/**
* Used to sync a diff of presence join and leave
* events from the server, as they happen. Like `syncState`, `syncDiff`
* accepts optional `onJoin` and `onLeave` callbacks to react to a user
* joining or leaving from a device.
*/
private static State SyncDiff(
State state,
Diff diff,
OnJoinDelegate onJoin,
OnLeaveDelegate onLeave
)
{
foreach (var key in diff.Joins.Keys)
{
var newPresence = diff.Joins[key];
var found = state.TryGetValue(key, out var currentPresence);
state[key] = newPresence;
if (found)
{
var joinedRefs = state[key].Metas.Select(m => m["phx_ref"]).ToList();
var curMetas = currentPresence.Metas.Where(m => joinedRefs.IndexOf(m["phx_ref"]) < 0).ToList();
state[key].Metas.InsertRange(0, curMetas);
}
onJoin?.Invoke(key, currentPresence, newPresence);
}
foreach (var key in diff.Leaves.Keys)
{
var leftPresence = diff.Leaves[key];
var found = state.TryGetValue(key, out var currentPresence);
if (!found)
{
continue;
}
var refsToRemove = leftPresence.Metas.Select(m => m["phx_ref"]).ToList();
var filteredMetas = currentPresence.Metas.Where(
m => refsToRemove.IndexOf(m["phx_ref"]) < 0).ToList();
var newPresence = new MetadataContainer {
Metas = filteredMetas
};
onLeave?.Invoke(key, newPresence, leftPresence);
if (newPresence.Metas.Count == 0)
{
state.Remove(key);
}
else
{
state[key] = newPresence;
}
}
return(state);
}
public static State SyncDiff(State currentState, Diff diff, OnJoinDelegate onJoin, OnLeaveDelegate onLeave)
{
var state = Clone(currentState);
foreach (var entry in diff["joins"])
{
Item currentItem = null;
if (state.ContainsKey(entry.Key))
{
currentItem = state[entry.Key];
}
state[entry.Key] = entry.Value;
if (currentItem != null)
{
var joinedRefs = state[entry.Key]["metas"].Select(m => m["phx_ref"]).ToList();
var curMetas = currentItem["metas"].Where(m => !joinedRefs.Contains(m["phx_ref"])).ToList();
state[entry.Key]["metas"] = curMetas.Concat(state[entry.Key]["metas"]).ToList();
}
onJoin?.Invoke(entry.Key, currentItem, entry.Value);
}
foreach (var entry in diff["leaves"])
{
if (!state.ContainsKey(entry.Key))
{
continue;
}
var currentItem = state[entry.Key];
var refsToRemove = entry.Value["metas"].Select(m => m["phx_ref"]).ToList();
currentItem["metas"] = currentItem["metas"].Where(m => !refsToRemove.Contains(m["phx_ref"])).ToList();
onLeave?.Invoke(entry.Key, currentItem, entry.Value);
if (currentItem["metas"].Count() == 0)
{
state.Remove(entry.Key);
}
}
return(state);
}