package com.tutego.exercise.string;

public class
Decolumnizer {

  //tag::solution-a[]
  private static boolean isSpaceAt( String string, int index ) {
    if ( index >= string.length() )
      return true;
    return string.charAt( index ) == ' ';
  }
  //end::solution-a[]

  //tag::solution-b[]
  private final static int COLUMN_NOT_FOUND = -1;

  private static int findColumnIndex( String[] lines ) {
    int length = lines[ 0 ].length();
    for ( String line : lines )
      length = Math.max( length, line.length() );

    mainLoop:
    for ( int column = 1; column < length - 1; column++ ) {
      for ( String line : lines )
        if ( ! isSpaceAt( line, column ) )
          continue mainLoop;
      return column;
    }

    return COLUMN_NOT_FOUND;
  }
  //end::solution-b[]

  //tag::solution-c[]
  public static void decolumnize( String string ) {
    String[] lines = string.split( "\n" );
    if ( lines.length < 2 ) {
      System.out.println( string );
      return;
    }

    int column = findColumnIndex( lines );

    if ( column == COLUMN_NOT_FOUND ) {
      System.out.println( string );
      return;
    }

    // Left column
    for ( String line : lines )
      System.out.println(
          line.substring( 0, Math.min( line.length(), column ) ).trim()
      );

    // Right column
    for ( String line : lines )
      if ( column < line.length() )
        System.out.println( line.substring( column + 1 ).trim() );
      else
        System.out.println();
  }
  //end::solution-c[]

  public static void main( String[] args ) {

    //    System.out.println( isSpaceAt( " b", 0 ) );
    //    System.out.println( isSpaceAt( " b", 1 ) );
    //    System.out.println( isSpaceAt( " b", 2 ) );
    //    System.out.println( isSpaceAt( " b", 3 ) );

    String text;
    text = """
        I’m dishonest, and a to watch out for,
        dishonest man you    because you can
        can always trust to  never predict when
        be dishonest.        they’re going to do
        Honestly, it’s the   something incredibly
        honest ones you want stupid.""";
    System.out.println( text + "\n=> " );
    decolumnize( text );

    text = """
        I’m dishonest, and a never predict when
        dishonest man you    they’re going to do
        can always trust to  something incredibly
        be dishonest.        stupid.
        Honestly, it’s the
        honest ones you want
        to watch out for,
        because you can""";
    System.out.println( text + "\n=> " );
    decolumnize( text );

    text = """
        I’m dishonest, and a
        dishonest man you
        can always trust to
        be dishonest.

        Honestly, it’s the
        honest ones you want
        to watch out for,
        because you can
        never predict when
        they’re going to do
        something incredibly
        stupid.""";
    System.out.println( text + "\n=> " );
    decolumnize( text );

    text = """
        I’m dishonest, and a never predict when
        dishonest man you    they’re going to do
        can always trust to  something incredibly
        be dishonest.
                             stupid.
        Honestly, it’s the
        honest ones you want
        to watch out for,
        because you can""";
    System.out.println( text + "\n=> " );
    decolumnize( text );

    text = """
        I’m dishonest, and a    never predict when
        dishonest man you       they’re going to do
        can always trust to     something incredibly
        be dishonest.           stupid.
        Honestly, it’s the
        honest ones you want
        to watch out for,
        because you can""";
    System.out.println( text + "\n=> " );
    decolumnize( text );

    decolumnize( "" );
    decolumnize( "One line" );
  }
}