package controllers

import (
	"crypto/rand"
	"encoding/base64"
	"golang-test/database"
	"golang-test/libs"
	"golang-test/types"
	"golang-test/validators"
	"log"
	"net/http"
	"strconv"

	"github.com/gin-gonic/gin"
	"github.com/go-playground/validator/v10"
	"golang.org/x/crypto/bcrypt"
)

type TokenStruct struct {
	UserID uint
	token  string
}

func RegisterUser(c *gin.Context, register types.RegisterRequest) {
	db := database.Connector()
	validate := validators.Validate
	var token database.Token
	var user database.User

	// Валидация входных данных
	if err := validate.Struct(register); err != nil {
		c.JSON(http.StatusBadRequest, libs.GetValidationErrors(err.(validator.ValidationErrors)))
		return
	}

	// Проверка, существует ли уже пользователь с таким email
	if userExists(register.Email) {
		c.JSON(http.StatusBadRequest, types.ErrorResponse{Message: "User already exists"})
		return
	}

	// Генерация хэшированного пароля
	hashedPassword, err := bcrypt.GenerateFromPassword([]byte(register.Password), 12)
	if err != nil {
		log.Println(err.Error())
		c.JSON(http.StatusInternalServerError, types.ErrorResponse{Message: err.Error()})
		return
	}

	// Создание нового пользователя
	user = database.User{
		Name:     register.Name,
		Email:    register.Email,
		Password: string(hashedPassword),
	}

	// Генерация токена для пользователя
	token.Token = generateToken()
	token.UserID = user.ID
	user.Tokens = append(user.Tokens, token)

	// Сохранение пользователя в базе данных
	if err := db.Create(&user).Error; err != nil {
		c.JSON(http.StatusInternalServerError, types.ErrorResponse{Message: err.Error()})
		return
	}

	// Отправка ответа с токеном
	c.JSON(http.StatusCreated, types.TokenResponse{Token: token.Token})
}

// userExists проверяет, существует ли пользователь с данным email
func userExists(email string) bool {
	db := database.Connector()
	var user database.User
	err := db.Where("email = ?", email).First(&user).Error
	return err == nil
}

func LoginUser(c *gin.Context, login types.LoginRequest) {
	var user database.User
	db := database.Connector()
	validate := validators.Validate
	var token database.Token

	if err := validate.Struct(login); err != nil {
		c.JSON(http.StatusBadRequest, libs.GetValidationErrors(err.(validator.ValidationErrors)))
		return
	}

	if err := db.Where("email = ?", login.Email).First(&user).Error; err != nil {
		c.JSON(http.StatusBadRequest, types.ErrorResponse{Message: "Invalid email or password"})
		return
	}

	if err := bcrypt.CompareHashAndPassword([]byte(user.Password), []byte(login.Password)); err != nil {
		c.JSON(http.StatusBadRequest, types.ErrorResponse{Message: "Invalid email or password"})
		return
	}

	token.Token = generateToken()
	token.UserID = user.ID

	user.Tokens = append(user.Tokens, token)

	db.Save(&user)

	c.JSON(http.StatusOK, types.TokenResponse{Token: token.Token})
}

func generateToken() string {
	b := make([]byte, 25)
	if _, err := rand.Read(b); err != nil {
		return ""
	}
	return base64.StdEncoding.EncodeToString(b)
}

func GetUser(c *gin.Context) {
	var products []types.ProductResponse
	user, err := libs.GetUserFromHeaders(c)
	if err != nil {
		c.JSON(http.StatusUnauthorized, types.ErrorResponse{Message: err.Error()})
		return
	}

	for _, product := range user.Products {
		products = append(products, types.ProductResponse{
			ID:    product.ID,
			Name:  product.Name,
			Price: product.Price,
		})
	}

	userResponse := types.UserResponse{
		ID:       user.ID,
		Name:     user.Name,
		Email:    user.Email,
		Products: products,
		Money:    user.Money,
	}

	c.JSON(http.StatusOK, userResponse)
}

func EditUserName(c *gin.Context, userName types.EditUserNameRequest) {
	db := database.Connector()
	validate := validators.Validate

	if err := validate.Struct(userName); err != nil {
		c.JSON(http.StatusBadRequest, libs.GetValidationErrors(err.(validator.ValidationErrors)))
		return
	}

	user, err := libs.GetUserFromHeaders(c)
	if err != nil {
		c.JSON(http.StatusUnauthorized, types.ErrorResponse{Message: err.Error()})
		return
	}

	user.Name = userName.Name

	if err := db.Save(user).Error; err != nil {
		c.JSON(http.StatusInternalServerError, types.ErrorResponse{Message: err.Error()})
		return
	}

	c.JSON(http.StatusOK, types.MessageResponse{Message: "User name successfully updated"})
}

func AddMoneyToUser(c *gin.Context, moneyRequest types.AddMoneyRequest) {
	db := database.Connector()
	user, err := libs.GetUserFromHeaders(c)
	if err != nil {
		c.JSON(http.StatusUnauthorized, types.ErrorResponse{Message: err.Error()})
		return
	}

	user.Money += moneyRequest.Money

	if err := db.Save(&user).Error; err != nil {
		c.JSON(http.StatusInternalServerError, types.ErrorResponse{Message: err.Error()})
	}

	c.JSON(http.StatusOK, types.MessageResponse{Message: "Money successfully added"})
}

func BuyProduct(c *gin.Context) {
	var product database.Product

	db := database.Connector()
	id, err := strconv.Atoi(c.Param("id"))

	if err != nil {
		c.JSON(http.StatusBadRequest, types.ErrorResponse{Message: err.Error()})
		return
	}

	if err := db.First(&product, id).Error; err != nil {
		c.JSON(http.StatusBadRequest, types.NotFoundError("Product", id))
		return
	}

	user, err := libs.GetUserFromHeaders(c)
	if err != nil {
		c.JSON(http.StatusUnauthorized, types.ErrorResponse{Message: err.Error()})
		return
	}

	if user.Money-product.Price < 0 {
		c.JSON(http.StatusOK, types.MessageResponse{Message: "Not enough money"})
		return
	}

	user.Money -= product.Price

	user.Products = append(user.Products, product)

	db.Save(&user)

	c.JSON(http.StatusOK, types.MessageResponse{Message: "Product successful buyed"})
}

func GetBuyedProducts(c *gin.Context) {
	var response []types.ProductResponse
	user, err := libs.GetUserFromHeaders(c)
	if err != nil {
		c.JSON(http.StatusUnauthorized, types.ErrorResponse{Message: err.Error()})
		return
	}

	for _, product := range user.Products {

		manufacturer := types.ManufacturerResponse{
			ID:   product.ManufacturerID,
			Name: product.Manufacturer.Name,
		}

		response = append(response, types.ProductResponse{
			ID:             product.ID,
			Name:           product.Manufacturer.Name,
			Price:          product.Price,
			ManufacturerID: manufacturer.ID,
			Manufacturer:   manufacturer,
		})
	}

	c.JSON(http.StatusOK, response)
}