#!/bin/bash
# Tier-1 dispatch for loki component operations.
set -euo pipefail

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

[ -f "${SCRIPT_DIR}/env-loki" ] && source "${SCRIPT_DIR}/env-loki"

LOKI_NAME="${LOKI_NAME:-loki}"
LOKI_NAMESPACE="${LOKI_NAMESPACE:-observability}"
LOKI_PORT="${LOKI_PORT:-3100}"
LOKI_STORAGE_CLASS="${LOKI_STORAGE_CLASS:-longhorn-single}"
LOKI_STORAGE_SIZE="${LOKI_STORAGE_SIZE:-5Gi}"
LOKI_STORAGE_BACKEND="${LOKI_STORAGE_BACKEND:-filesystem}"

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

source "${SCRIPT_DIR}/loki-lib.sh"

_resolve_kubeconfig() {
  if [ -n "${KUBECONFIG:-}" ] && [ -f "$KUBECONFIG" ]; then
    return
  fi
  for candidate in /var/lib/k0s/pki/admin.conf /etc/kubernetes/admin.conf /root/.kube/config; do
    if [ -f "$candidate" ]; then
      export KUBECONFIG="$candidate"
      return
    fi
  done
  echo "ERROR: kubeconfig not found — set KUBECONFIG explicitly" >&2; exit 1
}

_do_install() {
  [ -f "${SCRIPT_DIR}/_credentials.env" ] && source "${SCRIPT_DIR}/_credentials.env"

  if [ "${LOKI_STORAGE_BACKEND}" = "s3" ]; then
    _require_env LOKI_S3_ACCESS_KEY
    _require_env LOKI_S3_SECRET_KEY

    _kubectl create secret generic loki-s3-credentials \
      --namespace "$LOKI_NAMESPACE" \
      --from-literal=LOKI_S3_ACCESS_KEY="$LOKI_S3_ACCESS_KEY" \
      --from-literal=LOKI_S3_SECRET_KEY="$LOKI_S3_SECRET_KEY" \
      --dry-run=client -o yaml | _kubectl apply -f -
  else
    echo "  [skip] storage_backend=${LOKI_STORAGE_BACKEND} — no S3 credentials secret needed"
  fi

  for manifest in namespace.yaml configmap.yaml pvc.yaml deployment.yaml service.yaml; do
    local path="$SCRIPT_DIR/manifests/${manifest}"
    [ -f "$path" ] && _kubectl apply -f "$path"
  done
  echo "Waiting for ${LOKI_NAME} pod to be ready..."
  _wait_for_pod 180
  echo "${LOKI_NAME} installed in namespace ${LOKI_NAMESPACE}"
}

_do_update() {
  for manifest in configmap.yaml deployment.yaml; do
    local path="$SCRIPT_DIR/manifests/${manifest}"
    [ -f "$path" ] && _kubectl apply -f "$path"
  done
  _kubectl rollout restart "deployment/${LOKI_NAME}" --namespace "$LOKI_NAMESPACE"
  _wait_for_pod 180
  echo "${LOKI_NAME} updated"
}

_do_delete() {
  for manifest in deployment.yaml service.yaml; do
    local path="$SCRIPT_DIR/manifests/${manifest}"
    [ -f "$path" ] && _kubectl delete -f "$path" --ignore-not-found
  done
  echo "${LOKI_NAME} deleted from namespace ${LOKI_NAMESPACE}"
}

_do_restart() {
  _kubectl rollout restart "deployment/${LOKI_NAME}" --namespace "$LOKI_NAMESPACE"
  _wait_for_pod 180
  echo "${LOKI_NAME} restarted"
}

_do_health() {
  local pod
  pod=$(_pod_name 2>/dev/null || true)
  if [ -z "$pod" ]; then
    echo "UNHEALTHY: no loki pod found in namespace ${LOKI_NAMESPACE}" >&2; exit 1
  fi
  if _kubectl exec --namespace "$LOKI_NAMESPACE" "$pod" -- \
      wget -qO- "http://localhost:${LOKI_PORT}/ready" >/dev/null 2>&1; then
    echo "HEALTHY: ${LOKI_NAME} responding on /ready"
  else
    echo "UNHEALTHY: ${LOKI_NAME} did not respond on /ready" >&2; exit 1
  fi
}

_resolve_kubeconfig

case "$CMD_TSK" in
  install)  [ -f "$SCRIPT_DIR/run-init.sh" ]    && exec bash "$SCRIPT_DIR/run-init.sh";    _do_install  ;;
  update)   [ -f "$SCRIPT_DIR/run-update.sh" ]  && exec bash "$SCRIPT_DIR/run-update.sh";  _do_update   ;;
  delete)   [ -f "$SCRIPT_DIR/run-delete.sh" ]  && exec bash "$SCRIPT_DIR/run-delete.sh";  _do_delete   ;;
  restart)  [ -f "$SCRIPT_DIR/run-restart.sh" ] && exec bash "$SCRIPT_DIR/run-restart.sh"; _do_restart  ;;
  health)   _do_health ;;
  *)        echo "ERROR: unknown CMD_TSK='${CMD_TSK}'. Valid: install|update|delete|restart|health" >&2; exit 1 ;;
esac