module Byebug
  module ThreadFunctions # :nodoc:
    def display_context(c, show_top_frame=true)
      c_flag = c.thread == Thread.current ? '+' : ' '
      c_flag = '$' if c.suspended?
      d_flag = c.ignored? ? '!' : ' '
      print "%s%s", c_flag, d_flag
      print "%d ", c.thnum
      print "%s\t", c.thread.inspect
      if c.stack_size > 0 and show_top_frame
        print "%s:%d", c.frame_file(0), c.frame_line(0)
      end
      print "\n"
    end

    def parse_thread_num(subcmd, arg)
      if '' == arg
        errmsg "'%s' needs a thread number\n" % subcmd
        nil
      else
        thread_num = get_int(arg, "thread #{subcmd}", 1)
        return nil unless thread_num
        get_context(thread_num)
      end
    end

    def parse_thread_num_for_cmd(subcmd, arg)
      c = parse_thread_num(subcmd, arg)
      return nil unless c
      case
      when nil == c
        errmsg "No such thread.\n"
      when @state.context == c
        errmsg "It's the current thread.\n"
      when c.ignored?
        errmsg "Can't #{subcmd} to byebug's thread #{arg}.\n"
      else # Everything is okay
        return c
      end
      return nil
    end
  end

  class ThreadListCommand < Command # :nodoc:
    self.allow_in_control = true

    def regexp
      /^\s*th(?:read)?\s+l(?:ist)?\s*$/
    end

    def execute
      threads = Byebug.contexts.sort_by{|c| c.thnum}.each do |c|
        display_context(c)
      end
    end

    class << self
      def help_command
        'thread'
      end

      def help(cmd)
        %{
          th[read] l[ist]\t\t\tlist all threads
        }
      end
    end
  end

  class ThreadStopCommand < Command # :nodoc:
    self.allow_in_control     = true
    self.allow_in_post_mortem = false
    self.need_context         = true

    def regexp
      /^\s*th(?:read)?\s+stop\s*(\S*)\s*$/
    end

    def execute
      c = parse_thread_num_for_cmd("thread stop", @match[1])
      return unless c
      c.suspend
      display_context(c)
    end

    class << self
      def help_command
        'thread'
      end

      def help(cmd)
        %{
          th[read] stop <nnn>\t\tstop thread nnn
        }
      end
    end
  end

  class ThreadResumeCommand < Command # :nodoc:
    self.allow_in_post_mortem = false
    self.allow_in_control = true
    self.need_context = true

    def regexp
      /^\s*th(?:read)?\s+resume\s*(\S*)\s*$/
    end

    def execute
      c = parse_thread_num_for_cmd("thread resume", @match[1])
      return unless c
      if !c.thread.stop?
        print "Already running."
        return
      end
      c.resume
      display_context(c)
    end

    class << self
      def help_command
        'thread'
      end

      def help(cmd)
        %{
          th[read] resume <nnn>\t\tresume thread nnn
        }
      end
    end
  end

  # Thread switch Must come after "Thread resume" because "switch" is
  # optional

  class ThreadSwitchCommand < Command # :nodoc:
    self.allow_in_control     = true
    self.allow_in_post_mortem = false
    self.need_context         = true

    def regexp
      /^\s*th(?:read)?\s*(?:sw(?:itch)?)?\s+(\S+)\s*$/
    end

    def execute
      c = parse_thread_num_for_cmd("thread switch", @match[1])
      return unless c
      display_context(c)
      c.stop_next = 1
      c.thread.run
      @state.proceed
    end

    class << self
      def help_command
        'thread'
      end

      def help(cmd)
        %{
          th[read] [sw[itch]] <nnn>\tswitch thread context to nnn
        }
      end
    end
  end

  class ThreadCurrentCommand < Command # :nodoc:
    self.need_context = true

    def regexp
      /^\s*th(?:read)?\s*(?:cur(?:rent)?)?\s*$/
    end

    def execute
      display_context(@state.context)
    end

    class << self
      def help_command
        'thread'
      end

      def help(cmd)
        %{
          th[read] [cur[rent]]\t\tshow current thread
        }
      end
    end
  end
end