/* Copyright (c) 2023-present miku-666
 * This software is provided 'as-is', without any express or implied
 * warranty. In no event will the authors be held liable for any damages
 * arising from the use of this software.
 * 
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 * 
 * 1. The origin of this software must not be misrepresented; you must not
 *    claim that you wrote the original software. If you use this software
 *    in a product, an acknowledgment in the product documentation would be
 *    appreciated but is not required.
 * 2. Altered source versions must be plainly marked as such, and must not be
 *    misrepresented as being the original software.
 * 3. This notice may not be removed or altered from any source distribution.
**/
using System;
using System.IO;

namespace PckStudio.Core.Misc
{
    public class FileCacher
    {
        private string _cacheDirectory;

        public string CacheDirectory => _cacheDirectory;

        public FileCacher(string cacheDirectory)
        {
            _cacheDirectory = cacheDirectory;
        }

        public bool HasFileCached(string filename)
        {
            string destinationFilepath = Path.Combine(_cacheDirectory, filename);
            return File.Exists(destinationFilepath);
        }

        public string GetCachedFilepath(string filename)
        {
            if (HasFileCached(filename))
            {
                return Path.Combine(_cacheDirectory, filename);
            }
            return null;
        }

        /// <summary>
        /// Caches data if the <paramref name="filename"/> doesn't already exists in the <see cref="CacheDirectory"/>
        /// </summary>
        /// <param name="data">Data to cache</param>
        /// <param name="filename">Filename with extension</param>
        /// <exception cref="ArgumentNullException"></exception>
        public void Cache(byte[] data, string filename)
        {
            _ = filename ?? throw new ArgumentNullException("filename");
            string destinationFilepath = Path.Combine(_cacheDirectory, filename);
            if (!File.Exists(destinationFilepath))
            {
                using FileStream fsDst = File.OpenWrite(destinationFilepath);
                fsDst.Write(data, 0, data.Length);
            }
        }
    }
}