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# PhoenixKit.Entities.PresenceHelpers (phoenix_kit v1.6.19)

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Helper functions for collaborative editing with Phoenix.Presence.

Provides utilities for tracking editing sessions, determining owner/spectator roles, and syncing state between users.

# Summary

## Functions

count_editors(type, id)

Counts total number of people editing (owner + spectators).

editing_topic(atom, id)

Generates the Presence topic name for a resource.

get_editing_role(type, id, socket_id, current_user_id)

Determines if the current socket is the owner (first in the presence list).

get_lock_owner(type, id)

Gets the lock owner's metadata, or nil if no one is editing.

get_sorted_presences(type, id)

Gets all presences for a resource, sorted by join time (FIFO).

get_spectators(type, id)

Gets all spectators (everyone except the first person).

subscribe_to_editing(type, id)

Subscribes the current process to presence events for a resource.

track_editing_session(type, id, socket, user)

Tracks the current LiveView process in a Presence topic.

# Functions

# count_editors(type, id)

Counts total number of people editing (owner + spectators).

# editing_topic(atom, id)

Generates the Presence topic name for a resource.

## Examples

    editing_topic(:entity, 5)
    # => "entity_edit:5"

    editing_topic(:data, 10)
    # => "data_edit:10"

# get_editing_role(type, id, socket_id, current_user_id)

Determines if the current socket is the owner (first in the presence list).

Returns `{:owner, presences}` if this socket is the owner (or same user in different tab), or `{:spectator, owner_meta, presences}` if a different user is the owner.

## Examples

    case get_editing_role(:entity, 5, socket.id, current_user.id) do
      {:owner, all_presences} ->
        # I can edit!

      {:spectator, owner_metadata, all_presences} ->
        # I'm read-only, sync with owner's state
    end

# get_lock_owner(type, id)

Gets the lock owner's metadata, or nil if no one is editing.

## Examples

    case get_lock_owner(:entity, 5) do
      nil -> # No one editing
      meta -> # meta.user, meta.joined_at, etc.
    end

# get_sorted_presences(type, id)

Gets all presences for a resource, sorted by join time (FIFO).

Returns a list of tuples: `[{socket_id, metadata}, ...]`

## Examples

    get_sorted_presences(:entity, 5)
    # => [
    #   {"phx-abc123", %{user_id: 5, joined_at: 123456, ...}},
    #   {"phx-def456", %{user_id: 7, joined_at: 123458, ...}}
    # ]

# get_spectators(type, id)

Gets all spectators (everyone except the first person).

Returns a list of metadata for spectators only.

## Examples

    get_spectators(:entity, 5)
    # => [
    #   %{user_id: 7, user_email: "user@example.com", joined_at: 123458, ...},
    #   %{user_id: 9, user_email: "other@example.com", joined_at: 123460, ...}
    # ]

# subscribe_to_editing(type, id)

Subscribes the current process to presence events for a resource.

After subscribing, the process will receive:

- `%Phoenix.Socket.Broadcast{event: "presence_diff", ...}` when users join/leave

## Examples

    subscribe_to_editing(:entity, 5)
    # Now will receive presence_diff messages

# track_editing_session(type, id, socket, user)

Tracks the current LiveView process in a Presence topic.

## Parameters

- `type`: The resource type (`:entity` or `:data`)
- `id`: The resource ID
- `socket`: The LiveView socket
- `user`: The current user struct

## Examples

    track_editing_session(:entity, 5, socket, user)
    # => {:ok, ref}