laba3.2 (Delphi)

program laba3_2;
uses
    System.SysUtils;

function InputLineFromConsole(): String; Forward;
function InputLineFromFile(Path: String): String; Forward;
function InputPath(): String; Forward;
procedure OutputToFile(Path: String; NumberOfVowels: Integer; NumberOfConsonants: Integer); Forward;
procedure OutputToConsole(NumberOfVowels: Integer; NumberOfConsonants: Integer); Forward;

function ChooseSource(): Integer;
var
    Choice: Integer;
    IsCorrect: Boolean;
begin
    Writeln('Choose where to enter data. Enter 1 or 2:');
    Writeln('1.File');
    Writeln('2.Console');
    repeat
        IsCorrect := True;
        try
            Readln(Choice);
        except
            Writeln('Enter an integer!');
            IsCorrect := False;
        end;

        if (IsCorrect) and (Choice <> 1) and (Choice <> 2) then
        begin
            Writeln('Enter 1 or 2!');
            IsCorrect := False;
        end;
    until IsCorrect;
    ChooseSource := Choice;
end;

function InputData(Source: Integer): String;
var
    Line, PathInput: String;
begin
    Case Source of
        1:
        begin
            Writeln('Enter the absolute link to the input file');
            PathInput := InputPath();
            Line := InputLineFromFile(PathInput);
        end;
        2:
        begin
            Line := InputLineFromConsole();
        end;
    end;
    InputData := Line;
end;

function InputPath(): String;
var
    Path: String;
    IsCorrect: Boolean;
begin
    repeat
        IsCorrect := True;
        Readln(Path);

        if not FileExists(Path) then
        begin
            IsCorrect := False;
            Writeln('File not found! Enter the absolute link to the file');
        end;
    until IsCorrect;
    InputPath := Path;
end;

function InputLineFromFile(Path: String): String;
var
    Line: String;
    InputFile: TextFile;
begin
    AssignFile(InputFile, Path);
    Reset(InputFile);
    if not eof(InputFile) then
        Readln(InputFile, Line)
    else
    begin
        Writeln('The line is missing from your file! Enter it from console');
        Line := InputLineFromConsole();
    end;
    CloseFile(InputFile);
    InputLineFromFile := Line;
end;

function InputLineFromConsole(): String;
var
    Line: String;
    IsCorrect: Boolean;
begin
    Writeln('Enter the line');
    repeat
        IsCorrect := True;
        Readln(Line);
        if (Length(Line) = 0) then
        begin
            Writeln('You entered an empty line! Repeat enter');
            IsCorrect := False;
        end;
    until IsCorrect;
    InputLineFromConsole := Line;
end;

function CalculateVowels(Line: String): Integer;
const
    VOWELS_LETTERS = ['а','о','у','ы','э','я','ё','ю','и','е'];
var
    Amount, I: Integer;
begin
    Amount := 0;
    Line := AnsiLowerCase(Line);
    for I := 1 to Length(Line) do
    begin
        if CharInSet(AnsiString(Line)[I], VOWELS_LETTERS) then
            Amount := Amount + 1;
    end;
    CalculateVowels := Amount;
end;

function CalculateConsonants(Line: String): Integer;
const
     CONSONANTS_LETTERS = ['б','в','г','д','ж','з','й','к','л','м','н','п','р','с','т','ф','х','ц','ч','ш','щ'];
var
    Amount, I: Integer;
begin
    Amount := 0;
    Line := AnsiLowerCase(Line);
    for I := 1 to High(Line) do
    begin
        if CharInSet(AnsiString(Line)[i], CONSONANTS_LETTERS) then
            Inc(Amount);
    end;
    CalculateConsonants := Amount;
end;

procedure OutputData(Source: Integer; NumberOfVowels: Integer; NumberOfConsonants: Integer);
var
    PathOutput: String;
begin
    if Source = 1 then
    begin
        Writeln;
        Writeln('Enter the absolute link to the output file');
        PathOutput := InputPath();
        OutputToFile(PathOutput, NumberOfVowels, NumberOfConsonants);
    end
    else
    begin
        OutputToConsole(NumberOfVowels, NumberOfConsonants);
    end;
end;

procedure OutputToFile(Path: String; NumberOfVowels: Integer; NumberOfConsonants: Integer);
var
    OutputFile: TextFile;
begin
    AssignFile(OutputFile, Path);
    Reset(OutputFile);
    Rewrite(OutputFile);
    Writeln(OutputFile,'Vowels: ', NumberOfVowels, ' Consonants: ',NumberOfConsonants );
    CloseFile(OutputFile);
    Writeln('The data is successfully recorded in the file');
end;

procedure OutputToConsole(NumberOfVowels: Integer; NumberOfConsonants: Integer);
begin
    Writeln('Vowels: ', NumberOfVowels, ' Consonants: ',NumberOfConsonants );
end;

procedure Main();
var
    Source, numberOfVowels, numberOfConsonants: Integer;
    Line: String;
begin
    Source := ChooseSource();
    Line := InputData(Source);
    NumberOfVowels := CalculateVowels(Line);
    NumberOfConsonants := CalculateConsonants(Line);
    OutputData(Source, NumberOfVowels, NumberOfConsonants);
    Readln;
end;

begin
    Main;
end.