unit MainUnit;

interface

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

type
  TSubscriber = record
    yearOfReg: integer;
    surname: string[15];
    telephoneNumber: int64;
  end;
  TSubscriberArray = array of TSubscriber;
  TIndexArray = array of integer;
  TMainForm = class(TForm)
    SubscribersStringGrid: TStringGrid;
    MainMenu: TMainMenu;
    InstructionMenu: TMenuItem;
    Developermenu: TMenuItem;
    AddButton: TButton;
    DeleteButton: TButton;
    EditButton: TButton;
    SurnameEdit: TEdit;
    SurnameLabel: TLabel;
    YearLabel: TLabel;
    CountLabel: TLabel;
    ShowButton: TButton;
    YearSpinEdit: TSpinEdit;
    procedure FormShow(Sender: TObject);
    procedure ShowSubscribers(CurrSub: TSubscriber);
    procedure FormCreate(Sender: TObject);
    procedure ShowButtonClick(Sender: TObject);
    procedure SurnameEditKeyPress(Sender: TObject; var Key: Char);
    procedure DeleteButtonClick(Sender: TObject);
    procedure AddButtonClick(Sender: TObject);
    procedure EditButtonClick(Sender: TObject);
    procedure DevelopermenuClick(Sender: TObject);
    procedure InstructionMenuClick(Sender: TObject);
    procedure FormCloseQuery(Sender: TObject; var CanClose: Boolean);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
  procedure ReadSubsFromFile();
  procedure WriteSubsInFile();
  procedure SortBySurname(Subs: TSubscriberArray);
  function IsInputCorrect(CurrEdit: TEdit): boolean;
  function IsSubscriberFileEmpty(): boolean;
  function isSameString(Full: string; Part: string): boolean;

const
   MAX_SURNAME_LENGTH = 15;
   MIN_SURNAME_LENGTH = 3;
   MAX_TELEPHONE_LENGTH = 15;
   MIN_TELEPHONE_LENGTH = 1;
   MIN_YEAR_OF_REGISTRATION_LENGTH = 4;
   MIN_YEAR_OF_REGISTRATION = 1980;
   MAX_YEAR_OF_REGISTRATION = 2022;
   LETTERS = ['A'..'Z', 'a'..'z', 'А'..'Я', 'а'..'Я'];
   DIGITS = ['0'..'9'];

var
  MainForm: TMainForm;
  Subscribers: TSubscriberArray;
  IndexArray: TIndexArray;
  SelectedSub: integer;
  FullFileName: string;

implementation

{$R *.dfm}

uses
   AddUnit, EditUnit;

procedure SortBySurname(Subs: TSubscriberArray);
var
   i, j: integer;
   Temp: TSubscriber;
begin
   for i := 1 to high(Subs) do
   begin
      j := i;
      while Subs[j].surname < Subs[j - 1].surname do
      begin
         Temp := Subs[j - 1];
         Subs[j - 1] := Subs[j];
         Subs[j] := Temp;
      end;
   end;
end;

procedure ReadSubsFromFile();
var
   i: integer;
   RecordFile: File of TSubscriber;
begin
   i := 0;
   AssignFile(RecordFile, FullFileName);
   Reset(RecordFile);
   setlength(Subscribers, 0);
   while not EOF(RecordFile) do
   begin
      setlength(Subscribers, (length(Subscribers) + 1));
      Read(RecordFile, Subscribers[i]);
      inc(i);
   end;
   CLose(RecordFile);
end;

procedure WriteSubsInFile();
var
   i: integer;
   RecordFile: File of TSubscriber;
begin
   AssignFile(RecordFile, FullFileName);
   Rewrite(RecordFile);
   for i := 0 to high(Subscribers) do
   begin
      Write(RecordFile, Subscribers[i]);
   end;
   Close(RecordFile);
end;

function isSameString(Full: string; Part: string): boolean;
var
   IsSame: boolean;
   i: integer;
begin
   IsSame := true;
   i := 1;
   while (i <= length(part)) and IsSame do
   begin
      if full[i] <> part[i] then
         IsSame := false;
      inc(i);
   end;
   Result := IsSame;
end;

procedure TMainForm.ShowSubscribers(CurrSub: TSubscriber);
var
   i, j: integer;
begin
   setlength(IndexArray, 0);
   ReadSubsFromFile;
   sortBySurname(Subscribers);
   j := 0;
   SubscribersStringGrid.RowCount := 1;
   setlength(IndexArray,1);
   for i := 0 to high(Subscribers) do
   begin
      if (IsSameString(Subscribers[i].surname ,CurrSub.surname))
      and (CurrSub.yearOfReg <= Subscribers[i].yearOfReg) then
      begin
         SubscribersStringGrid.RowCount := SubscribersStringGrid.RowCount + 1;
         SubscribersStringGrid.Cells[0, j + 1] := Subscribers[i].surname;
         SubscribersStringGrid.Cells[1, j + 1] := intToStr(Subscribers[i].telephoneNumber);
         SubscribersStringGrid.Cells[2, j + 1] := IntToStr(Subscribers[i].yearOfReg);
         setlength(IndexArray,(length(IndexArray) + 1));
         IndexArray[j + 1] := i;
         inc(j);
      end;
   end;
   CountLabel.Caption := 'Количетсво абонентов зарагестрированных после ' +
                          YearSpinEdit.text + ' года: ' + IntToStr(j);
   CountLabel.Visible := true;
end;

