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using System;
using System.IO;

namespace console_sample
{
    internal class Program
    {
        private const string TemplatePath = "../../resources/daily_yyyymmdd.txt";
        private const string DestPath = "../../dest/";

        public static void Main(string[] args)
        {
            Console.WriteLine("-- start --");

            var pwd = Directory.GetCurrentDirectory();
            Console.WriteLine("pwd: " + pwd);

            var today = DateTime.Now;

            // コピー元ファイルを決める
            var srcPath = "../../dest/";
            // todo: １週間内の直近のファイルを読み込む
            var srcDay = today.AddDays(-1);
            do
            {
                var p = "daily_" + srcDay.ToString("yyyy-MM-dd") + ".txt";
                Console.WriteLine($"p: {p}");
                if (File.Exists(DestPath + p))
                {
                    Console.WriteLine($"exists!");
                    srcPath += p;
                    break;
                }

                srcDay = srcDay.AddDays(-1);
            } while (!srcDay.Equals(today.AddDays(-7)));

            if (srcPath.Equals("../../dest/"))
            {
                srcPath = TemplatePath;
            }

            Console.WriteLine("src: " + srcPath);

            var d = today.ToString("yyyy-MM-dd");
            File.Copy(srcPath, DestPath + $"daily_{d}.txt", true);

            Console.WriteLine("-- end --");
        }
    }
}