feat(api): add phone number registration endpoint and update related logic

pkg/whatsapp/businessapi/client.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"io"
 	"net/http"
+	"net/url"
 	"strings"
 	"sync"
 	"time"
@@ -20,18 +21,20 @@ import (
 
 // Client represents a WhatsApp Business API client
 type Client struct {
-	id          string
-	phoneNumber string
-	config      config.BusinessAPIConfig
-	httpClient  *http.Client
-	eventBus    *events.EventBus
-	mediaConfig config.MediaConfig
-	connected   bool
-	mu          sync.RWMutex
+	id              string
+	phoneNumber     string
+	config          config.BusinessAPIConfig
+	httpClient      *http.Client
+	eventBus        *events.EventBus
+	mediaConfig     config.MediaConfig
+	connected       bool
+	wabaID          string                       // WhatsApp Business Account ID, resolved at connect time
+	onWABAResolved  func(accountID, wabaID string) // called when WABA ID is resolved for the first time
+	mu              sync.RWMutex
 }
 
 // NewClient creates a new Business API client
-func NewClient(cfg config.WhatsAppConfig, eventBus *events.EventBus, mediaConfig config.MediaConfig) (*Client, error) {
+func NewClient(cfg config.WhatsAppConfig, eventBus *events.EventBus, mediaConfig config.MediaConfig, onWABAResolved func(accountID, wabaID string)) (*Client, error) {
 	if cfg.Type != "business-api" {
 		return nil, fmt.Errorf("invalid client type for business-api: %s", cfg.Type)
 	}
@@ -60,9 +63,10 @@ func NewClient(cfg config.WhatsAppConfig, eventBus *events.EventBus, mediaConfig
 		httpClient: &http.Client{
 			Timeout: 30 * time.Second,
 		},
-		eventBus:    eventBus,
-		mediaConfig: mediaConfig,
-		connected:   false,
+		eventBus:       eventBus,
+		mediaConfig:    mediaConfig,
+		connected:      false,
+		onWABAResolved: onWABAResolved,
 	}, nil
 }
 
@@ -123,7 +127,24 @@ func (c *Client) Connect(ctx context.Context) error {
 			"status", phoneDetails.CodeVerificationStatus)
 	}
 
-	// Step 3: Get business account details (if business_account_id is provided)
+	// Step 3: Resolve the WhatsApp Business Account (WABA) ID from the phone number.
+	// The WABA ID is required for phone number listing; it differs from the Facebook Business Manager ID.
+	// Use cached value from config if already known.
+	if c.config.WABAId != "" {
+		c.wabaID = c.config.WABAId
+		logging.Info("WhatsApp Business Account ID loaded from config", "account_id", c.id, "waba_id", c.wabaID)
+	} else if wabaID, err := c.fetchWABAID(ctx); err != nil {
+		logging.Warn("Failed to resolve WABA ID (non-critical)", "account_id", c.id, "error", err)
+	} else {
+		c.wabaID = wabaID
+		c.config.WABAId = wabaID
+		logging.Info("WhatsApp Business Account ID resolved", "account_id", c.id, "waba_id", wabaID)
+		if c.onWABAResolved != nil {
+			c.onWABAResolved(c.id, wabaID)
+		}
+	}
+
+	// Step 4: Get business account details (if business_account_id is provided)
 	if c.config.BusinessAccountID != "" {
 		businessDetails, err := c.getBusinessAccountDetails(ctx)
 		if err != nil {
@@ -532,6 +553,42 @@ func (c *Client) checkMissingScopes(currentScopes []string, requiredScopes []str
 	return missing
 }
 
+// fetchWABAID resolves the WhatsApp Business Account (WABA) ID by iterating the WABAs
+// owned by the configured business account and matching against our phone number ID.
+// Requires business_account_id to be set in config.
+// GET /{business-id}/owned_whatsapp_business_accounts?fields=id,phone_numbers{id}
+func (c *Client) fetchWABAID(ctx context.Context) (string, error) {
+	if c.config.BusinessAccountID == "" {
+		return "", fmt.Errorf("waba_id or business_account_id must be set in config to resolve WABA")
+	}
+
+	var result struct {
+		Data []struct {
+			ID           string `json:"id"`
+			PhoneNumbers struct {
+				Data []struct {
+					ID string `json:"id"`
+				} `json:"data"`
+			} `json:"phone_numbers"`
+		} `json:"data"`
+	}
+
+	params := url.Values{"fields": {"id,phone_numbers{id}"}}
+	if err := c.graphAPIGet(ctx, c.config.BusinessAccountID+"/owned_whatsapp_business_accounts", params, &result); err != nil {
+		return "", fmt.Errorf("failed to list WABAs for business %s: %w", c.config.BusinessAccountID, err)
+	}
+
+	for _, waba := range result.Data {
+		for _, phone := range waba.PhoneNumbers.Data {
+			if phone.ID == c.config.PhoneNumberID {
+				return waba.ID, nil
+			}
+		}
+	}
+
+	return "", fmt.Errorf("phone number %s not found in any WABA owned by business %s", c.config.PhoneNumberID, c.config.BusinessAccountID)
+}
+
 // formatExpiry formats the expiry timestamp for logging
 func (c *Client) formatExpiry(expiresAt int64) string {
 	if expiresAt == 0 {