refactor: add system initialization check and redirect to console if not initialized (#3892)

#### What type of PR is this?
/kind improvement
/area core
/milestone 2.5.2
#### What this PR does / why we need it:
添加系统初始化检查，如果未初始化则重定向到控制台。

此检查只针对首页，当用户访问首页时检查到未初始化则跳转到 Console 让用户初始化以优化没有数据时的访问体验。

SetupStateCache 用于缓存系统初始化状态，当数据库状态改变时会更新缓存以优化性能，避免每次访问首页都查询数据。

#### Which issue(s) this PR fixes:

A part of #3230

#### Does this PR introduce a user-facing change?

```release-note
添加系统初始化检查，如果未初始化则重定向到控制台
```

application/src/main/java/run/halo/app/infra/SetupStateCache.java

@@ -0,0 +1,96 @@
+package run.halo.app.infra;
+
+import io.micrometer.common.util.StringUtils;
+import java.util.Optional;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.function.Supplier;
+import lombok.Data;
+import org.springframework.lang.NonNull;
+import org.springframework.stereotype.Component;
+import run.halo.app.extension.ConfigMap;
+import run.halo.app.extension.ExtensionClient;
+import run.halo.app.extension.controller.Controller;
+import run.halo.app.extension.controller.ControllerBuilder;
+import run.halo.app.extension.controller.Reconciler;
+import run.halo.app.infra.utils.JsonUtils;
+
+/**
+ * <p>A cache that caches system setup state.</p>
+ * when setUp state changed, the cache will be updated.
+ *
+ * @author guqing
+ * @since 2.5.2
+ */
+@Component
+public class SetupStateCache implements Reconciler<Reconciler.Request>, Supplier<Boolean> {
+    public static final String SYSTEM_STATES_CONFIGMAP = "system-states";
+    private final ExtensionClient client;
+
+    private final InternalValueCache valueCache = new InternalValueCache();
+
+    public SetupStateCache(ExtensionClient client) {
+        this.client = client;
+    }
+
+    /**
+     * <p>Gets system setup state.</p>
+     * Never return null.
+     *
+     * @return <code>true</code> if system is initialized, <code>false</code> otherwise.
+     */
+    @NonNull
+    @Override
+    public Boolean get() {
+        return valueCache.get();
+    }
+
+    @Override
+    public Result reconcile(Request request) {
+        if (!SYSTEM_STATES_CONFIGMAP.equals(request.name())) {
+            return Result.doNotRetry();
+        }
+        valueCache.cache(isInitialized());
+        return Result.doNotRetry();
+    }
+
+    @Override
+    public Controller setupWith(ControllerBuilder builder) {
+        return builder
+            .extension(new ConfigMap())
+            .build();
+    }
+
+    /**
+     * Check if system is initialized.
+     *
+     * @return <code>true</code> if system is initialized, <code>false</code> otherwise.
+     */
+    private boolean isInitialized() {
+        return client.fetch(ConfigMap.class, SYSTEM_STATES_CONFIGMAP)
+            .filter(configMap -> configMap.getData() != null)
+            .map(ConfigMap::getData)
+            .flatMap(map -> Optional.ofNullable(map.get(SystemStates.GROUP))
+                .filter(StringUtils::isNotBlank)
+                .map(value -> JsonUtils.jsonToObject(value, SystemStates.class).getIsSetup())
+            )
+            .orElse(false);
+    }
+
+    @Data
+    static class SystemStates {
+        static final String GROUP = "states";
+        Boolean isSetup;
+    }
+
+    static class InternalValueCache {
+        private final AtomicBoolean value = new AtomicBoolean(false);
+
+        public boolean cache(boolean newValue) {
+            return value.getAndSet(newValue);
+        }
+
+        public boolean get() {
+            return value.get();
+        }
+    }
+}

application/src/main/java/run/halo/app/security/InitializeRedirectionWebFilter.java

@@ -0,0 +1,57 @@
+package run.halo.app.security;
+
+import java.net.URI;
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.HttpMethod;
+import org.springframework.lang.NonNull;
+import org.springframework.security.web.server.DefaultServerRedirectStrategy;
+import org.springframework.security.web.server.ServerRedirectStrategy;
+import org.springframework.security.web.server.util.matcher.PathPatternParserServerWebExchangeMatcher;
+import org.springframework.security.web.server.util.matcher.ServerWebExchangeMatcher;
+import org.springframework.stereotype.Component;
+import org.springframework.util.Assert;
+import org.springframework.web.server.ServerWebExchange;
+import org.springframework.web.server.WebFilter;
+import org.springframework.web.server.WebFilterChain;
+import reactor.core.publisher.Mono;
+import run.halo.app.infra.SetupStateCache;
+
+/**
+ * A web filter that will redirect user to set up page if system is not initialized.
+ *
+ * @author guqing
+ * @since 2.5.2
+ */
+@Component
+@RequiredArgsConstructor
+public class InitializeRedirectionWebFilter implements WebFilter {
+    private final URI location = URI.create("/console");
+    private final ServerWebExchangeMatcher redirectMatcher =
+        new PathPatternParserServerWebExchangeMatcher("/", HttpMethod.GET);
+
+    private final SetupStateCache setupStateCache;
+
+    private ServerRedirectStrategy redirectStrategy = new DefaultServerRedirectStrategy();
+
+    @Override
+    @NonNull
+    public Mono<Void> filter(@NonNull ServerWebExchange exchange, @NonNull WebFilterChain chain) {
+        return redirectMatcher.matches(exchange)
+            .flatMap(matched -> {
+                if (!matched.isMatch() || setupStateCache.get()) {
+                    return chain.filter(exchange);
+                }
+                // Redirect to set up page if system is not initialized.
+                return redirectStrategy.sendRedirect(exchange, location);
+            });
+    }
+
+    public ServerRedirectStrategy getRedirectStrategy() {
+        return redirectStrategy;
+    }
+
+    public void setRedirectStrategy(ServerRedirectStrategy redirectStrategy) {
+        Assert.notNull(redirectStrategy, "redirectStrategy cannot be null");
+        this.redirectStrategy = redirectStrategy;
+    }
+}

