#!/usr/bin/env bash
# init_cnpg_gke.sh
# Provision CloudNativePG on GKE with GCS backup via Workload Identity.
#
# Usage:
#   ./etc/init_cnpg_gke.sh [--project PROJECT_ID] [--region REGION] [--cluster CLUSTER_NAME]
#
# Env vars (override flags):
#   GCP_PROJECT_ID, GCP_REGION, GKE_CLUSTER, GCS_BACKUP_BUCKET,
#   CNPG_NAMESPACE, ARTIFACT_REGISTRY, CLOUDSDK_AUTH_ACCESS_TOKEN

set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
REPO_ROOT="$(cd "$SCRIPT_DIR/.." && pwd)"
GKE_MANIFEST_DIR="$REPO_ROOT/deploy/gcp/gke"

# ── Defaults ────────────────────────────────────────────────────────────────
GCP_PROJECT_ID="${GCP_PROJECT_ID:-}"
GCP_REGION="${GCP_REGION:-us-central1}"
GKE_CLUSTER="${GKE_CLUSTER:-knoe-dev-0}"
GCS_BACKUP_BUCKET="${GCS_BACKUP_BUCKET:-knoe-0-backups}"
GCS_WAL_BUCKET="${GCS_WAL_BUCKET:-knoe-0-wal}"
CNPG_NAMESPACE="${CNPG_NAMESPACE:-ecosystem-0}"
CNPG_BACKUP_SA="${CNPG_BACKUP_SA:-cnpg-backup}"
ARTIFACT_REGISTRY="${ARTIFACT_REGISTRY:-}"

# ── Argument parsing ─────────────────────────────────────────────────────────
while [[ $# -gt 0 ]]; do
  case "$1" in
    --project)   GCP_PROJECT_ID="$2"; shift 2 ;;
    --region)    GCP_REGION="$2";     shift 2 ;;
    --cluster)   GKE_CLUSTER="$2";   shift 2 ;;
    --bucket)    GCS_BACKUP_BUCKET="$2"; shift 2 ;;
    --namespace) CNPG_NAMESPACE="$2"; shift 2 ;;
    --registry)  ARTIFACT_REGISTRY="$2"; shift 2 ;;
    *) echo "Unknown argument: $1" >&2; exit 1 ;;
  esac
done

[[ -z "$GCP_PROJECT_ID" ]] && {
  # Try to read from gcp.cfg
  GCP_CFG="$REPO_ROOT/conf/prod/gcp.cfg"
  if [[ -f "$GCP_CFG" ]]; then
    GCP_PROJECT_ID=$(grep '^project_id' "$GCP_CFG" | sed 's/.*=\s*"\?\([^"]*\)"\?.*/\1/' | tr -d '[:space:]')
  fi
}
[[ -z "$GCP_PROJECT_ID" ]] && { echo "ERROR: GCP_PROJECT_ID not set and conf/prod/gcp.cfg not found." >&2; exit 1; }

GCP_SA_EMAIL="${CNPG_BACKUP_SA}@${GCP_PROJECT_ID}.iam.gserviceaccount.com"

log() { echo "[init_cnpg_gke] $*"; }

# ── Tool checks ──────────────────────────────────────────────────────────────
for tool in gcloud kubectl gsutil; do
  command -v "$tool" >/dev/null || { echo "ERROR: $tool not found in PATH." >&2; exit 1; }
done

# ── 1. Acquire kubeconfig ────────────────────────────────────────────────────
log "Fetching kubeconfig for $GKE_CLUSTER in $GCP_REGION ..."
gcloud container clusters get-credentials "$GKE_CLUSTER" \
  --project "$GCP_PROJECT_ID" \
  --region  "$GCP_REGION"

