package crypto

import (
	"fmt"
	"strconv"
	"time"

	"github.com/golang-jwt/jwt"
	"golang.org/x/crypto/bcrypt"

	"furtuna-be/internal/common/errors"
	"furtuna-be/internal/entity"
)

func NewCrypto(config CryptoConfig) *CryptoImpl {
	return &CryptoImpl{
		Config: config,
	}
}

type CryptoConfig interface {
	AccessTokenSecret() string
	AccessTokenOrderSecret() string
	AccessTokenOrderExpiresDate() time.Time
	AccessTokenExpiresDate() time.Time
	AccessTokenResetPasswordSecret() string
	AccessTokenResetPasswordExpire() time.Time
}

type CryptoImpl struct {
	Config CryptoConfig
}

func (c *CryptoImpl) CompareHashAndPassword(hash string, password string) bool {
	err := bcrypt.CompareHashAndPassword([]byte(hash), []byte(password))
	return err == nil
}

func (c *CryptoImpl) ValidateWT(tokenString string) (*jwt.Token, error) {
	token, err := jwt.Parse(tokenString, func(token *jwt.Token) (interface{}, error) {
		if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
			return nil, fmt.Errorf("Unexpected signing method: %v", token.Header["alg"])
		}
		return []byte(c.Config.AccessTokenSecret()), nil
	})

	return token, err
}

func (c *CryptoImpl) GenerateJWT(user *entity.User) (string, error) {
	partnerID := int64(0)
	if user.PartnerID != nil {
		partnerID = *user.PartnerID
	}

	siteID := int64(0)
	if user.SiteID != nil {
		siteID = *user.SiteID
	}

	claims := &entity.JWTAuthClaims{
		StandardClaims: jwt.StandardClaims{
			Subject:   strconv.FormatInt(user.ID, 10),
			ExpiresAt: c.Config.AccessTokenExpiresDate().Unix(),
			IssuedAt:  time.Now().Unix(),
			NotBefore: time.Now().Unix(),
		},
		UserID:    user.ID,
		Name:      user.Name,
		Email:     user.Email,
		Role:      int(user.RoleID),
		PartnerID: partnerID,
		SiteID:    siteID,
		SiteName:  user.SiteName,
	}

	token, err := jwt.
		NewWithClaims(jwt.SigningMethodHS256, claims).
		SignedString([]byte(c.Config.AccessTokenSecret()))

	if err != nil {
		return "", err
	}

	return token, nil
}

func (c *CryptoImpl) GenerateJWTReseetPassword(user *entity.User) (string, error) {
	claims := &entity.JWTAuthClaims{
		StandardClaims: jwt.StandardClaims{
			Subject:   strconv.FormatInt(user.ID, 10),
			ExpiresAt: c.Config.AccessTokenResetPasswordExpire().Unix(),
			IssuedAt:  time.Now().Unix(),
			NotBefore: time.Now().Unix(),
		},
		UserID: user.ID,
		Name:   user.Name,
		Email:  user.Email,
	}

	token, err := jwt.
		NewWithClaims(jwt.SigningMethodHS256, claims).
		SignedString([]byte(c.Config.AccessTokenResetPasswordSecret()))

	if err != nil {
		return "", err
	}

	return token, nil
}

func (c *CryptoImpl) ParseAndValidateJWT(tokenString string) (*entity.JWTAuthClaims, error) {
	token, err := jwt.ParseWithClaims(tokenString, &entity.JWTAuthClaims{}, func(token *jwt.Token) (interface{}, error) {
		return []byte(c.Config.AccessTokenSecret()), nil
	})
	if err != nil {
		return nil, err
	}

	if claims, ok := token.Claims.(*entity.JWTAuthClaims); ok && token.Valid {
		return claims, nil
	} else {
		return nil, errors.ErrorUnauthorized
	}
}

func (c *CryptoImpl) GenerateJWTOrder(order *entity.Order) (string, error) {
	claims := &entity.JWTOrderClaims{
		StandardClaims: jwt.StandardClaims{
			Subject:   strconv.FormatInt(order.ID, 10),
			ExpiresAt: c.Config.AccessTokenOrderExpiresDate().Unix(),
			IssuedAt:  time.Now().Unix(),
			NotBefore: time.Now().Unix(),
		},
		PartnerID: order.PartnerID,
		OrderID:   order.ID,
	}

	token, err := jwt.
		NewWithClaims(jwt.SigningMethodHS256, claims).
		SignedString([]byte(c.Config.AccessTokenOrderSecret()))

	if err != nil {
		return "", err
	}

	return token, nil
}

func (c *CryptoImpl) ValidateJWTOrder(tokenString string) (int64, int64, error) {
	token, err := jwt.ParseWithClaims(tokenString, &entity.JWTOrderClaims{}, func(token *jwt.Token) (interface{}, error) {
		if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
			return nil, fmt.Errorf("unexpected signing method: %v", token.Header["alg"])
		}
		return []byte(c.Config.AccessTokenOrderSecret()), nil
	})

	if err != nil {
		return 0, 0, err
	}

	claims, ok := token.Claims.(*entity.JWTOrderClaims)
	if !ok || !token.Valid {
		return 0, 0, fmt.Errorf("invalid token %v", token.Header["alg"])
	}

	return claims.PartnerID, claims.OrderID, nil
}

func (c *CryptoImpl) ValidateResetPassword(tokenString string) (int64, error) {
	token, err := jwt.ParseWithClaims(tokenString, &entity.JWTOrderClaims{}, func(token *jwt.Token) (interface{}, error) {
		if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
			return nil, fmt.Errorf("unexpected signing method: %v", token.Header["alg"])
		}
		return []byte(c.Config.AccessTokenResetPasswordSecret()), nil
	})

	if err != nil {
		return 0, err
	}

	claims, ok := token.Claims.(*entity.JWTAuthClaims)
	if !ok || !token.Valid {
		return 0, fmt.Errorf("invalid token %v", token.Header["alg"])
	}

	return claims.UserID, nil
}