Merge pull request #42 from kimanimichael/fix/handle_possible_duplicates

Handle possible duplicates
kimanimichael · Sep 19, 2024 · 4f7c605 · 4f7c605
2 parents a1f80a0 + d356fb1
commit 4f7c605
Show file tree

Hide file tree

Showing 10 changed files with 120 additions and 7 deletions.
diff --git a/handler_payments.go b/handler_payments.go
@@ -18,6 +18,8 @@ const MinCashPaid = 1000
 // MaxCashPaid prevents entry errors e.g. 400000 entry instead of 40000
 const MaxCashPaid = 100000
 
+const IdenticalTransactionInterval = 2 * time.Minute
+
 func (apiCfg *apiConfig) handlerCreatePayment(w http.ResponseWriter, r *http.Request, user database.User) {
 	type parameters struct {
 		Cash            int32  `json:"cash_paid"`
@@ -56,6 +58,37 @@ func (apiCfg *apiConfig) handlerCreatePayment(w http.ResponseWriter, r *http.Req
 		return
 	}
 
+	mostRecentPayment, err := apiCfg.DB.GetMostRecentPayment(r.Context())
+	if err != nil {
+		respondWithError(w, 404, fmt.Sprintf("Couldn't find most recent payment: %v", err))
+	}
+
+	currentTime := time.Now()
+	//fix stored time to EAT
+	correctedRecentPaymentTime := time.Date(
+		mostRecentPayment.CreatedAt.Year(),
+		mostRecentPayment.CreatedAt.Month(),
+		mostRecentPayment.CreatedAt.Day(),
+		mostRecentPayment.CreatedAt.Hour(),
+		mostRecentPayment.CreatedAt.Minute(),
+		mostRecentPayment.CreatedAt.Second(),
+		mostRecentPayment.CreatedAt.Nanosecond(),
+		time.FixedZone("EAT", 3*60*60),
+	)
+	durationSinceLastPayment := currentTime.Sub(correctedRecentPaymentTime)
+
+	if mostRecentPayment.FarmerID == farmer.ID {
+		if mostRecentPayment.CashPaid == params.Cash {
+			if mostRecentPayment.PricePerChickenPaid == params.PricePerChicken {
+				if durationSinceLastPayment < IdenticalTransactionInterval {
+					fmt.Printf("Identical transactions in less than %ds attempted", int(IdenticalTransactionInterval.Seconds()))
+					respondWithError(w, 404, fmt.Sprintf("Identical transaction made for Farmer %s. Wait for %d seconds", farmer.Name, int(IdenticalTransactionInterval.Seconds()-durationSinceLastPayment.Seconds())))
+					return
+				}
+			}
+		}
+	}
+
 	payment, err := apiCfg.DB.CreatePayment(r.Context(), database.CreatePaymentParams{
 		ID:                  uuid.New(),
 		CreatedAt:           time.Now(),

diff --git a/handler_purchases.go b/handler_purchases.go
@@ -60,6 +60,34 @@ func (apiCfg *apiConfig) handerCreatePurchases(w http.ResponseWriter, r *http.Re
 		respondWithError(w, 500, fmt.Sprintf("Error getting farmer: %v", err))
 		return
 	}
+	mostRecentPurchase, err := apiCfg.DB.GetMostRecentPurchase(r.Context())
+	if err != nil {
+		respondWithError(w, 500, fmt.Sprintf("Error getting most recent purchase: %v", err))
+	}
+	currentTime := time.Now()
+	correctedRecentPurchaseTime := time.Date(
+		mostRecentPurchase.CreatedAt.Year(),
+		mostRecentPurchase.CreatedAt.Month(),
+		mostRecentPurchase.CreatedAt.Day(),
+		mostRecentPurchase.CreatedAt.Hour(),
+		mostRecentPurchase.CreatedAt.Minute(),
+		mostRecentPurchase.CreatedAt.Second(),
+		mostRecentPurchase.CreatedAt.Nanosecond(),
+		time.FixedZone("EAT", 3*60*60),
+	)
+	durationSinceLastPayment := currentTime.Sub(correctedRecentPurchaseTime)
+
+	if mostRecentPurchase.FarmerID == farmer.ID {
+		if mostRecentPurchase.Chicken == params.Chicken {
+			if mostRecentPurchase.PricePerChicken == params.Price {
+				if durationSinceLastPayment < IdenticalTransactionInterval {
+					fmt.Printf("Identical transactions in less than %ds attempted", int(IdenticalTransactionInterval.Seconds()))
+					respondWithError(w, 404, fmt.Sprintf("Similar transaction for %s. Wait for %ds", farmer.Name, int(IdenticalTransactionInterval.Seconds()-durationSinceLastPayment.Seconds())))
+					return
+				}
+			}
+		}
+	}
 
 	purchase, err := apiCfg.DB.CreatePurchase(r.Context(), database.CreatePurchaseParams{
 		ID:              uuid.New(),

diff --git a/internal/database/db.go b/internal/database/db.go
diff --git a/internal/database/farmers.sql.go b/internal/database/farmers.sql.go
diff --git a/internal/database/models.go b/internal/database/models.go
diff --git a/internal/database/payments.sql.go b/internal/database/payments.sql.go
diff --git a/internal/database/purchases.sql.go b/internal/database/purchases.sql.go
diff --git a/internal/database/users.sql.go b/internal/database/users.sql.go
diff --git a/sql/queries/payments.sql b/sql/queries/payments.sql
@@ -11,4 +11,9 @@ SELECT * FROM payments
 WHERE id = $1;
 
 -- name: DeletePayments :exec
-DELETE FROM payments WHERE id = $1;
+DELETE FROM payments WHERE id = $1;
+
+-- name: GetMostRecentPayment :one
+SELECT * FROM payments
+ORDER BY created_at DESC
+LIMIT 1;
diff --git a/sql/queries/purchases.sql b/sql/queries/purchases.sql
@@ -16,3 +16,8 @@ WHERE id = $1;
 
 DELETE FROM purchases WHERE id = $1;
 
+-- name: GetMostRecentPurchase :one
+SELECT * FROM purchases
+ORDER BY created_at DESC
+LIMIT 1;
+