#!/usr/bin/env bash
set -euo pipefail

SOURCE_HOST="${SOURCE_HOST:-mevnode_bot}"
SOURCE_NAMESPACE="${SOURCE_NAMESPACE:-trade-staging}"
TARGET_HOST="${TARGET_HOST:-mevnode}"
PG_VERSION="${PG_VERSION:-16}"

ssh_source() {
  ssh -o StrictHostKeyChecking=no "$SOURCE_HOST" "$@"
}

ssh_target() {
  ssh -o StrictHostKeyChecking=no "$TARGET_HOST" "$@"
}

SRC_SECRET_JSON="$(ssh_source "sudo k3s kubectl -n ${SOURCE_NAMESPACE} get secret trade-postgres -o json")"
POSTGRES_USER="$(printf '%s' "$SRC_SECRET_JSON" | jq -r '.data.POSTGRES_USER' | base64 -d)"
POSTGRES_PASSWORD="$(printf '%s' "$SRC_SECRET_JSON" | jq -r '.data.POSTGRES_PASSWORD' | base64 -d)"
POSTGRES_DB="$(printf '%s' "$SRC_SECRET_JSON" | jq -r '.data.POSTGRES_DB' | base64 -d)"

ssh_target "if ! dpkg -l | grep -q '^ii  timescaledb-2-postgresql-${PG_VERSION} '; then curl -fsSL https://packagecloud.io/install/repositories/timescale/timescaledb/script.deb.sh | sudo bash && sudo apt-get update && sudo DEBIAN_FRONTEND=noninteractive apt-get install -y timescaledb-2-postgresql-${PG_VERSION}; fi"

CURRENT_PRELOAD="$(ssh_target "sudo -u postgres psql -Atqc \"show shared_preload_libraries\"")"
case ",${CURRENT_PRELOAD}," in
  *,timescaledb,*)
    NEW_PRELOAD="${CURRENT_PRELOAD}"
    ;;
  ,,)
    NEW_PRELOAD="timescaledb"
    ;;
  *)
    NEW_PRELOAD="${CURRENT_PRELOAD},timescaledb"
    ;;
esac

ssh_target "sudo -u postgres psql -Atqc \"ALTER SYSTEM SET shared_preload_libraries = '${NEW_PRELOAD}';\" && sudo systemctl restart postgresql"

APP_USER_SQL=$(printf "%s" "$POSTGRES_USER" | sed "s/'/''/g")
APP_PASSWORD_SQL=$(printf "%s" "$POSTGRES_PASSWORD" | sed "s/'/''/g")
APP_DB_SQL=$(printf "%s" "$POSTGRES_DB" | sed "s/'/''/g")

ssh_target "sudo -u postgres psql -v ON_ERROR_STOP=1 <<'SQL'
DO \$\$
BEGIN
  IF NOT EXISTS (SELECT 1 FROM pg_roles WHERE rolname = '${APP_USER_SQL}') THEN
    EXECUTE format('CREATE ROLE %I LOGIN PASSWORD %L', '${APP_USER_SQL}', '${APP_PASSWORD_SQL}');
  ELSE
    EXECUTE format('ALTER ROLE %I WITH LOGIN PASSWORD %L', '${APP_USER_SQL}', '${APP_PASSWORD_SQL}');
  END IF;
END
\$\$;
SELECT format('CREATE DATABASE %I OWNER %I', '${APP_DB_SQL}', '${APP_USER_SQL}')
WHERE NOT EXISTS (SELECT 1 FROM pg_database WHERE datname = '${APP_DB_SQL}')
\\gexec
ALTER DATABASE \"${POSTGRES_DB}\" OWNER TO \"${POSTGRES_USER}\";
SQL"

echo "Prepared host Postgres on ${TARGET_HOST} for ${POSTGRES_USER}/${POSTGRES_DB} with TimescaleDB enabled"