using System;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Text;

namespace XImaging.Automation.Library.HxDriverLib
{
    /// <summary>
    /// INI文件读写类
    /// </summary>
    public class IniHelper
    {
        #region API函数声明

        [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)] //返回0表示失败，非0为成功
        private static extern bool WritePrivateProfileString(string section, string key,
            string val, string filePath);

        [DllImport("kernel32.dll", CharSet = CharSet.Auto)] //返回取得字符串缓冲区的长度
        private static extern uint GetPrivateProfileString(string section, string key,
            string def, StringBuilder retVal, int size, string filePath);

        #endregion

        #region 封装

        /// <summary>
        /// 从INI文件读取值
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="iniFile"></param>
        /// <param name="section"></param>
        /// <param name="key"></param>
        /// <param name="defaultValue"></param>
        /// <returns></returns>
        public static T IniGetValue<T>(string iniFile, string section, string key, T defaultValue = default(T))
        {
            if (string.IsNullOrEmpty(section))
            {
                LogConstant.logger.Print("未指定节点名称(Section)");
                return defaultValue;
            }
            if (string.IsNullOrEmpty(key))
            {
                LogConstant.logger.Print("未指定节点名称(Key)");
                return defaultValue;
            }

            string strValue = defaultValue.ToString(); ;
            const int SIZE = 1024 * 10;


            StringBuilder sb = new StringBuilder(SIZE);
            uint bytesReturned = GetPrivateProfileString(section, key, defaultValue.ToString(), sb, SIZE, iniFile);

            if (bytesReturned != 0)
                strValue = sb.ToString();
            sb = null;

            Type t = typeof(T);
            if (t.IsGenericType && t.GetGenericTypeDefinition() == typeof(Nullable<>))   //支持可空类型
                t = t.GetGenericArguments()[0];

            var tryParse = t.GetMethod("TryParse", BindingFlags.Public | BindingFlags.Static, Type.DefaultBinder
                , new Type[] { strValue.GetType(), t.MakeByRefType() }
                , new ParameterModifier[] { new ParameterModifier(2) });

            if (tryParse != null)
            {
                var parameters = new object[] { strValue, Activator.CreateInstance(t) };
                bool success = (bool)tryParse.Invoke(null, parameters);
                if (success)
                    return (T)parameters[1];
                else
                    return defaultValue;
            }

            return (T)Convert.ChangeType(strValue, typeof(T));
        }

        /// <summary>
        /// 向INI文件写值
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="iniFile"></param>
        /// <param name="section"></param>
        /// <param name="key"></param>
        /// <param name="value"></param>
        /// <returns></returns>
        public static bool IniWriteValue<T>(string iniFile, string section, string key, T value)
        {
            if (string.IsNullOrEmpty(section))
            {
                LogConstant.logger.Print("未指定节点名称(Section)");
                return false;
            }
            if (string.IsNullOrEmpty(key))
            {
                LogConstant.logger.Print("未指定节点名称(Key)");
                return false;
            }

            return WritePrivateProfileString(section, key, value.ToString(), iniFile);
        }

        #endregion
    }
}