package service

import (
	"errors"
	"github.com/gofiber/fiber/v2"
	"io"
	quizdal "penahub.gitlab.yandexcloud.net/backend/quiz/common.git/dal"
	mw "penahub.gitlab.yandexcloud.net/backend/quiz/common.git/middleware"
	"penahub.gitlab.yandexcloud.net/backend/quiz/storer.git/dal"
	"strconv"
	"sync"

	"github.com/rs/xid"
)

type Service struct {
	store *dal.Storer
	dal   *quizdal.DAL
}

func New(s *dal.Storer, q *quizdal.DAL) *Service {
	return &Service{
		store: s,
		dal:   q,
	}
}

func (s *Service) Register(app *fiber.App) {
	app.Put("/quiz/customization", s.UploadCustom)
	app.Put("/quiz/putImages", s.UploadImages)
}

// MB Size constants
const (
	MB = 1 << 20
)

func (s *Service) UploadCustom(c *fiber.Ctx) error {
	accountId, ok := mw.GetAccountId(c)
	if !ok {
		return nil
	}

	// Check valid file
	form, err := c.MultipartForm()
	if err != nil || form == nil || form.File == nil {
		return c.Status(fiber.StatusBadRequest).SendString("expecting multipart form file")
	}

	squizIdStr := form.Value["quiz"]
	if len(squizIdStr) == 0 {
		return c.Status(fiber.StatusFailedDependency).SendString("no quiz id provided")
	}

	squizId, err := strconv.ParseInt(squizIdStr[0], 10, 64)
	if err != nil {
		return c.Status(fiber.StatusBadRequest).SendString("not valid quiz id provided " + err.Error())
	}

	quiz, err := s.dal.QuizRepo.GetQuizById(c.Context(), accountId, uint64(squizId))
	if err != nil {
		return c.Status(fiber.StatusNotAcceptable).SendString("not exists quiz id provided " + err.Error())
	}

	var (
		wg   sync.WaitGroup
		errm sync.Mutex
		errs []error
	)

	if len(form.File["script"]) >= 1 {
		wg.Add(1)
		go func() {
			defer wg.Done()
			fileHeader := form.File["script"][0]
			file, err := fileHeader.Open()
			if err != nil {
				errm.Lock()
				defer errm.Unlock()
				errs = append(errs, errors.New(err.Error()+" => script read"))
				return
			}
			defer file.Close()

			if err := s.store.UploadScript(c.Context(), quiz.Qid, file, fileHeader.Size); err != nil {
				errm.Lock()
				defer errm.Unlock()
				errs = append(errs, errors.New(err.Error()+" => script upload"))
			}
		}()
	}

	if len(form.File["style"]) >= 1 {
		wg.Add(1)
		go func() {
			defer wg.Done()
			fileHeader := form.File["style"][0]
			file, err := fileHeader.Open()
			if err != nil {
				errm.Lock()
				defer errm.Unlock()
				errs = append(errs, errors.New(err.Error()+" => style read"))
				return
			}
			defer file.Close()

			if err := s.store.UploadStyle(c.Context(), quiz.Qid, file, fileHeader.Size); err != nil {
				errm.Lock()
				defer errm.Unlock()
				errs = append(errs, errors.New(err.Error()+" => style upload"))
			}
		}()
	}

	if len(form.File["fonts"]) >= 1 {
		files, sizes := map[string]io.Reader{}, map[string]int64{}
		for _, fileHeader := range form.File["fonts"] {
			file, err := fileHeader.Open()
			if err != nil {
				errm.Lock()
				errs = append(errs, errors.New(err.Error()+" => fonts read"))
				errm.Unlock()
			}
			files[fileHeader.Filename] = file
			sizes[fileHeader.Filename] = fileHeader.Size
		}

		wg.Add(1)
		go func() {
			defer wg.Done()
			if errorsFontUploading := s.store.UploadFonts(c.Context(), quiz.Qid, files, sizes); err != nil {
				errm.Lock()
				defer errm.Unlock()
				errs = append(errs, errorsFontUploading...)
			}
		}()
	}
	wg.Wait()

	if len(errs) > 0 {
		return c.Status(fiber.StatusInternalServerError).JSON(errs)
	}

	return c.SendStatus(fiber.StatusOK)
}

func (s *Service) UploadImages(c *fiber.Ctx) error {
	accountId, ok := mw.GetAccountId(c)
	if !ok {
		return nil
	}

	// Check valid file
	form, err := c.MultipartForm()
	if err != nil || form == nil || form.File == nil {
		return c.Status(fiber.StatusBadRequest).SendString("expecting multipart form file")
	}

	squizIdStr := form.Value["quiz"]
	if len(squizIdStr) == 0 {
		return c.Status(fiber.StatusFailedDependency).SendString("no quiz id provided")
	}

	squizId, err := strconv.ParseInt(squizIdStr[0], 10, 64)
	if err != nil {
		return c.Status(fiber.StatusBadRequest).SendString("not valid quiz id provided " + err.Error())
	}

	quiz, err := s.dal.QuizRepo.GetQuizById(c.Context(), accountId, uint64(squizId))
	if err != nil {
		return c.Status(fiber.StatusNotAcceptable).SendString("not exists quiz id provided " + err.Error())
	}

	var errs []error
	imgids := make(map[string]string)

	if len(form.File["image"]) >= 1 {
		files, sizes := make(map[string]io.Reader), make(map[string]int64)
		for _, imgFile := range form.File["image"] {
			f, err := imgFile.Open()
			if err != nil {
				errs = append(errs, errors.New(err.Error()+" => imgs read"))
				continue
			}
			fname := xid.New().String()
			files[fname] = f
			sizes[fname] = imgFile.Size
			imgids[imgFile.Filename] = fname
			defer f.Close()
		}

		if err := s.store.UploadImages(c.Context(), quiz.Qid, files, sizes); err != nil {
			errs = append(errs, err...)
		}
	}

	if len(errs) > 0 {
		return c.Status(fiber.StatusInternalServerError).JSON(errs)
	}

	return c.Status(fiber.StatusOK).JSON(imgids)
}