# frozen_string_literal: true

module Lang
  module Core
    module_function

    # store a variable. ex: 1 'name' sto
    def sto
      args = stack_extract( [%i[name], :any] )

      @dictionary.add_var( args[0][:value],
                           args[1] )
    end

    # store a local variable
    def lsto
      args = stack_extract( [%i[name], :any] )

      @dictionary.add_local_var( args[0][:value],
                                 args[1] )
    end

    # recall a variable. ex: 'name' rcl
    def rcl
      args = stack_extract( [%i[name]] )

      content = @dictionary.lookup( args[0][:value] )

      @stack << content unless content.nil?
    end

    # delete a variable. ex: 'name' purge
    def purge
      args = stack_extract( [%i[name]] )

      @dictionary.remove_var( args[0][:value] )
    end

    # list all variables
    def vars
      @stack << { type: :list,
                  value: (@dictionary.vars.keys + @dictionary.local_vars_layers.reduce([]) { |memo, layer| memo + layer.keys }).map { |name| { type: :name, value: name } } }
    end

    # erase all variables
    def clusr
      @dictionary.remove_all_vars
    end

    # add to a stored variable. ex: 1 'name' sto+ 'name' 2 sto+
    def sto_add
      run( '
  dup type "name" ==
  « swap »
  ift
  over rcl + swap sto' )
    end

    # substract to a stored variable. ex: 1 'name' sto- 'name' 2 sto-
    def sto_subtract
      run( '
  dup type "name" ==
  « swap »
  ift
  over rcl swap - swap sto' )
    end

    # multiply a stored variable. ex: 3 'name' sto* 'name' 2 sto*
    def sto_multiply
      run( '
  dup type "name" ==
  « swap »
  ift
  over rcl * swap sto' )
    end

    # divide a stored variable. ex: 3 'name' sto/ 'name' 2 sto/
    def sto_divide
      run( '
  dup type "name" ==
  « swap »
  ift
  over rcl swap / swap sto' )
    end

    # negate a variable. ex: 'name' sneg
    def sto_negate
      run( 'dup rcl chs swap sto' )
    end

    # inverse a variable. ex: 1 'name' sinv
    def sto_inverse
      run( 'dup rcl inv swap sto' )
    end
  end
end