#!/bin/bash

# 安装 Image Builder 构建所需依赖
install_dependencies() {
  sudo apt install -y build-essential libncurses-dev zlib1g-dev gawk git \
    gettext libssl-dev xsltproc rsync wget unzip python3 qemu-utils mkisofs zstd
}

# =============================================================
# 交互输入函数
# 参数1: 提示信息
# 参数2: 默认值
# 返回: 用户输入值，直接回车返回默认值
# =============================================================
ask_input() {
  local prompt="$1"
  local default="$2"

  read -p "${prompt} [ 默认: ${default} ]: " value

  if [ -z "$value" ]; then
    echo "$default"
  else
    echo "$value"
  fi
}

# 获取lan口ip
input_lan_ip() {
  local default_ip="$1"

  while true; do
    local ip

    ip=$(ask_input "请输入lan口ip" "$default_ip")

    if valid_ipv4 "$ip"; then
      echo "$ip"
      return 0
    else
      echo "[错误] IP地址格式不正确，请重新输入" >&2
    fi
  done
}

valid_ipv4() {
  local ip="$1"

  # 第一层：检查格式，必须是4段数字
  echo "$ip" | grep -Eq '^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$' || return 1

  # 第二层：检查每段范围
  echo "$ip" | awk -F. '
    $1>=0 && $1<=255 &&
    $2>=0 && $2<=255 &&
    $3>=0 && $3<=255 &&
    $4>=0 && $4<=255
  ' | grep -q . || return 1

  return 0
}