auth: retry other managed accounts when token ensure fails

internal/auth/auth_edge_test.go

@@ -204,6 +204,45 @@ func TestSwitchAccountNilTriedAccounts(t *testing.T) {
 	r.Release(a)
 }
 
+func TestSwitchAccountSkipsLoginFailureAndContinues(t *testing.T) {
+	t.Setenv("DS2API_CONFIG_JSON", `{
+		"keys":["managed-key"],
+		"accounts":[
+			{"email":"acc1@test.com","password":"pwd","token":"t1"},
+			{"email":"acc2@test.com","password":"pwd"},
+			{"email":"acc3@test.com","password":"pwd","token":"t3"}
+		]
+	}`)
+	store := config.LoadStore()
+	pool := account.NewPool(store)
+	r := NewResolver(store, pool, func(_ context.Context, acc config.Account) (string, error) {
+		if acc.Email == "acc2@test.com" {
+			return "", errors.New("login failed")
+		}
+		return "new-token", nil
+	})
+
+	req, _ := http.NewRequest("POST", "/", nil)
+	req.Header.Set("Authorization", "Bearer managed-key")
+	a, err := r.Determine(req)
+	if err != nil {
+		t.Fatalf("determine failed: %v", err)
+	}
+	defer r.Release(a)
+	if a.AccountID != "acc1@test.com" {
+		t.Fatalf("expected first account, got %q", a.AccountID)
+	}
+	if !r.SwitchAccount(context.Background(), a) {
+		t.Fatal("expected switch to succeed after skipping failed account")
+	}
+	if a.AccountID != "acc3@test.com" {
+		t.Fatalf("expected fallback to third account, got %q", a.AccountID)
+	}
+	if !a.TriedAccounts["acc2@test.com"] {
+		t.Fatalf("expected failed account to be marked as tried")
+	}
+}
+
 // ─── Release edge cases ─────────────────────────────────────────────
 
 func TestReleaseNilAuth(t *testing.T) {

internal/auth/request.go

@@ -70,25 +70,45 @@ func (r *Resolver) Determine(req *http.Request) (*RequestAuth, error) {
 		}, nil
 	}
 	target := strings.TrimSpace(req.Header.Get("X-Ds2-Target-Account"))
-	acc, ok := r.Pool.AcquireWait(ctx, target, nil)
-	if !ok {
-		return nil, ErrNoAccount
-	}
-	a := &RequestAuth{
-		UseConfigToken: true,
-		CallerID:       callerID,
-		AccountID:      acc.Identifier(),
-		Account:        acc,
-		TriedAccounts:  map[string]bool{},
-		resolver:       r,
-	}
-	if err := r.ensureManagedToken(ctx, a); err != nil {
-		r.Pool.Release(a.AccountID)
+	a, err := r.acquireManagedRequestAuth(ctx, callerID, target)
+	if err != nil {
 		return nil, err
 	}
 	return a, nil
 }
 
+func (r *Resolver) acquireManagedRequestAuth(ctx context.Context, callerID, target string) (*RequestAuth, error) {
+	tried := map[string]bool{}
+	for {
+		if target == "" && len(tried) >= len(r.Store.Accounts()) {
+			return nil, ErrNoAccount
+		}
+		acc, ok := r.Pool.AcquireWait(ctx, target, tried)
+		if !ok {
+			return nil, ErrNoAccount
+		}
+
+		a := &RequestAuth{
+			UseConfigToken: true,
+			CallerID:       callerID,
+			AccountID:      acc.Identifier(),
+			Account:        acc,
+			TriedAccounts:  tried,
+			resolver:       r,
+		}
+
+		if err := r.ensureManagedToken(ctx, a); err != nil {
+			tried[a.AccountID] = true
+			r.Pool.Release(a.AccountID)
+			if target != "" {
+				return nil, err
+			}
+			continue
+		}
+		return a, nil
+	}
+}
+
 // DetermineCaller resolves caller identity without acquiring any pooled account.
 // Use this for local-cache lookup routes that only need tenant isolation.
 func (r *Resolver) DetermineCaller(req *http.Request) (*RequestAuth, error) {
@@ -164,16 +184,20 @@ func (r *Resolver) SwitchAccount(ctx context.Context, a *RequestAuth) bool {
 		a.TriedAccounts[a.AccountID] = true
 		r.Pool.Release(a.AccountID)
 	}
-	acc, ok := r.Pool.Acquire("", a.TriedAccounts)
-	if !ok {
-		return false
+	for {
+		acc, ok := r.Pool.Acquire("", a.TriedAccounts)
+		if !ok {
+			return false
+		}
+		a.Account = acc
+		a.AccountID = acc.Identifier()
+		if err := r.ensureManagedToken(ctx, a); err != nil {
+			a.TriedAccounts[a.AccountID] = true
+			r.Pool.Release(a.AccountID)
+			continue
+		}
+		return true
 	}
-	a.Account = acc
-	a.AccountID = acc.Identifier()
-	if err := r.ensureManagedToken(ctx, a); err != nil {
-		return false
-	}
-	return true
 }
 
