feat(notify): render slack order notification as block kit receipt with line items

api/handlers/cart.go

@@ -18,6 +18,7 @@ import (
 	"terminalShop/pkg/audit"
 	"terminalShop/pkg/database"
 	"terminalShop/pkg/models"
+	"terminalShop/pkg/notify"
 	"terminalShop/pkg/utils"
 )
 
@@ -482,6 +483,7 @@ func (h *CartHandler) ConvertCart(w http.ResponseWriter, r *http.Request) {
 		utils.RespondError(w, http.StatusInternalServerError, "INTERNAL_ERROR", "failed to preload items", nil)
 		return
 	}
+	go notify.SlackOrderPaid(&order)
 
 	utils.RespondSuccess(w, http.StatusOK, map[string]interface{}{
 		"order": order,

api/handlers/webhook.go

@@ -19,6 +19,7 @@ import (
 	"terminalShop/pkg/audit"
 	"terminalShop/pkg/database"
 	"terminalShop/pkg/models"
+	"terminalShop/pkg/notify"
 	"terminalShop/pkg/utils"
 )
 
@@ -113,7 +114,7 @@ func (h *WebhookHandler) handlePaymentIntentSucceeded(ctx context.Context, event
 
 	db := database.GetDB().WithContext(ctx)
 	var order models.Order
-	if err := db.Where("id = ?", orderIDStr).First(&order).Error; err != nil {
+	if err := db.Preload("Items").Where("id = ?", orderIDStr).First(&order).Error; err != nil {
 		webhookLog().Warn("order not found for payment intent", "order_id", orderIDStr, "pi", pi.ID)
 		return
 	}
@@ -150,6 +151,7 @@ func (h *WebhookHandler) handlePaymentIntentSucceeded(ctx context.Context, event
 	}
 
 	audit.OrderPaid(order.UserID, order.ID, int(pi.Amount), pi.ID)
+	go notify.SlackOrderPaid(&order)
 	webhookLog().Info("order marked paid", "order_id", orderIDStr, "pi", pi.ID)
 }
 

pkg/audit/audit.go

@@ -5,7 +5,6 @@ package audit
 
 import (
 	"log/slog"
-	"terminalShop/pkg/notify"
 )
 
 type eventType string
@@ -117,7 +116,6 @@ func OrderPaid(userID, orderID uint, amountCents int, stripePaymentIntentID stri
 		Amount:   amountCents,
 		StripeID: stripePaymentIntentID,
 	}.attrs()...)
-	go notify.SlackOrderPaid(orderID, amountCents)
 }
 
 // OrderShipped records that an order has been marked as shipped with carrier metadata

pkg/notify/slack.go

@@ -8,57 +8,94 @@ import (
 	"net/http"
 	"os"
 	"time"
+
+	"terminalShop/pkg/models"
 )
 
 var slackClient = &http.Client{Timeout: 5 * time.Second}
 
-type slackMessage struct {
-	Channel string       `json:"channel"`
-	Text    string       `json:"text"`
-	Blocks  []slackBlock `json:"blocks,omitempty"`
+func dollars(cents int) string {
+	return fmt.Sprintf("$%.2f", float64(cents)/100)
 }
 
-type slackBlock map[string]any
-
-func SlackOrderPaid(orderID uint, amountCents int) {
+// SlackOrderPaid posts a receipt-style Block Kit message with item lines,
+// totals, shipping address, and a "Buy Label" button. Caller must preload
+// order.Items before calling. No-op if SLACK_BOT_TOKEN or SLACK_CHANNEL unset.
+func SlackOrderPaid(order *models.Order) {
 	token := os.Getenv("SLACK_BOT_TOKEN")
 	channel := os.Getenv("SLACK_CHANNEL")
 	if token == "" || channel == "" {
 		return
 	}
 
-	text := fmt.Sprintf(":coffee: Order #%d paid - $%.2f", orderID, float64(amountCents)/100)
-	msg := slackMessage{
-		Channel: channel,
-		Text:    text,
-		Blocks: []slackBlock{
-			{
-				"type": "section",
-				"text": map[string]string{"type": "mrkdwn", "text": text},
+	fallback := fmt.Sprintf(":coffee: Order #%d paid - %s", order.ID, dollars(order.Total))
+
+	blocks := []map[string]any{
+		{
+			"type": "header",
+			"text": map[string]any{"type": "plain_text", "text": fallback, "emoji": true},
+		},
+		{"type": "divider"},
+	}
+
+	for _, item := range order.Items {
+		line := fmt.Sprintf("*%s* × %d\n%s", item.Name, item.Quantity, dollars(item.Price*item.Quantity))
+		blocks = append(blocks, map[string]any{
+			"type": "section",
+			"text": map[string]any{"type": "mrkdwn", "text": line},
+		})
+	}
+
+	blocks = append(blocks,
+		map[string]any{"type": "divider"},
+		map[string]any{
+			"type": "section",
+			"fields": []map[string]any{
+				{"type": "mrkdwn", "text": "*Subtotal:*\n" + dollars(order.Subtotal)},
+				{"type": "mrkdwn", "text": "*Shipping:*\n" + dollars(order.ShippingCost)},
+				{"type": "mrkdwn", "text": "*Total:*\n" + dollars(order.Total)},
 			},
-			{
-				"type": "actions",
-				"elements": []slackBlock{
-					{
-						"type":      "button",
-						"text":      map[string]string{"type": "plain_text", "text": "Buy Label"},
-						"value":     fmt.Sprintf("%d", orderID),
-						"action_id": "buy_label",
-						"style":     "primary",
-					},
+		},
+		map[string]any{
+			"type": "section",
+			"text": map[string]any{
+				"type": "mrkdwn",
+				"text": fmt.Sprintf(":package: *Ship to:*\n%s\n%s\n%s, %s %s",
+					order.ShippingName,
+					order.ShippingStreet,
+					order.ShippingCity,
+					order.ShippingZip,
+					order.ShippingCountry,
+				),
+			},
+		},
+		map[string]any{
+			"type": "actions",
+			"elements": []map[string]any{
+				{
+					"type":      "button",
+					"text":      map[string]any{"type": "plain_text", "text": "Buy Label", "emoji": true},
+					"value":     fmt.Sprintf("%d", order.ID),
+					"action_id": "buy_label",
+					"style":     "primary",
 				},
 			},
 		},
-	}
+	)
+
+	body, _ := json.Marshal(map[string]any{
+		"channel": channel,
+		"text":    fallback,
+		"blocks":  blocks,
+	})
 
-	body, _ := json.Marshal(msg)
 	req, _ := http.NewRequest(http.MethodPost, "https://slack.com/api/chat.postMessage", bytes.NewReader(body))
 	req.Header.Set("Content-Type", "application/json; charset=utf-8")
 	req.Header.Set("Authorization", "Bearer "+token)
 
 	resp, err := slackClient.Do(req)
 	if err != nil {
-		slog.Warn("slack notify failed", "error", err, "order_id", orderID)
+		slog.Warn("slack notify failed", "error", err, "order_id", order.ID)
 		return
 	}
 	defer resp.Body.Close()
@@ -69,7 +106,7 @@ func SlackOrderPaid(orderID uint, amountCents int) {
 	}
 	_ = json.NewDecoder(resp.Body).Decode(&parsed)
 	if !parsed.Ok {
-		slog.Warn("slack notify non-ok", "error", parsed.Error, "order_id", orderID)
+		slog.Warn("slack notify non-ok", "error", parsed.Error, "order_id", order.ID)
 	}
 }