package models

import (
	"GoMembership/internal/config"
	"GoMembership/internal/constants"
	"GoMembership/pkg/errors"
	"GoMembership/pkg/logger"
	"fmt"
	"slices"
	"strings"
	"time"

	"github.com/alexedwards/argon2id"
	"github.com/gin-gonic/gin"
	"github.com/golang-jwt/jwt/v5"
	"gorm.io/gorm"
	"gorm.io/gorm/clause"
)

type User struct {
	ID            uint `gorm:"primaryKey" json:"id"`
	CreatedAt     time.Time
	UpdatedAt     time.Time
	DeletedAt     *time.Time
	DateOfBirth   time.Time      `gorm:"not null" json:"dateofbirth" binding:"required_unless=RoleID 0,safe_content"`
	Company       string         `json:"company" binding:"omitempty,omitnil,safe_content"`
	Phone         string         `json:"phone" binding:"omitempty,omitnil,safe_content"`
	Notes         string         `json:"notes" binding:"safe_content"`
	FirstName     string         `gorm:"not null" json:"first_name" binding:"required,safe_content"`
	Password      string         `json:"password" binding:"safe_content"`
	Email         string         `gorm:"uniqueIndex:idx_users_email,not null" json:"email" binding:"required,email,safe_content"`
	LastName      string         `gorm:"not null" json:"last_name" binding:"required,safe_content"`
	Address       string         `gorm:"not null" json:"address" binding:"required,safe_content"`
	ZipCode       string         `gorm:"not null" json:"zip_code" binding:"required,alphanum,safe_content"`
	City          string         `form:"not null" json:"city" binding:"required,alphaunicode,safe_content"`
	Consents      []Consent      `gorm:"constraint:OnUpdate:CASCADE"`
	BankAccount   *BankAccount   `gorm:"foreignkey:UserID;constraint:OnUpdate:CASCADE,OnDelete:CASCADE" json:"bank_account"`
	Verifications []Verification `gorm:"constraint:OnUpdate:CASCADE,OnDelete:CASCADE"`
	Membership    *Membership    `gorm:"constraint:OnUpdate:CASCADE,OnDelete:CASCADE" json:"membership"`
	Licence       *Licence       `gorm:"constraint:OnUpdate:CASCADE,OnDelete:CASCADE" json:"licence"`
	Status        int8           `json:"status"`
	RoleID        int8           `json:"role_id"`
}

func (u *User) AfterCreate(tx *gorm.DB) (err error) {
	if u.BankAccount != nil && u.BankAccount.MandateReference == "" {
		u.BankAccount.MandateReference = u.BankAccount.GenerateMandateReference(u.ID)
		u.BankAccount.Update(tx)
	}
	return nil
}

func (u *User) BeforeSave(tx *gorm.DB) (err error) {
	u.Email = strings.ToLower(u.Email)
	if u.Password != "" {
		hash, err := argon2id.CreateHash(u.Password, argon2id.DefaultParams)
		if err != nil {
			return err
		}
		u.Password = hash
	}
	return nil
}

func (u *User) Create(db *gorm.DB) error {

	return db.Transaction(func(tx *gorm.DB) error {
		if err := tx.Preload(clause.Associations).Create(u).Error; err != nil {
			return err
		}

		return nil
	})
}

func (u *User) Update(db *gorm.DB) error {

	err := db.Transaction(func(tx *gorm.DB) error {
		// Check if the user exists in the database
		var existingUser User

		logger.Info.Printf("updating user: %#v", u)
		if err := tx.
			First(&existingUser, u.ID).Error; err != nil {
			return err
		}
		// Update the user's main fields
		result := tx.Session(&gorm.Session{FullSaveAssociations: true}).Omit("Verifications", "Licence.Categories").Updates(u)
		if result.Error != nil {
			logger.Error.Printf("User update error in update user: %#v", result.Error)
			return result.Error
		}
		if result.RowsAffected == 0 {
			return errors.ErrNoRowsAffected
		}

		if u.Verifications != nil {
			if err := tx.Save(u.Verifications).Error; err != nil {
				return err
			}
		}

