bitvid/content/roadmap/06_bitvid_Enhanced_Video_Comment_System_Specification.md

bitvid: Enhanced Video Comment System Specification

Objective

To implement a decentralized comment system for videos shared on a Nostr-based platform, combining multiple NIPs to provide structured, interactive, and scalable functionality for video comments, reactions, live discussions, and metadata tagging.

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Features

1. Post Comments:

   • Users can post comments on videos.
   • Comments are associated with a specific video event using the e tag.

2. Structured Threading:

   • Comments support threading by referencing parent comments using NIP-27 conventions.
   • Threaded replies are visually nested.

3. Reactions:

   • Users can react to comments (e.g., upvote, downvote) using NIP-25.

4. Live Discussions:

   • Real-time public chat using NIP-28 for live video events.

5. Optional Metadata:

   • Extra metadata fields are included for user preferences or administrative tags using NIP-24.

6. Real-Time Updates:

   • Comments, reactions, and live chats update in real-time using Nostr subscriptions.

7. Moderation:

   • Support for flagging or hiding inappropriate comments.

8. Privacy:

   • Encrypted comments for private videos (optional).

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Technical Specifications

1. Event Structure

Each component (comments, reactions, live chat) is represented as a Nostr event.

Comment Event:

{
    "kind": 1311,
    "pubkey": "abcdef1234567890...",
    "created_at": 1675000000,
    "tags": [
        ["e", "video-event-id"], // Reference to the video
        ["e", "parent-comment-id"], // Reference to the parent comment (optional, for replies)
        ["p", "commenter-pubkey"] // Optional: commenter pubkey
    ],
    "content": "This is a great video!"
}

Reaction Event:

{
    "kind": 7,
    "pubkey": "abcdef1234567890...",
    "created_at": 1675000000,
    "tags": [
        ["e", "comment-event-id"], // Reference to the comment being reacted to
        ["p", "reactor-pubkey"]
    ],
    "content": "+" // + for upvote, - for downvote
}

Live Chat Event:

{
    "kind": 42,
    "pubkey": "abcdef1234567890...",
    "created_at": 1675000000,
    "tags": [
        ["e", "video-event-id"], // Reference to the live video
        ["p", "participant-pubkey"]
    ],
    "content": "What a great discussion!"
}

Metadata (Optional):

Metadata tags are added to comments or live chat events as needed:

{
    "kind": 1311,
    "pubkey": "abcdef1234567890...",
    "created_at": 1675000000,
    "tags": [
        ["e", "video-event-id"],
        ["m", "featured-comment"], // Example metadata tag
        ["a", "admin-tag"] // Administrative tag
    ],
    "content": "Highlighted comment for this video."
}

---

Implementation Details

1. Posting a Comment

To post a comment:

1. The client constructs a comment event using NIP-22 for created_at validation.
2. The event includes references to the video (mandatory) and parent comments (optional).
3. The event is signed and published to relays.

API Example:

async function postComment(videoId, commentText, parentCommentId = null) {
    const event = {
        kind: 1311,
        pubkey: userPubkey,
        created_at: Math.floor(Date.now() / 1000),
        tags: [
            ['e', videoId],
            ...(parentCommentId ? [['e', parentCommentId]] : []),
        ],
        content: commentText
    };

    const signedEvent = await nostrClient.signEvent(event);
    await nostrClient.pool.publish(nostrClient.relays, signedEvent);
}

2. Reacting to a Comment

Reactions use NIP-25.

API Example:

async function reactToComment(commentId, reaction) {
    const event = {
        kind: 7,
        pubkey: userPubkey,
        created_at: Math.floor(Date.now() / 1000),
        tags: [['e', commentId]],
        content: reaction // Use "+" for upvote, "-" for downvote
    };

    const signedEvent = await nostrClient.signEvent(event);
    await nostrClient.pool.publish(nostrClient.relays, signedEvent);
}

3. Fetching Comments

Comments are retrieved using REQ messages filtered by the e tag for the video’s event ID and optionally by parent comment IDs for threading.

API Example:

async function fetchComments(videoId) {
    const filter = {
        kinds: [1311],
        '#e': [videoId],
        limit: 100
    };

    const comments = await nostrClient.pool.list(nostrClient.relays, [filter]);
    return comments.sort((a, b) => a.created_at - b.created_at);
}

4. Live Chat for Live Videos

Real-time public chats for live videos use NIP-28.

API Example:

function subscribeToLiveChat(videoId) {
    const sub = nostrClient.pool.sub(nostrClient.relays, [
        {
            kinds: [42],
            '#e': [videoId]
        }
    ]);

    sub.on('event', event => {
        console.log('New chat message:', event);
    });
}

5. Metadata Integration

Use NIP-24 to attach metadata to events for administrative or user-specific tags.

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Data Flow

1. Posting a Comment:
   • User creates a comment event.
   • Client signs and publishes the event to relays.
2. Fetching Comments:
   • Client requests comments for a video by filtering events with the e tag.
3. Reacting to Comments:
   • Users react to comments by posting reaction events.
4. Live Discussions:
   • Live chat messages are sent and received in real-time using NIP-28.
5. Metadata Management:
   • Metadata is attached during event creation or editing.

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UI/UX Considerations

1. Comment Form:

   • Input field for comments.
   • Button to post comments.
   • Optional reply button for threaded comments.

2. Reactions:

   • Upvote and downvote icons next to each comment.
   • Display reaction counts dynamically.

3. Live Chat:

   • Real-time message updates below live videos.
   • Highlight important messages using metadata tags.

4. Nested Threading:

   • Indent replies to show comment hierarchy.

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Testing and Validation

1. Validate:
   • Posting, retrieving, and displaying threaded comments.
   • Reactions and live chat events.
   • Metadata tagging.
2. Test:
   • Pagination for large comment threads.
   • Performance under high comment or chat volume.
3. Simulate:
   • Various timestamp scenarios to ensure NIP-22 compliance.

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Benefits

• Decentralized and censorship-resistant.
• Fully interoperable with other Nostr clients and relays.
• Extensible with reactions, live discussions, and metadata features.