#!/usr/bin/env bash

set -euo pipefail

# init_monitoring.sh
# Purpose:
# - Configure k3d environment for monitoring (Prometheus and Grafana)
# - Setup kube-prometheus-stack and CNPG prometheus rules

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

# Load environment and config via prole_cfg.sh
# shellcheck disable=SC1090
source "$SCRIPT_DIR/prole_cfg.sh"

if [[ "${1:-}" == "--mode" || "${1:-}" == "-m" ]]; then
  prole_set_mode "${2:-}"
  shift 2
elif [[ "${1:-}" == --mode=* || "${1:-}" == -m=* ]]; then
  prole_set_mode "${1#*=}"
  shift
fi

if [[ -z "${PROLE_SERVICE:-}" ]]; then
  echo "ERROR: PROLE_SERVICE is not defined. Provide PROLE_HOME/env.sh or ~/.prole/env.sh" >&2
  exit 1
fi

GRAFANA_RELEASE="grafana"
LEGACY_GRAFANA_RELEASE="grafana-prole"

log() {
  echo "==> $*"
}

err() {
  echo "ERROR: $*" >&2
}

ensure_tools() {
  for t in helm kubectl curl jq; do
    command -v "$t" >/dev/null || { err "Missing required tool: $t"; exit 1; }
  done
}

ensure_namespace() {
  local ns="$1"
  if ! kubectl get namespace "$ns" >/dev/null 2>&1; then
    log "Creating namespace '$ns' ..."
    kubectl create namespace "$ns" >/dev/null 2>&1 || true
  fi
}

helm_release_status() {
  local release="$1"
  local ns="$2"
  helm status "$release" -n "$ns" -o json 2>/dev/null | jq -r '.info.status' 2>/dev/null || true
}

wait_for_helm_release() {
  local release="$1"
  local ns="$2"
  local timeout="${HELM_WAIT_TIMEOUT:-300}"
  local interval="${HELM_WAIT_INTERVAL:-5}"
  local start
  start=$(date +%s)

  while true; do
    local status
    status=$(helm_release_status "$release" "$ns")
    if [[ -z "$status" || "$status" == "null" ]]; then
      return 0
    fi
    case "$status" in
      pending-*)
        if (( $(date +%s) - start > timeout )); then
          err "Timed out waiting for Helm release '$release' in '$ns' (status=$status)."
          return 1
        fi
        log "Helm release '$release' is $status; waiting..."
        sleep "$interval"
        ;;
      *)
        return 0
        ;;
    esac
  done
}

helm_upgrade_with_retry() {
  local release="$1"
  local ns="$2"
  local chart="$3"
  shift 3
  local attempts="${HELM_UPGRADE_RETRIES:-5}"
  local delay="${HELM_RETRY_DELAY:-5}"
  local attempt out rc

  for ((attempt=1; attempt<=attempts; attempt++)); do
    wait_for_helm_release "$release" "$ns" || true
    set +e
    out=$(helm upgrade --install "$release" "$chart" --namespace "$ns" "$@" 2>&1)
    rc=$?
    set -e
    if [[ $rc -eq 0 ]]; then
      printf '%s\n' "$out"
      return 0
    fi
    if echo "$out" | grep -q "another operation (install/upgrade/rollback) is in progress"; then
      log "Helm release '$release' is busy; retrying ($attempt/$attempts)..."
      wait_for_helm_release "$release" "$ns" || true
      sleep "$delay"
      continue
    fi
    echo "$out" >&2
    return "$rc"
  done

  err "Helm upgrade failed after $attempts attempts for release '$release' in '$ns'."
  return 1
}

openbao_url() {
  if [[ -n "${PROLE_OPENBAO_URL:-}" ]]; then
    echo "$PROLE_OPENBAO_URL"
    return 0
  fi
  if prole_is_in_cluster; then
    echo "http://openbao.${SERVICE_NAMESPACE:-${NAMESPACE:-default}}.svc.cluster.local:8200"
    return 0
  fi
  if curl -sS "http://127.0.0.1:8200/v1/sys/health" >/dev/null 2>&1; then
    echo "http://127.0.0.1:8200"
    return 0
  elif curl -sS "http://127.0.0.1:18200/v1/sys/health" >/dev/null 2>&1; then
    echo "http://127.0.0.1:18200"
    return 0
  else
    echo ""
    return 0
  fi
}

