Implement card management and admin dashboard functionality

backend/cmd/app/main.go

@@ -90,7 +90,8 @@ func main() {
 	//mux.HandleFunc("GET /logout",)
 
 	// super admin endpoints
-	mux.HandleFunc("GET /admin/platform-overview", adminHanlder.PlatformOverviewView)
+	mux.HandleFunc("GET /admin/dashboard", adminHanlder.AdminDashboardView)
+	mux.HandleFunc("POST /v1/admin/dashboard-data", adminHanlder.AdminDashboardDataHandler)
 	mux.HandleFunc("GET /admin/merchants", adminHanlder.MerchantManagementView)
 	mux.HandleFunc("GET /admin/terminals", adminHanlder.TerminalRegistryView)
 	mux.HandleFunc("GET /admin/settings", adminHanlder.SystemSettingsView)
@@ -102,6 +103,7 @@ func main() {
 	mux.HandleFunc("POST /v1/admin/addcardauth", adminHanlder.AddCardHandler)
 	mux.HandleFunc("POST /v1/admin/deactivatecardauth", adminHanlder.DeactivateCardHanlder)
 	mux.HandleFunc("POST /v1/admin/deletecardauth", adminHanlder.DeleteCardHandler)
+	mux.HandleFunc("GET /admin/delete-cards", adminHanlder.DeleteCardView)
 
 
 	// Wrap mux with custom handler for root redirect

backend/internal/admin/addCard.go → backend/internal/admin/add_card.go

@@ -12,13 +12,11 @@ import (
 	"strings"
 	"time"
 	jsonwrite "unicard-go/backend/internal/pkg/handler"
-	"unicard-go/backend/internal/pkg/structs"
+	structure "unicard-go/backend/internal/pkg/structs"
 
 	"github.com/go-playground/validator/v10"
 )
 
-// CardRequest struct mapped directly to your frontend JSON payload
-
 // AddCardsView renders the addCards.html template after checking the admin session.
 func (h *Handler) AddCardsView(w http.ResponseWriter, r *http.Request) {
 	fmt.Println("AddCardsView running...")
@@ -29,7 +27,8 @@ func (h *Handler) AddCardsView(w http.ResponseWriter, r *http.Request) {
 func (h *Handler) AddCardHandler(w http.ResponseWriter, r *http.Request) {
 	fmt.Println("AddCardHandler running...")
 
-	var req structs.CardData
+	// Define request struct
+	var req structure.CardData
 
 	// Decode JSON
 	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
@@ -50,8 +49,8 @@ func (h *Handler) AddCardHandler(w http.ResponseWriter, r *http.Request) {
 		var validationErrs validator.ValidationErrors
 		if errors.As(err, &validationErrs) {
 			errorMap := map[string]string{
-				"CardUID":       "Card UID is required.",
-				"InitialAmount": "Initial amount is required and cannot be negative.",
+				"CardUID": "Card UID is required.",
+				"Balance": "Initial amount is required and cannot be negative.",
 			}
 			if msg, ok := errorMap[validationErrs[0].Field()]; ok {
 				errorMessage = msg

