using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;

namespace demo.ClassHelper.FileOperate
{
    class IniHelper
    {
        /// <summary>
        /// Windows API 对INI文件写方法
        /// </summary>
        /// <param name="lpAppName">要在其中写入新字串的段名。这个字串不区分大小写</param>
        /// <param name="lpKeyName">要设置的项名或条目名。这个字串不区分大小写。用null可删除这个小节的所有设置项</param>
        /// <param name="lpString">指定为这个项写入的字串值。用null表示删除这个项现有的字串</param>
        /// <param name="lpFileName">初始化文件的名字。如果没有指定完整路径名，则windows会在windows目录查找文件。如果文件没有找到，则函数会创建它</param>
        /// <returns></returns>
        [DllImport("kernel32")]
        public static extern long WritePrivateProfileString(string section, string key, string val, string strPath);

        /// <summary>
        /// 获取所有节点名称(Section)
        /// </summary>
        /// <param name="lpszReturnBuffer">存放节点名称的内存地址,每个节点之间用\0分隔</param>
        /// <param name="nSize">内存大小(characters)</param>
        /// <param name="lpFileName">Ini文件</param>
        /// <returns>内容的实际长度,为0表示没有内容,为nSize-2表示内存大小不够</returns>
        [DllImport("kernel32.dll", CharSet = CharSet.Auto)]
        private static extern uint GetPrivateProfileSectionNames(IntPtr lpszReturnBuffer, uint nSize, string lpFileName);

        /// <summary>
        /// 获取某个指定节点(Section)中所有KEY和Value
        /// </summary>
        /// <param name="lpAppName">节点名称</param>
        /// <param name="lpReturnedString">返回值的内存地址,每个之间用\0分隔</param>
        /// <param name="nSize">内存大小(characters)</param>
        /// <param name="lpFileName">Ini文件</param>
        /// <returns>内容的实际长度,为0表示没有内容,为nSize-2表示内存大小不够</returns>
        [DllImport("kernel32.dll", CharSet = CharSet.Auto)]
        private static extern uint GetPrivateProfileSection(string lpAppName, IntPtr lpReturnedString, uint nSize, string lpFileName);

        /// <summary>
        /// 读取INI文件中指定的Key的值
        /// </summary>
        /// <param name="lpAppName">节点名称。如果为null,则读取INI中所有节点名称,每个节点名称之间用\0分隔</param>
        /// <param name="lpKeyName">Key名称。如果为null,则读取INI中指定节点中的所有KEY,每个KEY之间用\0分隔</param>
        /// <param name="lpDefault">读取失败时的默认值</param>
        /// <param name="lpReturnedString">读取的内容缓冲区，读取之后，多余的地方使用\0填充</param>
        /// <param name="nSize">内容缓冲区的长度</param>
        /// <param name="lpFileName">INI文件名</param>
        /// <returns>实际读取到的长度</returns>
        [DllImport("kernel32.dll", CharSet = CharSet.Auto)]
        private static extern uint GetPrivateProfileString(string lpAppName, string lpKeyName, string lpDefault, [In, Out] char[] lpReturnedString, uint nSize, string lpFileName);

        /// Windows API 对INI文件字符串的读方法
        /// </summary>
        /// <param name="lpAppName">要在其中读取字符串的段名。这个字串不区分大小写</param>
        /// <param name="lpKeyName">要读取数据的关键字名称。这个字串不区分大小写。</param>
        /// <param name="lpDefault">当不存在指定关键字名称时，默认返回的字符串</param>
        /// <param name="lpReturnedString">返回的字符串</param>
        /// <param name="nSize">lpReturnedString参数的空间字节大小</param>
        /// <param name="lpFileName">初始化文件的名字。如果没有指定完整路径名，则windows会在windows目录查找文件。如果文件没有找到，则函数会创建它</param>
        /// <returns></returns>
        [DllImport("kernel32")]
        public static extern int GetPrivateProfileString(string section, string key, string def,
                                                         StringBuilder sb, int size, string strPath);


        [DllImport("kernel32")]
        private static extern int GetPrivateProfileString(string section, string key, string def, byte[] retVal, int size, string filePath);

