2_3 pre_prod

program Project1;
{$APPTYPE CONSOLE}
uses
   SysUtils;
type
   TMatrix = array of array of Integer;
const
   ErrorMessage = 'Error! N should be natural value from 1 to 2147483647';
   ReadFileError = 'Error! File contains invalid data';
   FileCompositionError = 'Error! Your file is composed incorrectly';
   OutputFileName = 'output.txt';
   NoSuchFileError = 'Error! No such file. ';
   WritePermissionError = 'Error! Chech ''w'' permission of this file';

procedure TransposeMatrix(var MyMatrix : TMatrix);
var
   LastIndex, i, j, Temp : Integer;
begin
   LastIndex := High(MyMatrix);
   for i := 0 to LastIndex do
      for j := i to LastIndex do
      begin
         Temp := MyMatrix[i][j];
         MyMatrix[i][j] := MyMatrix[j][i];
         MyMatrix[j][i] := Temp;
      end;
end;

function EnterInputFileName() : string;
var
   Name : string;
begin
   Writeln('Enter input file name');
   Readln(Name);
   while not FileExists(Name) do
   begin
      Writeln(NoSuchFileError, 'Input file name again');
      Readln(Name);
   end;
   EnterInputFileName := Name;
end;

function EnterOutputFileName() : string;
var
   Name : string;
begin
   Writeln('Enter output file name');
   Readln(Name);
   EnterOutputFileName := Name;
end;

procedure ReadFile(var Matrix : TMatrix; Order : Integer; var InputFile : TextFile);
var
   LastIndex, i, j : Integer;
begin
   SetLength(Matrix, Order, Order);
   LastIndex := Order - 1;
   Reset(InputFile);
   for i := 0 to LastIndex do
      for j := 0 to LastIndex do
         Read(InputFile, Matrix[i][j]);
end;

procedure OutputAnswer(Matrix : TMatrix; OutputFileName : string);
var
   OutputFile : TextFile;
   i, j, LastIndex : Integer;
begin
   try
      AssignFile(OutputFile, OutputFileName);
      if not FileExists(OutputFileName) then
         Rewrite(OutputFile)
      else
         Append(OutputFile);
      LastIndex := High(Matrix);
      for i := 0 to LastIndex do
      begin
         for j := 0 to LastIndex do
         begin
            Write(OutputFile, Matrix[i][j],' ');
            Write(Matrix[i][j],' ');
         end;
         Writeln(OutputFile, '');
         Writeln('');
      end;
      Writeln(OutputFile, '');
      Writeln('');
   except
      Writeln(WritePermissionError);
      CloseFile(OutputFile);
   end;
   CloseFile(OutputFile);
end;

function CheckOrder(var InputFile : TextFile) : Integer;
var
   Item : Integer;
   AssumedSize, Counter, i : Integer;
   IsValid : Boolean;
begin
   AssumedSize := 0;
   IsValid := True;
   Reset(InputFile);
   while not EoLN(InputFile) do
   begin
      Read(InputFile, Item);
      Inc(AssumedSize);
   end;
   Readln(InputFile);
   for i := 2 to AssumedSize do
   begin
      Counter := 0;
      while not EoLN(InputFile) do
      begin
         Read(InputFile, Item);
         Inc(Counter);
      end;
      if Counter <> AssumedSize then
      begin
         IsValid := False;
      end;
      Readln(InputFile);
   end;
   if not EoF(InputFile) then
      IsValid := False;
   if IsValid then
      CheckOrder := AssumedSize
   else
      CheckOrder := -1;
end;

procedure Main;
var
   Matrix : TMatrix;
   InputFile : TextFile;
   InputFileName, OutputFileName : string;
   Order : Integer;
begin
   Writeln('This program can transpose the NxN matrix!');
   try
      InputFileName := EnterInputFileName();
      AssignFile(InputFile, InputFileName);
      Reset(InputFile);
      Order := CheckOrder(InputFile);
      if Order <> -1 then
      begin
         ReadFile(Matrix, Order, InputFile);
         OutputFileName := EnterOutputFileName();
         OutputAnswer(Matrix, OutputFileName);
         TransposeMatrix(Matrix);
         OutputAnswer(Matrix, OutputFileName);
      end
      else
         Writeln(FileCompositionError);
   except
      Writeln(ReadFileError);
   end;
   CloseFile(InputFile);
   Readln;
end;


begin
   Main;
end.