#!/usr/bin/env ruby

$:.insert(0, 'lib')

require 'thor'
require 'rly'
require 'namarara'
require 'json'

module Namarara
  class ParseCli < Thor
    class_option :debug, 
      type: :boolean, 
      aliases: '-d', 
      default: false, 
      desc: "Enable debugging output"
    class_option :format, 
      type: :string, 
      aliases: '-f', 
      default: 'text', 
      enum: ['text','json'],
      desc: "Output format"

    desc 'file FILE VARS', 
      'Parse FILE into tokens then compute with VARS'
    def file(infile, *vars)
      line = File.read(infile).gsub(/\n/,'')
      vars_hash = get_vars_hash(vars)
      res = parse_string(line, vars_hash, options[:debug])
      puts format(res, options[:format])
    end

    desc 'string STRING VARS', 
      'Parse STRING into tokens then compute with VARS'
    def string(line, *vars)
      vars_hash = get_vars_hash(vars)
      res = parse_string(line, vars_hash, options[:debug])
      puts format(res, options[:format])
    end

    private

    # Convert VAR=value list into hash
    def get_vars_hash(vars)
      tab_vars = {}
      vars.each do |var|
        tab_vars[var.split('=')[0]] = var.split('=')[1]
      end
      tab_vars
    end

    def format(result, format)
      case format 
      when 'text' then
        txt = []
        txt << "EXPR: #{result[:expr]}"
        txt << "TREE: #{result[:tree]}"
        result[:errors].each do |error|
          txt << "ERROR: #{error}"
        end
        txt << "RESULT: #{result[:result]}"
        txt.join("\n")
      when 'json'
        JSON.generate(result)
      else
        raise 'Unknown output format'
      end
    end
  end
end

Namarara::ParseCli.start(ARGV)