package session

import (
	"context"
	"net/http"

	"github.com/pkg/errors"
	"gitlab.com/wpetit/goweb/middleware/container"
	"gitlab.com/wpetit/goweb/service/session"
)

type contextKey string

const userEmailKey contextKey = "user_email"

var (
	ErrUserEmailNotFound = errors.New("user email not found")
)

func UserEmailMiddleware(next http.Handler) http.Handler {
	fn := func(w http.ResponseWriter, r *http.Request) {
		userEmail, err := GetUserEmail(w, r)
		if err != nil {
			panic(errors.Wrap(err, "could not find user email"))
		}

		ctx := WithUserEmail(r.Context(), userEmail)
		r = r.WithContext(ctx)

		next.ServeHTTP(w, r)
	}

	return http.HandlerFunc(fn)
}

func WithUserEmail(ctx context.Context, email string) context.Context {
	return context.WithValue(ctx, userEmailKey, email)
}

func UserEmail(ctx context.Context) (string, error) {
	email, ok := ctx.Value(userEmailKey).(string)
	if !ok {
		return "", errors.WithStack(ErrUserEmailNotFound)
	}

	return email, nil
}

func SaveUserEmail(w http.ResponseWriter, r *http.Request, email string) error {
	sess, err := getSession(w, r)
	if err != nil {
		return errors.WithStack(err)
	}

	sess.Set(string(userEmailKey), email)

	if err := sess.Save(w, r); err != nil {
		return errors.WithStack(err)
	}

	return nil
}

func ClearUserEmail(w http.ResponseWriter, r *http.Request, saveSession bool) error {
	sess, err := getSession(w, r)
	if err != nil {
		return errors.WithStack(err)
	}

	sess.Unset(string(userEmailKey))

	if saveSession {
		if err := sess.Save(w, r); err != nil {
			return errors.WithStack(err)
		}
	}

	return nil
}

func GetUserEmail(w http.ResponseWriter, r *http.Request) (string, error) {
	sess, err := getSession(w, r)
	if err != nil {
		return "", errors.WithStack(err)
	}

	email, ok := sess.Get(string(userEmailKey)).(string)
	if !ok {
		return "", errors.WithStack(ErrUserEmailNotFound)
	}

	return email, nil
}

func getSession(w http.ResponseWriter, r *http.Request) (session.Session, error) {
	ctx := r.Context()

	ctn, err := container.From(ctx)
	if err != nil {
		return nil, errors.WithStack(err)
	}

	session, err := session.From(ctn)
	if err != nil {
		return nil, errors.WithStack(err)
	}

	sess, err := session.Get(w, r)
	if err != nil {
		return nil, errors.WithStack(err)
	}

	return sess, nil
}