using System;
using System.Collections.Generic;
using System.IO;

namespace osrepodbmgr.Core
{
    public static class IO
    {
        public static List<string> EnumerateFiles(string path, string searchPattern, SearchOption searchOption, bool followLinks = true, bool symlinks = true)
        {
            if (followLinks)
                return new List<string>(Directory.EnumerateFiles(path, searchPattern, searchOption));

            List<string> files = new List<string>();
            List<string> directories = new List<string>();

            foreach (string file in Directory.EnumerateFiles(path, searchPattern))
            {
                FileInfo fi = new FileInfo(file);
                if (fi.Attributes.HasFlag(FileAttributes.ReparsePoint) && symlinks)
                    files.Add(file);
                else if (!fi.Attributes.HasFlag(FileAttributes.ReparsePoint))
                    files.Add(file);
            }

            if (searchOption == SearchOption.AllDirectories)
            {
                foreach (string directory in Directory.EnumerateDirectories(path, searchPattern))
                {
                    DirectoryInfo di = new DirectoryInfo(directory);
                    if (!di.Attributes.HasFlag(FileAttributes.ReparsePoint))
                        files.AddRange(EnumerateFiles(directory, searchPattern, searchOption, followLinks, symlinks));
                }
            }

            return files;
        }

        public static List<string> EnumerateDirectories(string path, string searchPattern, SearchOption searchOption, bool followLinks = true, bool symlinks = true)
        {
            if (followLinks)
                return new List<string>(Directory.EnumerateDirectories(path, searchPattern, searchOption));

            List<string> directories = new List<string>();

            if (searchOption == SearchOption.AllDirectories)
            {
                foreach (string directory in Directory.EnumerateDirectories(path, searchPattern))
                {
                    DirectoryInfo di = new DirectoryInfo(directory);
                    if (!di.Attributes.HasFlag(FileAttributes.ReparsePoint))
                        directories.Add(directory);
                }

                List<string> newDirectories = new List<string>();

                foreach (string directory in directories)
                    newDirectories.AddRange(EnumerateDirectories(directory, searchPattern, searchOption, followLinks, symlinks));

                directories.AddRange(newDirectories);
            }

            return directories;
        }

        public static List<string> EnumerateSymlinks(string path, string searchPattern, SearchOption searchOption)
        {
            List<string> links = new List<string>();
            List<string> directories = new List<string>();

            foreach (string file in Directory.EnumerateFiles(path, searchPattern))
            {
                FileInfo fi = new FileInfo(file);
                if (fi.Attributes.HasFlag(FileAttributes.ReparsePoint))
                    links.Add(file);
            }

            if (searchOption == SearchOption.AllDirectories)
            {
                foreach (string directory in Directory.EnumerateDirectories(path, searchPattern))
                {
                    DirectoryInfo di = new DirectoryInfo(directory);
                    if (!di.Attributes.HasFlag(FileAttributes.ReparsePoint))
                        directories.Add(directory);
                    else //if (!links.Contains(directory))
                        links.Add(directory);
                }

                foreach (string directory in directories)
                    links.AddRange(EnumerateSymlinks(directory, searchPattern, searchOption));
            }

            return links;
        }
    }
}