package handlers

import (
	"fmt"
	"github.com/gofiber/fiber/v2"
	"github.com/golang-jwt/jwt/v5"
	"golang.org/x/crypto/bcrypt"
	"os"
	"relay-server/config"
	"relay-server/database"
	"relay-server/helpers"
	"relay-server/model"
	"time"
)

func Signup(c *fiber.Ctx) error {
	db := database.DB
	u := new(model.SignupStruct)
	if err := c.BodyParser(u); err != nil {
		return err
	}
	// Checks if username or passwords are empty
	if u.Username == "" {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "username is empty"})
	} else if u.Password == "" {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "password is empty"})
	}

	// Checks if passwords or username have valid length and characters
	if !helpers.IsValidPassword(u.Password) {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "invalid password"})
	} else if !helpers.IsValidUsername(u.Username) {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "invalid username"})
	}

	// Checks if username already exist in database
	exist, _ := database.CheckUserExists(db, u.Username)
	if exist {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "user already exists"})
	}

	// Create password hash
	passwordHash, err := bcrypt.GenerateFromPassword([]byte(u.Password), config.BCRYPT_COST)
	if err != nil {
		fmt.Printf("error hashing password: %v\n", err)
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "internal server error"})
	}

	// Insert username and password hash to database
	userId, err := database.InsertUser(db, u.Username, string(passwordHash))
	if err != nil {
		fmt.Printf("error inserting user: %v\n", err)
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "Internal server error"})
	}

	// Generate token with user id and username
	token := jwt.NewWithClaims(jwt.SigningMethodHS256, jwt.MapClaims{
		"user_id":  userId,
		"username": u.Username,
	})
	// Sign token
	signedToken, err := token.SignedString([]byte(os.Getenv("JWT_SECRET")))

	// Set token to cookies
	tokenCookie := new(fiber.Cookie)
	tokenCookie.Name = "token"
	tokenCookie.Value = signedToken
	tokenCookie.Expires = time.Now().Add(30 * 24 * time.Hour)
	//tokenCookie.HTTPOnly = true
	c.Cookie(tokenCookie)

	// If everything went well sent username and user_id assigned by database
	return c.Status(fiber.StatusOK).JSON(fiber.Map{"message": "Successfully signed up", "username": u.Username, "user_id": userId})
}

func Login(c *fiber.Ctx) error {
	db := database.DB
	u := new(model.LoginStruct)

	if err := c.BodyParser(u); err != nil {
		return err
	}

	// Checks if username or passwords are empty
	if u.Username == "" {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "username is empty"})
	} else if u.Password == "" {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "password is empty"})
	}

	// Checks if username or passwords have valid length and characters
	if !helpers.IsValidUsername(u.Username) {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "invalid username"})
	} else if !helpers.IsValidPassword(u.Password) {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "invalid password"})
	}

	// Checks if username exist in database
	exist, _ := database.CheckUserExists(db, u.Username)
	if !exist {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "user does not exists"})
	}

	// Verifies password matching
	passwordHash, _ := database.GetPasswordHash(db, u.Username)
	if bcrypt.CompareHashAndPassword([]byte(passwordHash), []byte(u.Password)) != nil {
		return c.Status(fiber.StatusUnauthorized).JSON(fiber.Map{"error": "invalid password"})
	}

	userId, err := database.GetUserId(db, u.Username)
	if err != nil {
		fmt.Printf("error getting user id: %v\n", err)
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "internal server error"})
	}
	// Generate token with user id and username
	token := jwt.NewWithClaims(jwt.SigningMethodHS256, jwt.MapClaims{
		"user_id":  userId,
		"username": u.Username,
	})
	// Sign token
	signedToken, err := token.SignedString([]byte(os.Getenv("JWT_SECRET")))

	// Set token to cookies
	tokenCookie := new(fiber.Cookie)
	tokenCookie.Name = "token"
	tokenCookie.Value = signedToken
	tokenCookie.Expires = time.Now().Add(30 * 24 * time.Hour)
	//tokenCookie.HTTPOnly = true
	c.Cookie(tokenCookie)

	return c.Status(fiber.StatusOK).JSON(fiber.Map{"message": "Successfully logged in", "username": u.Username, "user_id": userId})
}

//func ValidateToken(c *fiber.Ctx) error {
//
//}