discourse-ai/app/services/discourse_ai/topic_summarization.rb

146 lines
3.8 KiB
Ruby

# frozen_string_literal: true
module DiscourseAi
class TopicSummarization
def self.summarize(topic, user, skip_age_check: false, &on_partial_blk)
new(DiscourseAi::Summarization.default_strategy, topic, user).summarize(
skip_age_check: skip_age_check,
&on_partial_blk
)
end
def self.cached_summary(topic, user)
new(DiscourseAi::Summarization.default_strategy, topic, user).cached_summary
end
def initialize(strategy, topic, user)
@strategy = strategy
@topic = topic
@user = user
end
attr_reader :strategy, :topic, :user
def cached_summary
existing_summary
end
def summarize(skip_age_check: false, &on_partial_blk)
# Existing summary shouldn't be nil in this scenario because the controller checks its existence.
return if !user && !existing_summary
return existing_summary if use_cached?(skip_age_check)
delete_cached_summaries! if existing_summary
content = {
resource_path: "#{Discourse.base_path}/t/-/#{topic.id}",
content_title: topic.title,
contents: [],
}
summary_targets_data.map do |(pn, raw, username)|
raw_text = raw
if pn == 1 && topic.topic_embed&.embed_content_cache.present?
raw_text = topic.topic_embed&.embed_content_cache
end
content[:contents] << { poster: username, id: pn, text: raw_text }
end
summarization_result = strategy.summarize(content, user, &on_partial_blk)
cache_summary(summarization_result)
end
def summary_targets
topic.has_summary? ? best_replies : pick_selection
end
private
def summary_sha
@summary_sha ||= build_sha(summary_targets_data.map(&:first))
end
def summary_targets_data
@summary_targets_data ||= summary_targets.pluck(:post_number, :raw, :username)
end
def existing_summary
if !defined?(@existing_summary)
@existing_summary = AiSummary.find_by(target: topic)
if @existing_summary && existing_summary.original_content_sha != summary_sha
@existing_summary.mark_as_outdated
end
end
@existing_summary
end
def best_replies
Post
.summary(topic.id)
.where("post_type = ?", Post.types[:regular])
.where("NOT hidden")
.joins(:user)
.order(:post_number)
end
def pick_selection
posts =
Post
.where(topic_id: topic.id)
.where("post_type = ?", Post.types[:regular])
.where("NOT hidden")
.order(:post_number)
post_numbers = posts.limit(5).pluck(:post_number)
post_numbers += posts.reorder("posts.score desc").limit(50).pluck(:post_number)
post_numbers += posts.reorder("post_number desc").limit(5).pluck(:post_number)
Post
.where(topic_id: topic.id)
.joins(:user)
.where("post_number in (?)", post_numbers)
.order(:post_number)
end
def delete_cached_summaries!
AiSummary.where(target: topic).destroy_all
end
def use_cached?(skip_age_check)
can_summarize = Guardian.new(user).can_request_summary?
existing_summary &&
!(
can_summarize && new_targets? &&
(skip_age_check || existing_summary.created_at < 1.hour.ago)
)
end
def new_targets?
existing_summary&.original_content_sha != summary_sha
end
def cache_summary(result)
post_numbers = summary_targets_data.map(&:first)
cached_summary =
AiSummary.create!(
target: topic,
algorithm: strategy.display_name,
content_range: (post_numbers.first..post_numbers.last),
summarized_text: result[:summary],
original_content_sha: summary_sha,
)
cached_summary
end
def build_sha(ids)
Digest::SHA256.hexdigest(ids.join)
end
end
end