module Byebug

  class ConditionCommand < Command # :nodoc:

    def regexp
      /^\s* cond(?:ition)? (?:\s+(\d+)\s*(.*))?$/ix
    end

    def execute
      return errmsg "\"condition\" must be followed by " \
                    "breakpoint number and expression\n" unless @match[1]

      breakpoints = Byebug.breakpoints.sort_by{|b| b.id }
      largest = breakpoints.inject(0) do |tally, b|
        tally = b.id if b.id > tally
      end

      return print "No breakpoints have been set.\n" if 0 == largest
      return unless pos = get_int(@match[1], "Condition", 1, largest)
      breakpoints.each do |b|
        if b.id == pos
          b.expr = @match[2].empty? ? nil : @match[2]
          break
        end
      end
    end

    class << self
      def names
        %w(condition)
      end

      def description
        %{
          cond[ition] nnn[ expr]

          Specify breakpoint number nnn to break only if expr is true. nnn is an
          integer and expr is an expression to be evaluated whenever breakpoint
          nnn is reached. If no expression is specified, the condition is
          removed.
        }
      end
    end
  end

end # module Byebug