Synology unreachable at $(date)" || true
fi

# B2: clear any stale lock before attempting (safe no-op if no lock exists)
restic -r "b2:${B2_BUCKET}:" unlock 2>&1 | tee -a "$LOG" || true
run_and_notify "b2:${B2_BUCKET}:" "Backblaze B2" "desktop" "backblaze-b2"

echo "=== Backup complete $(date) ===" | tee -a "$LOG"