class BenchmarkDriver::Runner::Ips

def debug_output(name, text)
  sep = '-' * 30
  $stdout.puts "\n\n#{sep}[#{name} begin]#{sep}\n#{text}#{sep}[#{name} end]#{sep}\n\n"
end

def execute(*args, exception: true)
  $stderr.puts "$ #{args.shelljoin}" if @config.verbose >= 2
  stdout = IO.popen(args, &:read)
  debug_output('Command output', stdout) if @config.verbose >= 2
  if exception && !$?.success?
    raise "Failed to execute: #{args.shelljoin} (status: #{$?})"
  end
  $?.success?
end

def initialize(config:, output:, contexts:)
  @config = config
  @output = output
  @contexts = contexts
end

def metric
  METRIC
end

def run(jobs)
  if jobs.any? { |job| job.loop_count.nil? }
    @output.with_warmup do
      jobs = jobs.map do |job|
        next job if job.loop_count # skip warmup if loop_count is set
        @output.with_job(name: job.name) do
          context = job.runnable_contexts(@contexts).first
          duration, loop_count = run_warmup(job, context: context)
          value, duration = value_duration(duration: duration, loop_count: loop_count)
          @output.with_context(name: context.name, executable: context.executable, gems: context.gems, prelude: context.prelude) do
            @output.report(values: { metric => value }, duration: duration, loop_count: loop_count)
          end
          job.loop_count = (loop_count.to_f * @config.run_duration / duration).floor
          job
        end
      end
    end
  end
  @output.with_benchmark do
    jobs.each do |job|
      @output.with_job(name: job.name) do
        job.runnable_contexts(@contexts).each do |context|
          repeat_params = { config: @config, larger_better: true, rest_on_average: :average }
          result = BenchmarkDriver::Repeater.with_repeat(**repeat_params) do
            run_benchmark(job, context: context)
          end
          value, duration = result.value
          @output.with_context(name: context.name, executable: context.executable, gems: context.gems, prelude: context.prelude) do
            @output.report(
              values: { metric => value },
              all_values: { metric => result.all_values },
              duration: duration,
              loop_count: job.loop_count,
            )
          end
        end
      end
    end
  end
end

def run_benchmark(job, context:)
  benchmark = BenchmarkScript.new(
    preludes:   [context.prelude, job.prelude],
    script:     job.script,
    teardown:   job.teardown,
    loop_count: job.loop_count,
  )
  duration = Tempfile.open(['benchmark_driver-', '.rb']) do |f|
    with_script(benchmark.render(result: f.path)) do |path|
      success = execute(*context.executable.command, path, exception: false)
      if success && ((value = Float(f.read)) > 0)
        value
      else
        BenchmarkDriver::Result::ERROR
      end
    end
  end
  value_duration(
    loop_count: job.loop_count,
    duration: duration,
  )
end

def run_warmup(job, context:)
  warmup = WarmupScript.new(
    preludes:   [context.prelude, job.prelude],
    script:     job.script,
    teardown:   job.teardown,
    loop_count: job.loop_count,
    first_warmup_duration: @config.run_duration / 6.0,  # default: 0.5
    second_warmup_duration: @config.run_duration / 3.0, # default: 1.0
  )
  duration, loop_count = Tempfile.open(['benchmark_driver-', '.rb']) do |f|
    with_script(warmup.render(result: f.path)) do |path|
      execute(*context.executable.command, path)
    end
    eval(f.read)
  end
  [duration, loop_count]
end

def value_duration(duration:, loop_count:)
  if BenchmarkDriver::Result::ERROR.equal?(duration)
    [BenchmarkDriver::Result::ERROR, BenchmarkDriver::Result::ERROR]
  else
    [loop_count.to_f / duration, duration]
  end
end

def with_script(script)
  debug_output('Script', script) if @config.verbose >= 2
  Tempfile.open(['benchmark_driver-', '.rb']) do |f|
    f.puts script
    f.close
    return yield(f.path)
  end
end