Early Watson Idea

watson.rb

#!/usr/bin/env ruby

require 'io/console'
require_relative 'ansi'

class App
  attr_accessor :input
  attr_accessor :selection

  class << self
    attr_accessor :queries
  end

  self.queries = []

  def initialize
    @input = ''
    @selection = 0
  end

  def run
    IO.console.raw do
      ANSI.clear_screen
      ANSI.move_cursor(0, 0)
      loop do
        render
        handle_input
      end
    end
  end

  def render
    ANSI.clear_screen
    ANSI.move_cursor(0, 0)
    puts input_line
    ANSI.move_cursor(1, 0)
    results.each do |result|
      puts result.join(': ')
      print "\r"
    end
    ANSI.move_cursor(0, input_line.length)
  end

  def handle_input
    char = $stdin.getc
    case char
    when "\u0003" # ctrl-c
      ANSI.clear_screen
      exit 0
    when "\u007F" # backspace
      self.input = input[0..-2]
    else
      input << char
    end
  end

  def input_line
    '------> ' << input
  end

  def results
    return [] if input.empty?

    App.queries.map do |query|
      query.new(input).preview_text
    end.compact
  end
end

# This module contains helpers for various ansi-code operations
module ANSI
  # ANSI color escape codes set the foreground and background colors.
  # Forground color is a number between 30 and 37.
  # Background color is a number between 40 and 47.
  # The ones place represents the same color for both.
  COLORS = [:black, :red, :green, :yellow, :blue, :magenta, :cyan, 'white', nil, :white].freeze

  def self.clear_screen
    $stdout.write "\e[2J"
  end

  def self.move_cursor(row, col)
    $stdout.write "\e[#{row + 1};#{col + 1}H"
  end

  def self.color(text, fg: :white, bg: :black)
    fg = COLORS.index(fg) + 30
    bg = COLORS.index(bg) + 40
    code = "\e[#{[fg, bg].compact.join(';')}m"
    "#{code}#{text}\e[0m"
  end

  def self.reset
    "\e[0m"
  end

  def self.size
    win = IO.console.winsize
    {
      height: win[0],
      width: win[1]
    }
  end
end

class Query
  attr_reader :input
  def initialize(input)
    @input = input
  end

  def preview_text
    res = result
    [self.class.name, res] if res
  end

  def result
    input
  end
end

class Calc < Query
  include Math

  def result
    begin
      [input, eval(input + '.to_f')].join(' = ')
    rescue Exception => _e
    end
  end

  def pi
    PI
  end

  def e
    E
  end
end

class Google < Query
end

class DuckDuckGo < Query
end

App.queries.push(Calc)
App.queries.push(Google)
App.queries.push(DuckDuckGo)

App.new.run