#!/bin/bash
set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
cd "$SCRIPT_DIR"
[ -f "${SCRIPT_DIR}/env-surrealdb" ]    && source "${SCRIPT_DIR}/env-surrealdb"
[ -f "${SCRIPT_DIR}/_credentials.env" ] && source "${SCRIPT_DIR}/_credentials.env"

SURREALDB_NAMESPACE="${SURREALDB_NAMESPACE:-data}"
SURREALDB_IMAGE="${SURREALDB_IMAGE:-surrealdb/surrealdb:v3.0.5}"
SURREALDB_PORT="${SURREALDB_PORT:-8000}"
SURREALDB_DATA_DIR="${SURREALDB_DATA_DIR:-/data}"
SURREALDB_STORAGE_CLASS="${SURREALDB_STORAGE_CLASS:-longhorn-retain}"
SURREALDB_STORAGE_SIZE="${SURREALDB_STORAGE_SIZE:-2Gi}"
KUBECONFIG="${KUBECONFIG:-/etc/kubernetes/admin.conf}"

export KUBECONFIG

CMD_TSK="${CMD_TSK:-${1:-install}}"

_kubectl() {
  if command -v kubectl >/dev/null 2>&1; then
    command kubectl "$@"
  elif command -v k0s >/dev/null 2>&1; then
    k0s kubectl "$@"
  else
    echo "ERROR: no kubectl or k0s binary found" >&2; exit 127
  fi
}

_require_env() {
  local var="$1"
  if [ -z "${!var:-}" ]; then
    echo "ERROR: required variable $var is not set" >&2
    exit 1
  fi
}

_namespace_exists() {
  _kubectl get namespace "$SURREALDB_NAMESPACE" >/dev/null 2>&1
}

_pod_name() {
  _kubectl get pod \
    --namespace "$SURREALDB_NAMESPACE" \
    --selector "app.kubernetes.io/name=surrealdb" \
    -o jsonpath='{.items[0].metadata.name}' 2>/dev/null
}

_wait_for_pod() {
  local timeout="${1:-180}"
  _kubectl wait pod \
    --namespace "$SURREALDB_NAMESPACE" \
    --selector "app.kubernetes.io/name=surrealdb" \
    --for=condition=Ready \
    --timeout="${timeout}s"
}

_do_install() {
  _require_env SURREAL_USER
  _require_env SURREAL_PASS

  if ! _namespace_exists; then
    _kubectl create namespace "$SURREALDB_NAMESPACE"
  fi

  _kubectl create secret generic surrealdb-credentials \
    --namespace "$SURREALDB_NAMESPACE" \
    --from-literal=SURREAL_USER="$SURREAL_USER" \
    --from-literal=SURREAL_PASS="$SURREAL_PASS" \
    --dry-run=client -o yaml | _kubectl apply -f -

  for manifest in storageclass.yaml namespace.yaml pvc.yaml statefulset.yaml service.yaml; do
    local path="$SCRIPT_DIR/manifests/${manifest}"
    [ -f "$path" ] && _kubectl apply -f "$path"
  done

  echo "Waiting for SurrealDB pod to be ready..."
  _wait_for_pod 180

  local post_install="$SCRIPT_DIR/manifests/post-install.sh"
  if [ -f "$post_install" ]; then
    bash "$post_install"
  fi

  echo "SurrealDB installed in namespace $SURREALDB_NAMESPACE"
}

_do_update() {
  _kubectl rollout restart statefulset/surrealdb --namespace "$SURREALDB_NAMESPACE"
  echo "Waiting for SurrealDB to restart..."
  _wait_for_pod 120
  echo "SurrealDB updated"
}

_do_delete() {
  if _namespace_exists; then
    _kubectl delete namespace "$SURREALDB_NAMESPACE" --timeout=60s
    echo "Namespace $SURREALDB_NAMESPACE deleted"
  else
    echo "Namespace $SURREALDB_NAMESPACE does not exist, nothing to delete"
  fi
}

_do_backup() {
  _require_env BACKUP_DIR
  _require_env SURREAL_USER
  _require_env SURREAL_PASS
  local pod timestamp backup_file
  pod=$(_pod_name)
  timestamp=$(date +%Y%m%d_%H%M%S)
  backup_file="${BACKUP_DIR}/surrealdb_${timestamp}.surql.gz"
  mkdir -p "$BACKUP_DIR"
  _kubectl exec --namespace "$SURREALDB_NAMESPACE" "$pod" -- \
    surreal export \
      --endpoint "http://localhost:${SURREALDB_PORT}" \
      --username "$SURREAL_USER" \
      --password "$SURREAL_PASS" \
      - | gzip > "$backup_file"
  echo "Backup written to $backup_file"
}

_do_restore() {
  _require_env BACKUP_FILE
  _require_env SURREAL_USER
  _require_env SURREAL_PASS
  local pod
  pod=$(_pod_name)
  if [[ "$BACKUP_FILE" == *.gz ]]; then
    gunzip -c "$BACKUP_FILE" | _kubectl exec --stdin --namespace "$SURREALDB_NAMESPACE" "$pod" -- \
      surreal import \
        --endpoint "http://localhost:${SURREALDB_PORT}" \
        --username "$SURREAL_USER" \
        --password "$SURREAL_PASS" \
        -
  else
    _kubectl exec --stdin --namespace "$SURREALDB_NAMESPACE" "$pod" -- \
      surreal import \
        --endpoint "http://localhost:${SURREALDB_PORT}" \
        --username "$SURREAL_USER" \
        --password "$SURREAL_PASS" \
        - < "$BACKUP_FILE"
  fi
  echo "Restore completed from $BACKUP_FILE"
}

_do_health() {
  local pod
  pod=$(_pod_name 2>/dev/null || true)
  if [ -z "$pod" ]; then
    echo "UNHEALTHY: no surrealdb pod found in namespace $SURREALDB_NAMESPACE" >&2
    exit 1
  fi
  local status_code
  status_code=$(_kubectl exec --namespace "$SURREALDB_NAMESPACE" "$pod" -- \
    sh -c "wget -qO /dev/null -S http://localhost:${SURREALDB_PORT}/health 2>&1 | grep 'HTTP/' | awk '{print \$2}'" \
    2>/dev/null || echo "0")
  if [ "$status_code" = "200" ]; then
    echo "HEALTHY: surrealdb /health returned 200"
  else
    echo "UNHEALTHY: surrealdb /health returned $status_code" >&2
    exit 1
  fi
}

case "$CMD_TSK" in
  install) _do_install ;;
  update)  _do_update  ;;
  delete)  _do_delete  ;;
  backup)  _do_backup  ;;
  restore) _do_restore ;;
  health)  _do_health  ;;
  *)
    echo "ERROR: unknown CMD_TSK='$CMD_TSK'. Valid: install|update|delete|backup|restore|health" >&2
    exit 1
    ;;
esac