feat: add and delete amende and point by admin

backend/gestion/db/db_parrain.go

@@ -0,0 +1,69 @@
+package db
+
+import (
+	"fmt"
+	"gestion/models"
+)
+
+func (d *Database) SetClientParrain(clientUsername, parrainUsername string) error {
+	result := d.GDB.Model(&models.Client{}).
+		Where("username = ? AND (parrain IS NULL OR parrain = '')", clientUsername).
+		Update("parrain", parrainUsername)
+	if result.Error != nil {
+		return result.Error
+	}
+	if result.RowsAffected == 0 {
+		return fmt.Errorf("client introuvable ou parrain déjà défini")
+	}
+	return nil
+}
+
+func (d *Database) GetClientParrain(clientUsername string) (string, error) {
+	var parrain string
+	err := d.GDB.Table("clients").
+		Select("parrain").
+		Where("username = ?", clientUsername).
+		Scan(&parrain).Error
+	return parrain, err
+}
+
+func (d *Database) GetClientsByParrain(parrainUsername string) ([]models.Client, error) {
+	var clients []models.Client
+	err := d.GDB.
+		Where("parrain = ?", parrainUsername).
+		Find(&clients).Error
+	return clients, err
+}
+
+func (d *Database) GetParrainStats() ([]map[string]any, error) {
+	var rows []struct {
+		Parrain         string  `gorm:"column:parrain"`
+		FilleulCount    int     `gorm:"column:filleul_count"`
+		ReferralBalance float64 `gorm:"column:referral_balance"`
+	}
+
+	err := d.GDB.Raw(`
+		SELECT
+			c.parrain,
+			COUNT(c.username) AS filleul_count,
+			p.referral_balance
+		FROM clients c
+		JOIN clients p ON p.username = c.parrain
+		WHERE c.parrain IS NOT NULL AND c.parrain <> ''
+		GROUP BY c.parrain, p.referral_balance
+		ORDER BY filleul_count DESC
+	`).Scan(&rows).Error
+	if err != nil {
+		return nil, err
+	}
+
+	result := make([]map[string]any, 0, len(rows))
+	for _, r := range rows {
+		result = append(result, map[string]any{
+			"parrain":          r.Parrain,
+			"filleul_count":    r.FilleulCount,
+			"referral_balance": r.ReferralBalance,
+		})
+	}
+	return result, nil
+}