require "open3"

module PeerCommander
  # A single command to be executed, with access to results statuses, output, and timings
  class Command
    attr_reader :command, :exception, :opts, :env, :stdin_data

    # The env specified will be passed directly to Open3.capture2e as the env to run with
    # The opts provided will also be passed directly to Open3.capture2e as opts
    # stdin_data will also be passed directly to Open3.capture2e
    def initialize(command, stdin_data: nil, env: {}, opts: {})
      @command = command
      @stdin_data = stdin_data
      @env = env
      @opts = opts
    end

    # Execute the command, will capture any exceptions that inherit from StandardError raised by the execution of
    # the given command and store it in the exception attribute, NOTE: This means it _will not_ propogate the
    # exception upwards
    #
    # Returns self
    def execute
      raise Errors::CommandAlreadyExecutedError if executed?

      start_time = Time.now

      begin
        @command_output, @status = Open3.capture2e(env, command, execution_options)
      rescue StandardError => e
        @exception = e
      ensure
        @timing = Time.now - start_time
      end

      self
    end

    # Return true if the command was successful
    def success?
      raise Errors::CommandNotExecutedError unless executed?

      exception.nil? && status.success?
    end

    # Return true if the command failed
    def failed?
      !success?
    end

    # Return the output (stdout and stderr interleaved) of running the command
    def output
      raise Errors::CommandNotExecutedError unless executed?

      command_output
    end

    # How long the command took to run in seconds
    def duration
      raise Errors::CommandNotExecutedError unless executed?

      timing
    end

    # Returns a truthy object if the command has been executed, or nil
    # if it has not.
    #
    # If the command has been executed it will either return the status code or
    # the exception that was raised
    def executed?
      exception || status
    end

    def exit_code
      raise Errors::CommandNotExecutedError unless executed?

      return nil if exception

      status.exitstatus
    end

    private

    attr_reader :status, :command_output, :timing

    def execution_options
      opts.tap do |options|
        options[:stdin_data] = stdin_data unless stdin_data.nil?
      end
    end
  end
end