package etl

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

	"gitea.urkob.com/urko/crono"
	"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
}

func (etl *Etl) FanOut2(ctx context.Context, employeeNumber []string, from, to string) error {
	employeeWIChan := make(chan []domain.EmployeeWorkInformation, len(employeeNumber))
	xmlChan := make(chan []byte, len(employeeNumber))
	errChan := make(chan error, 1)

	go func() {
		for {
			select {
			case v, ok := <-employeeWIChan:
				if !ok {
					errChan <- nil
					return
				}
				err := etl.repo.InsertMany(ctx, v)
				if err != nil {
					errChan <- err
					return
				}
			}
		}
	}()

	go func() {
		for {
			select {
			case bts, ok := <-xmlChan:
				if !ok {
					close(employeeWIChan)
					return
				}
				wi, err := xml_loader.GoLoadFromXML(bts)
				if err != nil {
					errChan <- err
					return
				}
				employeeWIChan <- wi
			}
		}
	}()

	go func() {
		var wg sync.WaitGroup
		wg.Add(len(employeeNumber))
		for i := range employeeNumber {
			go func(v string) {
				defer wg.Done()
				bts, err := etl.ewiLoader.GoLoadEmployee(v, from, to)
				if err != nil {
					errChan <- err
					return
				}
				xmlChan <- bts
			}(employeeNumber[i])
		}
		wg.Wait()
		close(xmlChan)
	}()
	return <-errChan
}

func (etl *Etl) Main(ctx context.Context, cr *crono.Crono, employeeNumber []string, from, to string) error {
	ctx, cancel := context.WithCancel(ctx)

	errChan := make(chan error, 1)
	ewiChan := make(chan []domain.EmployeeWorkInformation, len(employeeNumber))
	var wg sync.WaitGroup
	wg.Add(1 + len(employeeNumber))

	go func() {
		defer wg.Done()
		for _, v := range employeeNumber {
			go func(v string) {
				cr.Restart()
				defer wg.Done()
				wi, err := etl.ewiLoader.LoadEmployee(v, from, to)
				if err != nil {
					errChan <- err
					return
				}
				ewiChan <- wi
				cr.MarkAndRestart(fmt.Sprintf("ewiLoader.LoadEmployee | %s | from: %s to: %s", v, from, to))
			}(v)
		}
	}()

	go func() {
		if err := <-errChan; err != nil {
			log.Fatalln("error while process", err)
			cancel()
			return
		}
	}()

	go func() {
		for v := range ewiChan {
			// log.Println("len v", len(v))
			err := etl.repo.InsertMany(ctx, v)
			if err != nil {
				errChan <- err
				return
			}
			cr.MarkAndRestart(fmt.Sprintf("database inserted: %d", len(v)))
		}
		errChan <- nil
	}()

	wg.Wait()
	return nil
}