backend/internal/admin/admin_dashboard.go

@@ -0,0 +1,156 @@
+package admin
+
+import (
+	"encoding/json"
+	"log"
+	"net/http"
+	jsonwrite "unicard-go/backend/internal/pkg/handler"
+)
+
+// AdminDashboardData struct represents the data to be displayed on the admin dashboard
+type AdminDashboardData struct {
+	GrossRevenue    float64 `json:"grossRevenue"`
+	NetRevenue      float64 `json:"netRevenue"`
+	TotalUsers      int     `json:"totalUsers"`
+	TotalCards      int     `json:"totalCards"`
+	ActiveMerchants int     `json:"activeMerchants"`
+	ActiveTerminals int     `json:"activeTerminals"`
+}
+
+// AdminDashboardView renders the platform_overview.html template after checking the admin session.
+func (h *Handler) AdminDashboardView(w http.ResponseWriter, r *http.Request) {
+	log.Println("AdminDashboardView running...")
+	h.Tpl.ExecuteTemplate(w, "admin_dashboard.html", nil)
+}
+
+// AdminDashboardDataHandler handles the request for admin dashboard data and returns JSON response.
+// AdminDashboardDataHandler handles the request for admin dashboard data and returns JSON response.
+func (h *Handler) AdminDashboardDataHandler(w http.ResponseWriter, r *http.Request) {
+	log.Println("AdminDashboardDataHandler running...")
+
+	var req AdminDashboardData
+
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		log.Println("Error decoding JSON:", err)
+		jsonwrite.WriteJSON(w, http.StatusBadRequest, jsonwrite.APIResponse{
+			Success: false,
+			Message: "Invalid request format",
+		})
+		return
+	}
+
+	// Compute UniCard's Absolute Gross Revenue
+	// (Transaction Service Fees)
+	query := `SELECT COALESCE(SUM(service_fee), 0.00) FROM transactions WHERE transaction_type = 'payment'`
+	row := h.DB.QueryRow(query)
+
+	var grossRevenue float64
+	if err := row.Scan(&grossRevenue); err != nil {
+		log.Println("Error scanning gross revenue:", err)
+		jsonwrite.WriteJSON(w, http.StatusInternalServerError, jsonwrite.APIResponse{
+			Success: false,
+			Message: "Internal server error",
+		})
+		return
+	}
+	log.Println("Gross revenue row:", grossRevenue)
+
+	// Compute UniCard's Net Revenue
+	// (Service fees from successful payments MINUS service fees lost to refunds/reversals)
+	query = `SELECT COALESCE(SUM(
+			CASE 
+				WHEN transaction_type = 'payment' THEN service_fee 
+				WHEN transaction_type IN ('refund', 'reversal') THEN -service_fee 
+				ELSE 0 
+			END
+        ), 0.00) FROM transactions`
+
+	row = h.DB.QueryRow(query)
+
+	var netRevenue float64
+	if err := row.Scan(&netRevenue); err != nil {
+		log.Println("Error scanning net revenue:", err)
+		jsonwrite.WriteJSON(w, http.StatusInternalServerError, jsonwrite.APIResponse{
+			Success: false,
+			Message: "Internal server error while calculating Net Revenue",
+		})
+		return
+	}
+	log.Println("Net revenue row:", netRevenue)
+
+	// Display the number of users
+	// Counting only 'active' customers (excluding suspended or inactive accounts)
+	row = h.DB.QueryRow("SELECT COUNT(*) FROM users WHERE role = 'customer'") // status = 'active'
+
+	var totalUsers int
+	if err := row.Scan(&totalUsers); err != nil {
+		log.Println("Error scanning total users:", err)
+		jsonwrite.WriteJSON(w, http.StatusInternalServerError, jsonwrite.APIResponse{
+			Success: false,
+			Message: "Internal server error",
+		})
+		return
+	}
+	log.Println("Total users row:", totalUsers)
+
+	// Display the number of cards
+	// Counting only 'active' cards to show actual circulatory supply
+	row = h.DB.QueryRow("SELECT COUNT(*) FROM cards") // WHERE status = 'active'
+
+	var totalCards int
+	if err := row.Scan(&totalCards); err != nil {
+		log.Println("Error scanning total cards:", err)
+		jsonwrite.WriteJSON(w, http.StatusInternalServerError, jsonwrite.APIResponse{
+			Success: false,
+			Message: "Internal server error",
+		})
+		return
+	}
+	log.Println("Total cards row:", totalCards)
+
+	// Display the number of merchants
+	// Counting only 'active' merchants (excluding 'pending_approval' or 'suspended')
+	row = h.DB.QueryRow("SELECT COUNT(*) FROM merchants WHERE status = 'active'")
+
+	var totalMerchants int
+	if err := row.Scan(&totalMerchants); err != nil {
+		log.Println("Error scanning total merchants:", err)
+		jsonwrite.WriteJSON(w, http.StatusInternalServerError, jsonwrite.APIResponse{
+			Success: false,
+			Message: "Internal server error",
+		})
+		return
+	}
+	log.Println("Total merchants row:", totalMerchants)
+
+	// Display the number of terminals
+	// Counting 'active' ESP32 nodes (excluding 'offline' or 'suspended')
+	row = h.DB.QueryRow("SELECT COUNT(*) FROM terminals WHERE status = 'active'")
+
+	var totalTerminals int
+	if err := row.Scan(&totalTerminals); err != nil {
+		log.Println("Error scanning total terminals:", err)
+		jsonwrite.WriteJSON(w, http.StatusInternalServerError, jsonwrite.APIResponse{
+			Success: false,
+			Message: "Internal server error",
+		})
+		return
+	}
+	log.Println("Total terminals row:", totalTerminals)
+
+	// Return the data as JSON
+	response := AdminDashboardData{
+		GrossRevenue:    grossRevenue,
+		NetRevenue:      netRevenue,
+		TotalUsers:      totalUsers,
+		TotalCards:      totalCards,
+		ActiveMerchants: totalMerchants,
+		ActiveTerminals: totalTerminals,
+	}
+	jsonwrite.WriteJSON(w, http.StatusOK, jsonwrite.APIResponse{
+		Success: true,
+		Message: "Admin dashboard data retrieved successfully",
+		Data:    response,
+	})
+	log.Println("AdminDashboardDataHandler finished")
+}

backend/internal/admin/deactivate_card.go

@@ -8,13 +8,13 @@ import (
 	"net/http"
 	"strings"
 	jsonwrite "unicard-go/backend/internal/pkg/handler"
-	"unicard-go/backend/internal/pkg/structs"
+	structure "unicard-go/backend/internal/pkg/structs"
 