		if u.Licence != nil {
			if err := tx.Model(u.Licence).Association("Categories").Replace(u.Licence.Categories); err != nil {
				return err
			}
		}
		return nil
	})

	if err != nil {
		return err
	}

	return db.
		Preload(clause.Associations).
		Preload("Membership.Subscription").
		Preload("Licence.Categories").
		First(&u, u.ID).Error
}

func (u *User) Delete(db *gorm.DB) error {
	return db.Delete(&User{}, "id = ?", u.ID).Error
}

func (u *User) FromID(db *gorm.DB, userID *uint) error {
	var user User
	result := db.
		Preload(clause.Associations).
		Preload("Membership.Subscription").
		Preload("Licence.Categories").
		First(&user, userID)
	if result.Error != nil {
		if result.Error == gorm.ErrRecordNotFound {
			return gorm.ErrRecordNotFound
		}
		return result.Error
	}
	*u = user
	return nil
}

func (u *User) FromEmail(db *gorm.DB, email *string) error {
	var user User
	result := db.
		Preload(clause.Associations).
		Preload("Membership.Subscription").
		Preload("Licence.Categories").
		Where("email = ?", email).First(&user)
	if result.Error != nil {
		if result.Error == gorm.ErrRecordNotFound {
			return gorm.ErrRecordNotFound
		}
		return result.Error
	}
	*u = user
	return nil
}

func (u *User) FromContext(db *gorm.DB, c *gin.Context) error {
	tokenString, err := c.Cookie("jwt")
	if err != nil {
		return err
	}
	jwtUserID, err := extractUserIDFrom(tokenString)
	if err != nil {
		return err
	}
	if err = u.FromID(db, &jwtUserID); err != nil {
		return err
	}
	return nil
}

func (u *User) PasswordMatches(plaintextPassword string) (bool, error) {
	return argon2id.ComparePasswordAndHash(plaintextPassword, u.Password)
}

func (u *User) PasswordExists() bool {
	return u.Password != ""
}

func (u *User) IsVerified() bool {
	return u.Status > constants.DisabledStatus
}

func (u *User) HasPrivilege(privilege int8) bool {
	return u.RoleID >= privilege
}

func (u *User) IsAdmin() bool {
	return u.RoleID == constants.Roles.Admin
}

func (u *User) IsMember() bool {
	return u.RoleID == constants.Roles.Member
}

func (u *User) IsSupporter() bool {
	return u.RoleID == constants.Roles.Supporter
}

func (u *User) SetVerification(verificationType string) (*Verification, error) {
	if u.Verifications == nil {
		u.Verifications = []Verification{}
	}
	v, err := CreateVerification(verificationType)
	if err != nil {
		return nil, err
	}
	v.UserID = u.ID
	if vi := slices.IndexFunc(u.Verifications, func(vsl Verification) bool { return vsl.Type == v.Type }); vi > -1 {
		u.Verifications[vi] = *v
	} else {
		u.Verifications = append(u.Verifications, *v)
	}
	return v, nil
}

func (u *User) FindVerification(verificationType string) (*Verification, error) {
	if u.Verifications == nil {
		return nil, errors.ErrNoData
	}
	vi := slices.IndexFunc(u.Verifications, func(vsl Verification) bool { return vsl.Type == verificationType })
	if vi == -1 {
		return nil, errors.ErrNotFound
	}
	return &u.Verifications[vi], nil
}

func (u *User) Verify(token string, verificationType string) error {
	if token == "" || verificationType == "" {
		logger.Error.Printf("token or verification type are empty in user.Verify")
		return errors.ErrNoData
	}

	vi := slices.IndexFunc(u.Verifications, func(vsl Verification) bool {
		return vsl.Type == verificationType && vsl.VerificationToken == token
	})

	if vi == -1 {
		logger.Error.Printf("Couldn't find verification in users verifications")
		return errors.ErrNotFound
	}
	return u.Verifications[vi].Validate()
}

