package dispatch

import (
	"context"
	"fmt"

	"example.com/mqtt5-learning/internal/contracts"
	"example.com/mqtt5-learning/internal/mqtt"
)

type Processor func(context.Context, mqtt.Message) error

// Receiver validates the route, selects a pool, and copies payload ownership.
type Receiver struct {
	Telemetry *Pool
	Important *Pool
	Process   Processor
}

func (r *Receiver) Submit(ctx context.Context, message mqtt.Message) (Outcome, error) {
	if r.Process == nil {
		return Stopping, fmt.Errorf("message processor is required")
	}
	topic, err := contracts.ParseTopic(message.Topic)
	if err != nil {
		return Stopping, err
	}
	pool := r.Telemetry
	if topic.Kind == contracts.KindCommands || topic.Kind == contracts.KindResponses || topic.Kind == contracts.KindSales {
		pool = r.Important
	}
	if pool == nil {
		return Stopping, fmt.Errorf("no queue configured for topic kind %q", topic.Kind)
	}
	copyOfMessage := message
	copyOfMessage.Payload = append([]byte(nil), message.Payload...)
	return pool.Submit(ctx, func(jobCtx context.Context) error { return r.Process(jobCtx, copyOfMessage) })
}