package taskrunner

import (
)

type Runner struct {
	Controller controlChan
	Error controlChan
	Data dataChan
	dataSize int
	longLived bool
	Dispatcher fn
	Executor fn
}

func NewRunner(size int, longlived bool, d fn, e fn) *Runner {
	return &Runner {
		Controller: make(chan string, 1), 
		Error: make(chan string, 1),
		Data: make(chan interface{}, size), 
		longLived: longlived,
		dataSize: size,
		Dispatcher: d,
		Executor: e,
	}
}

func (r *Runner) startDispatch() {
	defer func() {
		if !r.longLived {
			close(r.Controller)
			close(r.Data)
			close(r.Error)
		}
	}()

	for {
		select {
		case c:=<-r.Controller:
			if c==READY_TO_DISPATCH {
				err:=r.Dispatcher(r.Data)
				if err!=nil{
					r.Error<-CLOSE
				} else {
					r.Controller <-READY_TO_EXECUTE
				}
			}

			if c==READY_TO_EXECUTE {
				err:=r.Executor(r.Data)
				if err!=nil {
					r.Error <- CLOSE
				} else {
					r.Controller <- READY_TO_DISPATCH
				}
			}
		case e:=<-r.Error:
			if e==CLOSE {
				return
			}	
		}
	}
}

func (r *Runner) StartAll() {
	r.Controller <- READY_TO_DISPATCH
	r.startDispatch()
}