package db

import (
	"fmt"

	"gorm.io/gorm"
)

func (d *Database) GetClientReferralBalance(username string) (float64, error) {
	var balance float64
	err := d.GDB.Table("clients").Select("referral_balance").Where("username = ?", username).Scan(&balance).Error
	if err != nil {
		return 0, err
	}
	return balance, nil
}

func (d *Database) CreditClientReferral(username string, amount float64) error {
	if amount <= 0 {
		return fmt.Errorf("le montant doit être positif")
	}
	result := d.GDB.Exec(`UPDATE clients SET referral_balance = referral_balance + ? WHERE username = ?`, amount, username)
	if result.Error != nil {
		return result.Error
	}
	if result.RowsAffected == 0 {
		return fmt.Errorf("client non trouvé")
	}
	return nil
}

func (d *Database) DebitReferralBalance(username string, amount float64) error {
	if amount <= 0 {
		return nil
	}
	return d.GDB.Transaction(func(tx *gorm.DB) error {
		var balance float64
		if err := tx.Raw(`SELECT referral_balance FROM clients WHERE username = ? FOR UPDATE`, username).Scan(&balance).Error; err != nil {
			return fmt.Errorf("client non trouvé")
		}
		if balance < amount {
			return fmt.Errorf("solde parrainage insuffisant (disponible: %.2f€)", balance)
		}
		return tx.Exec(`UPDATE clients SET referral_balance = referral_balance - ? WHERE username = ?`, amount, username).Error
	})
}

func (d *Database) UseClientReferralBalance(tx *gorm.DB, username string, amount float64) error {
	if amount <= 0 {
		return nil
	}
	var balance float64
	if err := tx.Raw(`SELECT referral_balance FROM clients WHERE username = ? FOR UPDATE`, username).Scan(&balance).Error; err != nil {
		return fmt.Errorf("client non trouvé")
	}
	if balance < amount {
		return fmt.Errorf("solde parrainage insuffisant (disponible: %.2f€)", balance)
	}
	return tx.Exec(`UPDATE clients SET referral_balance = referral_balance - ? WHERE username = ?`, amount, username).Error
}