//  Windows.swift  Copyright (c) Kari Laitinen

//  http://www.naturalprogramming.com

//  2014-10-07  File created.
//  2016-11-09  Last modification.

/*  This program displays simple character-based 'windows' to
    the Terminal screen.

    The classes of this program provide an example of
    a class hierarchy.

    Each class has at least one constructor. Constructors
    are commondly called initializers in Swift.
*/


import Foundation

/* Class Window is the topmost class in the class hierarchy.
   A Window could look like

////////////
////////////
////////////
////////////

In this window the width is 12, the height is 4, and the 
background character is '/'
*/

class  Window
{
   var MAXIMUM_WINDOW_WIDTH   =  78
   var MAXIMUM_WINDOW_HEIGHT  =  22

   // Window contents consist of characters that are stored
   // in a two-dimensional array. The characters are stored
   // as single-character Strings.

   var window_contents = Array<Array<String>>()

   var  window_width  : Int 
   var  window_height : Int
   var  background_character  =  " "

   init()
   {
      window_width   =  MAXIMUM_WINDOW_WIDTH
      window_height  =  MAXIMUM_WINDOW_HEIGHT

      fill_with_character( background_character )
   }

   init( _ desired_window_width : Int,
         _ desired_window_height : Int,
         _ given_background_character : String )
   {
      window_width          =  desired_window_width
      window_height         =  desired_window_height
      background_character  =  given_background_character

      fill_with_character( background_character )
   }

   func fill_with_character( _ filling_character : String )
   {
      // This method creates the multidimensional array
      // that contains the window contents

      for _ in 1 ... window_width
      {
         var new_column_to_array = Array<String>() 

         for  _ in 1 ... window_height
         {
            new_column_to_array.append( filling_character )
         }

         window_contents.append( new_column_to_array )
      }
   }



   func print_this_window()
   {
      print( "\n", terminator: "" )

      for row_index in 0 ..< window_height
      {
         for column_index in 0 ..< window_width
         {
            print( window_contents[ column_index ] [ row_index ],
                   terminator: "" )
         }

         print( "\n", terminator: "" )
      }
   }

   //  The following method moves another window over 'this' window.


   func move( _ given_destination_x_index : Int,
              _ given_destination_y_index : Int,
              _ another_window : Window )
   {
      // Swift no longer accepts function parameters to be used
      // as variables. Therefore, we copy the given parameters
      // to local variables.

      var  destination_x_index = given_destination_x_index
      var  destination_y_index = given_destination_y_index

      var  source_y_index  =  0

      while  source_y_index  <  another_window.window_height 
      {
         if  destination_y_index  >=  0   &&
             destination_y_index  <   window_height 
         {
            var  source_x_index  =  0
            let  saved_destination_x_index  =  destination_x_index

            while  source_x_index < another_window.window_width 
            {
               if  destination_x_index  >=  0  &&
                   destination_x_index  <   window_width 
               {
                  window_contents [ destination_x_index ][ 

                                    destination_y_index ]  =


                     another_window.window_contents[ source_x_index ] [
                                                     source_y_index ]
               }

               source_x_index        +=  1
               destination_x_index   +=  1
            }

            destination_x_index  =  saved_destination_x_index
         }

         source_y_index        +=  1
         destination_y_index   +=  1
      }
   }
}

/* Class FrameWindow represents a window  that looks like

|----------------------|
|                      |
|                      |
|                      |
|                      |
|                      |
|----------------------|

The window has frames that are made by using characters '|' and '-'.
The inner area of the window contains space characters.
*/


class  FrameWindow  :  Window
{

   init( _ desired_window_width : Int,
         _ desired_window_height : Int )
   {
      super.init( desired_window_width, desired_window_height, "|" )

      let horizontal_frames  =  Window( window_width - 2,
                                        window_height,  "-" )

      let spaces_inside_window  =  Window( window_width - 2,
                                           window_height - 2, " " )

      move( 1, 0, horizontal_frames )
      move( 1, 1, spaces_inside_window )
   }

   // Convenience initializers are used to call other
   // initializers (constructors) of the same class.

   convenience override init()
   {
      self.init( 40, 10 ) ;  // Calling the other initializer above.
   }
}


/* A TextWindow can look like the following

|----------------------------|
|                            |
|                            |
|                            |
|       Hello, world.        |
|                            |
|                            |
|----------------------------|

*/


class  TextWindow  :  FrameWindow
{
   var text_inside_window : String = ""

   func embed_text_in_window()
   {
      let  text_length  =  text_inside_window.characters.count
      let  text_row     =  window_height / 2

      let  text_start_column = (window_width - text_length) / 2

      for character_index in 0 ..< text_length
      {
         let character_column = text_start_column + character_index 

         let actual_index =
                 text_inside_window.index( text_inside_window.startIndex,
                                           offsetBy: character_index )

         window_contents[ character_column ] [ text_row ]  =
                                String( text_inside_window[ actual_index ] )
      }

   }

   init( _ desired_window_width : Int,
         _ desired_window_height : Int,
         _ given_line_of_text : String )
   {
      super.init( desired_window_width, desired_window_height )

      text_inside_window  =  given_line_of_text
      embed_text_in_window()
   }

   func change_text( _ new_line_of_text : String )
   {
      text_inside_window  =  new_line_of_text
      embed_text_in_window()
   }
}


/*  The lowest class in the hierarchy is DecoratedTextWindow.
    Such a window has a decoration frame that is made with characters '*':

****************************
*|------------------------|*
*|                        |*
*|                        |*
*|                        |*
*|         Smile!         |*
*|                        |*
*|                        |*
*|                        |*
*|------------------------|*
****************************

*/

class DecoratedTextWindow  :  TextWindow
{
   override init( _ desired_window_width : Int,
                  _ desired_window_height : Int,
                  _ given_line_of_text : String )
   {
      super.init( desired_window_width,
                  desired_window_height,
                  given_line_of_text )

      let decoration_frame  =  Window( desired_window_width,
                                       desired_window_height,
                                       "*" )
      let window_inside_window  =
                           TextWindow( desired_window_width - 2,
                                       desired_window_height - 2,
                                       given_line_of_text )

      decoration_frame.move( 1, 1, window_inside_window )

      move( 0, 0, decoration_frame )
   }
}



var  background_window  =  Window( 76, 22, "/" )

var  empty_window       =  FrameWindow( 24, 7 )


var  greeting_window  =  TextWindow( 30, 8, "Hello, world." )

var  smiling_window   =  DecoratedTextWindow( 28, 11, "Smile!" )


background_window.move(  6,  2, empty_window )

background_window.move(  4, 12, greeting_window )

greeting_window.change_text( "HELLO, UNIVERSE!" )
background_window.move( 43, 11, greeting_window )

background_window.move( 40,  3, smiling_window )


background_window.print_this_window()