chore: consolidate local integration changes

backend/internal/service/kratos_admin_service.go

@@ -9,6 +9,7 @@ import (
 	"io"
 	"net"
 	"net/http"
+	"net/url"
 	"os"
 	"strings"
 	"time"
@@ -68,27 +69,76 @@ func NewKratosAdminService() KratosAdminService {
 
 func (s *kratosAdminService) ListIdentities(ctx context.Context) ([]KratosIdentity, error) {
 	endpoint := strings.TrimRight(s.AdminURL, "/") + "/admin/identities"
-	req, err := http.NewRequestWithContext(ctx, http.MethodGet, endpoint, nil)
-	if err != nil {
-		return nil, err
-	}
-
-	resp, err := s.httpClient().Do(req)
-	if err != nil {
-		return nil, err
-	}
-	defer resp.Body.Close()
-
-	if resp.StatusCode >= 300 {
-		body, _ := io.ReadAll(io.LimitReader(resp.Body, 2048))
-		return nil, fmt.Errorf("kratos admin list identities failed status=%d body=%s", resp.StatusCode, string(body))
-	}
-
 	var identities []KratosIdentity
-	if err := json.NewDecoder(resp.Body).Decode(&identities); err != nil {
-		return nil, err
+	pageToken := ""
+	seenTokens := make(map[string]bool)
+
+	for {
+		req, err := http.NewRequestWithContext(ctx, http.MethodGet, endpoint, nil)
+		if err != nil {
+			return nil, err
+		}
+		query := req.URL.Query()
+		query.Set("page_size", "250")
+		if pageToken != "" {
+			query.Set("page_token", pageToken)
+		}
+		req.URL.RawQuery = query.Encode()
+
+		resp, err := s.httpClient().Do(req)
+		if err != nil {
+			return nil, err
+		}
+
+		if resp.StatusCode >= 300 {
+			body, _ := io.ReadAll(io.LimitReader(resp.Body, 2048))
+			_ = resp.Body.Close()
+			return nil, fmt.Errorf("kratos admin list identities failed status=%d body=%s", resp.StatusCode, string(body))
+		}
+
+		var page []KratosIdentity
+		if err := json.NewDecoder(resp.Body).Decode(&page); err != nil {
+			_ = resp.Body.Close()
+			return nil, err
+		}
+		_ = resp.Body.Close()
+		identities = append(identities, page...)
+
+		nextToken := kratosNextPageToken(resp.Header.Values("Link"))
+		if nextToken == "" {
+			return identities, nil
+		}
+		if seenTokens[nextToken] {
+			return nil, fmt.Errorf("kratos admin list identities pagination loop detected page_token=%s", nextToken)
+		}
+		seenTokens[nextToken] = true
+		pageToken = nextToken
 	}
-	return identities, nil
+}
+
+func kratosNextPageToken(linkHeaders []string) string {
+	for _, header := range linkHeaders {
+		for _, part := range strings.Split(header, ",") {
+			part = strings.TrimSpace(part)
+			if !strings.Contains(part, `rel="next"`) && !strings.Contains(part, `rel=next`) {
+				continue
+			}
+			start := strings.Index(part, "<")
+			end := strings.Index(part, ">")
+			if start < 0 || end <= start+1 {
+				continue
+			}
+			rawURL := part[start+1 : end]
+			parsed, err := url.Parse(rawURL)
+			if err != nil {
+				continue
+			}
+			if token := strings.TrimSpace(parsed.Query().Get("page_token")); token != "" {
+				return token
+			}
+		}
+	}
+	return ""
 }
 
 func (s *kratosAdminService) FindIdentityIDByIdentifier(ctx context.Context, identifier string) (string, error) {