package airport

import (
	"fmt"
	"time"
)

type BaggageProcessor interface {
	ProcessBaggage(FlightNumber, Baggage) error
}

type BaggageHandlingSystem struct {
	processingTime time.Duration
	sinks          map[FlightNumber]BaggageProcessor
	lostBaggage    chan LostBaggage
}

type LostBaggage struct {
	Baggage
	FlightNumber FlightNumber
	Err          error
}

var _ BaggageProcessor = &BaggageHandlingSystem{}

func NewBaggageHandlingSystem(processingTime time.Duration, sinks map[FlightNumber]BaggageProcessor) BaggageHandlingSystem {
	return BaggageHandlingSystem{
		processingTime: processingTime,
		sinks:          sinks,
		lostBaggage:    make(chan LostBaggage),
	}
}

func (bhs *BaggageHandlingSystem) ProcessBaggage(fn FlightNumber, b Baggage) error {
	sink, ok := bhs.sinks[fn]
	if !ok {
		return fmt.Errorf("invalid flight %v", fn)
	}

	go func() {
		time.Sleep(bhs.processingTime)
		if err := sink.ProcessBaggage(fn, b); err != nil {
			bhs.lostBaggage <- LostBaggage{b, fn, err}
		}
	}()

	return nil

}

func (bhs *BaggageHandlingSystem) CollectLostBaggage() []LostBaggage {
	lostBaggage := []LostBaggage{}
	for {
		select {
		case lb := <-bhs.lostBaggage:
			lostBaggage = append(lostBaggage, lb)
		default:
			return lostBaggage
		}
	}
}
func (bhs *BaggageHandlingSystem) Start() {
	defer fmt.Println("baggage handling terminated")
	select {}
}