using System;

namespace cs_gankin
{
	/// <summary>
	/// Class1 の概要の説明です。
	/// 元金均等方式の返済シュミレーション
	/// 端数の扱いはここでは計算しない
	/// </summary>
	public class GankinHensai
	{
		/// <summary>
		/// 元金返済額の計算
		/// 引数'Kirisute'により丸められた返済額を算出
		/// </summary>
		/// <param name="Ganpon">所要資金</param>
		/// <param name="HensaiKaisu">返済回数</param>
		/// <param name="Kirisute">切り捨てる桁数</param>
		/// <returns>月額元金返済額</returns>
		public static int GetGankin(int Ganpon, int HensaiKaisu, double Kirisute){
			int theTemp;
			double theRoundDown = Math.Pow((double)10,Kirisute);
			theTemp             = Ganpon / HensaiKaisu / (int)theRoundDown;
			return theTemp * (int)theRoundDown;
		}

		/// <summary>
		/// 返済後の残債額を算出
		/// </summary>
		/// <param name="Ganpon">所要資金</param>
		/// <param name="Gankin">月額元金返済額額</param>
		/// <param name="Kaisu">何回目の返済</param>
		/// <returns>返済後残債額</returns>
		public static int GetZansai(int Ganpon, int Gankin, int Kaisu){
			return Ganpon - (Gankin * Kaisu);
		}

		/// <summary>
		/// 返済に伴う利息額の算出
		/// </summary>
		/// <param name="Zansai">残債額</param>
		/// <param name="Geturi">月利</param>
		/// <returns>月額利息額</returns>
		public static int GetRisoku(int Zansai, double Geturi){
			return Convert.ToInt32(Convert.ToDouble(Zansai) * Geturi);
		}

		/// <summary>
		/// 月額返済額
		/// </summary>
		/// <param name="Gankin">月額元金返済額</param>
		/// <param name="Risoku">月額利息額</param>
		/// <returns>月額返済額合計</returns>
		public static int GetHensaiGaku(int Gankin, int Risoku){
			return Gankin + Risoku;
		}
	}
}