/* EventDB 的作用是存储模拟器模拟区间内所有的事件.
同时在使用外部调度器时，发生时间线变动时，方便修
改某个instance 在时间线中的所有的事件*/
package core

type EventTable struct {
	ie map[InstanceKey]*eventTableRow // store all the instance event info
	me []MachineEvent                 // store all the machines event info
}

func NewEventTable(i []InstanceEvent, m []MachineEvent) (table *EventTable) {
	table = &EventTable{}
	table.ie = make(map[InstanceKey]*eventTableRow)
	table.me = m

	for _, e := range i {
		if e.AllocID != 0 {
			continue
		}
		if _, ok := table.ie[e.InstanceId]; !ok {
			table.ie[e.InstanceId] = &eventTableRow{curPeriod: 0, lifeEvents: []InstanceEvent{e}}
		} else {
			table.ie[e.InstanceId].lifeEvents = append(table.ie[e.InstanceId].lifeEvents, e)
		}
	}

	for _, row := range table.ie {
		row.sortPeriod()
	}

	return table
}

// one row in the EventTable.ie is the eventTableRow
// lifeEvents is the all  instance events happend in the google trace data
// curPeriod is the events period the instance is experienced ,a period looks like : enable->schdule->finish
// periods is the result after sort the lifeEvents according to the period
type eventTableRow struct {
	lifeEvents []InstanceEvent // the life events of the instance
	curPeriod  int             // the periods is waitting for join in the timeline
	periods    [][]InstanceEvent
}

func (t *eventTableRow) sortPeriod() {
	t.periods = make([][]InstanceEvent, 0)
	periodStart := []int{}
	if t.lifeEvents[0].Type != INSTANCEEnable {
		periodStart = append(periodStart, 0)
	}
	for i, e := range t.lifeEvents {
		if e.Type == INSTANCEEnable {
			periodStart = append(periodStart, i)
		}
	}
	periodStart = append(periodStart, len(t.lifeEvents))

	for i := 0; i <= len(periodStart)-2; i++ {
		start := periodStart[i]
		end := periodStart[i+1]
		t.periods = append(t.periods, t.lifeEvents[start:end])
	}
}