#!/bin/bash
set -euo pipefail

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

CLUSTER="${1:?Usage: $0 <cluster> (e.g., aks-dev, eks-prod)}"
PLATFORM="${CLUSTER%%-*}"
ENV="${CLUSTER#*-}"

KUBECONFIG_FILE="$PROJECT_ROOT/private/$CLUSTER/kubeconfig"

if [[ -f "$KUBECONFIG_FILE" ]]; then
  echo "Kubeconfig already exists: $KUBECONFIG_FILE"
  echo ""
  echo "  export KUBECONFIG=$KUBECONFIG_FILE"
else
  echo "No cached kubeconfig. Fetching from platform..."

  # Load platform credentials
  ENV_FILE="$TOFU_ROOT/configs/$PLATFORM.env"
  if [[ -f "$ENV_FILE" ]]; then
    set -a; source "$ENV_FILE"; set +a
  fi

  TOFU_DIR="$TOFU_ROOT/platforms/$PLATFORM/$ENV"
  mkdir -p "$(dirname "$KUBECONFIG_FILE")"

  case "$PLATFORM" in
    aks)
      cd "$TOFU_DIR"
      RG=$(tofu output -raw resource_group_name 2>/dev/null || echo "$CLUSTER-rg")
      NAME=$(tofu output -raw cluster_name 2>/dev/null || echo "$CLUSTER")
      az aks get-credentials --resource-group "$RG" --name "$NAME" --file "$KUBECONFIG_FILE" --overwrite-existing
      ;;
    eks)
      cd "$TOFU_DIR"
      NAME=$(tofu output -raw cluster_name 2>/dev/null || echo "$CLUSTER")
      REGION=$(tofu output -raw aws_region 2>/dev/null || echo "${AWS_REGION:-eu-west-1}")
      aws eks update-kubeconfig --name "$NAME" --region "$REGION" --kubeconfig "$KUBECONFIG_FILE"
      ;;
    gke)
      cd "$TOFU_DIR"
      NAME=$(tofu output -raw cluster_name 2>/dev/null || echo "$CLUSTER")
      REGION=$(tofu output -raw region 2>/dev/null || echo "${GCP_REGION:-europe-west4}")
      PROJECT=$(tofu output -raw project_id 2>/dev/null || echo "${GCP_PROJECT_ID:-}")
      gcloud container clusters get-credentials "$NAME" --region "$REGION" --project "$PROJECT"
      cp ~/.kube/config "$KUBECONFIG_FILE"
      ;;
    upc)
      cd "$TOFU_DIR"
      CLUSTER_ID=$(tofu output -raw cluster_id 2>/dev/null || echo "${UPCLOUD_CLUSTER_ID:-}")
      upctl kubernetes config "$CLUSTER_ID" > "$KUBECONFIG_FILE"
      ;;
    *)
      echo "Error: unknown platform '$PLATFORM'"
      exit 1
      ;;
  esac

  chmod 600 "$KUBECONFIG_FILE"
  echo "Kubeconfig saved: $KUBECONFIG_FILE"
  echo ""
  echo "  export KUBECONFIG=$KUBECONFIG_FILE"
fi