openbao_token() {
  if [[ -f "$PROLE_SERVICE/secrets/openbao-root-token" ]]; then
    cat "$PROLE_SERVICE/secrets/openbao-root-token"
  else
    echo "${OPENBAO_ROOT_TOKEN:-}"
  fi
}

fetch_openbao_secret() {
  local path="$1"
  local key="$2"
  local token url
  token=$(openbao_token)
  url=$(openbao_url)
  if [[ -z "$token" || -z "$url" ]]; then
    echo ""
    return 0
  fi
  curl -sS -H "X-Vault-Token: $token" "$url/v1/kv/data/$path" | jq -r ".data.data.\"$key\"" || echo ""
}

resolve_grafana_password() {
  if [[ -z "${GRAFANA_ADMIN_PASSWORD:-}" || "${GRAFANA_ADMIN_PASSWORD}" == '${OPENBAO:'* || "${GRAFANA_ADMIN_PASSWORD}" == '${PROLE_SECRET:'* ]]; then
    local fetched
    fetched=$(fetch_openbao_secret "prole/${NAMESPACE:-default}/monitoring" "grafana_admin_password")
    if [[ -n "$fetched" && "$fetched" != "null" ]]; then
      GRAFANA_ADMIN_PASSWORD="$fetched"
    fi
  fi

  if [[ -z "${GRAFANA_ADMIN_PASSWORD:-}" || "${GRAFANA_ADMIN_PASSWORD}" == '${OPENBAO:'* || "${GRAFANA_ADMIN_PASSWORD}" == '${PROLE_SECRET:'* ]]; then
    local db_pw="${DB_PASSWORD:-}"
    if [[ -z "$db_pw" || "$db_pw" == '${OPENBAO:'* || "$db_pw" == '${PROLE_SECRET:'* ]]; then
      local fetched_db
      fetched_db=$(fetch_openbao_secret "prole/${NAMESPACE:-default}/db" "password")
      if [[ -n "$fetched_db" && "$fetched_db" != "null" ]]; then
        db_pw="$fetched_db"
      fi
    fi
    if [[ -n "$db_pw" ]]; then
      GRAFANA_ADMIN_PASSWORD="$db_pw"
    fi
  fi
}

write_grafana_password_to_openbao() {
  local token url
  token=$(openbao_token)
  url=$(openbao_url)
  if [[ -z "$token" || -z "$url" || -z "${GRAFANA_ADMIN_PASSWORD:-}" ]]; then
    return 0
  fi
  curl -sS -H "X-Vault-Token: $token" -H 'Content-Type: application/json' \
    -X POST "$url/v1/kv/data/prole/${NAMESPACE:-default}/monitoring" \
    -d "{\"data\":{\"grafana_admin_password\":\"$GRAFANA_ADMIN_PASSWORD\"}}" >/dev/null || true
}

cleanup_grafana_rbac_conflicts() {
  local release="$GRAFANA_RELEASE"
  local ns="$NAMESPACE"
  local cr="${release}-clusterrole"
  local crb="${release}-clusterrolebinding"
  local rel_ns rel_name

