#!/usr/bin/env bash

set -euo pipefail

# etc/init_k8s.sh
# Purpose: Manage k3d/k8s environment

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

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

# Default values
VERBOSE=false
ENVIRONMENT="prod"
HOST=""
CLUSTER_NAME_DEFAULT="knoe-dev-cluster"
CLUSTER_PORT_DEFAULT="6443"

usage() {
  cat <<EOF
Usage: $0 [initialize|start|stop|restart|status] [options]

Actions:
  initialize  Create a k3d cluster (dev) or fetch kubeconfig (service/prod)
  start       Start the k3d cluster
  stop        Stop the k3d cluster
  restart     Restart the k3d cluster
  status      Show status of Docker and k3d cluster

Options:
  -v, --verbose      Enable verbose output
  -m, --mode         k3d|k3s|k8s (maps to dev|service|prod)
  -e, --environment  dev|service|prod (default: $ENVIRONMENT)
  -h, --host         Remote host for service/prod environments
  -n, --name         k3d cluster name
EOF
  exit 1
}

log() {
  echo "[INFO] $*"
}

debug() {
  if [[ "$VERBOSE" == "true" ]]; then
    echo "[DEBUG] $*"
  fi
}

# Parse options
POSITIONAL_ARGS=()
CLUSTER_NAME=""
while [[ $# -gt 0 ]]; do
  case $1 in
    -v|--verbose)
      VERBOSE=true
      shift
      ;;
    -m|--mode)
      knoe_set_mode "${2:-}"
      case "${KNOE_MODE:-}" in
        k3d) ENVIRONMENT="dev" ;;
        k3s) ENVIRONMENT="service" ;;
        k8s) ENVIRONMENT="prod" ;;
      esac
      shift 2
      ;;
    --mode=*|-m=*)
      knoe_set_mode "${1#*=}"
      case "${KNOE_MODE:-}" in
        k3d) ENVIRONMENT="dev" ;;
        k3s) ENVIRONMENT="service" ;;
        k8s) ENVIRONMENT="prod" ;;
      esac
      shift
      ;;
    -e|--environment)
      ENVIRONMENT="$2"
      shift 2
      ;;
    -h|--host)
      HOST="$2"
      shift 2
      ;;
    -n|--name)
      CLUSTER_NAME="$2"
      shift 2
      ;;
    *)
      POSITIONAL_ARGS+=("$1")
      shift
      ;;
  esac
done

set -- "${POSITIONAL_ARGS[@]}"
ACTION=${1:-}

if [[ -z "$ACTION" ]]; then
  usage
fi

ensure_tools() {
  if [[ "$ENVIRONMENT" == "dev" ]]; then
    for t in k3d docker; do
      command -v "$t" >/dev/null || { echo "ERROR: Missing required tool: $t" >&2; exit 1; }
    done
  else
    command -v kubectl >/dev/null || { echo "ERROR: Missing required tool: kubectl" >&2; exit 1; }
  fi
}

ensure_docker() {
  if [[ "$ENVIRONMENT" != "dev" ]]; then
    return 0
  fi
  if ! docker info >/dev/null 2>&1; then
    echo "ERROR: Docker is not running." >&2
    exit 1
  fi
}

initialize() {
  ensure_tools
  ensure_docker

  if [[ "$ENVIRONMENT" == "dev" ]]; then
    if [[ -z "$CLUSTER_NAME" ]]; then
      if [[ -t 0 ]]; then
        read -p "Enter k3d cluster name [$CLUSTER_NAME_DEFAULT]: " CLUSTER_NAME
        CLUSTER_NAME=${CLUSTER_NAME:-$CLUSTER_NAME_DEFAULT}
      else
        CLUSTER_NAME=$CLUSTER_NAME_DEFAULT
      fi
    fi
    
