[r/boards] thread flagging

[salmad3]

Context

Flagging is a critical moderation function for identifying and managing inappropriate, spam, or otherwise undesirable content at the thread level. Threads are typically top-level posts within a board. Building on the broader flagging system, we now want to introduce thread-specific flagging that:

• Allows authorized users (moderators, admins, owners) to flag entire threads.
• Hides or restricts flagged threads once they reach a configurable threshold.
• Integrates smoothly with the permissions system (HasPermission or WithPermission).

Acceptance Criteria

• Struct Updates

  • Extend the Thread struct (or Post with ParentID == 0) to include a Flags field of type []Flag, plus a Hidden boolean.

    Example

    type Thread struct {
        ThreadID   string
        Title      string
        Author     Address
        Content    string
        Timestamp  time.Time
        Flags      []Flag // appended for thread-level flags
        Hidden     bool
        // ... other potential fields
    }
    
    type Flag struct {
        User   Address
        Reason string
        Date   time.Time
    }

• Flagging Function

  • Add a FlagThread(threadID string, reason string) function that:

    1. Checks if the caller has permission to flag threads (e.g., "flag:thread").

    2. Locates the thread by threadID.

    3. Appends a new Flag to the thread.Flags.

    4. If len(thread.Flags) >= ThreadFlagThreshold, set thread.Hidden = true.

    5. Returns an error if the thread is already hidden or if the caller lacks permission.

       Example

       func (br *BoardsRealm) FlagThread(caller Address, threadID string, reason string) error {
           if !br.HasPermission(caller, "flag:thread", []interface{}{threadID}) {
               return errors.New("caller does not have permission to flag threads")
           }
       
           thread := br.GetThreadByID(threadID)
           if thread == nil {
               return errors.New("thread not found")
           }
           if thread.Hidden {
              return errors.New("thread is already hidden")
           }
       
           newFlag := Flag{
               User:   caller,
               Reason: reason,
               Date:   time.Now(),
           }
           thread.Flags = append(thread.Flags, newFlag)
       
           if len(thread.Flags) >= br.Config.ThreadFlagThreshold {
               thread.Hidden = true
           }
       
           br.UpdateThread(thread)
           return nil
       }

• Permissions

  • Must verify the correct permission key (e.g., "flag:thread").
  • By default, only moderators or admins can flag threads in the MVP.

• Configuration

  • A ThreadFlagThreshold in BoardsRealmConfig, defaulting to 1 or a small integer.
  • Possibly overridden by a board-specific or AdminDAO-based setting later.

• Tests

  • Confirm that a user with "flag:thread" can successfully flag a thread.
  • Ensure unauthorized users fail to flag.
  • Validate that a hidden thread cannot be flagged again.
  • Test repeated flags from the same user, invalid threadID, etc.

Notes

• Initially, ThreadFlagThreshold might be set globally.
• Future expansions:
  • Differing thresholds per board.
  • More detailed reason codes (e.g. “spam,” “abuse,” “off-topic”).
  • Automatic triggers for freezing a board if multiple threads get flagged quickly.

[salmad3]

• feat(boards2): add core flagging logic #3451
• feat(boardsv2): hide flagged comments #3536