more cart

pkg/order/email_preferences.go

@@ -0,0 +1,106 @@
+package order
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"time"
+)
+
+// ProfilePreferencesClient is the subset of the profile service's UCP customer
+// API that returns email preferences for a given email address.
+type ProfilePreferencesClient struct {
+	baseURL    string
+	httpClient *http.Client
+	timeout    time.Duration
+}
+
+// NewProfilePreferencesClient creates a client that talks to the profile
+// service's UCP customer endpoint at baseURL (e.g. "http://profile:8080/ucp/v1/customers").
+func NewProfilePreferencesClient(baseURL string) *ProfilePreferencesClient {
+	return &ProfilePreferencesClient{
+		baseURL:    strings.TrimRight(baseURL, "/"),
+		httpClient: &http.Client{Timeout: 5 * time.Second},
+		timeout:    5 * time.Second,
+	}
+}
+
+// emailPreferencesResponse mirrors ucp.EmailPreferencesResponse for decoding.
+type emailPreferencesResponse struct {
+	OrderEmails     *bool `json:"orderEmails,omitempty"`
+	MarketingEmails *bool `json:"marketingEmails,omitempty"`
+}
+
+// customerLookupResponse mirrors the UCP customer response, but we only need
+// email preferences.
+type customerLookupResponse struct {
+	EmailPreferences *emailPreferencesResponse `json:"emailPreferences,omitempty"`
+}
+
+// fetchPreferences calls GET /by-email/{email} on the profile service and
+// returns the parsed email preferences. Returns nil, nil when the profile
+// is not found (unknown email -> allow all).
+func (c *ProfilePreferencesClient) fetchPreferences(ctx context.Context, email string) (*emailPreferencesResponse, error) {
+	url := fmt.Sprintf("%s/by-email/%s", c.baseURL, email)
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	resp, err := c.httpClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("profile prefs: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode == http.StatusNotFound {
+		return nil, nil // unknown email -> no preferences
+	}
+	if resp.StatusCode != http.StatusOK {
+		body, _ := io.ReadAll(resp.Body)
+		return nil, fmt.Errorf("profile prefs: unexpected status %d: %s", resp.StatusCode, string(body))
+	}
+
+	var data customerLookupResponse
+	if err := json.NewDecoder(resp.Body).Decode(&data); err != nil {
+		return nil, fmt.Errorf("profile prefs: decode: %w", err)
+	}
+	return data.EmailPreferences, nil
+}
+
+// PreferencesChecker wraps ProfilePreferencesClient to implement
+// EmailPreferenceChecker.
+type PreferencesChecker struct {
+	client *ProfilePreferencesClient
+}
+
+// NewPreferencesChecker creates an EmailPreferenceChecker that looks up
+// preferences from the profile service at the given base URL.
+func NewPreferencesChecker(profileServiceURL string) *PreferencesChecker {
+	return &PreferencesChecker{
+		client: NewProfilePreferencesClient(profileServiceURL),
+	}
+}
+
+// Allowed returns true when the customer has not opted out of the given
+// category. Categories are "order" (order confirmations, shipping updates,
+// receipts) and "marketing" (promotional offers, newsletters). Returns true
+// when preferences are unknown (profile not found) — the safe default.
+func (c *PreferencesChecker) Allowed(ctx context.Context, email string, category string) bool {
+	prefs, err := c.client.fetchPreferences(ctx, email)
+	if err != nil || prefs == nil {
+		return true // safe default: allow when unknown
+	}
+
+	switch category {
+	case "order":
+		return prefs.OrderEmails == nil || *prefs.OrderEmails
+	case "marketing":
+		return prefs.MarketingEmails == nil || *prefs.MarketingEmails
+	default:
+		return true // unknown category -> allow
+	}
+}