package scheduler

import (
	"context"
	"git.dragse.it/anthrove/e621-to-graph/pkg/e621"
	"git.dragse.it/anthrove/e621-to-graph/pkg/util/queue"
	log "github.com/sirupsen/logrus"
	"golang.org/x/time/rate"
	"reflect"
)

type Scheduler struct {
	queue   queue.Queue
	limiter *rate.Limiter
}

func NewScheduler() *Scheduler {
	scheduler := &Scheduler{
		queue:   queue.NewQueue(),
		limiter: nil,
	}
	go scheduler.StartExecutionHandler()
	return scheduler
}

func Schedule[T e621.DataType](s *Scheduler, t e621.Task[T], username string, apiKey string) func() (T, error) {
	channel := make(chan e621.DataResponse[T])
	schedulerTask := NewSchedulerTaskImpl[T](t, channel, username, apiKey)
	log.WithFields(log.Fields{
		"type": reflect.TypeOf(*new(T)),
	}).Debug("scheduler: pushing task to queue")

	err := s.queue.Push(schedulerTask)
	if err != nil {
		return func() (T, error) {
			var nil T
			return nil, err
		}
	}

	log.WithFields(log.Fields{
		"type": reflect.TypeOf(*new(T)),
	}).Trace("scheduler: pushed task to queue")

	return func() (T, error) {
		log.Trace("scheduler: getting data from channel")
		data := <-channel
		return data.Data, data.Error
	}
}

func (s *Scheduler) SetLimiter(limiter *rate.Limiter) {
	log.WithFields(log.Fields{
		"burst":  limiter.Burst(),
		"limit":  limiter.Limit(),
		"tokens": limiter.Tokens(),
	}).Debug("scheduler: setting limiter")
	s.limiter = limiter
}

func (s *Scheduler) StartExecutionHandler() {
	for {
		if s.limiter != nil {
			s.limiter.Wait(context.Background())
		}
		s.queue.WaitForElement()
		log.Trace("scheduler: element found")
		task, err := s.queue.Pop()
		if err != nil {
			continue
		}
		GetAPIRequest(task)
	}

}