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

using Android.App;
using Android.Content;
using Android.OS;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Java.IO;

namespace CommonLib
{
    class FileListManager
    {
        const int INCREASE_UNIT = 10;
        public static string[] Get(string[] filterArray, string strPath = "")
        {
            int nFilePos = 0;
            if(string.IsNullOrEmpty(strPath)==true)
                strPath = Android.OS.Environment.ExternalStorageDirectory.AbsolutePath;
            string[] fileArray = new string[INCREASE_UNIT];
            Array.Clear(fileArray, 0, INCREASE_UNIT);
            Get(strPath, filterArray, ref fileArray, ref nFilePos);

            string[] fileArrayBuff = new string[nFilePos];
            for(int i = 0; i < nFilePos; i++)
                fileArrayBuff[i] = fileArray[i];
            return fileArrayBuff;
        }

        public static string[] Get(string strFilter, string strPath = "")
        {
            string[] filterArray = new string[1];
            filterArray[0] = strFilter;
            return Get(filterArray, strPath);
        }

        public static string[] GetAdjustFileNames(string[] fileArray, int nLength = 20)
        {
            string[] fileNames = new string[fileArray.Length];
            int nPos;
            for (int i = 0; i < fileArray.Length; i++)
            {
                nPos = fileArray[i].LastIndexOf("/");       //µð·ºÅ丮 Á¦°Å
                if (nPos >= 0)
                    fileNames[i] = fileArray[i].Substring(nPos + 1);
                else
                    fileNames[i] = fileArray[i];
                nPos = fileNames[i].LastIndexOf(".");       //È®ÀåÀÚ Á¦°Å
                if (nPos >= 0)
                    fileNames[i] = fileNames[i].Substring(0, nPos);
                nPos = fileNames[i].Length;                 //nLengthº¸´Ù ±æ¸é À߶ó³¿
                if (nLength <= 0)
                    continue;
                if (nPos <= nLength - 3)
                    continue;
                nPos = nLength - 3;
                fileNames[i] = fileNames[i].Substring(0, nPos);
                fileNames[i] += "...";
            }
            return fileNames;
        }

        static void SetFile(ref string[] fileArray, ref int nFilePos, string strFile)
        {
            if (nFilePos >= fileArray.Length)
            {
                int nSize = fileArray.Length;
                Array.Resize(ref fileArray, nSize + 100);
                Array.Clear(fileArray, nSize, INCREASE_UNIT);
            }
            fileArray[nFilePos++] = strFile;
        }

        static void Get(string strPath, string[] filterArray, ref string[] fileArray, ref int nFilePos)
        {
            try
            {
                File home = new File(strPath);  // homeÀ¸·Î sdÄ«µåÀÇ root¸¦ ÁöÁ¤ÇÕ´Ï´Ù. 
                File file = null;
                bool bStatus;
                string strPathFile;
                string[] files = home.List();
                if (files == null)
                    return;
                for (int i = 0; i < files.Length; i++)
                {
                    strPathFile = strPath + "/" + files[i];
                    file = new File(strPathFile);
                    if (file.IsDirectory == true)
                    {
                        Get(strPathFile, filterArray, ref fileArray, ref nFilePos);
                    }
                    else
                    {
                        if (files[i].Length <= 4)
                            continue;
                        string strExt = files[i].Substring(files[i].Length - 4);
                        bStatus = false;
                        for (int j = 0; j < filterArray.Length; j++)
                        {
                            if (strExt == filterArray[j])
                            {
                                bStatus = true;
                                break;
                            }
                        }
                        if(bStatus==true)
                            SetFile(ref fileArray, ref nFilePos, strPathFile);
                    }
                }
            }
            catch (Exception e)
            {
                e.ToString();
            }
        }
    }
}