package v2

import (
	"fmt"
)

// XXX: what about state here, we need per routine state
// So handle func should take an event and a reference to state and return
// events and the new state
type handleFunc = func(event Event) Events

// Routine
type Routine struct {
	name    string
	input   chan Event
	errors  chan errEvent
	output  chan Event
	stopped chan struct{}
	handle  handleFunc
}

func newRoutine(name string, output chan Event, handleFunc handleFunc) *Routine {
	return &Routine{
		name:    name,
		input:   make(chan Event, 1),
		errors:  make(chan errEvent, 1),
		output:  output,
		stopped: make(chan struct{}, 1),
		handle:  handleFunc,
	}
}

func (rt *Routine) run() {
	fmt.Printf("%s: run\n", rt.name)
	for {
		select {
		case iEvent, ok := <-rt.input:
			if !ok {
				fmt.Printf("%s: stopping\n", rt.name)
				rt.stopped <- struct{}{}
				return
			}
			oEvents := rt.handle(iEvent)
			fmt.Printf("%s handled %d events\n", rt.name, len(oEvents))
			for _, event := range oEvents {
				rt.output <- event
			}
		case iEvent, ok := <-rt.errors:
			if !ok {
				fmt.Printf("%s: errors closed\n", rt.name)
				continue
			}
			oEvents := rt.handle(iEvent)
			fmt.Printf("%s handled %d events from errors\n", rt.name, len(oEvents))
			for _, event := range oEvents {
				rt.output <- event
			}
		}
	}
}

func (rt *Routine) send(event Event) bool {
	fmt.Printf("%s: send\n", rt.name)
	if err, ok := event.(errEvent); ok {
		select {
		case rt.errors <- err:
			return true
		default:
			fmt.Printf("%s: errors channel was full\n", rt.name)
			return false
		}
	} else {
		select {
		case rt.input <- event:
			return true
		default:
			fmt.Printf("%s: channel was full\n", rt.name)
			return false
		}
	}
}

func (rt *Routine) stop() {
	fmt.Printf("%s: stop\n", rt.name)
	close(rt.errors)
	close(rt.input)
	<-rt.stopped
}

func schedulerHandle(event Event) Events {
	switch event.(type) {
	case timeCheck:
		fmt.Println("scheduler handle timeCheck")
	case testEvent:
		fmt.Println("scheduler handle testEvent")
		return Events{scTestEvent{}}
	}
	return Events{}
}

func processorHandle(event Event) Events {
	switch event.(type) {
	case timeCheck:
		fmt.Println("processor handle timeCheck")
	case testEvent:
		fmt.Println("processor handle testEvent")
	case scTestEvent:
		fmt.Println("processor handle scTestEvent")
		// should i stop myself?
		return Events{pcFinished{}}
	}
	return Events{}
}

type demuxer struct {
	eventbus  chan Event
	scheduler *Routine
	processor *Routine
	finished  chan struct{}
	stopped   chan struct{}
}

func newDemuxer(scheduler *Routine, processor *Routine) *demuxer {
	return &demuxer{
		eventbus:  make(chan Event, 10),
		scheduler: scheduler,
		processor: processor,
		stopped:   make(chan struct{}, 1),
		finished:  make(chan struct{}, 1),
	}
}

func (dm *demuxer) run() {
	fmt.Printf("demuxer: run\n")
	for {
		select {
		case event, ok := <-dm.eventbus:
			if !ok {
				fmt.Printf("demuxer: stopping\n")
				dm.stopped <- struct{}{}
				return
			}
			oEvents := dm.handle(event)
			for _, event := range oEvents {
				dm.eventbus <- event
			}
		case event, ok := <-dm.scheduler.output:
			if !ok {
				fmt.Printf("demuxer: scheduler output closed\n")
				continue
				// todo: close?
			}
			oEvents := dm.handle(event)
			for _, event := range oEvents {
				dm.eventbus <- event
			}
		case event, ok := <-dm.processor.output:
			if !ok {
				fmt.Printf("demuxer: pricessor output closed\n")
				continue
				// todo: close?
			}
			oEvents := dm.handle(event)
			for _, event := range oEvents {
				dm.eventbus <- event
			}
		}
	}
}

type scFull struct{}
type pcFull struct{}