require 'vedeu/dsl/components/all'
require 'vedeu/repositories/model'

require 'vedeu/geometry/area'
require 'vedeu/geometry/dimension'
require 'vedeu/support/terminal'

module Vedeu

  # @todo Consider storing the Terminal size at the time of first creation,
  # this allows us to return the interface to its original dimensions if
  # the terminal resizes back to normal size.
  #
  # Calculates and provides interface geometry determined by both the client's
  # requirements and the terminal's current viewing area.
  #
  # Geometry for Vedeu, as the same for ANSI terminals, has the origin at
  # top-left, y = 1, x = 1. The 'y' coordinate is deliberately first.
  #
  #       x    north    xn           # north:  y - 1
  #     y +--------------+           # top:    y
  #       |     top      |           # west:   x - 1
  #       |              |           # left:   x
  #  west | left   right | east      # right:  xn
  #       |              |           # east:   xn + 1
  #       |    bottom    |           # bottom: yn
  #    yn +--------------+           # south:  yn + 1
  #            south
  #
  class Geometry

    extend Forwardable
    include Vedeu::Model

    def_delegators :area,
      :north,
      :east,
      :south,
      :west,
      :top,
      :right,
      :bottom,
      :left,
      :y,
      :xn,
      :yn,
      :x,
      :height,
      :width,
      :top_left,
      :top_right,
      :bottom_left,
      :bottom_right

    # @!attribute [rw] centred
    # @return [Boolean]
    attr_accessor :centred

    # @!attribute [rw] name
    # @return [String]
    attr_accessor :name

    # @!attribute [r] attributes
    # @return [Hash]
    attr_reader :attributes

    # @!attribute [w] height
    # @return [Fixnum]
    attr_writer :height

    # @!attribute [w] width
    # @return [Fixnum]
    attr_writer :width

    # @!attribute [w] x
    # @return [Fixnum]
    attr_writer :x

    # @!attribute [w] xn
    # @return [Fixnum]
    attr_writer :xn

    # @!attribute [w] y
    # @return [Fixnum]
    attr_writer :y

    # @!attribute [w] yn
    # @return [Fixnum]
    attr_writer :yn

    # Returns a new instance of Vedeu::Geometry.
    #
    # @param attributes [Hash]
    # @option attributes centred [Boolean]
    # @option attributes height [Fixnum]
    # @option attributes name [String]
    # @option attributes width [Fixnum]
    # @option attributes x [Fixnum]
    # @option attributes xn [Fixnum]
    # @option attributes y [Fixnum]
    # @option attributes yn [Fixnum]
    # @return [Geometry]
    def initialize(attributes = {})
      @attributes = attributes
      @centred    = @attributes[:centred]
      @height     = @attributes[:height]
      @name       = @attributes[:name]
      @width      = @attributes[:width]
      @x          = @attributes[:x]
      @xn         = @attributes[:xn]
      @y          = @attributes[:y]
      @yn         = @attributes[:yn]
      @repository = Vedeu.geometries
    end

    private

    # @return [Vedeu::Area]
    def area
      @area ||= Vedeu::Area.from_dimensions(y_yn: y_yn, x_xn: x_xn)
    end

    # @return [Array<Fixnum>]
    def x_xn
      @x_xn ||= Vedeu::Dimension.pair({ d:        _x,
                                        dn:      _xn,
                                        d_dn:    @width,
                                        default: Vedeu::Terminal.width,
                                        options: { centred: centred }
                                      })
    end

    # @return [Array<Fixnum>]
    def y_yn
      @y_yn ||= Vedeu::Dimension.pair({ d:       _y,
                                        dn:      _yn,
                                        d_dn:    @height,
                                        default: Vedeu::Terminal.height,
                                        options: { centred: centred }
                                      })
    end

    # Returns the row/line start position for the interface.
    #
    # @return [Fixnum]
    def _y
      @y.is_a?(Proc) ? @y.call : @y
    end

    # Returns the row/line end position for the interface.
    #
    # @return [Fixnum]
    def _yn
      @yn.is_a?(Proc) ? @yn.call : @yn
    end

    # Returns the column/character start position for the interface.
    #
    # @return [Fixnum]
    def _x
      @x.is_a?(Proc) ? @x.call : @x
    end

    # Returns the column/character end position for the interface.
    #
    # @return [Fixnum]
    def _xn
      @xn.is_a?(Proc) ? @xn.call : @xn
    end

  end # Geometry

end # Vedeu