procedure TMainForm.SurnameEditKeyPress(Sender: TObject; var Key: Char);
begin
   if (Key <> #08) then
   begin
      if not(Key in LETTERS) then
         Key := #0;
   end;
end;

procedure TMainForm.ShowButtonClick(Sender: TObject);
var
   CurrSub: TSubscriber;
begin
   if IsInputCorrect(SurnameEdit) then
   begin
      if not IsSubscriberFileEmpty then
      begin
         CurrSub.yearOfReg := YearSpinEdit.Value;
         CurrSub.surname := SurnameEdit.text;
         ShowSubscribers(CurrSub);
      end
      else
         Application.MessageBox('Файл с абонентами пуст!', 'Ошибка!', MB_ICONERROR);
   end
   else
      Application.MessageBox('Введены некорректные данные!', 'Ошибка!', MB_ICONERROR);
end;

function IsSubscriberFileEmpty(): boolean;
var
   RecordFile: File of TSubscriber;
begin
   AssignFile(RecordFile, FullFileName);
   Reset(RecordFile);
   Result := FileSize(RecordFile) = 0;
   Close(RecordFile);
end;

function IsInputCorrect(CurrEdit: TEdit): boolean;
var
   IsCorrect: boolean;
   i: integer;
   Text: string;
begin
   IsCorrect := true;
   i := 1;
   Text := CurrEdit.Text;
   if (length(Text) > CurrEdit.MaxLength) then
      IsCorrect := false
   else
      while (i <= length(Text)) and IsCorrect do
      begin
         if not (Text[i] in LETTERS) then
            IsCorrect := false;
         inc(i);
      end;
   Result := IsCorrect;
end;

procedure TMainForm.AddButtonClick(Sender: TObject);
begin
   MainForm.hide;
   AddForm.show;
end;

procedure TMainForm.DeleteButtonClick(Sender: TObject);
var
   Index, i: integer;
begin
   Index := IndexArray[SubscribersStringGrid.Row];
   for i := index to (high(Subscribers) - 1) do
      Subscribers[i] := Subscribers[i + 1];
   SetLength(Subscribers, (length(Subscribers) - 1));
   WriteSubsInFile;
   if SubscribersStringGrid.RowCount > 2 then
      ShowButtonClick(Sender)
   else
   begin
      SubscribersStringGrid.RowCount := 1;
      CountLabel.Visible := false;
   end;
end;

procedure TMainForm.DevelopermenuClick(Sender: TObject);
begin
   MessageDlg('Раводин Александр. Группа 151002', MtInformation, [mbOk], 0);
end;

procedure TMainForm.EditButtonClick(Sender: TObject);
begin
   SelectedSub := IndexArray[SubscribersStringGrid.Row];
   MainForm.hide;
   EditForm.show;
end;

procedure TMainForm.FormCloseQuery(Sender: TObject; var CanClose: Boolean);
begin
   CanClose := False;
    if MessageDlg('Вы уверены, что хотите выйти?',mtConfirmation, mbOKCancel, 0) = mrOk then
    begin
        CanClose := True;
    end;
end;

procedure TMainForm.FormCreate(Sender: TObject);
const
   FILE_NAME = 'records.bin';
begin
   FullFileName := GetCurrentDir + '\' + FILE_NAME;
   YearSpinEdit.MinValue := MIN_YEAR_OF_REGISTRATION;
   YearSpinEdit.MaxValue := MAX_YEAR_OF_REGISTRATION;
   YearSpinEdit.MaxLength := MIN_YEAR_OF_REGISTRATION_LENGTH;
   SubscribersStringGrid.Cells[0, 0] := '                    Фамилия';
   SubscribersStringGrid.Cells[1, 0] := '             Номер телефона';
   SubscribersStringGrid.Cells[2, 0] :=  'Год регистрации';
end;

procedure TMainForm.FormShow(Sender: TObject);
const
   NUM_COL_COEF = 2.7;
   SUR_COL_COEF = 2.5;
   YEAR_COL_COEF = 5.1;
var
   FrameWidth: integer;
begin
   FrameWidth := SubscribersStringGrid.Width;
   SubscribersStringGrid.ColWidths[0] :=  Round(FrameWidth / SUR_COL_COEF);
   SubscribersStringGrid.ColWidths[1] :=  Round(FrameWidth / NUM_COL_COEF);
   SubscribersStringGrid.ColWidths[2] :=  Round(FrameWidth / YEAR_COL_COEF);
   CountLabel.Visible := false;
   SubscribersStringGrid.RowCount := 1;
end;

procedure TMainForm.InstructionMenuClick(Sender: TObject);
begin
   MessageDlg('Главное окно приложения.' + #13#10 + #13#10 +
               'Абоненты отображаются в таблице в соответсвии с введёнными данными.'
               + #13#10 + 'Для изменения данных в базе используйте клавиши:' + #13#10
               + 'Добавить;' + #13#10 + 'Изменить;' + #13#10 + 'Удалить.' + #13#10 +
               'Количество абонентов, зарегистрированных с ХХХХ года отображается снизу.'
               , MtInformation, [mbOk], 0);
end;

end.