#!/usr/bin/env bash

set -euo pipefail

# init_prole-db-backup.sh
# Purpose:
# - Configure CloudNative-PG to backup to Garage (S3-compatible)
# - Create initial backup

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

ACTION=${1:-start}

# Load env
if [[ -n "${PROLE_HOME:-}" && -f "$PROLE_HOME/env.sh" ]]; then
  set --
  # shellcheck disable=SC1090
  source "$PROLE_HOME/env.sh"
elif [[ -f "$HOME/.prole/env.sh" ]]; then
  set --
  # shellcheck disable=SC1090
  source "$HOME/.prole/env.sh"
fi

NAMESPACE=${NAMESPACE:-default}
CNPG_CLUSTER_NAME=${CNPG_CLUSTER_NAME:-prole-db}
GARAGE_NAME=${GARAGE_NAME:-garage}
GARAGE_BACKUP_BUCKET=${GARAGE_BACKUP_BUCKET:-prole-db-backups}
GARAGE_BACKUP_KEY_NAME=${GARAGE_BACKUP_KEY_NAME:-prole-db-backup}
GARAGE_BACKUP_SECRET_NAME=${GARAGE_BACKUP_SECRET_NAME:-prole-db-barman-s3}
GARAGE_S3_ENDPOINT=${GARAGE_S3_ENDPOINT:-http://$GARAGE_NAME.$NAMESPACE.svc.cluster.local:3900}
RUN_FIRST_BACKUP=${RUN_FIRST_BACKUP:-1}

usage() {
  cat <<USAGE
Usage: $0 [start|backup|status]

Actions:
  start     Configure Garage-backed backups and run initial backup
  backup    Trigger a new backup now
  status    Show backup resources
USAGE
  exit 1
}

ensure_tools() {
  for t in kubectl; do
    command -v "$t" >/dev/null || { echo "Missing required tool: $t" >&2; exit 1; }
  done
}

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

ensure_cluster() {
  if ! kubectl get cluster "$CNPG_CLUSTER_NAME" -n "$NAMESPACE" >/dev/null 2>&1; then
    echo "ERROR: CNPG cluster '$CNPG_CLUSTER_NAME' not found in namespace '$NAMESPACE'." >&2
    exit 1
  fi
}

get_garage_pod() {
  kubectl get pods -n "$NAMESPACE" -l "app=$GARAGE_NAME" -o jsonpath='{.items[0].metadata.name}' 2>/dev/null || true
}

garage_exec() {
  local pod
  pod=$(get_garage_pod)
  if [[ -z "$pod" ]]; then
    echo "ERROR: Garage pod not found in namespace '$NAMESPACE'." >&2
    exit 1
  fi
  kubectl exec -n "$NAMESPACE" "$pod" -- /garage "$@"
}

parse_key_output() {
  local output="$1"
  local access_key secret_key
  access_key=$(echo "$output" | sed -nE 's/^(Access key ID|Key ID):[[:space:]]+//p' | head -n1)
  secret_key=$(echo "$output" | sed -nE 's/^(Secret access key|Secret key):[[:space:]]+//p' | head -n1)
  if [[ -z "$access_key" || -z "$secret_key" ]]; then
    return 1
  fi
  printf "%s\n%s" "$access_key" "$secret_key"
}

ensure_garage_bucket_and_key() {
  echo "Ensuring Garage bucket and access key for backups ..."
  local key_info parsed access_key secret_key
  if key_info=$(garage_exec key info --show-secret "$GARAGE_BACKUP_KEY_NAME" 2>/dev/null); then
    :
  else
    key_info=$(garage_exec key create "$GARAGE_BACKUP_KEY_NAME")
  fi

  if ! parsed=$(parse_key_output "$key_info"); then
    echo "ERROR: Unable to parse Garage key output." >&2
    echo "$key_info" >&2
    exit 1
  fi
  access_key=$(echo "$parsed" | sed -n '1p')
  secret_key=$(echo "$parsed" | sed -n '2p')

  if ! garage_exec bucket info "$GARAGE_BACKUP_BUCKET" >/dev/null 2>&1; then
    garage_exec bucket create "$GARAGE_BACKUP_BUCKET"
  fi

  garage_exec bucket allow --read --write --owner --key "$GARAGE_BACKUP_KEY_NAME" "$GARAGE_BACKUP_BUCKET" || true

  echo "Creating/updating Kubernetes secret '$GARAGE_BACKUP_SECRET_NAME' ..."
  kubectl create secret generic "$GARAGE_BACKUP_SECRET_NAME" -n "$NAMESPACE" \
    --from-literal=ACCESS_KEY_ID="$access_key" \
    --from-literal=SECRET_ACCESS_KEY="$secret_key" \
    --dry-run=client -o yaml | kubectl apply -f -
}

configure_cnpg_backup() {
  echo "Configuring CNPG backup to use Garage bucket '$GARAGE_BACKUP_BUCKET' ..."
  kubectl patch cluster "$CNPG_CLUSTER_NAME" -n "$NAMESPACE" --type merge -p "{
    \"spec\": {
      \"backup\": {
        \"barmanObjectStore\": {
          \"destinationPath\": \"s3://$GARAGE_BACKUP_BUCKET/\",
          \"endpointURL\": \"$GARAGE_S3_ENDPOINT\",
          \"s3Credentials\": {
            \"accessKeyId\": {\"name\": \"$GARAGE_BACKUP_SECRET_NAME\", \"key\": \"ACCESS_KEY_ID\"},
            \"secretAccessKey\": {\"name\": \"$GARAGE_BACKUP_SECRET_NAME\", \"key\": \"SECRET_ACCESS_KEY\"}
          },
          \"wal\": {\"compression\": \"gzip\"},
          \"data\": {\"compression\": \"gzip\"}
        },
        \"retentionPolicy\": \"30d\"
      }
    }
  }"
}

trigger_backup() {
  local backup_name
  backup_name="${CNPG_CLUSTER_NAME}-backup-$(date +%Y%m%d%H%M%S)"
  echo "Triggering backup $backup_name ..."
  kubectl apply -n "$NAMESPACE" -f - <<BACKUP
apiVersion: postgresql.cnpg.io/v1
kind: Backup
metadata:
  name: $backup_name
spec:
  cluster:
    name: $CNPG_CLUSTER_NAME
BACKUP
}

status() {
  ensure_tools
  echo "Backups for cluster '$CNPG_CLUSTER_NAME' in namespace '$NAMESPACE':"
  kubectl get backup -n "$NAMESPACE" | grep "$CNPG_CLUSTER_NAME" || true
}

case "$ACTION" in
  start)
    ensure_tools
    ensure_namespace
    ensure_cluster
    ensure_garage_bucket_and_key
    configure_cnpg_backup
    if [[ "$RUN_FIRST_BACKUP" == "1" ]]; then
      trigger_backup
    fi
    ;;
  backup)
    ensure_tools
    ensure_namespace
    ensure_cluster
    trigger_backup
    ;;
  status)
    status
    ;;
  *)
    usage
    ;;
esac