#!/usr/bin/env bash
#
# VYNDR — daily PostgreSQL backup.
#
# Runs from Coolify cron (3am ET). Dumps the Supabase database via the
# provided connection string, gzips it, uploads to Cloudflare R2 via
# rclone, and prunes local copies older than 7 days. Failures POST to
# ntfy so we hear about them within the hour.
#
# Required environment:
#   SUPABASE_DB_URL  — postgres connection string
#   NTFY_PORT        — ntfy port for alerts (default: 8080)
#   NTFY_TOPIC       — ntfy topic (default: vyndr-admin)
#   R2_REMOTE        — rclone remote name targeting R2 (default: r2)
#   R2_BUCKET        — R2 bucket path (default: vyndr-backups/daily)
#
# Prerequisites on the host:
#   pg_dump (PostgreSQL client tools)
#   gzip
#   rclone configured with R2 credentials (`rclone config`)
#   curl (for ntfy)

set -euo pipefail

DATE="$(date -u +%Y-%m-%dT%H%M%SZ)"
BACKUP_DIR="${BACKUP_DIR:-/tmp/vyndr-backups}"
BACKUP_FILE="${BACKUP_DIR}/vyndr-${DATE}.sql.gz"
LOG_FILE="${LOG_FILE:-/var/log/vyndr-backup.log}"
NTFY_PORT="${NTFY_PORT:-8080}"
NTFY_TOPIC="${NTFY_TOPIC:-vyndr-admin}"
R2_REMOTE="${R2_REMOTE:-r2}"
R2_BUCKET="${R2_BUCKET:-vyndr-backups/daily}"
RETENTION_DAYS="${BACKUP_RETENTION_DAYS:-7}"

log() {
  printf '[%s] %s\n' "$(date -u +%Y-%m-%dT%H:%M:%SZ)" "$*" | tee -a "$LOG_FILE"
}

alert() {
  # Fire-and-forget — never fail the script because the alerter is down.
  curl -s --max-time 5 -d "$1" "http://localhost:${NTFY_PORT}/${NTFY_TOPIC}" >/dev/null 2>&1 || true
}

if [[ -z "${SUPABASE_DB_URL:-}" ]]; then
  log "ERROR: SUPABASE_DB_URL is not set"
  alert "VYNDR backup failed: SUPABASE_DB_URL missing"
  exit 1
fi

mkdir -p "$BACKUP_DIR"
log "Starting backup → ${BACKUP_FILE}"

if ! pg_dump --no-owner --no-privileges "$SUPABASE_DB_URL" | gzip > "$BACKUP_FILE"; then
  log "ERROR: pg_dump failed"
  alert "VYNDR backup FAILED at ${DATE} — pg_dump"
  exit 1
fi

SIZE="$(du -h "$BACKUP_FILE" | cut -f1)"
log "Dump complete: ${SIZE}"

if ! rclone copy "$BACKUP_FILE" "${R2_REMOTE}:${R2_BUCKET}/"; then
  log "ERROR: rclone upload failed"
  alert "VYNDR backup upload FAILED at ${DATE}"
  exit 1
fi

log "Upload to ${R2_REMOTE}:${R2_BUCKET} complete"

# Prune old local copies. R2 retention is configured on the bucket; this
# script doesn't try to manage remote retention to avoid accidental deletes.
find "$BACKUP_DIR" -name 'vyndr-*.sql.gz' -mtime "+${RETENTION_DAYS}" -delete

log "Backup ${DATE} complete (${SIZE})"