discourse/plugins/chat/app/services/chat/lookup_channel_threads.rb
2024-12-02 17:31:36 +01:00

145 lines
4.7 KiB
Ruby

# frozen_string_literal: true
module Chat
# Gets a list of threads for a channel to be shown in an index.
# In future pagination and filtering will be added -- for now
# we just want to return N threads ordered by the latest
# message that a user has sent in a thread.
#
# Only threads that the user is a member of with a notification level
# of normal or tracking will be returned.
#
# @example
# Chat::LookupChannelThreads.call(params: { channel_id: 2, limit: 5, offset: 2 }, guardian: guardian)
#
class LookupChannelThreads
include Service::Base
THREADS_LIMIT = 10
# @!method self.call(guardian:, params:)
# @param [Guardian] guardian
# @param [Hash] params
# @option params [Integer] :channel_id
# @option params [Integer] :limit
# @option params [Integer] :offset
# @return [Service::Base::Context]
params do
attribute :channel_id, :integer
attribute :limit, :integer
attribute :offset, :integer
validates :channel_id, presence: true
validates :limit,
numericality: {
less_than_or_equal_to: THREADS_LIMIT,
only_integer: true,
},
allow_nil: true
after_validation do
self.limit = (limit || THREADS_LIMIT).to_i.clamp(1, THREADS_LIMIT)
self.offset = [offset || 0, 0].max
end
end
model :channel
policy :threading_enabled_for_channel
policy :can_view_channel
model :threads
step :fetch_tracking
step :fetch_memberships
step :fetch_participants
step :build_load_more_url
private
def fetch_channel(params:)
::Chat::Channel.strict_loading.includes(:chatable).find_by(id: params.channel_id)
end
def threading_enabled_for_channel(channel:)
channel.threading_enabled
end
def can_view_channel(guardian:, channel:)
guardian.can_preview_chat_channel?(channel)
end
def fetch_threads(guardian:, channel:, params:)
::Chat::Thread
.includes(
:channel,
:user_chat_thread_memberships,
original_message_user: :user_status,
last_message: [
:uploads,
:chat_webhook_event,
:chat_channel,
user_mentions: {
user: :user_status,
},
user: :user_status,
],
original_message: [
:uploads,
:chat_webhook_event,
:chat_channel,
user_mentions: {
user: :user_status,
},
user: :user_status,
],
)
.joins(
"LEFT JOIN user_chat_thread_memberships ON chat_threads.id = user_chat_thread_memberships.thread_id AND user_chat_thread_memberships.user_id = #{guardian.user.id} AND user_chat_thread_memberships.notification_level NOT IN (#{::Chat::UserChatThreadMembership.notification_levels[:muted]})",
)
.joins(
"LEFT JOIN chat_messages AS last_message ON chat_threads.last_message_id = last_message.id",
)
.joins(
"INNER JOIN chat_messages AS original_message ON chat_threads.original_message_id = original_message.id",
)
.where(channel_id: channel.id)
.where("original_message.chat_channel_id = chat_threads.channel_id")
.where("original_message.deleted_at IS NULL")
.where("last_message.chat_channel_id = chat_threads.channel_id")
.where("last_message.deleted_at IS NULL")
.where("chat_threads.replies_count > 0")
.order(
"CASE WHEN user_chat_thread_memberships.last_read_message_id IS NULL OR user_chat_thread_memberships.last_read_message_id < chat_threads.last_message_id THEN true ELSE false END DESC, last_message.created_at DESC",
)
.limit(params.limit)
.offset(params.offset)
end
def fetch_tracking(guardian:, threads:)
context[:tracking] = ::Chat::TrackingStateReportQuery.call(
guardian: guardian,
thread_ids: threads.map(&:id),
include_threads: true,
).thread_tracking
end
def fetch_memberships(guardian:, threads:)
context[:memberships] = ::Chat::UserChatThreadMembership.where(
thread_id: threads.map(&:id),
user_id: guardian.user.id,
)
end
def fetch_participants(threads:)
context[:participants] = ::Chat::ThreadParticipantQuery.call(thread_ids: threads.map(&:id))
end
def build_load_more_url(channel:, params:)
load_more_params = { offset: params.offset + params.limit }.to_query
context[:load_more_url] = ::URI::HTTP.build(
path: "/chat/api/channels/#{channel.id}/threads",
query: load_more_params,
).request_uri
end
end
end