package util

import (

"fmt"

"time"

)

type timerStep struct {

name string

start time.Time

duration time.Duration

}

type Timer struct {

steps []*timerStep

}

func NewTimer() *Timer {

return &Timer{

steps: []*timerStep{

{name: "pending", start: time.Now()},

},

}

}

func (t *Timer) Duration() time.Duration {

return time.Since(t.steps[0].start)

}

func (t *Timer) Step(name string) {

t.Done(name)

t.steps = append(t.steps, t.newStep())

}

func (t *Timer) lastStep() *timerStep {

return t.steps[len(t.steps)-1]

}

func (t *Timer) newStep() *timerStep {

return &timerStep{name: "pending", start: time.Now()}

}

func (t *Timer) Done(name string) {

lastStep := t.lastStep()

if lastStep.duration == 0 {

lastStep.name = name

lastStep.duration = time.Since(lastStep.start)

}

}

func (t *Timer) String() string {

t.Done("last")

if len(t.steps) == 1 {

return fmt.Sprintf("Total: %v", t.Duration())

}

stepsStr := ""

for _, st := range t.steps {

stepsStr += fmt.Sprintf(", %v=%v", st.name, st.duration)

}

return fmt.Sprintf("Total: %v%s", t.Duration(), stepsStr)

}