package wkrp

import "sync"

type TJobChan chan IJob
type TJobPool chan TJobChan

type Dispacher struct {
	size    int
	enqchan TJobChan
	pool    TJobPool
	workers map[int]*Worker
	quit    chan struct{}
	wg      sync.WaitGroup
}

func NewDispacher(q_size int) *Dispacher {
	p := &Dispacher{
		size:    q_size,
		enqchan: make(TJobChan, 64),
		pool:    make(TJobPool, q_size),
		workers: make(map[int]*Worker),
		quit:    make(chan struct{}),
		wg:      sync.WaitGroup{},
	}

	go p.run()

	return p
}

func (self *Dispacher) Stop() {
	go func() {
		close(self.quit)
		close(self.enqchan)

		for _, w := range self.workers {
			w.stop()
		}

		self.wg.Wait()

		close(self.pool)
	}()
}

func (self *Dispacher) Do(job IJob) {
	go func() {
		select {
		case <-self.quit:
		case self.enqchan <- job:
		}
	}()
}

func (self *Dispacher) run() {
	for i := 0; i < self.size; i++ {
		w := newWorker(i+1, self)
		self.workers[i+1] = w

		self.wg.Add(1);

		w.start()
	}

	for {
		select {
		case job, ok := <-self.enqchan:
			if !ok {
				continue
			}
			for {
				jobchan, ok := <-self.pool
				if ok {
					jobchan <- job
					break // break from for
				}
			} // for
		case <-self.quit:
			return
		} // select
	} // for
}