package airport

import (
	"fmt"
	"time"
)

var prohibitedItems = map[string]bool{"Knife": true, "Gun": true, "Explosives": true}

type SecurityCheck struct {
	processingTime time.Duration
	queue          chan securityCheckData
}

type securityCheckData struct {
	p   Passenger
	err chan error
}

func NewSecurityCheck(processingTime time.Duration) SecurityCheck {
	return SecurityCheck{
		processingTime: processingTime,
		queue:          make(chan securityCheckData),
	}
}

// processes one passenger at a time. Each passenger must at least spend the processingTime at the security check
func (sc *SecurityCheck) Start() {
	defer fmt.Println("security terminated")
	for el := range sc.queue {

		time.Sleep(sc.processingTime)

		if el.p.BoardingPass == nil {
			el.err <- fmt.Errorf("no boarding pass")
			continue
		}

		if el.p.Name != el.p.BoardingPass.Name {
			el.err <- fmt.Errorf("boarding pass does not match passenger name")
			continue
		}

		prohibited := false
		for _, item := range el.p.CarryOnItems {
			if prohibitedItems[item] {
				el.err <- fmt.Errorf("prohibited item detected: %v", item)
				prohibited = true
				break
			}
		}
		if prohibited {
			continue
		}

		el.err <- nil
	}
}

// returns an error if
//   - the passenger has no boarding pass
//   - the passenger's boardings pass does not match the name
//   - the passenger carries a prohibited item
func (sc SecurityCheck) Process(p Passenger) error {
	errc := make(chan error)
	sc.queue <- securityCheckData{p: p, err: errc}
	return <-errc
}