 	"github.com/go-playground/validator/v10"
 )
 
 // Type alias for CardData to resolve the redeclaration error
-type CardData = structs.CardData
+type CardData = structure.CardData
 
 func (h *Handler) DeactivateView(w http.ResponseWriter, r *http.Request) {
 	fmt.Println("DeactivateView running...")

backend/internal/admin/deleteCard.go → backend/internal/admin/delete_card.go

@@ -2,48 +2,54 @@ package admin
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
 	"net/http"
 	"strings"
 	jsonwrite "unicard-go/backend/internal/pkg/handler"
+	structure "unicard-go/backend/internal/pkg/structs"
+
+	"github.com/go-playground/validator/v10"
 )
 
 func (h *Handler) DeleteCardView(w http.ResponseWriter, r *http.Request) {
 	fmt.Println("DeleteCardView running...")
 
-	h.Tpl.ExecuteTemplate(w, "deleteCard.html", nil)
+	h.Tpl.ExecuteTemplate(w, "delete_card.html", nil)
 }
 
 // DeleteCardHandler handles deleting a card by card_number and returns JSON.
 func (h *Handler) DeleteCardHandler(w http.ResponseWriter, r *http.Request) {
 	fmt.Println("DeleteCardHandler running...")
 
-	if r.Method != http.MethodPost {
-		jsonwrite.WriteJSON(w, http.StatusMethodNotAllowed, jsonwrite.APIResponse{
+	var req structure.CardData
+
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		jsonwrite.WriteJSON(w, http.StatusBadRequest, jsonwrite.APIResponse{
 			Success: false,
-			Message: "Method not allowed",
+			Message: "Invalid request format",
 		})
 		return
 	}
 
-	var req struct {
-		CardNumber string `json:"cardNumber"`
-	}
+	cardNumber := strings.TrimSpace(req.CardNumber)
 
-	// Try reading JSON body
-	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
-		// Fallback to post form values
-		if err := r.ParseForm(); err == nil {
-			req.CardNumber = r.PostFormValue("cardNumber")
+	validate := validator.New()
+	if err := validate.Struct(req); err != nil {
+		errorMessage := "Invalid input provided."
+		var validationErrs validator.ValidationErrors
+		if errors.As(err, &validationErrs) {
+			errorMap := map[string]string{
+				"CardNumber": "Card number is required.",
+			}
+			if msg, ok := errorMap[validationErrs[0].Field()]; ok {
+				errorMessage = msg
+			}
 		}
-	}
 
-	cardNumber := strings.TrimSpace(req.CardNumber)
-
-	if cardNumber == "" {
-		jsonwrite.WriteJSON(w, http.StatusOK, jsonwrite.APIResponse{
+		jsonwrite.WriteJSON(w, http.StatusBadRequest, jsonwrite.APIResponse{
 			Success: false,
-			Message: "Card number is required for deletion.",
+			Message: errorMessage,
 		})
 		return
 	}
@@ -54,7 +60,7 @@ func (h *Handler) DeleteCardHandler(w http.ResponseWriter, r *http.Request) {
 		fmt.Println("Error deleting card from DB:", err)
 		jsonwrite.WriteJSON(w, http.StatusOK, jsonwrite.APIResponse{
 			Success: false,
-			Message: "Failed to delete card due to database error.",
+			Message: "Failed to delete card.",
 		})
 		return
 	}

backend/internal/pkg/handler/jsonWrite.go

@@ -10,6 +10,7 @@ type APIResponse struct {
 	Success bool   `json:"success"`
 	Message string `json:"message"`
 	Field   string `json:"field,omitempty"`
+    Data    any    `json:"data,omitempty"` // Optional field for additional data
 }
 
 // Login specific response — returns user data after login

backend/internal/pkg/structs/card_struct.go → backend/internal/pkg/structs/struct.go

@@ -1,9 +1,10 @@
-package structs
+package structure
 
+// CardData struct represents the data required to create a new card
 type CardData struct {
-	CardUID string  `json:"card_uid" db:"card_uid" validate:"required"`
+	CardUID    string  `json:"card_uid" db:"card_uid" validate:"required"`
 	CardNumber string  `json:"cardNumber" db:"card_number" validate:"required"`
 	CardHolder string  `json:"cardHolder" db:"user_id" validate:"required"`
 	CardType   string  `json:"cardType" db:"card_type" validate:"required"`
 	Balance    float64 `json:"initial_amount" db:"balance" validate:"required,min=0"`
-}
+}