feat: 添加分类提案功能，包括提案表单和相关后端逻辑

backend/src/main/java/com/openisle/controller/PostController.java

@@ -73,7 +73,12 @@ public class PostController {
       req.getStartTime(),
       req.getEndTime(),
       req.getOptions(),
-      req.getMultiple()
+      req.getMultiple(),
+      req.getProposedName(),
+      req.getProposedSlug(),
+      req.getProposalDescription(),
+      req.getApproveThreshold(),
+      req.getQuorum()
     );
     draftService.deleteDraft(auth.getName());
     PostDetailDto dto = postMapper.toDetailDto(post, auth.getName());

backend/src/main/java/com/openisle/dto/PostRequest.java

@@ -28,4 +28,11 @@ public class PostRequest {
   // fields for poll posts
   private List<String> options;
   private Boolean multiple;
+
+  // fields for category proposal posts
+  private String proposedName;
+  private String proposedSlug;
+  private String proposalDescription;
+  private Integer approveThreshold;
+  private Integer quorum;
 }

backend/src/main/java/com/openisle/model/CategoryProposalPost.java

@@ -0,0 +1,65 @@
+package com.openisle.model;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.EnumType;
+import jakarta.persistence.Enumerated;
+import jakarta.persistence.Index;
+import jakarta.persistence.PrimaryKeyJoinColumn;
+import jakarta.persistence.Table;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+import java.time.LocalDateTime;
+
+/**
+ * A specialized post type used for proposing new categories.
+ * It reuses poll mechanics (participants, votes, endTime) by extending PollPost.
+ */
+@Entity
+@Table(name = "category_proposal_posts", indexes = {
+        @Index(name = "idx_category_proposal_posts_status", columnList = "status"),
+        @Index(name = "idx_category_proposal_posts_slug", columnList = "proposed_slug", unique = true)
+})
+@Getter
+@Setter
+@NoArgsConstructor
+@PrimaryKeyJoinColumn(name = "post_id")
+public class CategoryProposalPost extends PollPost {
+
+    @Enumerated(EnumType.STRING)
+    @Column(name = "status", nullable = false)
+    private CategoryProposalStatus proposalStatus = CategoryProposalStatus.PENDING;
+
+    @Column(name = "proposed_name", nullable = false)
+    private String proposedName;
+
+    @Column(name = "proposed_slug", nullable = false, unique = true)
+    private String proposedSlug;
+
+    @Column(name = "description")
+    private String description;
+
+    // Approval threshold as percentage (0-100), default 60
+    @Column(name = "approve_threshold", nullable = false)
+    private int approveThreshold = 60;
+
+    // Minimum number of participants required to meet quorum
+    @Column(name = "quorum", nullable = false)
+    private int quorum = 10;
+
+    // Optional voting start time (end time inherited from PollPost)
+    @Column(name = "start_at")
+    private LocalDateTime startAt;
+
+    // Snapshot of poll results at finalization (e.g., JSON)
+    @Column(name = "result_snapshot", columnDefinition = "TEXT")
+    private String resultSnapshot;
+
+    // Reason when proposal is rejected
+    @Column(name = "reject_reason")
+    private String rejectReason;
+}
+
+

backend/src/main/java/com/openisle/model/CategoryProposalStatus.java

@@ -0,0 +1,10 @@
+package com.openisle.model;
+
+public enum CategoryProposalStatus {
+    PENDING,
+    APPROVED,
+    REJECTED
+}
+
+
+

backend/src/main/java/com/openisle/model/PostType.java

@@ -4,4 +4,5 @@ public enum PostType {
   NORMAL,
   LOTTERY,
   POLL,
+  PROPOSAL
 }

backend/src/main/java/com/openisle/repository/CategoryProposalPostRepository.java

@@ -0,0 +1,18 @@
+package com.openisle.repository;
+
+import com.openisle.model.CategoryProposalPost;
+import com.openisle.model.CategoryProposalStatus;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+
+import java.time.LocalDateTime;
+import java.util.List;
+
+public interface CategoryProposalPostRepository extends JpaRepository<CategoryProposalPost, Long> {
+    List<CategoryProposalPost> findByEndTimeAfterAndProposalStatus(LocalDateTime now, CategoryProposalStatus status);
+    List<CategoryProposalPost> findByEndTimeBeforeAndProposalStatus(LocalDateTime now, CategoryProposalStatus status);
+    boolean existsByProposedSlug(String proposedSlug);
+}
+
+
+

backend/src/main/java/com/openisle/service/PostService.java

@@ -1,6 +1,30 @@
 package com.openisle.service;
 