  if kubectl get clusterrole "$cr" >/dev/null 2>&1; then
    rel_ns=$(kubectl get clusterrole "$cr" -o jsonpath='{.metadata.annotations.meta\.helm\.sh/release-namespace}' 2>/dev/null || true)
    rel_name=$(kubectl get clusterrole "$cr" -o jsonpath='{.metadata.annotations.meta\.helm\.sh/release-name}' 2>/dev/null || true)
    if [[ -n "$rel_ns" && "$rel_ns" != "$ns" ]]; then
      log "Detected existing ClusterRole '$cr' owned by release '${rel_name:-unknown}' in namespace '$rel_ns'."
      if [[ -n "$rel_name" ]] && helm status "$rel_name" -n "$rel_ns" >/dev/null 2>&1; then
        log "Uninstalling old Grafana release '$rel_name' from '$rel_ns' ..."
        helm uninstall "$rel_name" -n "$rel_ns" || true
      fi
      if kubectl get clusterrole "$cr" >/dev/null 2>&1; then
        log "Deleting orphaned ClusterRole '$cr' ..."
        kubectl delete clusterrole "$cr" || true
      fi
    fi
  fi

  if kubectl get clusterrolebinding "$crb" >/dev/null 2>&1; then
    rel_ns=$(kubectl get clusterrolebinding "$crb" -o jsonpath='{.metadata.annotations.meta\.helm\.sh/release-namespace}' 2>/dev/null || true)
    rel_name=$(kubectl get clusterrolebinding "$crb" -o jsonpath='{.metadata.annotations.meta\.helm\.sh/release-name}' 2>/dev/null || true)
    if [[ -n "$rel_ns" && "$rel_ns" != "$ns" ]]; then
      log "Detected existing ClusterRoleBinding '$crb' owned by release '${rel_name:-unknown}' in namespace '$rel_ns'."
      if [[ -n "$rel_name" ]] && helm status "$rel_name" -n "$rel_ns" >/dev/null 2>&1; then
        log "Uninstalling old Grafana release '$rel_name' from '$rel_ns' ..."
        helm uninstall "$rel_name" -n "$rel_ns" || true
      fi
      if kubectl get clusterrolebinding "$crb" >/dev/null 2>&1; then
        log "Deleting orphaned ClusterRoleBinding '$crb' ..."
        kubectl delete clusterrolebinding "$crb" || true
      fi
    fi
  fi
}

cleanup_legacy_grafana_release() {
  local ns="$NAMESPACE"
  if helm status "$LEGACY_GRAFANA_RELEASE" -n "$ns" >/dev/null 2>&1; then
    log "Uninstalling legacy Grafana release '$LEGACY_GRAFANA_RELEASE' from '$ns' ..."
    helm uninstall "$LEGACY_GRAFANA_RELEASE" -n "$ns" || true
  fi
}

install_monitoring() {
  ensure_tools
  local monitoring_ns="default"
  ensure_namespace "$monitoring_ns"
  ensure_namespace "$NAMESPACE"

  log "Installing kube-prometheus-stack in namespace '$monitoring_ns' ..."
  helm repo add prometheus-community https://prometheus-community.github.io/helm-charts || true
  helm repo update prometheus-community || true
  
  # Install Prometheus stack in default namespace, but disable Grafana there
  # Also set grafana.enabled=false explicitly to avoid conflicts if it was previously enabled.
  # Use --force-conflicts with Server-Side Apply (SSA) to handle webhook conflicts.
  # SSA is more robust for managing shared resources like webhooks.
  helm_upgrade_with_retry \
    "prometheus-community" \
    "$monitoring_ns" \
    "prometheus-community/kube-prometheus-stack" \
    --set grafana.enabled=false \
    --force-conflicts \
    --server-side=true \
    -f https://raw.githubusercontent.com/cloudnative-pg/cloudnative-pg/main/docs/src/samples/monitoring/kube-stack-config.yaml

  log "Installing Grafana in namespace '$NAMESPACE' ..."
  # We use the same chart but only for Grafana, or we could use the standalone grafana chart.
  # Using the same chart ensures we can use the same config if needed, but we must avoid ClusterRole conflicts.
  # Actually, standalone grafana chart is cleaner if we only want Grafana.
  helm repo add grafana https://grafana.github.io/helm-charts || true
  helm repo update grafana || true

  local prometheus_svc="http://prometheus-community-kube-prometheus.$monitoring_ns.svc.cluster.local:9090"

