# Copyright (C) 2010-2011, 2013 Rocky Bernstein <rockyb@rubyforge.net>
require 'redcard/rubinius'

class Trepan
  module Util

    module_function
    def safe_repr(str, max, elipsis='... ')
      if str.is_a?(String) && max > 0 && str.size > max && !str.index("\n")
        "%s%s%s" % [ str[0...max/2], elipsis,  str[str.size-max/2..str.size]]
      else
        str
      end
    end

    # name is String and list is an Array of String.
    # If name is a unique leading prefix of one of the entries of list,
    # then return that. Otherwise return name.
    def uniq_abbrev(list, name)
      candidates = list.select do |try_name|
        try_name.start_with?(name)
      end
      candidates.size == 1 ? candidates.first : name
    end

    # extract the "expression" part of a line of source code.
    #
    def extract_expression(text)
      if text =~ /^\s*(?:if|elsif|unless)\s+/
        text.gsub!(/^\s*(?:if|elsif|unless)\s+/,'')
        text.gsub!(/\s+then\s*$/, '')
      elsif text =~ /^\s*(?:until|while)\s+/
        text.gsub!(/^\s*(?:until|while)\s+/,'')
        text.gsub!(/\s+do\s*$/, '')
      elsif text =~ /^\s*return\s+/
        # EXPRESION in: return EXPRESSION
        text.gsub!(/^\s*return\s+/,'')
      elsif text =~ /^\s*case\s+/
        # EXPRESSION in: case EXPESSION
        text.gsub!(/^\s*case\s*/,'')
      elsif text =~ /^\s*def\s*.*\(.+\)/
        text.gsub!(/^\s*def\s*.*\((.*)\)/,'[\1]')
      elsif text =~ /^\s*[A-Za-z_][A-Za-z0-9_\[\]]*\s*=[^=>]/
        # RHS of an assignment statement.
        text.gsub!(/^\s*[A-Za-z_][A-Za-z0-9_\[\]]*\s*=/,'')
      end
      return text
    end


    def rubinius_internal?(loc)
      ('Object#' == loc.describe_receiver &&
       :__script__ == loc.name && RedCard.check('1.8')) or
        ('Rubinius::Loader#' == loc.describe_receiver && RedCard.check('1.9'))
    end

    # Find user portion of script skipping over Rubinius code loading.
    # Unless hidestack is off, we don't show parts of the frame below this.
    def find_main_script(locs)
      candidate = nil
      (locs.size-1).downto(0) do |i|
        loc = locs[i]
        if rubinius_internal?(loc)
          if loc.method.active_path =~ /\/trepanx$/ ||
            loc.method.active_path == 'kernel/loader.rb'
            # Might have been run from standalone trepanx.
            candidate = i
          else
            return locs.size - i
          end
        end
      end
      candidate ? locs.size - candidate - 1 : nil
    end

    # Suppress warnings. The main one we encounter is "already initialized
    # constant" because perhaps another version readline has done that already.
    def suppress_warnings
      original_verbosity = $VERBOSE
      $VERBOSE = nil
      result = yield
      $VERBOSE = original_verbosity
      return result
    end
  end
end

if __FILE__ == $0
  include Trepan::Util
  string = 'The time has come to talk of many things.'
  puts safe_repr(string, 50)
  puts safe_repr(string, 17)
  puts safe_repr(string.inspect, 17)
  puts safe_repr(string.inspect, 17, '')
  locs = Rubinius::VM.backtrace(0)
  locs.each_with_index do |l, i|
    puts "#{i}: #{l.describe}"
  end
  ## puts "main script in above is #{locs.size() - 1 - find_main_script(locs)}"

  list = %w(disassemble disable distance up)
  p list
  %w(dis disa u upper foo).each do |name|
    puts "uniq_abbrev of #{name} is #{uniq_abbrev(list, name)}"
  end
end