 import com.openisle.config.CachingConfig;
+import com.openisle.exception.NotFoundException;
+import com.openisle.exception.RateLimitException;
+import com.openisle.model.*;
+import com.openisle.repository.*;
+import lombok.extern.slf4j.Slf4j;
+import org.apache.commons.lang3.StringUtils;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.boot.context.event.ApplicationReadyEvent;
+import org.springframework.cache.annotation.CacheEvict;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.event.EventListener;
+import org.springframework.data.domain.PageRequest;
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.domain.Sort;
+import org.springframework.data.redis.core.RedisTemplate;
+import org.springframework.scheduling.TaskScheduler;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+import org.springframework.util.CollectionUtils;
+
+import java.time.Duration;
+import java.time.LocalDateTime;
+import java.time.ZoneId;
+import java.util.*;
 import com.openisle.exception.RateLimitException;
 import com.openisle.mapper.PostMapper;
 import com.openisle.model.*;
@@ -26,22 +50,6 @@ import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.ScheduledFuture;
 import java.util.stream.Collectors;
-import lombok.extern.slf4j.Slf4j;
-import org.apache.commons.lang3.StringUtils;
-import org.springframework.beans.factory.annotation.Value;
-import org.springframework.boot.context.event.ApplicationReadyEvent;
-import org.springframework.cache.annotation.CacheEvict;
-import org.springframework.cache.annotation.Cacheable;
-import org.springframework.context.ApplicationContext;
-import org.springframework.context.event.EventListener;
-import org.springframework.data.domain.PageRequest;
-import org.springframework.data.domain.Pageable;
-import org.springframework.data.domain.Sort;
-import org.springframework.data.redis.core.RedisTemplate;
-import org.springframework.scheduling.TaskScheduler;
-import org.springframework.stereotype.Service;
-import org.springframework.transaction.annotation.Transactional;
-import org.springframework.util.CollectionUtils;
 
 @Slf4j
 @Service
@@ -53,6 +61,7 @@ public class PostService {
   private final TagRepository tagRepository;
   private final LotteryPostRepository lotteryPostRepository;
   private final PollPostRepository pollPostRepository;
+  private final CategoryProposalPostRepository categoryProposalPostRepository;
   private final PollVoteRepository pollVoteRepository;
   private PublishMode publishMode;
   private final NotificationService notificationService;
@@ -86,6 +95,7 @@ public class PostService {
     TagRepository tagRepository,
     LotteryPostRepository lotteryPostRepository,
     PollPostRepository pollPostRepository,
+    CategoryProposalPostRepository categoryProposalPostRepository,
     PollVoteRepository pollVoteRepository,
     NotificationService notificationService,
     SubscriptionService subscriptionService,
@@ -155,6 +165,19 @@ public class PostService {
     for (PollPost pp : pollPostRepository.findByEndTimeBeforeAndResultAnnouncedFalse(now)) {
       applicationContext.getBean(PostService.class).finalizePoll(pp.getId());
     }
+    for (CategoryProposalPost cp : categoryProposalPostRepository
+            .findByEndTimeAfterAndProposalStatus(now, CategoryProposalStatus.PENDING)) {
+        if (cp.getEndTime() != null) {
+            ScheduledFuture<?> future = taskScheduler.schedule(
+                    () -> applicationContext.getBean(PostService.class).finalizeProposal(cp.getId()),
+                    java.util.Date.from(cp.getEndTime().atZone(ZoneId.systemDefault()).toInstant()));
+            scheduledFinalizations.put(cp.getId(), future);
+        }
+    }
+    for (CategoryProposalPost cp : categoryProposalPostRepository
+            .findByEndTimeBeforeAndProposalStatus(now, CategoryProposalStatus.PENDING)) {
+        applicationContext.getBean(PostService.class).finalizeProposal(cp.getId());
+    }
   }
 
