#!/usr/bin/env bash

set -euo pipefail

# init_redis.sh
# Purpose:
# - Deploy Redis as a shared common service via Bitnami Helm chart
# - Provides a pub/sub-capable Redis instance for knoe CLI, desktop, and GitLab
# - Runs in knoe-system (or SERVICE_NAMESPACE) so all services can reach it
# - Service endpoint: redis-master.<namespace>.svc.cluster.local:6379

SCRIPT_DIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)

# Shared option parsing for common core scripts
# shellcheck disable=SC1090
source "$SCRIPT_DIR/common_core_lib.sh"

# Inject default config if not provided
_has_config=0
for _arg in "$@"; do
  [[ "$_arg" == "-c" || "$_arg" == "--config" || "$_arg" == -c=* || "$_arg" == --config=* ]] && _has_config=1
done
if [[ $_has_config -eq 0 ]]; then
  _default_cfg="$(common_core_default_config_path "$SCRIPT_DIR" || true)"
  if [[ -n "$_default_cfg" ]]; then
    set -- "-c" "$_default_cfg" "$@"
  fi
fi
unset _has_config _arg _default_cfg

common_core_preparse_config "$@"

# shellcheck disable=SC1090
source "$SCRIPT_DIR/prole_cfg.sh"

set -- "${COMMON_CORE_ARGS[@]}"
common_core_parse_args "$@"

if [[ -z "${PROLE_MODE:-}" ]]; then
  export PROLE_MODE="k3s"
fi

if [[ "${COMMON_CORE_HELP:-0}" == 1 ]]; then
  common_core_usage "$0"
  exit 0
fi

if [[ -n "${COMMON_CORE_PARSE_ERROR:-}" ]]; then
  echo "ERROR: ${COMMON_CORE_PARSE_ERROR}" >&2
  common_core_usage "$0"
  exit 2
fi

ACTION="$COMMON_CORE_ACTION"
NAMESPACE="$(common_core_resolve_namespace "${SERVICE_NAMESPACE:-knoe-system}")"
common_core_apply_namespace "$NAMESPACE"

REDIS_RELEASE="${REDIS_RELEASE:-redis}"
REDIS_REPO_NAME="bitnami"
REDIS_REPO_URL="https://charts.bitnami.com/bitnami"
REDIS_CHART="bitnami/redis"
REDIS_CHART_VERSION="${REDIS_CHART_VERSION:-}"
REDIS_PORT="${REDIS_PORT:-6379}"
REDIS_PVC_SIZE="${REDIS_PVC_SIZE:-1Gi}"
# No dynamic provisioner is available in the service cluster; persistence disabled by default
# (Redis is used as a pub/sub broker — durable storage is not required)
REDIS_STORAGE_CLASS="${REDIS_STORAGE_CLASS:-${STORAGE_CLASS:-}}"
REDIS_PERSISTENCE_ENABLED="${REDIS_PERSISTENCE_ENABLED:-false}"
# Image registry override — set to "registry.bitnami.com" if docker.io is unreachable
# Bitnami OCI registry works as an alternative when Docker Hub times out on constrained networks.
REDIS_IMAGE_REGISTRY="${REDIS_IMAGE_REGISTRY:-}"
# Helm timeout — increase for slow image pulls on constrained network links (e.g. Pi cluster)
REDIS_HELM_TIMEOUT="${REDIS_HELM_TIMEOUT:-8m}"

log()  { echo "[INFO]  $*"; }
warn() { echo "[WARN]  $*" >&2; }
die()  { echo "[ERROR] $*" >&2; exit 1; }

command -v helm    >/dev/null 2>&1 || die "helm not found"
command -v kubectl >/dev/null 2>&1 || die "kubectl not found"