  cleanup_legacy_grafana_release

  # Note: kube-prometheus-stack may have already been installed with Grafana enabled in 'default'.
  # If we want to move Grafana to $NAMESPACE, we install it there.
  # We use the grafana/grafana chart for the per-namespace instance.
  if kubectl get deployment "$GRAFANA_RELEASE" -n "$NAMESPACE" >/dev/null 2>&1; then
    log "Grafana deployment '$GRAFANA_RELEASE' already exists in '$NAMESPACE'; skipping Helm install."
  else
    cleanup_grafana_rbac_conflicts

    resolve_grafana_password
    if [[ -z "${GRAFANA_ADMIN_PASSWORD:-}" ]]; then
      err "GRAFANA_ADMIN_PASSWORD is empty. Set it or ensure DB_PASSWORD is available."
      exit 1
    fi
    write_grafana_password_to_openbao

    # Use --force-conflicts with Server-Side Apply (SSA) to handle potential conflicts during upgrade.
    local grafana_persistence_enabled="true"
    local grafana_storage_class="prole-iscsi"
    if [[ "${PROLE_MODE:-}" == "k3d" ]]; then
      grafana_persistence_enabled="false"
      grafana_storage_class=""
    fi

    helm_upgrade_with_retry \
      "$GRAFANA_RELEASE" \
      "$NAMESPACE" \
      "grafana/grafana" \
      --force-conflicts \
      --server-side=true \
      --set "rbac.namespaced=true" \
      --set "persistence.enabled=${grafana_persistence_enabled}" \
      --set "persistence.size=5Gi" \
      $(if [[ -n "$grafana_storage_class" ]]; then printf '%s ' --set "persistence.storageClassName=${grafana_storage_class}"; fi) \
      --set "service.port=3000" \
      --set "datasources.datasources\.yaml.apiVersion=1" \
      --set "datasources.datasources\.yaml.datasources[0].name=Prometheus" \
      --set "datasources.datasources\.yaml.datasources[0].type=prometheus" \
      --set "datasources.datasources\.yaml.datasources[0].url=$prometheus_svc" \
      --set "datasources.datasources\.yaml.datasources[0].access=proxy" \
      --set "datasources.datasources\.yaml.datasources[0].isDefault=true" \
      --set "adminPassword=$GRAFANA_ADMIN_PASSWORD"
  fi

  log "Applying CNPG prometheus rules in namespace '$NAMESPACE'..."
  kubectl apply --namespace "$NAMESPACE" -f https://raw.githubusercontent.com/cloudnative-pg/cloudnative-pg/main/docs/src/samples/monitoring/prometheusrule.yaml

  log "Retrieving Grafana admin password from namespace '$NAMESPACE'..."
  local grafana_secret="$GRAFANA_RELEASE"
  if ! kubectl --namespace "$NAMESPACE" get secret "$grafana_secret" >/dev/null 2>&1; then
    grafana_secret="grafana-admin"
  fi
  GRAFANA_PASSWORD=$(kubectl --namespace "$NAMESPACE" get secret "$grafana_secret" -o jsonpath="{.data.admin-password}" 2>/dev/null | base64 -d || true)
  
  if [[ -n "$GRAFANA_PASSWORD" ]]; then
    log "Grafana installation password: $GRAFANA_PASSWORD"
    # We will save this to prole.cfg via the installer, but also output it here for logs
    echo "GRAFANA_ADMIN_PASSWORD=$GRAFANA_PASSWORD"
  else
    err "Failed to retrieve Grafana admin password."
  fi

  # Register port forwards
  prole_register_port_forward "prometheus" "default" "svc/prometheus-community-kube-prometheus" "9090" "9090" "127.0.0.1" "TCP" "Prometheus"
  prole_register_port_forward "grafana" "${NAMESPACE:-default}" "svc/grafana" "3000" "3000" "0.0.0.0" "TCP" "Grafana"
}

case "${1:-}" in
  initialize)
    install_monitoring
    ;;
  *)
    echo "Usage: $0 initialize"
    exit 1
    ;;
esac