application/src/test/java/run/halo/app/security/InitializeRedirectionWebFilterTest.java

@@ -0,0 +1,109 @@
+package run.halo.app.security;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.net.URI;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.springframework.mock.http.server.reactive.MockServerHttpRequest;
+import org.springframework.mock.web.server.MockServerWebExchange;
+import org.springframework.security.web.server.ServerRedirectStrategy;
+import org.springframework.web.server.WebFilterChain;
+import reactor.core.publisher.Mono;
+import reactor.test.StepVerifier;
+import run.halo.app.infra.SetupStateCache;
+
+/**
+ * Tests for {@link InitializeRedirectionWebFilter}.
+ *
+ * @author guqing
+ * @since 2.5.2
+ */
+@ExtendWith(MockitoExtension.class)
+class InitializeRedirectionWebFilterTest {
+
+    @Mock
+    private SetupStateCache setupStateCache;
+
+    @Mock
+    private ServerRedirectStrategy serverRedirectStrategy;
+
+    @InjectMocks
+    private InitializeRedirectionWebFilter filter;
+
+    @BeforeEach
+    void setUp() {
+        filter.setRedirectStrategy(serverRedirectStrategy);
+    }
+
+    @Test
+    void shouldRedirectWhenSystemNotInitialized() {
+        when(setupStateCache.get()).thenReturn(false);
+
+        WebFilterChain chain = mock(WebFilterChain.class);
+
+        MockServerHttpRequest request = MockServerHttpRequest.get("/").build();
+        MockServerWebExchange exchange = MockServerWebExchange.from(request);
+
+        when(serverRedirectStrategy.sendRedirect(any(), any())).thenReturn(Mono.empty().then());
+
+        Mono<Void> result = filter.filter(exchange, chain);
+
+        StepVerifier.create(result)
+            .expectNextCount(0)
+            .expectComplete()
+            .verify();
+
+        verify(serverRedirectStrategy).sendRedirect(eq(exchange), eq(URI.create("/console")));
+        verify(chain, never()).filter(eq(exchange));
+    }
+
+    @Test
+    void shouldNotRedirectWhenSystemInitialized() {
+        when(setupStateCache.get()).thenReturn(true);
+
+        WebFilterChain chain = mock(WebFilterChain.class);
+
+        MockServerHttpRequest request = MockServerHttpRequest.get("/").build();
+        MockServerWebExchange exchange = MockServerWebExchange.from(request);
+        when(chain.filter(any())).thenReturn(Mono.empty().then());
+        Mono<Void> result = filter.filter(exchange, chain);
+
+        StepVerifier.create(result)
+            .expectNextCount(0)
+            .expectComplete()
+            .verify();
+
+        verify(serverRedirectStrategy, never()).sendRedirect(eq(exchange),
+            eq(URI.create("/console")));
+        verify(chain).filter(eq(exchange));
+    }
+
+    @Test
+    void shouldNotRedirectWhenNotHomePage() {
+        WebFilterChain chain = mock(WebFilterChain.class);
+
+        MockServerHttpRequest request = MockServerHttpRequest.get("/test").build();
+        MockServerWebExchange exchange = MockServerWebExchange.from(request);
+        when(chain.filter(any())).thenReturn(Mono.empty().then());
+        Mono<Void> result = filter.filter(exchange, chain);
+
+        StepVerifier.create(result)
+            .expectNextCount(0)
+            .expectComplete()
+            .verify();
+
+        verify(serverRedirectStrategy, never()).sendRedirect(eq(exchange),
+            eq(URI.create("/console")));
+        verify(chain).filter(eq(exchange));
+    }
+}

application/src/test/java/run/halo/app/theme/message/ThemeMessageResolverIntegrationTest.java

@@ -24,6 +24,7 @@ import org.springframework.web.reactive.function.server.RouterFunctions;
 import org.springframework.web.reactive.function.server.ServerResponse;
 import org.springframework.web.server.ServerWebExchange;
 import reactor.core.publisher.Mono;
+import run.halo.app.infra.SetupStateCache;
 import run.halo.app.theme.ThemeContext;
 import run.halo.app.theme.ThemeResolver;
 
@@ -44,11 +45,15 @@ public class ThemeMessageResolverIntegrationTest {
 
     private URL otherThemeUrl;
 
+    @SpyBean
+    private SetupStateCache setupStateCache;
+
     @Autowired
     private WebTestClient webTestClient;
 
     @BeforeEach
     void setUp() throws FileNotFoundException, URISyntaxException {
+        when(setupStateCache.get()).thenReturn(true);
         defaultThemeUrl = ResourceUtils.getURL("classpath:themes/default");
         otherThemeUrl = ResourceUtils.getURL("classpath:themes/other");