lab3_1(delphi)

program lab3_1;
{$APPTYPE CONSOLE}
{$R *.res}
uses
  System.SysUtils;

type
    TArray = array of String;

Function TakeSource: Byte;
const
    CHOOSING_CONSOLE = 1;
    CHOOSING_FILE = 2;
var
    Source: Byte;
    IsCorrect: Boolean;
begin
    Source := 0;
    repeat
        IsCorrect := True;
        try
            Readln(Source);
        except
            Write('Incorrect input!!! Select the source:' + #13#10 + '1:Console'  + #13#10 + '2:File'  + #13#10 + 'Enter 1 or 2: ');
            IsCorrect := False;
        end;
        if (IsCorrect and (Source <> CHOOSING_CONSOLE) and (Source <> CHOOSING_FILE)) then
        begin
            Write('Incorrect input!!! Select the source:' + #13#10 + '1:Console'  + #13#10 + '2:File'  + #13#10 + 'Enter 1 or 2: ');
            IsCorrect := False;
        end;
    until IsCorrect;
    TakeSource := Source;
end;

Function TakeInPath: String;
var
    Path: String;
    IsCorrect: Boolean;
    InFile: TextFile;
begin
    Write('Enter file path: ');
    repeat
        IsCorrect := True;
        Readln(Path);
        if not FileExists(Path) then
        begin
            Write('File is not found' + #13#10 + 'Enter file path: ');
            IsCorrect := False;
        end
        else
            if ((Path[Length(Path)] <> 't') or (Path[Length(Path) - 1] <> 'x') or
                (Path[Length(Path)- 2] <> 't') or (Path[Length(Path)- 3] <> '.')) then
            begin
                Write('File is found, but it is not ".txt" type file' + #13#10 + 'Enter file path: ');
                IsCorrect := False;
            end
            else
            begin
                Assign(InFile, Path);
                try
                    Reset(InFile);
                except
                    Write('Error!!! Program can''t open file!' + #13#10 + 'Enter file path: ');
                    IsCorrect := False;

                end;
            end;
    until IsCorrect;
    CloseFile(InFile);
    TakeInPath := Path;
end;

Function TakeOutPath: String;
var
    Path: String;
    IsCorrect: Boolean;
    OutFile: TextFile;
begin
    Write('Enter file path: ');
    repeat
        IsCorrect := True;
        Readln(Path);
        if ((Path[Length(Path)] <> 't') or (Path[Length(Path) - 1] <> 'x') or
            (Path[Length(Path)- 2] <> 't') or (Path[Length(Path) - 3] <> '.')) then
        begin
            Write('It should be a ".txt" type file' + #13#10 + 'Enter file path: ');
            IsCorrect := False;
        end
        else
        begin
            AssignFile(OutFile, Path);
            try
                Rewrite(OutFile);
            except
                Write('Error!!! There are problems with file!' + #13#10 + 'Enter file path: ');
                IsCorrect := False;
            end;
        end;
    until IsCorrect;
    CloseFile(OutFile);
    TakeOutPath := Path;
end;

Function TakeSentenceFromConsole: String;
var
    Sentence: String;
begin
    Write('Enter the sentence: ');
    Readln(Sentence);
    TakeSentenceFromConsole := Sentence;
end;

Function TakeSentenceFromFile(const Path: String): String;
var
    InFile: TextFile;
    IsCorrect: Boolean;
   Sentence: String;
begin
    IsCorrect := True;
    AssignFile(InFile, Path);
    Reset(InFile);
    try
        Read(InFile,Sentence);
    except
        Writeln('Incorrect file content!!!');
        IsCorrect := False;
    end;
    if ((IsCorrect) and (not Eof(InFile))) then
    begin
        Writeln('Incorrect file content!!!');
        IsCorrect := False;
    end;
    if  not IsCorrect then
        Sentence := '';
    TakeSentenceFromFile := Sentence;
    CloseFile(InFile);
end;

Function TakeSentence(Source: Byte): String;
var
    InPath: String;
    Sentence: String;
begin
    if (Source = 1) then
        Sentence := TakeSentenceFromConsole
    else
    begin
        InPath := TakeInPath;
        Sentence := TakeSentenceFromFile(InPath);
        while (Sentence = '') do
        begin
            InPath := TakeInPath;
            Sentence := TakeSentenceFromFile(InPath);
        end;
    end;
    TakeSentence := Sentence;
end;

