package main

import (
	"github.com/probakowski/go-satel"
)

func FilterByType(ev <-chan satel.Event, allowedTypes []satel.ChangeType) <-chan satel.Event {
	returnChan := make(chan satel.Event)

	go func() {
		for e := range ev {
			for _, allowedType := range allowedTypes {
				if allowedType == e.Type {
					returnChan <- e
					continue
				}
			}
		}
		close(returnChan)
	}()

	return returnChan
}

type EventKey struct {
	ChangeType satel.ChangeType
	Index      int
}

func FilterByLastSeen(ev <-chan satel.Event) <-chan satel.Event {
	returnChan := make(chan satel.Event)

	go func() {
		lastSeen := make(map[EventKey]bool) // key: ChangeType/Index; value: Value
		for e := range ev {
			val, ok := lastSeen[EventKey{e.Type, e.Index}]
			if !ok || val != e.Value {
				lastSeen[EventKey{e.Type, e.Index}] = e.Value
				returnChan <- e
			}
		}
		close(returnChan)
	}()

	return returnChan
}