package handlers

import (
	"fmt"
	"strings"
	"sync"

	"github.com/sirupsen/logrus"

	"github.com/authelia/authelia/v4/internal/authentication"
	"github.com/authelia/authelia/v4/internal/middlewares"
	"github.com/authelia/authelia/v4/internal/storage"
	"github.com/authelia/authelia/v4/internal/utils"
)

func loadInfo(username string, storageProvider storage.Provider, userInfo *UserInfo, logger *logrus.Entry) []error {
	var wg sync.WaitGroup

	wg.Add(3)

	errors := make([]error, 0)

	go func() {
		defer wg.Done()

		method, err := storageProvider.LoadPreferred2FAMethod(username)
		if err != nil {
			errors = append(errors, err)
			logger.Error(err)

			return
		}

		if method == "" {
			userInfo.Method = authentication.PossibleMethods[0]
		} else {
			userInfo.Method = method
		}
	}()

	go func() {
		defer wg.Done()

		_, _, err := storageProvider.LoadU2FDeviceHandle(username)
		if err != nil {
			if err == storage.ErrNoU2FDeviceHandle {
				return
			}

			errors = append(errors, err)
			logger.Error(err)

			return
		}

		userInfo.HasU2F = true
	}()

	go func() {
		defer wg.Done()

		_, err := storageProvider.LoadTOTPSecret(username)
		if err != nil {
			if err == storage.ErrNoTOTPSecret {
				return
			}

			errors = append(errors, err)
			logger.Error(err)

			return
		}

		userInfo.HasTOTP = true
	}()

	wg.Wait()

	return errors
}

// UserInfoGet get the info related to the user identified by the session.
func UserInfoGet(ctx *middlewares.AutheliaCtx) {
	userSession := ctx.GetSession()

	userInfo := UserInfo{}
	errors := loadInfo(userSession.Username, ctx.Providers.StorageProvider, &userInfo, ctx.Logger)

	if len(errors) > 0 {
		ctx.Error(fmt.Errorf("unable to load user information"), messageOperationFailed)
		return
	}

	userInfo.DisplayName = userSession.DisplayName

	err := ctx.SetJSONBody(userInfo)
	if err != nil {
		ctx.Logger.Errorf("Unable to set user info response in body: %s", err)
	}
}

// MethodBody the selected 2FA method.
type MethodBody struct {
	Method string `json:"method" valid:"required"`
}

// MethodPreferencePost update the user preferences regarding 2FA method.
func MethodPreferencePost(ctx *middlewares.AutheliaCtx) {
	bodyJSON := MethodBody{}

	err := ctx.ParseBody(&bodyJSON)
	if err != nil {
		ctx.Error(err, messageOperationFailed)
		return
	}

	if !utils.IsStringInSlice(bodyJSON.Method, authentication.PossibleMethods) {
		ctx.Error(fmt.Errorf("unknown method '%s', it should be one of %s", bodyJSON.Method, strings.Join(authentication.PossibleMethods, ", ")), messageOperationFailed)
		return
	}

	userSession := ctx.GetSession()
	ctx.Logger.Debugf("Save new preferred 2FA method of user %s to %s", userSession.Username, bodyJSON.Method)
	err = ctx.Providers.StorageProvider.SavePreferred2FAMethod(userSession.Username, bodyJSON.Method)

	if err != nil {
		ctx.Error(fmt.Errorf("unable to save new preferred 2FA method: %s", err), messageOperationFailed)
		return
	}

	ctx.ReplyOK()
}