using System;

namespace cs_addon
{
	/// <summary>
	/// Class1 の概要の説明です。
	/// </summary>
	public class AddonHensai
	{
		/// <summary>
		/// 総支払利息
		/// </summary>
		/// <param name="Ganpon">所要資金</param>
		/// <param name="HensaiKaisu">返済回数</param>
		/// <param name="Geturi">月利</param>
		/// <returns>総支払利息を返す</returns>
		public static int GetRisokuSum(int Ganpon, int HensaiKaisu, double Geturi){
			double theTemp;
			theTemp = (double)Ganpon * Geturi * (double)HensaiKaisu;
			return (int)theTemp;
		}

		/// <summary>
		/// 月額返済額
		/// </summary>
		/// <param name="Ganpon">所要資金</param>
		/// <param name="HensaiKaisu">返済回数</param>
		/// <param name="RisokuSum">総支払利息額</param>
		/// <returns>月額返済額を返す</returns>
		public static int GetHensai(int Ganpon, int HensaiKaisu, int RisokuSum){
			return (Ganpon + RisokuSum) / HensaiKaisu;
		}

		/// <summary>
		/// 元金返済額
		/// 信販会社アドオンのため元利均等方式を採用
		/// 本来は「借入金÷返済回数」
		/// </summary>
		/// <param name="Ganpon">所要資金</param>
		/// <param name="Hensai">月額返済額</param>
		/// <param name="Kaisu">何回目の回数</param>
		/// <param name="Geturi">月利</param>
		/// <returns>月額元金返済額を返す</returns>
		public static int GetGankin(int Ganpon, int Hensai, int Kaisu, double Geturi){
			int theTemp;

			if(Kaisu > 1){
				theTemp = GetZansai(Ganpon,Hensai,Kaisu - 1,Geturi) 
					- GetZansai(Ganpon,Hensai,Kaisu,Geturi);
			}else{
				theTemp = Ganpon - GetZansai(Ganpon,Hensai,Kaisu,Geturi);
			}
			return theTemp;
		}

		/// <summary>
		/// 残債額
		/// 信販会社アドオンのため元利均等方式を採用
		/// 本来は「所要資金−返済回数×元金」
		/// </summary>
		/// <param name="Ganpon">所要資金</param>
		/// <param name="Hensai">月額返済額</param>
		/// <param name="Kaisu">何回目返済</param>
		/// <param name="Geturi">月利</param>
		/// <returns>残債額を返す</returns>
		public static int GetZansai(int Ganpon, int Hensai, int Kaisu, double Geturi){
			double theTemp;
			theTemp = (Math.Pow(((double)1 + Geturi),(double)Kaisu) * ((double)Ganpon - (double)Hensai / Geturi) + (double)Hensai / Geturi);
			return Convert.ToInt32(theTemp);
		}

		/// <summary>
		/// 月額利息額
		/// </summary>
		/// <param name="Hensai">月額元利込み返済総額</param>
		/// <param name="Gankin">月額元金返済額</param>
		/// <returns>月額利息額</returns>
		public static int GetRisoku(int Hensai, int Gankin){
			return Hensai - Gankin;
		}
	}
}