#!/bin/bash
set -euo pipefail

# Load environment variables from .env.docker if it exists
if [ -f "/opt/memento/.env.docker" ]; then
  set -a
  source "/opt/memento/.env.docker"
  set +a
fi

BACKUP_DIR="/opt/memento/backups"
WAL_DIR="$BACKUP_DIR/wal"
PG_CONTAINER="memento-postgres"
PG_USER="${POSTGRES_USER:-memento}"
PG_DB="${POSTGRES_DB:-memento}"
PG_PASSWORD="${POSTGRES_PASSWORD:-}"
LOG_FILE="$BACKUP_DIR/backup.log"

mkdir -p "$WAL_DIR"

log() {
  echo "[$(date '+%Y-%m-%d %H:%M:%S')] $1" | tee -a "$LOG_FILE"
}

log "=== Setting up WAL archiving ==="

docker exec "$PG_CONTAINER" bash -c "mkdir -p /var/lib/postgresql/backups/wal"

log "Configuring PostgreSQL WAL parameters..."
docker exec "$PG_CONTAINER" psql -U "$PG_USER" -d "$PG_DB" -c "ALTER SYSTEM SET wal_level = replica;"
docker exec "$PG_CONTAINER" psql -U "$PG_USER" -d "$PG_DB" -c "ALTER SYSTEM SET archive_mode = on;"
docker exec "$PG_CONTAINER" psql -U "$PG_USER" -d "$PG_DB" -c "ALTER SYSTEM SET archive_command = 'cp %p /var/lib/postgresql/backups/wal/%f';"
docker exec "$PG_CONTAINER" psql -U "$PG_USER" -d "$PG_DB" -c "ALTER SYSTEM SET max_wal_senders = 3;"
docker exec "$PG_CONTAINER" psql -U "$PG_USER" -d "$PG_DB" -c "ALTER SYSTEM SET wal_keep_size = '1GB';"

log "Restarting PostgreSQL container to apply WAL parameters (required for wal_level)..."
docker restart "$PG_CONTAINER"

# Wait for PostgreSQL to be ready
log "Waiting for PostgreSQL to be ready..."
until docker exec "$PG_CONTAINER" pg_isready -U "$PG_USER" -d "$PG_DB" >/dev/null 2>&1; do
  sleep 1
done

log "PostgreSQL is ready. Reloading config..."
docker exec "$PG_CONTAINER" psql -U "$PG_USER" -d "$PG_DB" -c "SELECT pg_reload_conf();"

log "WAL archiving enabled. Archives stored in /var/lib/postgresql/backups/wal/"

WAL_COUNT=$(docker exec "$PG_CONTAINER" ls /var/lib/postgresql/backups/wal/ 2>/dev/null | wc -l)
log "Existing WAL segments: $WAL_COUNT"