        //再一种声明，使用string作为缓冲区的类型同char[]
        [DllImport("kernel32.dll", CharSet = CharSet.Auto)]
        private static extern uint GetPrivateProfileString(string lpAppName, string lpKeyName, string lpDefault, string lpReturnedString, uint nSize, string lpFileName);

        /// <summary>
        /// Windows API 对INI文件整数的读方法
        /// </summary>
        /// <param name="lpAppName">要在其中读取字符串的段名。这个字串不区分大小写</param>
        /// <param name="lpKeyName">要读取数据的关键字名称。这个字串不区分大小写。用null可删除这个小节的所有设置项</param>
        /// <param name="nDefault">当未能找到指定的关键字名称时，则返回的默认值</param>
        /// <param name="lpFileName">初始化文件的名字。如果没有指定完整路径名，则windows会在windows目录查找文件。如果文件没有找到，则函数会创建它</param>
        /// <returns></returns>
        [DllImport("kernel32.dll", EntryPoint = "GetPrivateProfileInt", CharSet = CharSet.Unicode)]
        public static extern int GetPrivateProfileInt(
            string lpAppName,
            string lpKeyName,
            int nDefault,
            string lpFileName);


        /// <summary>
        /// 写入配置文件
        /// </summary>
        /// <param name="strSection"></param>
        /// <param name="strKey"></param>
        /// <param name="strValue"></param>
        public static void WriteToIni(string strSection, string strKey, string strValue, string strPath)
        {
            WritePrivateProfileString(strSection, strKey, strValue, strPath);
        }

        /// <summary>
        /// 从配置文件中读取
        /// </summary>
        /// <param name="strSection"></param>
        /// <param name="strKey"></param>
        /// <returns></returns>
        public static string ReadStrFromIni(string strSection, string strKey, string strPath)
        {
            StringBuilder stringBuilder = new StringBuilder(500);
            GetPrivateProfileString(strSection.Trim(), strKey.Trim(), "", stringBuilder, 500, strPath);
            return stringBuilder.ToString();
        }

        /// <summary>
        /// 从配置文件中读取
        /// </summary>
        /// <param name="strSection"></param>
        /// <param name="strKey"></param>
        /// <returns></returns>
        public static int ReadIntFromIni(string strSection, string strKey, string strPath)
        {
            int defualt = 0;
            return GetPrivateProfileInt(strSection.Trim(), strKey.Trim(), defualt, strPath);
        }

        /// <summary>
        /// 获取section下的keys
        /// </summary>
        /// <param name="Section"></param>
        /// <param name="iniFilename"></param>
        /// <returns></returns>
        public static List<string> ReadSingleSection(string Section, string iniFilename)
        {
            List<string> result = new List<string>();
            byte[] buf = new byte[65536];
            int lenf = GetPrivateProfileString(Section, null, null, buf, buf.Length, iniFilename);
            int j = 0;
            for (int i = 0; i < lenf; i++)
                if (buf[i] == 0)
                {
                    result.Add(Encoding.Default.GetString(buf, j, i - j));
                    j = i + 1;
                }
            return result;
        }

        /// <summary>
        /// 获取指定section下的values
        /// </summary>
        /// <param name="Section"></param>
        /// <param name="iniFilename"></param>
        /// <returns></returns>
        public static List<string> ReadSectionValues(string Section, string iniFilename)
        {
            List<string> keys = new List<string>();
            List<string> values = new List<string>();
            byte[] buf = new byte[100];
            keys = ReadSingleSection(Section, iniFilename);
            for (int i = 0; i < keys.Count; i++ )
            {
                int len = GetPrivateProfileString(Section, keys[i], null, buf, buf.Length, iniFilename);
                values.Add(Encoding.Default.GetString(buf,0,len));
                Array.Clear(buf, 0, buf.Length);
            }
            return values;
        }

