scrapper-mandarake/internal/tasks/handler.go

package tasks

import (
	"context"
	"encoding/json"
	log "github.com/sirupsen/logrus"
	rabbit "repo.nqws.ru/merch-tracker-v2/mt-rabbit"
	"scrapper-mandarake/internal/common"
)

const pkgLogHeader string = "Tasks client |"

type Handler struct {
	consumer  rabbit.Consumer
	publisher rabbit.Publisher
	chanLen   uint
}

type Deps struct {
	Username        string
	Password        string
	Host            string
	Port            uint16
	Vhost           string
	TaskSourceQueue string
	TaskResultQueue string
	LoggingEnabled  bool
	ChanLen         uint
}

func New(deps Deps) TaskTransport {
	var h Handler

	h.chanLen = deps.ChanLen

	if err := h.initConsumer(&deps); err != nil {
		log.WithError(err).Fatalf("%v Failed to create consumer", pkgLogHeader)
		panic(err)
	}

	if err := h.initProducer(&deps); err != nil {
		log.WithError(err).Fatalf("%v Failed to create publisher", pkgLogHeader)
		panic(err)
	}

	return &h
}

func (h *Handler) initConsumer(deps *Deps) error {
	client, err := rabbit.NewClient(rabbit.Address{
		Username: deps.Username,
		Password: deps.Password,
		Host:     deps.Host,
		Port:     deps.Port,
		Vhost:    deps.Vhost,
	}, deps.TaskSourceQueue, rabbit.WithLogging(deps.LoggingEnabled))
	if err != nil {
		return err
	}

	h.consumer = rabbit.NewConsumer(client)
	return nil
}

func (h *Handler) initProducer(deps *Deps) error {
	client, err := rabbit.NewClient(rabbit.Address{
		Username: deps.Username,
		Password: deps.Password,
		Host:     deps.Host,
		Port:     deps.Port,
		Vhost:    deps.Vhost,
	}, deps.TaskResultQueue, rabbit.WithLogging(deps.LoggingEnabled))
	if err != nil {
		return err
	}

	h.publisher = rabbit.NewPublisher(client)
	return nil
}

func (h *Handler) GetTasks(ctx context.Context) <-chan common.Task {
	getTasks := make(chan common.Task, 100)

	taskChan := h.consumer.Start(ctx, h.chanLen)

	go func() {
		defer close(getTasks)
		for {
			select {
			case <-ctx.Done():
				return
			case bytes, ok := <-taskChan:
				if !ok {
					return
				}
				var task common.Task
				if err := json.Unmarshal(bytes, &task); err != nil {
					log.WithError(err).Errorf("%v Failed to unmarshal task", pkgLogHeader)
					continue
				}

				getTasks <- task
			}
		}
	}()

	return getTasks
}

func (h *Handler) SendResult(ctx context.Context) chan common.Result {
	pub := h.publisher.Start(ctx, h.chanLen)
	resultChan := make(chan common.Result, h.chanLen)

	go func() {
		defer close(resultChan)
		for {
			select {
			case <-ctx.Done():
				return
			case result, ok := <-resultChan:
				if !ok {
					return
				}
				bytes, err := json.Marshal(result)
				if err != nil {
					log.WithError(err).Errorf("%v Failed to marshal result", pkgLogHeader)
					continue
				}
				pub <- bytes
			}
		}
	}()
	return resultChan
}