package etl

import (
	"context"
	"log"
	"runtime"
	"sync"

	"gitea.urkob.com/urko/ess-etl-go/internal/xml_loader"
	"gitea.urkob.com/urko/ess-etl-go/pkg/adapter/repository/mongodb/employee_wi"
	"gitea.urkob.com/urko/ess-etl-go/pkg/domain"
)

type Etl struct {
	ewiLoader xml_loader.EmployeeWILoader
	repo      employee_wi.Repo
}

func New(ewiLoader xml_loader.EmployeeWILoader, repo employee_wi.Repo) *Etl {
	return &Etl{
		ewiLoader: ewiLoader,
		repo:      repo,
	}
}

func (etl *Etl) FanOut(ctx context.Context, employeeNumber []string, from, to string) error {
	g := runtime.GOMAXPROCS(0)
	var wg sync.WaitGroup
	wg.Add(g)

	employeeWIChan := make(chan []domain.EmployeeWorkInformation, g)
	errChan := make(chan error, 1)

	for i := 0; i < g; i++ {
		go func() {
			defer func() {
				wg.Done()
			}()
			for v := range employeeWIChan {
				func() {
					err := etl.repo.InsertMany(ctx, v)
					if err != nil {
						errChan <- err
						return
					}
				}()
			}
		}()
	}
	go func() {
		var wg2 sync.WaitGroup
		wg2.Add(len(employeeNumber))
		for i := range employeeNumber {
			go func(v string) {
				defer wg2.Done()
				wi, err := etl.ewiLoader.LoadEmployee(v, from, to)
				if err != nil {
					log.Println("err", err)
					errChan <- err
					return
				}
				employeeWIChan <- wi
			}(employeeNumber[i])
		}
		wg2.Wait()
		close(employeeWIChan)
	}()

	wg.Wait()
	errChan <- nil
	return <-errChan
}