# Migrate PostgreSQL from bare metal (n97-1) to CloudNative PG (k3s)
#
# Prerequisites:
# - CNPG operator installed in k3s
# - postgres-scobleclaw cluster created (apps/postgres/cluster.yaml)
# - Both clusters accessible from n97-1
#
set -euo pipefail

SOURCE_HOST="127.0.0.1"
SOURCE_PORT="5432"
CNPG_HOST="postgres-scobleclaw-rw.database.svc.cluster.local"
CNPG_PORT="5432"

echo "==> Starting PostgreSQL migration"
echo "    Source: $SOURCE_HOST:$SOURCE_PORT (bare metal)"
echo "    Target: $CNPG_HOST:$CNPG_PORT (k3s/CNPG)"

# 1. Dump all databases
echo "==> Dumping databases from bare metal..."
sudo -u postgres pg_dumpall --clean --if-exists > /tmp/pg-migration-dump.sql

# 2. Wait for CNPG cluster to be ready
echo "==> Waiting for CNPG cluster to be ready..."
kubectl -n database wait --for=condition=Ready cluster/postgres-scobleclaw --timeout=300s

# 3. Get CNPG superuser password
CNPG_PASSWORD=$(kubectl -n database get secret postgres-scobleclaw-superuser -o jsonpath='{.data.password}' | base64 -d)

# 4. Restore dump into CNPG
echo "==> Restoring dump into CNPG..."
PGPASSWORD="$CNPG_PASSWORD" psql -h "$CNPG_HOST" -p "$CNPG_PORT" -U postgres < /tmp/pg-migration-dump.sql

# 5. Verify
echo "==> Verifying migration..."
DB_COUNT=$(PGPASSWORD="$CNPG_PASSWORD" psql -h "$CNPG_HOST" -p "$CNPG_PORT" -U postgres -t -c "SELECT count(*) FROM pg_database WHERE datname IN ('forgejo','umami');" | tr -d ' ')
echo "    Databases found: $DB_COUNT (expected: 2)"

if [ "$DB_COUNT" = "2" ]; then
  echo "==> Migration successful! You can now disable bare-metal PostgreSQL:"
  echo "    Set services.postgresql.enable = false; in nodes/n97-1.nix"
  echo "    And rebuild: nixos-rebuild switch --flake .#n97-1"
else
  echo "==> WARNING: Not all databases migrated. Check manually."
  exit 1
fi

# Cleanup
rm -f /tmp/pg-migration-dump.sql