unit CountyNumberDelete;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes,
  Vcl.Graphics, Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls;

type
  TCountyNumberDeleteFrame = class(TFrame)
    LBPK: TLabel;
    GroupBox1: TGroupBox;
    Label1: TLabel;
    Label2: TLabel;
    Label5: TLabel;
    EditNumberCounty: TEdit;
    EditNameCounty: TEdit;
    EditRegion: TEdit;
    BtnPrev: TButton;
    BtnNext: TButton;
    BtnDelete: TButton;
    procedure FrameEnter(Sender: TObject);
    procedure BtnDeleteClick(Sender: TObject);
    procedure BtnPrevClick(Sender: TObject);
    procedure BtnNextClick(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
    procedure FillComponents();
  end;

implementation

{$R *.dfm}

uses BidirectionalCountyNumber, CountyNumber, Main, MainView,
  BidirectionalCandidate;

var
    CurrentCountyNumber : Integer;

Function GetCountyNumber() : TCountyNumber;
var
    TempHead : PCountyNumberList;
    CurrentCountyNumberNode : TCountyNumber;
    Counter : Integer;
begin
    TempHead := Main.CountyNumberList.Head;
    CurrentCountyNumberNode := NIL;
    Counter := 0;

    While TempHead <> NIL Do
    Begin
        if Counter = CurrentCountyNumber then
        begin
            CurrentCountyNumberNode := TempHead.CountyNumber;
            break
        end
        else
            Inc(Counter);
        TempHead := TempHead^.Next;
    End;
    GetCountyNumber := CurrentCountyNumberNode;
end;

Function CheckOnExistCandidateWithSelfCountyNumber(CountyNumberID : Integer) : Boolean;
var
    TempHeadCandidateList : PCandidateList;
begin
    CheckOnExistCandidateWithSelfCountyNumber := false;
    TempHeadCandidateList := Main.CandidateList.Head;

    while TempHeadCandidateList <> NIL do
    begin

        if TempHeadCandidateList.Candidate.CountyNumberId = CountyNumberID then
        begin
            CheckOnExistCandidateWithSelfCountyNumber := True;
            break;
        end;

        TempHeadCandidateList := TempHeadCandidateList^.Next;
    end;
end;

procedure TCountyNumberDeleteFrame.BtnDeleteClick(Sender: TObject);
begin
    try
        if NOT CheckOnExistCandidateWithSelfCountyNumber(StrToInt(LBPK.Caption)) then
        begin
            Main.CountyNumberList.DeleteCountyNumberByID(StrToInt(LBPK.Caption));
            Application.MessageBox(PChar('Успешное удаление округа - ' + EditNumberCounty.Text),
                                         'Удаление округа',MB_OK+MB_ICONINFORMATION);
            Self.FrameEnter(NIL);
        end
        else
        begin
            Application.MessageBox('Невозможно удалить округ, так как он используется кандидатом(-ами). Сначала удалите кандидата(-ов) или измените параметры округа на актуальные.','Удаление округа',MB_OK+MB_ICONINFORMATION);
        end;
    except
        On E : Exception do
            Application.MessageBox(PChar('Ошибка' + E.Message),'Удаление округа', MB_OK + MB_ICONSTOP);
    end;
end;

procedure TCountyNumberDeleteFrame.BtnNextClick(Sender: TObject);
begin
    if CurrentCountyNumber <> Main.CountyNumberList.Count - 1 then
    begin
        Inc(CurrentCountyNumber);
        FillComponents;
    end;
end;

procedure TCountyNumberDeleteFrame.BtnPrevClick(Sender: TObject);
begin
    if CurrentCountyNumber <> 0 then
    begin
        Dec(CurrentCountyNumber);
        FillComponents;
    end;
end;

Procedure TCountyNumberDeleteFrame.FillComponents();
var
    CountyNumber : TCountyNumber;
begin
    CountyNumber := GetCountyNumber;

    if CountyNumber <> NIL then
    begin
        LBPK.Caption := CountyNumber.IdCountyNumber.ToString;
        EditNumberCounty.Text := CountyNumber.Number.ToString;
        EditNameCounty.Text := CountyNumber.Name;
        EditRegion.Text := CountyNumber.Region;
        BtnDelete.Enabled := True;
        BtnPrev.Enabled := True;
        BtnNext.Enabled := True;
    end
    else
    begin
        LBPK.Caption := '';
        EditNumberCounty.Text := '';
        EditNameCounty.Text := '';
        EditRegion.Text := '';
        BtnDelete.Enabled := False;
        BtnPrev.Enabled := False;
        BtnNext.Enabled := False;
    end;
end;

procedure TCountyNumberDeleteFrame.FrameEnter(Sender: TObject);
begin
    CurrentCountyNumber := 0;
    FillComponents;
end;

end.