Function MakeSentenceNormal(Sentence: String): String;
begin
    Sentence := StringReplace(Sentence, '.', ' ', [rfReplaceAll, rfIgnoreCase]);
    Sentence := StringReplace(Sentence, ',', ' ', [rfReplaceAll, rfIgnoreCase]);
    Sentence := StringReplace(Sentence, ',', ' ', [rfReplaceAll, rfIgnoreCase]);
    Sentence := StringReplace(Sentence, '-', ' ', [rfReplaceAll, rfIgnoreCase]);
    Sentence := StringReplace(Sentence, ';', ' ', [rfReplaceAll, rfIgnoreCase]);
    Sentence := StringReplace(Sentence, ':', ' ', [rfReplaceAll, rfIgnoreCase]);
    Sentence := StringReplace(Sentence, '!', ' ', [rfReplaceAll, rfIgnoreCase]);
    Sentence := StringReplace(Sentence, '?', ' ', [rfReplaceAll, rfIgnoreCase]);
    Sentence := StringReplace(Sentence, '—', ' ', [rfReplaceAll, rfIgnoreCase]);
    Sentence := Trim(Sentence);
    MakeSentenceNormal := Sentence;
end;

Function FindArrayOfWords(Sentence: String): TArray;
var
    ArrayOfWords, TotalArrayOfWords: TArray;
    WordsCounter, Index, i: Integer;
    Word: String;
begin
    Sentence := MakeSentenceNormal(Sentence);
    SetLength(ArrayOfWords, 100);
    WordsCounter := 0;
    Index := Pos(' ', Sentence);
    while (Index <> 0) do
    begin
        Word := Copy(Sentence, 0, Index - 1);
        If (Word <> '') then
        begin
            ArrayOfWords[wordsCounter] := Word;
            WordsCounter := WordsCounter + 1;
        end;
        Sentence := Copy(Sentence, Index + 1);
        Index := Pos(' ', Sentence);
    end;
    if (Sentence <> '') then
    begin
        ArrayOfWords[wordsCounter] := Sentence;
        WordsCounter := WordsCounter + 1;
    end;
    SetLength(TotalArrayOfWords, WordsCounter);
    for i := 0 to (WordsCounter - 1) do
        TotalArrayOfWords[i] := ArrayOfWords[i];
    FindArrayOfWords := TotalArrayOfWords;
end;

Function FindAnswer(ArrayOfWords: TArray): Integer;
var
    Counter, i: Integer;
begin
    Counter := 0;
    for i := 0 to (Length(ArrayOfWords) - 1) do
        if (AnsiCompareText(ArrayOfWords[i],ArrayOfWords[Length(ArrayOfWords) - 1]) = 0) then
            Counter := Counter + 1;
    FindAnswer := Counter;
end;

Procedure OutputToConsole(const Sentence: String;  const Answer: Integer);
begin
    Writeln('Sentence is:', #13#10, Sentence, #13#10, 'Last word founded ',  Answer, ' times.');
end;

Procedure OutputToFile(const Path: String; const Sentence: String;  const Answer: Integer);
var
    OutFile: TextFile;
begin
    AssignFile(OutFile, Path);
    Rewrite(OutFile);
    Writeln(OutFile, 'Sentence is:', #13#10, Sentence, #13#10, 'Last word founded ',  Answer, ' times.');
    CloseFile(OutFile);
    Writeln('Done');
end;

Procedure Output(const Source: Byte; const Sentence: String;  const Answer: Integer);
var
    OutPath: String;
begin
    if (Source = 1) then
        OutputToConsole(Sentence,Answer)
    else
    begin
        OutPath := TakeOutPath;
        OutputToFile(OutPath,Sentence,Answer);
    end;
end;

var
    InputSource, OutputSource: Byte;
    Sentence: String;
    Answer: Integer;
    ArrayOfWords: TArray;
begin
    Write('Welcome to the program that count how many times the last word occurs in a sentence.' + #13#10 + 'Select the source for entering the sentence:' + #13#10 + '1:Console' + #13#10 + '2:File' + #13#10 + 'Enter 1 or 2: ');
    InputSource := TakeSource();
    Sentence := TakeSentence(InputSource);
    ArrayOfWords := FindArrayOfWords(Sentence);
    Answer := FindAnswer(ArrayOfWords);
    Write('Select the source for output: '+ #13#10 + '1:Console' + #13#10 + '2:File' + #13#10 + 'Enter 1 or 2: ');
    OutputSource := TakeSource();
    Output(OutputSource, Sentence, Answer);
    Readln;
end.