#!/usr/bin/env bash
#
# glitchtip-backup.sh — daily postgres dump for the GlitchTip database.
#
# Usage:
#   bash scripts/glitchtip-backup.sh
#
# Cron example (production host):
#   # /etc/cron.d/glitchtip-backup
#   0 3 * * * crewli /opt/crewli/scripts/glitchtip-backup.sh >> /var/log/glitchtip-backup.log 2>&1
#
# Configurable via env vars (defaults shown):
#   GLITCHTIP_BACKUP_DIR=./backups/glitchtip
#   GLITCHTIP_BACKUP_RETENTION_DAYS=30
#   GLITCHTIP_DB_CONTAINER=glitchtip-postgres
#   GLITCHTIP_DB_USER=postgres
#   GLITCHTIP_DB_NAME=glitchtip
#
# Restore (full):
#   gunzip < <dump>.gz \
#     | docker exec -i glitchtip-postgres pg_restore -U postgres -d glitchtip --clean --if-exists
#
# Per RFC-WS-7-OBSERVABILITY §5 (daily postgres-backup) and acceptance
# criterion 11. See dev-docs/GLITCHTIP.md for the full restore drill.

set -euo pipefail

BACKUP_DIR="${GLITCHTIP_BACKUP_DIR:-./backups/glitchtip}"
RETENTION_DAYS="${GLITCHTIP_BACKUP_RETENTION_DAYS:-30}"
DB_CONTAINER="${GLITCHTIP_DB_CONTAINER:-glitchtip-postgres}"
DB_USER="${GLITCHTIP_DB_USER:-postgres}"
DB_NAME="${GLITCHTIP_DB_NAME:-glitchtip}"

mkdir -p "$BACKUP_DIR"

timestamp="$(date +%Y%m%d-%H%M%S)"
output="$BACKUP_DIR/glitchtip-${timestamp}.dump.gz"

echo "[$(date -Iseconds)] Dumping ${DB_NAME} from ${DB_CONTAINER} to ${output}"

# Stream pg_dump (custom format) directly through gzip — no intermediate file.
# `set -o pipefail` already in effect so a pg_dump failure aborts before retention.
docker exec -i "$DB_CONTAINER" \
    pg_dump -U "$DB_USER" -d "$DB_NAME" --format=custom --no-owner --no-privileges \
  | gzip -c > "$output"

chmod 0600 "$output"

size="$(wc -c < "$output" | tr -d ' ')"
echo "[$(date -Iseconds)] Wrote ${output} (${size} bytes)"

echo "[$(date -Iseconds)] Pruning dumps older than ${RETENTION_DAYS} days"
find "$BACKUP_DIR" -type f -name 'glitchtip-*.dump.gz' -mtime "+${RETENTION_DAYS}" -print -delete

echo "[$(date -Iseconds)] Done."