    if k3d cluster list "$CLUSTER_NAME" >/dev/null 2>&1; then
      log "Cluster '$CLUSTER_NAME' already exists."
    else
      data_dir="${PROLE_DATA:-}"
      if [[ -z "$data_dir" && -f "$SCRIPT_DIR/../env.sh" ]]; then
        # shellcheck disable=SC1090
        source "$SCRIPT_DIR/../env.sh"
        data_dir="${PROLE_DATA:-}"
      fi
      if [[ -z "$data_dir" ]]; then
        data_dir="$SCRIPT_DIR/../data"
      fi
      mkdir -p "$data_dir" >/dev/null 2>&1 || true
      volume_args=()
      if [[ -n "$data_dir" ]]; then
        volume_args=(--volume "${data_dir}:/var/lib/rancher/k3s/storage@all")
      fi
      # Generate a registries.yaml so k3d nodes can pull from the local
      # registry over plain HTTP (insecure).  The file is written to a
      # temp location and passed via --registry-config at creation time.
      registry_config_args=()
      local reg_cfg
      reg_cfg=$(mktemp "${TMPDIR:-/tmp}/k3d-registries-XXXXXX.yaml")
      cat > "$reg_cfg" <<'REGEOF'
mirrors:
  "k3d-knoe-registry:5000":
    endpoint:
      - "http://k3d-knoe-registry:5000"
REGEOF
      registry_config_args=(--registry-config "$reg_cfg")
      log "Creating k3d cluster '$CLUSTER_NAME'..."
      k3d cluster create "$CLUSTER_NAME" \
        --api-port "0.0.0.0:${CLUSTER_PORT_DEFAULT}" \
        --agents 2 \
        -p "0.0.0.0:${CLUSTER_PORT_DEFAULT}:6443@server:0" \
        "${volume_args[@]}" \
        "${registry_config_args[@]}"
      rm -f "$reg_cfg" 2>/dev/null || true
    fi
  else
    if [[ -n "$HOST" ]]; then
      log "Environment is $ENVIRONMENT. Host is $HOST."
      log "TODO: Fetch kubeconfig from $HOST (placeholder)."
    else
      log "Environment is $ENVIRONMENT. Use -h|--host to specify the remote cluster host."
    fi
  fi
}

status() {
  ensure_tools
  log "Checking Docker status..."
  if docker info >/dev/null 2>&1; then
    echo "Docker is running."
  else
    echo "Docker is NOT running."
  fi

  log "Listing k3d clusters..."
  k3d cluster list
}

get_cluster_name() {
  # If a name was provided or exists in env, use it.
  # Otherwise, if there is only one cluster, use it. 
  # Finally, use default.
  if [[ -n "${CLUSTER_NAME:-}" ]]; then
    echo "$CLUSTER_NAME"
    return
  fi

  local clusters
  clusters=$(k3d cluster list --no-headers | awk '{print $1}')
  local count
  count=$(echo "$clusters" | grep -c . || true)
  
  if [[ "$count" -eq 1 ]]; then
    echo "$clusters"
  else
    echo "$CLUSTER_NAME_DEFAULT"
  fi
}

case "$ACTION" in
  initialize)
    initialize
    ;;
  status)
    status
    ;;
  start)
    ensure_tools
    CLUSTER_NAME=$(get_cluster_name)
    log "Starting k3d cluster '$CLUSTER_NAME'..."
    k3d cluster start "$CLUSTER_NAME"
    ;;
  stop)
    ensure_tools
    CLUSTER_NAME=$(get_cluster_name)
    log "Stopping k3d cluster '$CLUSTER_NAME'..."
    k3d cluster stop "$CLUSTER_NAME"
    ;;
  restart)
    ensure_tools
    CLUSTER_NAME=$(get_cluster_name)
    log "Restarting k3d cluster '$CLUSTER_NAME'..."
    k3d cluster stop "$CLUSTER_NAME"
    k3d cluster start "$CLUSTER_NAME"
    ;;
  *)
    usage
    ;;
esac