package handler

import (
	"errors"
	"github.com/gofiber/fiber/v2"
	"github.com/gofiber/fiber/v2/middleware/session"
	"github.com/uptrace/bun"
	"go.uber.org/zap"
	"omnibill.net/omnibill/models"
	"omnibill.net/omnibill/web/utils"
)

func GetUserID(logger *zap.Logger, sess *session.Session, ctx *fiber.Ctx) (string, error) {
	userID := sess.Get("uid").(string)
	if userID == "" {
		return "", DestroySession(logger, sess, ctx, "/auth/login")
	}
	return userID, nil
}

func GetUser(logger *zap.Logger, sess *session.Session, db *bun.DB, ctx *fiber.Ctx) (*models.User, error) {
	userID, err := GetUserID(logger, sess, ctx)
	if err != nil {
		return nil, err
	}

	user := new(models.User)
	if err := db.NewSelect().Model(&user).Where("id = ?", userID).Scan(ctx.UserContext()); err != nil {
		logger.Error("error getting columns", zap.Error(err))
		sessErr := DestroySession(logger, sess, ctx, "/auth/login")
		return nil, errors.Join(err, sessErr)
	}

	return user, nil
}

// Register registers the handler with the webserver.
// It takes a handler as it's input.
// If the handler does not implement any of the handler interfaces, it will panic.
func Register(handler any) {
	var hasHandler bool
	if _, ok := handler.(utils.GET); ok {
		hasHandler = true
	}
	if _, ok := handler.(utils.POST); ok {
		hasHandler = true
	}
	if _, ok := handler.(utils.PUT); ok {
		hasHandler = true
	}
	if _, ok := handler.(utils.DELETE); ok {
		hasHandler = true
	}
	if _, ok := handler.(utils.PATCH); ok {
		hasHandler = true
	}
	if _, ok := handler.(utils.HEAD); ok {
		hasHandler = true
	}
	if _, ok := handler.(utils.OPTIONS); ok {
		hasHandler = true
	}

	if !hasHandler {
		panic("Invalid handler")
	}

	utils.Handlers = append(utils.Handlers, handler)
}

// DestroySession destroys any Session provided to it.
// It takes: zap.Logger, session.Session, fiber.Ctx, and an optional redirectPath of type string.
// The function returns a redirect with an error, or just an error, if any.
func DestroySession(logger *zap.Logger, sess *session.Session, ctx *fiber.Ctx, redirectPath ...string) error {
	if err := sess.Destroy(); err != nil {
		logger.Error("error destroying session", zap.Error(err))
		return fiber.ErrInternalServerError
	}
	if err := sess.Save(); err != nil {
		logger.Error("error saving session", zap.Error(err))
		return fiber.ErrInternalServerError
	}

	if redirectPath != nil && len(redirectPath) > 0 {
		return ctx.Redirect(redirectPath[0])
	} else {
		return nil
	}
}