   public PublishMode getPublishMode() {
@@ -227,7 +250,12 @@ public class PostService {
     LocalDateTime startTime,
     LocalDateTime endTime,
     java.util.List<String> options,
-    Boolean multiple
+    Boolean multiple,
+    String proposedName,
+    String proposedSlug,
+    String proposalDescription,
+    Integer approveThreshold,
+    Integer quorum
   ) {
     // 限制访问次数
     boolean limitResult = postRateLimit(username);
@@ -273,6 +301,42 @@ public class PostService {
       pp.setEndTime(endTime);
       pp.setMultiple(multiple != null && multiple);
       post = pp;
+    } else if (actualType == PostType.PROPOSAL) {
+        CategoryProposalPost cp = new CategoryProposalPost();
+        if (proposedName == null || proposedName.isBlank()) {
+            throw new IllegalArgumentException("Proposed name required");
+        }
+        if (proposedSlug == null || proposedSlug.isBlank()) {
+            throw new IllegalArgumentException("Proposed slug required");
+        }
+        if (categoryProposalPostRepository.existsByProposedSlug(proposedSlug)) {
+            throw new IllegalArgumentException("Proposed slug already exists: " + proposedSlug);
+        }
+        cp.setProposedName(proposedName);
+        cp.setProposedSlug(proposedSlug);
+        cp.setDescription(proposalDescription);
+        if (approveThreshold != null) {
+            if (approveThreshold < 0 || approveThreshold > 100) {
+                throw new IllegalArgumentException("approveThreshold must be between 0 and 100");
+            }
+            cp.setApproveThreshold(approveThreshold);
+        }
+        if (quorum != null) {
+            if (quorum < 0) {
+                throw new IllegalArgumentException("quorum must be >= 0");
+            }
+            cp.setQuorum(quorum);
+        }
+        cp.setStartAt(startTime);
+        cp.setEndTime(endTime);
+        // default yes/no options if not provided
+        if (options == null || options.size() < 2) {
+            cp.setOptions(List.of("同意", "反对"));
+        } else {
+            cp.setOptions(options);
+        }
+        cp.setMultiple(false);
+        post = cp;
     } else {
       post = new Post();
     }
@@ -285,6 +349,8 @@ public class PostService {
     post.setStatus(publishMode == PublishMode.REVIEW ? PostStatus.PENDING : PostStatus.PUBLISHED);
     if (post instanceof LotteryPost) {
       post = lotteryPostRepository.save((LotteryPost) post);
+    }else if (post instanceof CategoryProposalPost categoryProposalPost) {
+        post = categoryProposalPostRepository.save(categoryProposalPost);
     } else if (post instanceof PollPost) {
       post = pollPostRepository.save((PollPost) post);
     } else {
@@ -339,6 +405,11 @@ public class PostService {
         java.util.Date.from(lp.getEndTime().atZone(ZoneId.systemDefault()).toInstant())
       );
       scheduledFinalizations.put(lp.getId(), future);
+    } else if (post instanceof CategoryProposalPost cp && cp.getEndTime() != null) {
+        ScheduledFuture<?> future = taskScheduler.schedule(
+                () -> applicationContext.getBean(PostService.class).finalizeProposal(cp.getId()),
+                java.util.Date.from(cp.getEndTime().atZone(ZoneId.systemDefault()).toInstant()));
+        scheduledFinalizations.put(cp.getId(), future);
     } else if (post instanceof PollPost pp && pp.getEndTime() != null) {
       ScheduledFuture<?> future = taskScheduler.schedule(
         () -> applicationContext.getBean(PostService.class).finalizePoll(pp.getId()),
@@ -349,6 +420,50 @@ public class PostService {
     return post;
   }
 
+  @CacheEvict(
+    value = CachingConfig.POST_CACHE_NAME, allEntries = true
+  )
+  @Transactional
+  public void finalizeProposal(Long postId) {
+    scheduledFinalizations.remove(postId);
+    categoryProposalPostRepository.findById(postId).ifPresent(cp -> {
+    if (cp.getProposalStatus() != CategoryProposalStatus.PENDING) {
+      return;
+    }
+    int totalParticipants = cp.getParticipants() != null ? cp.getParticipants().size() : 0;
+    int approveVotes = 0;
+    if (cp.getVotes() != null) {
+      approveVotes = cp.getVotes().getOrDefault(0, 0);
+    }
+    boolean quorumMet = totalParticipants >= cp.getQuorum();
+    int approvePercent = totalParticipants > 0 ? (approveVotes * 100) / totalParticipants : 0;
+    boolean thresholdMet = approvePercent >= cp.getApproveThreshold();
+    if (quorumMet && thresholdMet) {
+      cp.setProposalStatus(CategoryProposalStatus.APPROVED);
+    } else {
+      cp.setProposalStatus(CategoryProposalStatus.REJECTED);
+      String reason;
+      if (!quorumMet && !thresholdMet) {
+        reason = "未达到法定人数且赞成率不足";
+      } else if (!quorumMet) {
+        reason = "未达到法定人数";
+      } else {
+        reason = "赞成率不足";
+      }
+        cp.setRejectReason(reason);
+    }
+    cp.setResultSnapshot("approveVotes=" + approveVotes + ", totalParticipants=" + totalParticipants + ", approvePercent=" + approvePercent);
+    categoryProposalPostRepository.save(cp);
+    if (cp.getAuthor() != null) {
+      notificationService.createNotification(cp.getAuthor(), NotificationType.POLL_RESULT_OWNER, cp, null, null, null, null, null);
+    }
+    for (User participant : cp.getParticipants()) {
+      notificationService.createNotification(participant, NotificationType.POLL_RESULT_PARTICIPANT, cp, null, null, null, null, null);
+    }
+    postChangeLogService.recordVoteResult(cp);
+      });
+  }
+
   /**
    * 限制发帖频率
    * @param username