// Copyright 2024 Matthew Rich <matthewrich.conf@gmail.com>. All rights reserved.
 
package context;

import (
  "log"
  "feudal/message"
  "feudal/feudal"
)

type Runner interface {
  Start(d Dispatcher, c feudal.Context)
  Stop()
}

type Queue struct {
  receive chan message.Envelope
  quit chan bool
  stopped chan bool
}

func NewQueue() *Queue {
  return &Queue{ receive: make(chan message.Envelope), quit: make(chan bool), stopped: make(chan bool) }
}

func NewBufferedQueue(size int) *Queue {
  return &Queue{ receive: make(chan message.Envelope, size), quit: make(chan bool), stopped: make(chan bool) }
}

func (q *Queue) Add(m message.Envelope) {
  q.receive <- m
}

func (q *Queue) Remove() message.Envelope {
  return <- q.receive
}

func (q *Queue) contextTrigger(c feudal.Context, trigger string) {
  if c != nil {
    log.Printf("triggering %s on %s", trigger, c.Address())
    c.Trigger(trigger)
  }
}

func (q *Queue) Start(d Dispatcher, c feudal.Context) {
  go func() {
    q.contextTrigger(c, "start")
    for {
      select {
      case m := <- q.receive:
        d.Dispatch(m, c)
      case <- q.quit:
        close(q.receive)
        c.Disolve() // change to trigger
        close(q.stopped)
        q.contextTrigger(c, "stop")
        return
      }
    }
  }()
}

func (q *Queue) Stop() {
  close(q.quit)
  select {
  case <- q.stopped:
  }
}

func (q *Queue) Len() int {
  return len(q.receive)
}