package activator

import (
	"strings"
	"time"
)

// wakeSteps times one wake step by step for the operator's journal. The
// member's wake event carries the total and the spawn (wakeEventMessage);
// this says where the rest went, which is what a slow wake's diagnosis
// needs and what no single figure can show.
type wakeSteps struct {
	last  time.Time
	steps []wakeStep
}

type wakeStep struct {
	name string
	took time.Duration
}

// begin starts the clock. A mark before it records nothing.
func (s *wakeSteps) begin(now time.Time) { s.last = now }

// mark closes the step called name at now and starts the next.
func (s *wakeSteps) mark(now time.Time, name string) {
	if s.last.IsZero() {
		return
	}
	s.steps = append(s.steps, wakeStep{name, now.Sub(s.last)})
	s.last = now
}

func (s *wakeSteps) String() string {
	parts := make([]string, len(s.steps))
	for i, st := range s.steps {
		parts[i] = st.name + " " + st.took.Round(time.Millisecond).String()
	}
	return strings.Join(parts, ", ")
}