# ── 2. Create GCS buckets ────────────────────────────────────────────────────
for bucket in "$GCS_BACKUP_BUCKET" "$GCS_WAL_BUCKET"; do
  if gsutil ls -b "gs://$bucket" >/dev/null 2>&1; then
    log "Bucket gs://$bucket already exists."
  else
    log "Creating bucket gs://$bucket ..."
    gsutil mb -p "$GCP_PROJECT_ID" -l "$GCP_REGION" "gs://$bucket"
    gsutil versioning set on "gs://$bucket"
    gsutil lifecycle set /dev/stdin "gs://$bucket" <<EOF
{"rule":[{"action":{"type":"Delete"},"condition":{"age":30}}]}
EOF
  fi
done

# ── 3. Create GCP service account ────────────────────────────────────────────
if gcloud iam service-accounts describe "$GCP_SA_EMAIL" --project "$GCP_PROJECT_ID" >/dev/null 2>&1; then
  log "Service account $GCP_SA_EMAIL already exists."
else
  log "Creating service account $GCP_SA_EMAIL ..."
  gcloud iam service-accounts create "$CNPG_BACKUP_SA" \
    --display-name="CNPG GCS Backup" \
    --project="$GCP_PROJECT_ID"
fi

# ── 4. Grant storage access ───────────────────────────────────────────────────
log "Granting objectAdmin on backup buckets to $GCP_SA_EMAIL ..."
for bucket in "$GCS_BACKUP_BUCKET" "$GCS_WAL_BUCKET"; do
  gsutil iam ch \
    "serviceAccount:${GCP_SA_EMAIL}:objectAdmin" \
    "gs://$bucket"
done

# ── 5. Bind Workload Identity ─────────────────────────────────────────────────
log "Binding Workload Identity ..."
gcloud iam service-accounts add-iam-policy-binding "$GCP_SA_EMAIL" \
  --role=roles/iam.workloadIdentityUser \
  --member="serviceAccount:${GCP_PROJECT_ID}.svc.id.goog[${CNPG_NAMESPACE}/cnpg-backup-sa]" \
  --project="$GCP_PROJECT_ID"

# ── 6. Apply namespace ────────────────────────────────────────────────────────
log "Applying namespace $CNPG_NAMESPACE ..."
kubectl apply -f "$GKE_MANIFEST_DIR/namespace.yaml"

# ── 7. Install CNPG operator (if not present) ─────────────────────────────────
if ! kubectl get crd clusters.postgresql.cnpg.io >/dev/null 2>&1; then
  log "Installing CloudNativePG operator ..."
  kubectl apply --server-side -f \
    https://raw.githubusercontent.com/cloudnative-pg/cloudnative-pg/main/releases/cnpg-1.24.0.yaml
  log "Waiting for CNPG operator to be ready ..."
  kubectl rollout status deployment/cnpg-controller-manager -n cnpg-system --timeout=120s
else
  log "CNPG operator already installed."
fi

# ── 8. Apply ServiceAccount + annotate with WI ───────────────────────────────
log "Applying CNPG backup ServiceAccount with Workload Identity annotation ..."
GCP_PROJECT_ID="$GCP_PROJECT_ID" envsubst < "$GKE_MANIFEST_DIR/knoe-db-backup-gcs.yaml" \
  | kubectl apply -f -

kubectl annotate serviceaccount cnpg-backup-sa \
  -n "$CNPG_NAMESPACE" \
  "iam.gke.io/gcp-service-account=${GCP_SA_EMAIL}" \
  --overwrite

# ── 9. Apply CNPG cluster ────────────────────────────────────────────────────
log "Applying knoe-db CNPG cluster ..."
ARTIFACT_REGISTRY="${ARTIFACT_REGISTRY}" envsubst < "$GKE_MANIFEST_DIR/knoe-db.yaml" \
  | kubectl apply -f -

log ""
log "Done. Monitor with:"
log "  kubectl -n $CNPG_NAMESPACE get cluster knoe-db"
log "  kubectl -n $CNPG_NAMESPACE get pods -l cnpg.io/cluster=knoe-db"
log "  kubectl -n $CNPG_NAMESPACE get scheduledbackup"