unit UnitAddHomework;

interface

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

type
  TfrmAddHomework = class(TForm)
    lblAddHomework: TLabel;
    ledtHomeworkName: TLabeledEdit;
    btnAddHomework: TButton;
    btnClose: TButton;
    cboAHSelectGroup: TComboBox;
    Label1: TLabel;
    procedure btnCloseClick(Sender: TObject);
    procedure btnAddHomeworkClick(Sender: TObject);
    procedure ledtHomeworkNameKeyPress(Sender: TObject; var Key: Char);
    procedure FormShow(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  frmAddHomework: TfrmAddHomework;

implementation

uses UnitGroupProfiles, UnitdmDatabasecomponents;

{$R *.dfm}

procedure ErrorOutput(ErrorMessage : string; Ledt : TLabeledEdit);
begin
  {  ----------  Highlight the input with an error  ----------  }
  Ledt.Color := clRed;  // Turn the input into a red color
  ledt.Font.Color := clWhite;  // Turn the text into the input to white
  PlaySound('SYSTEMEXCLAMATION', 0, SND_ASYNC);  //  Play error sound
  Showmessage(ErrorMessage);  //  Output an error message
  {  ----------  Remove the highlight  ----------}
  Ledt.Color := clWhite;  // Make the input white again
  ledt.Font.Color := clBlack;  //  Make the font black again
end;

procedure TfrmAddHomework.btnAddHomeworkClick(Sender: TObject);
var
  ErrorMessagePram : string;
begin
  { ----------  Validation  ---------- }
  { ---------- Assessment Name ---------- }
  { ----------  Length Check  ---------- }
  if Length(ledtHomeworkName.Text) > 50 then  //  Check to see if input length is greater than 50
  begin
    ErrorMessagePram := '';
    ErrorMessagePram := 'ERROR: Homework name must be 50 characters or less';
    ErrorOutput(ErrorMessagePram, ledtHomeworkName);
  end    //  End of else if statement

  { ----------  Presence Check  ---------- }
  else if ledtHomeworkName.Text = '' then  //  if the assessment title is empty
  begin
    ErrorMessagePram := '';
    ErrorMessagePram := 'ERROR: Please enter a homework name';
    ErrorOutput(ErrorMessagePram, ledtHomeworkName);
  end  // end else if

  { ----------  Group Name  ---------- }

  {  ----------  Presence Check  ----------  }
  else if cboAHSelectGroup.Text = '' then  // Check to see if input is empty
  begin
    ErrorMessagePram := '';
    ErrorMessagePram := 'ERROR: Please enter a Group Name';
    ErrorOutput(ErrorMessagePram, ledtAHGroupName);
  end    //  End of else if statement

  else
  begin
    { ----------  Add a column as an Homework  ---------- }
    with dmDatabaseComponents.adoUnitAddHomework do
    begin
      SQL.Clear; // Initialize the SQL
      // Set SQL
      SQL.Text:='ALTER TABLE [HOMEWORK'+cboAHSelectGroup.Items[cboAHSelectGroup.ItemIndex]+'] ADD ['+ledtHomeworkName.Text+'] varchar(50)';
      ExecSQL;  // Execute SQL
    end;  //  End of with statement

   Showmessage('Homework has successfully been added');  // Produce a confirmation message
   {  ----------    ----------  }
   // Once homework is saved clear inputs
   ledtHomeworkName.Text := '';
   cboAHSelectGroup.Text := '';
  end;
end;

procedure TfrmAddHomework.btnCloseClick(Sender: TObject);
begin
  close;
end;

procedure TfrmAddHomework.FormShow(Sender: TObject);
begin
  with dmDatabaseComponents.adoASDisplayGroup do
  begin
    Close;
    SQL.Clear;  //  Initialize the SQL
    //  Set the SQL
    SQL.Text := 'SELECT GroupName FROM GroupDetails';
    ExecSQL;  //  Execute the SQL
    Open;

    cboAHSelectGroup.Clear; // Clear all contents of the combo box
    First;  //  Start at the first record
    while not Eof do
    begin
      //  Add the group name to the current contents of the combo box
      cboAHSelectGroup.Items.Add(FieldByName('GroupName').AsString);
      Next;  //  Move to the next record
    end;  //  End of while loop
  end;  //  end of with statement

end;

procedure TfrmAddHomework.ledtHomeworkNameKeyPress(Sender: TObject;
  var Key: Char);
begin
  if (not (Key in ['A'..'Z','a'..'z','-','/','0'..'9', #32])) then // If a letter key is not pressed
  begin
    PlaySound('SYSTEMEXCLAMATION', 0, SND_ASYNC);  //  Play error sound
    Showmessage('ERROR: Invalid key entered for group name');  //  Produce an error message
    Key := #0; // Remove the last character
  end; // end if
end;

end.