# ---------------------------------------------------------------------------
# Helpers
# ---------------------------------------------------------------------------
redis_service_host() {
  printf '%s-master.%s.svc.cluster.local' "$REDIS_RELEASE" "$NAMESPACE"
}

redis_is_running() {
  kubectl -n "$NAMESPACE" get deployment "${REDIS_RELEASE}-master" >/dev/null 2>&1 || \
  kubectl -n "$NAMESPACE" get statefulset "${REDIS_RELEASE}-master" >/dev/null 2>&1
}

# ---------------------------------------------------------------------------
# Deploy
# ---------------------------------------------------------------------------
deploy_redis() {
  # If Redis is already running and REDIS_FORCE_UPGRADE is not set, skip the
  # helm upgrade to avoid Docker Hub / OCI registry timeouts on constrained
  # networks (e.g. Pi cluster where registry-1.docker.io may be unreachable).
  # Set REDIS_FORCE_UPGRADE=1 to force a chart upgrade regardless.
  if [[ "${REDIS_FORCE_UPGRADE:-0}" != "1" ]] && redis_is_running; then
    log "Redis already running in '${NAMESPACE}'; skipping upgrade."
    log "Set REDIS_FORCE_UPGRADE=1 to force a helm upgrade."
    return 0
  fi

  log "Adding/updating Bitnami Helm repo..."
  helm repo add "$REDIS_REPO_NAME" "$REDIS_REPO_URL" 2>&1 || true
  helm repo update "$REDIS_REPO_NAME" 2>&1 || warn "helm repo update returned non-zero; continuing..."

  kubectl get namespace "$NAMESPACE" >/dev/null 2>&1 || kubectl create namespace "$NAMESPACE" >/dev/null

  local helm_args=(
    upgrade --install "$REDIS_RELEASE" "$REDIS_CHART"
    --namespace "$NAMESPACE"
    --create-namespace
    --timeout "$REDIS_HELM_TIMEOUT"
    --wait
    --set architecture=standalone
    --set auth.enabled=false
    --set master.persistence.enabled="${REDIS_PERSISTENCE_ENABLED}"
    --set master.persistence.size="$REDIS_PVC_SIZE"
    --set master.resources.requests.memory=128Mi
    --set master.resources.requests.cpu=50m
    --set master.resources.limits.memory=512Mi
    --set master.resources.limits.cpu=500m
  )

  if [[ -n "$REDIS_CHART_VERSION" ]]; then
    helm_args+=(--version "$REDIS_CHART_VERSION")
  fi

  if [[ -n "$REDIS_STORAGE_CLASS" ]]; then
    helm_args+=(--set master.persistence.storageClass="$REDIS_STORAGE_CLASS")
  fi

  if [[ -n "$REDIS_IMAGE_REGISTRY" ]]; then
    log "Using image registry override: ${REDIS_IMAGE_REGISTRY}"
    helm_args+=(--set global.imageRegistry="$REDIS_IMAGE_REGISTRY")
  fi

  log "Deploying Redis (release=${REDIS_RELEASE}, ns=${NAMESPACE})..."
  helm "${helm_args[@]}"

  log "Redis ready. Endpoint: $(redis_service_host):${REDIS_PORT}"
  log "Pub/sub: redis-cli -h $(redis_service_host) -p ${REDIS_PORT} subscribe <channel>"
}

# ---------------------------------------------------------------------------
# Action dispatch
# ---------------------------------------------------------------------------
case "$ACTION" in
  start|update|reload|initialize|restart)
    deploy_redis
    ;;
  stop)
    log "Removing Redis (${REDIS_RELEASE}) from namespace ${NAMESPACE}..."
    helm -n "$NAMESPACE" uninstall "$REDIS_RELEASE" 2>/dev/null || warn "Redis release not found."
    ;;
  status)
    log "Redis status in namespace ${NAMESPACE}:"
    kubectl -n "$NAMESPACE" get pods -l "app.kubernetes.io/name=redis" 2>/dev/null || \
      echo "  No Redis pods found."
    kubectl -n "$NAMESPACE" get svc -l "app.kubernetes.io/name=redis" 2>/dev/null || true
    ;;
  *)
    die "Unknown action: $ACTION"
    ;;
esac