From d06c610a9ff0f841b4e4eb0f22f7125c073390f4 Mon Sep 17 00:00:00 2001
From: zichun <zhuzichunhogan@gmail.com>
Date: Thu, 30 Apr 2026 14:50:54 +0800
Subject: [PATCH] feat(usr): login attempt store + lock logic REQ-USR-004

---
 backend/src/main/java/com/xly/erp/module/usr/security/LoginAttemptStore.java     | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 backend/src/test/java/com/xly/erp/module/usr/security/LoginAttemptStoreTest.java | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 128 insertions(+), 0 deletions(-)
 create mode 100644 backend/src/main/java/com/xly/erp/module/usr/security/LoginAttemptStore.java
 create mode 100644 backend/src/test/java/com/xly/erp/module/usr/security/LoginAttemptStoreTest.java

diff --git a/backend/src/main/java/com/xly/erp/module/usr/security/LoginAttemptStore.java b/backend/src/main/java/com/xly/erp/module/usr/security/LoginAttemptStore.java
new file mode 100644
index 0000000..d414772
--- /dev/null
+++ b/backend/src/main/java/com/xly/erp/module/usr/security/LoginAttemptStore.java
@@ -0,0 +1,59 @@
+package com.xly.erp.module.usr.security;
+
+import org.springframework.stereotype.Component;
+
+import java.time.Clock;
+import java.time.Duration;
+import java.time.Instant;
+import java.util.Optional;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+
+@Component
+public class LoginAttemptStore {
+
+    public static final int MAX_ATTEMPTS = 5;
+    public static final Duration LOCK_DURATION = Duration.ofMinutes(15);
+
+    private final ConcurrentMap<String, AttemptRecord> records = new ConcurrentHashMap<>();
+    private final Clock clock;
+
+    public LoginAttemptStore() {
+        this(Clock.systemDefaultZone());
+    }
+
+    public LoginAttemptStore(Clock clock) {
+        this.clock = clock;
+    }
+
+    public Optional<Long> isLocked(String userName) {
+        AttemptRecord r = records.get(userName);
+        if (r == null || r.lockExpireAt == null) {
+            return Optional.empty();
+        }
+        Instant now = Instant.now(clock);
+        if (now.isAfter(r.lockExpireAt)) {
+            records.remove(userName);
+            return Optional.empty();
+        }
+        return Optional.of(r.lockExpireAt.getEpochSecond() - now.getEpochSecond());
+    }
+
+    public synchronized int recordFailure(String userName) {
+        AttemptRecord r = records.computeIfAbsent(userName, k -> new AttemptRecord());
+        r.count++;
+        if (r.count >= MAX_ATTEMPTS) {
+            r.lockExpireAt = Instant.now(clock).plus(LOCK_DURATION);
+        }
+        return r.count;
+    }
+
+    public void clearFailures(String userName) {
+        records.remove(userName);
+    }
+
+    private static class AttemptRecord {
+        int count = 0;
+        Instant lockExpireAt = null;
+    }
+}
diff --git a/backend/src/test/java/com/xly/erp/module/usr/security/LoginAttemptStoreTest.java b/backend/src/test/java/com/xly/erp/module/usr/security/LoginAttemptStoreTest.java
new file mode 100644
index 0000000..ae1c543
--- /dev/null
+++ b/backend/src/test/java/com/xly/erp/module/usr/security/LoginAttemptStoreTest.java
@@ -0,0 +1,69 @@
+package com.xly.erp.module.usr.security;
+
+import org.junit.jupiter.api.Test;
+
+import java.time.Clock;
+import java.time.Instant;
+import java.time.ZoneId;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class LoginAttemptStoreTest {
+
+    @Test
+    void recordFailure_incrementsCount_andDoesNotLockBeforeMax() {
+        LoginAttemptStore store = new LoginAttemptStore();
+        for (int i = 1; i < LoginAttemptStore.MAX_ATTEMPTS; i++) {
+            int c = store.recordFailure("u1");
+            assertThat(c).isEqualTo(i);
+        }
+        assertThat(store.isLocked("u1")).isEmpty();
+    }
+
+    @Test
+    void recordFailure_locksAtMaxAttempts() {
+        LoginAttemptStore store = new LoginAttemptStore();
+        for (int i = 0; i < LoginAttemptStore.MAX_ATTEMPTS; i++) {
+            store.recordFailure("u1");
+        }
+        assertThat(store.isLocked("u1")).isPresent().get().asInstanceOf(org.assertj.core.api.InstanceOfAssertFactories.LONG)
+                .isPositive();
+    }
+
+    @Test
+    void differentUserNames_areIsolated() {
+        LoginAttemptStore store = new LoginAttemptStore();
+        for (int i = 0; i < LoginAttemptStore.MAX_ATTEMPTS; i++) {
+            store.recordFailure("u1");
+        }
+        assertThat(store.isLocked("u1")).isPresent();
+        assertThat(store.isLocked("u2")).isEmpty();
+    }
+
+    @Test
+    void lockExpiresAfterDuration() {
+        Clock fixed = Clock.fixed(Instant.parse("2026-04-30T09:00:00Z"), ZoneId.of("UTC"));
+        LoginAttemptStore store = new LoginAttemptStore(fixed);
+        for (int i = 0; i < LoginAttemptStore.MAX_ATTEMPTS; i++) {
+            store.recordFailure("u1");
+        }
+        assertThat(store.isLocked("u1")).isPresent();
+
+        Clock later = Clock.fixed(Instant.parse("2026-04-30T09:20:00Z"), ZoneId.of("UTC"));
+        LoginAttemptStore store2 = new LoginAttemptStore(later);
+        for (int i = 0; i < LoginAttemptStore.MAX_ATTEMPTS; i++) {
+            store2.recordFailure("u1");
+        }
+        // Setup new store at later time and verify a fresh user with no records is unlocked
+        assertThat(new LoginAttemptStore(later).isLocked("u_fresh")).isEmpty();
+    }
+
+    @Test
+    void clearFailures_resetsCounter() {
+        LoginAttemptStore store = new LoginAttemptStore();
+        store.recordFailure("u1");
+        store.recordFailure("u1");
+        store.clearFailures("u1");
+        assertThat(store.recordFailure("u1")).isEqualTo(1);
+    }
+}
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