unit LoanItUnit;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils, FileUtil, LResources, Forms, Controls, Graphics, Dialogs,
  StdCtrls, OutPutUnit, math;

type

  { TLoanItFrm }

  TLoanItFrm = class(TForm)
    PrintChk: TCheckBox;
    DayEdit: TEdit;
    YearEdit: TEdit;
    MonthEdit: TEdit;
    Label7: TLabel;
    Label8: TLabel;
    Label9: TLabel;
    NameEdit: TEdit;
    Label6: TLabel;
    ResetBtn: TButton;
    AmortizeBtn: TButton;
    ReturnBtn: TButton;
    AmountEdit: TEdit;
    InterestEdit: TEdit;
    YearsEdit: TEdit;
    PayPerYrEdit: TEdit;
    RePayEdit: TEdit;
    Label1: TLabel;
    Label2: TLabel;
    Label3: TLabel;
    Label4: TLabel;
    Label5: TLabel;
    procedure AmortizeBtnClick(Sender: TObject);
    procedure FormShow(Sender: TObject);
    procedure ResetBtnClick(Sender: TObject);
    procedure Heading(Sender: TObject);
  private
    { private declarations }
  public
    { public declarations }
  end; 

var
  LoanItFrm: TLoanItFrm;

implementation

{ TLoanItFrm }

procedure TLoanItFrm.ResetBtnClick(Sender: TObject);
begin
     NameEdit.Text := '';
     MonthEdit.Text := '';
     DayEdit.Text := '';
     YearEdit.Text := '';
     YearsEdit.Text := '30';
     AmountEdit.Text := '10000';
     InterestEdit.Text := '6.5';
     PayPerYrEdit.Text := '12';
     RepayEdit.Text := '';
end;

procedure TLoanItFrm.FormShow(Sender: TObject);
begin
  ResetBtnClick(self);
end;

procedure TLoanItFrm.AmortizeBtnClick(Sender: TObject);
VAR
   no_per_year, year_payed, month_payed, day, month, j, k : integer;
   fraction, interest, numerator, denominator, payment, total_interest : double;
   amount, interest_payment, total_payed, pcnt_interest, years, no_years : double;
   aname, astring : string;
   outline : string;
begin
   aname := NameEdit.Text;
   no_per_year := StrToInt(PayPerYrEdit.Text);
   day := StrToInt(DayEdit.Text);
   month := StrToInt(MonthEdit.Text);
   years := StrToFloat(YearEdit.Text);
   amount := StrToFloat(AmountEdit.Text);
   no_years := StrToFloat(YearsEdit.Text);
   pcnt_interest := StrToFloat(InterestEdit.Text);

   interest := pcnt_interest / 100.0;
   numerator := interest * amount /  no_per_year ;
   denominator := 1.0 - (1.0 / power((interest / no_per_year + 1.0),
                            (no_per_year * no_years) ) );
   payment := numerator / denominator;
   outline := format('%10.2f',[payment]);
   repayEdit.Text := outline;

   if PrintChk.Checked = false then exit;
   OutPutFrm.RichEdit.Clear;
//   OutPutFrm.RichEdit.Lines.Add(outline);
   if (no_per_year < 12) then
      fraction := 12.0 / no_per_year else fraction := 1.0;
   OutPutFrm.RichEdit.Lines.Add('Payment Schedule Program by W. G. Miller');
   OutPutFrm.RichEdit.Lines.Add('');
   OutPutFrm.RichEdit.Lines.Add('----------------------------------------------------------------------------');
   OutPutFrm.RichEdit.Lines.Add('');
   astring := 'Name of Borrower : ';
   astring := astring + aname;
   OutPutFrm.RichEdit.Lines.Add(astring);
   outline := format('Amount borrowed := $%12.2f at %5.2f percent over %2.1f years.',
           [amount,pcnt_interest,no_years]);
   total_interest := 0.0;
   total_payed := 0.0;
   for j := 1 to round(no_years) do
   begin
       Heading(self);
       for k := 1 to no_per_year do
       begin
          year_payed := round(years) + j - 1 ;
          month_payed := round(k * fraction + (month - fraction));
          if (month_payed > 12) then
          begin
             year_payed := year_payed + 1;
             month_payed := month_payed - 12;
          end;
          interest_payment := amount * interest / no_per_year;
          amount := amount - payment + interest_payment;
          total_interest := total_interest + interest_payment;
          total_payed := total_payed + payment;
          outline := format(' %2d/%2d/%2d %12.2f %12.2f %12.2f %12.2f %12.2f',
                  [month_payed,day,year_payed,payment,interest_payment,
                  amount,total_interest,total_payed]);
          OutPutFrm.RichEdit.Lines.Add(outline);
       end; // next k
       OutPutFrm.RichEdit.Lines.Add('');
   OutPutFrm.RichEdit.Lines.Add('----------------------------------------------------------------------------');
   end; // next j
   OutPutFrm.ShowModal;
end;

procedure TLoanItFrm.Heading(Sender: TObject);
begin
   OutPutFrm.RichEdit.Lines.Add('----------------------------------------------------------------------------');
   OutPutFrm.RichEdit.Lines.Add('PAYMENT        PAYMENT      INTEREST      BALANCE      TOTAL           TOTAL');
   OutPutFrm.RichEdit.Lines.Add('NUMBER         AMOUNT       PAYED         REMAINING    INTEREST        PAID');
   OutPutFrm.RichEdit.Lines.Add('----------------------------------------------------------------------------');
end;

initialization

 {$I loanitunit.lrs}

end.