#!/usr/bin/env bash
set -euo pipefail

APP_DIR="${APP_DIR:-/opt/hw}"
CONFIG_DIR="${CONFIG_DIR:-/opt/hw.conf.d}"
DEFAULT_HOST_USER="${SUDO_USER:-$(id -un)}"
APP_USER="${APP_USER:-$DEFAULT_HOST_USER}"
APP_GROUP="${APP_GROUP:-$(id -gn "$APP_USER" 2>/dev/null || id -gn)}"
PROJECT_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
ENV_TEMPLATE_SOURCE="${ENV_TEMPLATE_SOURCE:-$PROJECT_ROOT/deploy/env/hw.env.example}"
ENV_FILE_NAME="${ENV_FILE_NAME:-hw.env}"
DOCKER_INSTALL_SCRIPT_URL="https://get.docker.com"
ALLOW_NON_ROOT="${ALLOW_NON_ROOT:-0}"
CONTAINER_UID="${CONTAINER_UID:-10001}"
CONTAINER_GID="${CONTAINER_GID:-10001}"

require_root() {
  if [[ "$ALLOW_NON_ROOT" == "1" ]]; then
    return
  fi
  if [[ "${EUID}" -ne 0 ]]; then
    printf 'Please run this script as root.\n' >&2
    exit 1
  fi
}

command_exists() {
  command -v "$1" >/dev/null 2>&1
}

require_command() {
  if ! command_exists "$1"; then
    printf 'Required command not found: %s\n' "$1" >&2
    exit 1
  fi
}

install_docker_if_missing() {
  if command_exists docker; then
    return
  fi

  if command_exists apt-get; then
    printf 'Docker not found. Installing Docker via %s ...\n' "$DOCKER_INSTALL_SCRIPT_URL"
    curl -fsSL "$DOCKER_INSTALL_SCRIPT_URL" | sh
    return
  fi

  printf 'Docker is not installed and automatic installation is only supported on apt-based hosts.\n' >&2
  printf 'Please install Docker manually, then re-run this script.\n' >&2
  exit 1
}

main() {
  require_root
  require_command curl
  install_docker_if_missing

  install -d -m 755 -o "$APP_USER" -g "$APP_GROUP" "$APP_DIR"
  install -d -m 755 -o "$APP_USER" -g "$APP_GROUP" "$APP_DIR/instance"
  install -d -m 755 -o "$APP_USER" -g "$APP_GROUP" "$APP_DIR/instance/csv_previews"

  if [[ "$ALLOW_NON_ROOT" == "1" ]]; then
    install -d -m 750 "$CONFIG_DIR"
  else
    install -d -m 750 -o root -g "$APP_GROUP" "$CONFIG_DIR"
  fi

  if [[ "$ALLOW_NON_ROOT" == "1" ]]; then
    chown -R "$CONTAINER_UID:$CONTAINER_GID" "$APP_DIR/instance" >/dev/null 2>&1 || true
  else
    chown -R "$CONTAINER_UID:$CONTAINER_GID" "$APP_DIR/instance"
  fi

  if [[ ! -f "$CONFIG_DIR/$ENV_FILE_NAME" ]]; then
    if [[ "$ALLOW_NON_ROOT" == "1" ]]; then
      install -m 640 "$ENV_TEMPLATE_SOURCE" "$CONFIG_DIR/$ENV_FILE_NAME"
    else
      install -m 640 -o root -g "$APP_GROUP" "$ENV_TEMPLATE_SOURCE" "$CONFIG_DIR/$ENV_FILE_NAME"
    fi
    printf 'Created %s from template. Please edit it before deployment.\n' "$CONFIG_DIR/$ENV_FILE_NAME"
  else
    printf 'Keeping existing %s\n' "$CONFIG_DIR/$ENV_FILE_NAME"
  fi

  if [[ "$ALLOW_NON_ROOT" != "1" ]] && id -u "$APP_USER" >/dev/null 2>&1; then
    usermod -aG docker "$APP_USER" >/dev/null 2>&1 || true
  fi

  printf '\nContainer deployment prerequisites are ready.\n'
  printf 'Next steps:\n'
  printf '1. Sync project files into %s\n' "$APP_DIR"
  printf '2. Edit %s/%s with real production values\n' "$CONFIG_DIR" "$ENV_FILE_NAME"
  if [[ "$ALLOW_NON_ROOT" == "1" ]]; then
    printf '3. Run ALLOW_NON_ROOT=1 bash scripts/deploy-container.sh\n'
  else
    printf '3. Run sudo bash scripts/deploy-container.sh\n'
  fi
}

main "$@"