 func (r *Resolver) Release(a *RequestAuth) {

internal/auth/request_test.go

@@ -2,6 +2,7 @@ package auth
 
 import (
 	"context"
+	"errors"
 	"net/http"
 	"sync/atomic"
 	"testing"
@@ -301,3 +302,66 @@ func TestDetermineManagedAccountUsesUpdatedRefreshInterval(t *testing.T) {
 		t.Fatalf("expected exactly one login after runtime update, got %d", got)
 	}
 }
+
+func TestDetermineManagedAccountRetriesOtherAccountOnLoginFailure(t *testing.T) {
+	t.Setenv("DS2API_CONFIG_JSON", `{
+		"keys":["managed-key"],
+		"accounts":[
+			{"email":"bad@example.com","password":"pwd"},
+			{"email":"good@example.com","password":"pwd","token":"good-token"}
+		]
+	}`)
+	store := config.LoadStore()
+	pool := account.NewPool(store)
+	resolver := NewResolver(store, pool, func(_ context.Context, acc config.Account) (string, error) {
+		if acc.Email == "bad@example.com" {
+			return "", errors.New("stale account")
+		}
+		return "fresh-good-token", nil
+	})
+
+	req, _ := http.NewRequest(http.MethodPost, "/v1/chat/completions", nil)
+	req.Header.Set("x-api-key", "managed-key")
+
+	a, err := resolver.Determine(req)
+	if err != nil {
+		t.Fatalf("determine failed: %v", err)
+	}
+	defer resolver.Release(a)
+	if a.AccountID != "good@example.com" {
+		t.Fatalf("expected fallback to good account, got %q", a.AccountID)
+	}
+	if a.DeepSeekToken == "" {
+		t.Fatal("expected non-empty token from fallback account")
+	}
+	if !a.TriedAccounts["bad@example.com"] {
+		t.Fatalf("expected bad account to be tracked as tried")
+	}
+}
+
+func TestDetermineTargetAccountDoesNotFallbackOnLoginFailure(t *testing.T) {
+	t.Setenv("DS2API_CONFIG_JSON", `{
+		"keys":["managed-key"],
+		"accounts":[
+			{"email":"bad@example.com","password":"pwd"},
+			{"email":"good@example.com","password":"pwd","token":"good-token"}
+		]
+	}`)
+	store := config.LoadStore()
+	pool := account.NewPool(store)
+	resolver := NewResolver(store, pool, func(_ context.Context, acc config.Account) (string, error) {
+		if acc.Email == "bad@example.com" {
+			return "", errors.New("stale account")
+		}
+		return "fresh-good-token", nil
+	})
+
+	req, _ := http.NewRequest(http.MethodPost, "/v1/chat/completions", nil)
+	req.Header.Set("x-api-key", "managed-key")
+	req.Header.Set("X-Ds2-Target-Account", "bad@example.com")
+
+	_, err := resolver.Determine(req)
+	if err == nil {
+		t.Fatal("expected determine to fail for broken target account")
+	}
+}