        /// <summary>
        /// 读取INI文件中指定INI文件中的所有节点名称(Section)
        /// </summary>
        /// <param name="iniFile">Ini文件</param>
        /// <returns>所有节点,没有内容返回string[0]</returns>
        public static string[] INIGetAllSectionNames(string iniFile)
        {
            uint MAX_BUFFER = 32767;    //默认为32767

            string[] sections = new string[0];      //返回值

            //申请内存
            IntPtr pReturnedString = Marshal.AllocCoTaskMem((int)MAX_BUFFER * sizeof(char));
            uint bytesReturned = GetPrivateProfileSectionNames(pReturnedString, MAX_BUFFER, iniFile);
            if (bytesReturned != 0)
            {
                //读取指定内存的内容
                string local = Marshal.PtrToStringAuto(pReturnedString, (int)bytesReturned).ToString();

                //每个节点之间用\0分隔,末尾有一个\0
                sections = local.Split(new char[] { '\0' }, StringSplitOptions.RemoveEmptyEntries);
            }

            //释放内存
            Marshal.FreeCoTaskMem(pReturnedString);

            return sections;
        }

        /// <summary>
        /// 获取INI文件中指定节点(Section)中的所有条目(key=value形式)
        /// </summary>
        /// <param name="iniFile">Ini文件</param>
        /// <param name="section">节点名称</param>
        /// <returns>指定节点中的所有项目,没有内容返回string[0]</returns>
        public static string[] INIGetAllItems(string iniFile, string section)
        {
            //返回值形式为 key=value,例如 Color=Red
            uint MAX_BUFFER = 32767;    //默认为32767

            string[] items = new string[0];      //返回值

            //分配内存
            IntPtr pReturnedString = Marshal.AllocCoTaskMem((int)MAX_BUFFER * sizeof(char));

            uint bytesReturned = GetPrivateProfileSection(section, pReturnedString, MAX_BUFFER, iniFile);

            if (!(bytesReturned == MAX_BUFFER - 2) || (bytesReturned == 0))
            {

                string returnedString = Marshal.PtrToStringAuto(pReturnedString, (int)bytesReturned);
                items = returnedString.Split(new char[] { '\0' }, StringSplitOptions.RemoveEmptyEntries);
            }

            Marshal.FreeCoTaskMem(pReturnedString);     //释放内存

            return items;
        }

        /// <summary>
        /// 获取INI文件中指定节点(Section)中的所有条目的Key列表
        /// </summary>
        /// <param name="iniFile">Ini文件</param>
        /// <param name="section">节点名称</param>
        /// <returns>如果没有内容,反回string[0]</returns>
        public static string[] INIGetAllItemKeys(string iniFile, string section)
        {
            string[] value = new string[0];
            const int SIZE = 1024 * 10;

            if (string.IsNullOrEmpty(section))
            {
                throw new ArgumentException("必须指定节点名称", "section");
            }

            char[] chars = new char[SIZE];
            uint bytesReturned = GetPrivateProfileString(section, null, null, chars, SIZE, iniFile);

            if (bytesReturned != 0)
            {
                value = new string(chars).Split(new char[] { '\0' }, StringSplitOptions.RemoveEmptyEntries);
            }
            chars = null;

            return value;
        }

        /// <summary>
        /// 读取INI文件中指定KEY的字符串型值
        /// </summary>
        /// <param name="iniFile">Ini文件</param>
        /// <param name="section">节点名称</param>
        /// <param name="key">键名称</param>
        /// <param name="defaultValue">如果没此KEY所使用的默认值</param>
        /// <returns>读取到的值</returns>
        public static string INIGetStringValue(string iniFile, string section, string key, string defaultValue)
        {
            string value = defaultValue;
            const int SIZE = 1024 * 10;

            if (string.IsNullOrEmpty(section))
            {
                throw new ArgumentException("必须指定节点名称", "section");
            }

            if (string.IsNullOrEmpty(key))
            {
                throw new ArgumentException("必须指定键名称(key)", "key");
            }

            StringBuilder sb = new StringBuilder(SIZE);
            int bytesReturned = GetPrivateProfileString(section, key, defaultValue, sb, SIZE, iniFile);

            if (bytesReturned != 0)
            {
                value = sb.ToString();
            }
            sb = null;

            return value;
        }
    }
}