package scheduler

import (
	"context"
	"encoding/json"
	"fmt"
	"time"

	"github.com/google/uuid"
	"github.com/hibiken/asynq"
)

const TypeReminder = "reminder:send"

type ReminderPayload struct {
	EventID    uuid.UUID `json:"event_id"`
	ReminderID uuid.UUID `json:"reminder_id"`
	UserID     uuid.UUID `json:"user_id"`
}

type Scheduler struct {
	client *asynq.Client
}

func NewScheduler(redisAddr string) *Scheduler {
	client := asynq.NewClient(asynq.RedisClientOpt{Addr: redisAddr})
	return &Scheduler{client: client}
}

func (s *Scheduler) ScheduleReminder(_ context.Context, eventID, reminderID, userID uuid.UUID, triggerAt time.Time) error {
	payload, err := json.Marshal(ReminderPayload{
		EventID:    eventID,
		ReminderID: reminderID,
		UserID:     userID,
	})
	if err != nil {
		return fmt.Errorf("marshal reminder payload: %w", err)
	}

	task := asynq.NewTask(TypeReminder, payload)
	_, err = s.client.Enqueue(task,
		asynq.ProcessAt(triggerAt),
		asynq.MaxRetry(5),
		asynq.Queue("reminders"),
	)
	if err != nil {
		return fmt.Errorf("enqueue reminder: %w", err)
	}

	return nil
}

func (s *Scheduler) Close() error {
	return s.client.Close()
}

type NoopScheduler struct{}

func (NoopScheduler) ScheduleReminder(_ context.Context, _, _, _ uuid.UUID, _ time.Time) error {
	return nil
}

func (NoopScheduler) Close() error { return nil }