func (u *User) Safe() map[string]interface{} {
	var membership map[string]interface{} = nil
	var licence map[string]interface{} = nil
	var bankAccount map[string]interface{} = nil
	if u.Membership != nil {
		membership = map[string]interface{}{
			"id":         u.Membership.ID,
			"start_date": u.Membership.StartDate,
			"end_date":   u.Membership.EndDate,
			"status":     u.Membership.Status,
			"subscription": map[string]interface{}{
				"id":                 u.Membership.Subscription.ID,
				"name":               u.Membership.Subscription.Name,
				"details":            u.Membership.Subscription.Details,
				"conditions":         u.Membership.Subscription.Conditions,
				"monthly_fee":        u.Membership.Subscription.MonthlyFee,
				"hourly_rate":        u.Membership.Subscription.HourlyRate,
				"included_per_year":  u.Membership.Subscription.IncludedPerYear,
				"included_per_month": u.Membership.Subscription.IncludedPerMonth,
			},
		}
	}

	if u.Licence != nil {
		licence = map[string]interface{}{
			"id":              u.Licence.ID,
			"number":          u.Licence.Number,
			"status":          u.Licence.Status,
			"issued_date":     u.Licence.IssuedDate,
			"expiration_date": u.Licence.ExpirationDate,
			"country":         u.Licence.IssuingCountry,
			"categories":      u.Licence.Categories,
		}
	}

	if u.BankAccount != nil {
		bankAccount = map[string]interface{}{
			"id":                  u.BankAccount.ID,
			"mandate_date_signed": u.BankAccount.MandateDateSigned,
			"bank":                u.BankAccount.Bank,
			"account_holder_name": u.BankAccount.AccountHolderName,
			"iban":                u.BankAccount.IBAN,
			"bic":                 u.BankAccount.BIC,
			"mandate_reference":   u.BankAccount.MandateReference,
		}
	}
	result := map[string]interface{}{
		"email":        u.Email,
		"first_name":   u.FirstName,
		"last_name":    u.LastName,
		"phone":        u.Phone,
		"notes":        u.Notes,
		"address":      u.Address,
		"zip_code":     u.ZipCode,
		"city":         u.City,
		"status":       u.Status,
		"id":           u.ID,
		"role_id":      u.RoleID,
		"company":      u.Company,
		"dateofbirth":  u.DateOfBirth,
		"membership":   membership,
		"licence":      licence,
		"bank_account": bankAccount,
	}

	return result
}

func extractUserIDFrom(tokenString string) (uint, error) {
	jwtSigningMethod := jwt.SigningMethodHS256
	jwtParser := jwt.NewParser(jwt.WithValidMethods([]string{jwtSigningMethod.Alg()}))
	token, err := jwtParser.Parse(tokenString, func(_ *jwt.Token) (interface{}, error) {
		return []byte(config.Auth.JWTSecret), nil
	})

	// Handle parsing errors (excluding expiration error)
	if err != nil && !errors.Is(err, jwt.ErrTokenExpired) || token == nil {
		logger.Error.Printf("Error parsing token: %v", err)
		return 0, err
	}

	claims, ok := token.Claims.(jwt.MapClaims)
	if !ok {
		logger.Error.Print("Invalid token claims structure")
		return 0, fmt.Errorf("invalid token claims format")
	}

	// Validate required session_id claim
	if _, exists := claims["session_id"]; !exists {
		logger.Error.Print("Missing session_id in token claims")
		return 0, fmt.Errorf("missing session_id claim")
	}

	// Return token, claims, and original error (might be expiration)

	if _, exists := claims["session_id"]; !exists {
		logger.Error.Print("Missing session_id in token claims")
		return 0, fmt.Errorf("missing session_id claim")
	}
	id, ok := claims["user_id"]
	if !ok {
		return 0, fmt.Errorf("missing user_id claim")
	}

	return uint(id.(float64)), nil
}

func GetUsersWhere(db *gorm.DB, where map[string]interface{}) (*[]User, error) {
	logger.Error.Printf("where: %#v", where)
	var users []User
	result := db.
		Preload(clause.Associations).
		Preload("Membership.Subscription").
		Preload("Licence.Categories").
		Where(where).Find(&users)
	if result.Error != nil {
		if result.Error == gorm.ErrRecordNotFound {
			return nil, gorm.ErrRecordNotFound
		}
		return nil, result.Error
	}
	return &users, nil
}