discourse/app/models/topic_link.rb

307 lines
10 KiB
Ruby

require 'uri'
require_dependency 'slug'
require_dependency 'discourse'
class TopicLink < ActiveRecord::Base
def self.max_domain_length
100
end
def self.max_url_length
500
end
belongs_to :topic
belongs_to :user
belongs_to :post
belongs_to :link_topic, class_name: 'Topic'
belongs_to :link_post, class_name: 'Post'
validates_presence_of :url
validates_length_of :url, maximum: 500
validates_uniqueness_of :url, scope: [:topic_id, :post_id]
has_many :topic_link_clicks, dependent: :destroy
validate :link_to_self
after_commit :crawl_link_title
# Make sure a topic can't link to itself
def link_to_self
errors.add(:base, "can't link to the same topic") if (topic_id == link_topic_id)
end
def self.topic_map(guardian, topic_id)
# Sam: complicated reports are really hard in AR
builder = SqlBuilder.new <<-SQL
SELECT ftl.url,
COALESCE(ft.title, ftl.title) AS title,
ftl.link_topic_id,
ftl.reflection,
ftl.internal,
ftl.domain,
MIN(ftl.user_id) AS user_id,
SUM(clicks) AS clicks
FROM topic_links AS ftl
LEFT JOIN topics AS ft ON ftl.link_topic_id = ft.id
LEFT JOIN categories AS c ON c.id = ft.category_id
/*where*/
GROUP BY ftl.url, ft.title, ftl.title, ftl.link_topic_id, ftl.reflection, ftl.internal, ftl.domain
ORDER BY clicks DESC, count(*) DESC
LIMIT 50
SQL
builder.where('ftl.topic_id = :topic_id', topic_id: topic_id)
builder.where('ft.deleted_at IS NULL')
# note that ILIKE means "case insensitive LIKE"
builder.where("NOT(ftl.url ILIKE '%.png' OR ftl.url ILIKE '%.jpg' OR ftl.url ILIKE '%.gif')")
builder.where("COALESCE(ft.archetype, 'regular') <> :archetype", archetype: Archetype.private_message)
builder.secure_category(guardian.secure_category_ids)
builder.exec.to_a
end
def self.counts_for(guardian, topic, posts)
return {} if posts.blank?
# Sam: I don't know how to write this cleanly in AR,
# in particular the securing logic is tricky and would fallback to SQL anyway
builder = SqlBuilder.new("SELECT
l.post_id,
l.url,
l.clicks,
COALESCE(t.title, l.title) AS title,
l.internal,
l.reflection,
l.domain
FROM topic_links l
LEFT JOIN topics t ON t.id = l.link_topic_id
LEFT JOIN categories AS c ON c.id = t.category_id
/*where*/
ORDER BY reflection ASC, clicks DESC")
builder.where('t.deleted_at IS NULL')
builder.where("COALESCE(t.archetype, 'regular') <> :archetype", archetype: Archetype.private_message)
# not certain if pluck is right, cause it may interfere with caching
builder.where('l.post_id IN (:post_ids)', post_ids: posts.map(&:id))
builder.secure_category(guardian.secure_category_ids)
builder.map_exec(OpenStruct).each_with_object({}) do |l, result|
result[l.post_id] ||= []
result[l.post_id] << { url: l.url,
clicks: l.clicks,
title: l.title,
internal: l.internal,
reflection: l.reflection }
end
end
def self.extract_from(post)
return if post.blank? || post.whisper?
added_urls = []
TopicLink.transaction do
added_urls = []
reflected_ids = []
PrettyText
.extract_links(post.cooked)
.map do |u|
uri = begin
URI.parse(u.url)
rescue URI::Error
end
[u, uri]
end
.reject { |_, p| p.nil? || "mailto".freeze == p.scheme }
.uniq { |_, p| p }
.each do |link, parsed|
begin
url = link.url
internal = false
topic_id = nil
post_number = nil
if Discourse.store.has_been_uploaded?(url)
internal = Discourse.store.internal?
elsif route = Discourse.route_for(parsed)
internal = true
# We aren't interested in tracking internal links to users
next if route[:controller] == 'users'
topic_id = route[:topic_id].to_i
post_number = route[:post_number] || 1
# Store the canonical URL
topic = Topic.find_by(id: topic_id)
topic_id = nil unless topic
if topic.present?
url = "#{Discourse.base_url_no_prefix}#{topic.relative_url}"
url << "/#{post_number}" if post_number.to_i > 1
end
end
# Skip linking to ourselves
next if topic_id == post.topic_id
reflected_post = nil
if post_number && topic_id
reflected_post = Post.find_by(topic_id: topic_id, post_number: post_number.to_i)
end
url = url[0...TopicLink.max_url_length]
next if parsed && parsed.host && parsed.host.length > TopicLink.max_domain_length
added_urls << url
unless TopicLink.exists?(topic_id: post.topic_id, post_id: post.id, url: url)
file_extension = File.extname(parsed.path)[1..10].downcase unless parsed.path.nil? || File.extname(parsed.path).empty?
begin
TopicLink.create!(post_id: post.id,
user_id: post.user_id,
topic_id: post.topic_id,
url: url,
domain: parsed.host || Discourse.current_hostname,
internal: internal,
link_topic_id: topic_id,
link_post_id: reflected_post.try(:id),
quote: link.is_quote,
extension: file_extension)
rescue ActiveRecord::RecordNotUnique, PG::UniqueViolation
# it's fine
end
end
# Create the reflection if we can
if topic_id.present?
topic = Topic.find_by(id: topic_id)
if topic && post.topic && topic.archetype != 'private_message' && post.topic.archetype != 'private_message' && post.topic.visible?
prefix = Discourse.base_url_no_prefix
reflected_url = "#{prefix}#{post.topic.relative_url(post.post_number)}"
tl = TopicLink.find_by(topic_id: topic_id,
post_id: reflected_post.try(:id),
url: reflected_url)
unless tl
tl = TopicLink.create(user_id: post.user_id,
topic_id: topic_id,
post_id: reflected_post.try(:id),
url: reflected_url,
domain: Discourse.current_hostname,
reflection: true,
internal: true,
link_topic_id: post.topic_id,
link_post_id: post.id)
end
reflected_ids << tl.id if tl.persisted?
end
end
rescue URI::InvalidURIError
# if the URI is invalid, don't store it.
rescue ActionController::RoutingError
# If we can't find the route, no big deal
end
end
# Remove links that aren't there anymore
if added_urls.present?
TopicLink.where(
"(url not in (:urls)) AND (post_id = :post_id AND NOT reflection)",
urls: added_urls, post_id: post.id
).delete_all
reflected_ids.compact!
if reflected_ids.present?
TopicLink.where(
"(id not in (:reflected_ids)) AND (link_post_id = :post_id AND reflection)",
reflected_ids: reflected_ids, post_id: post.id
).delete_all
else
TopicLink
.where("link_post_id = :post_id AND reflection", post_id: post.id)
.delete_all
end
else
TopicLink
.where(
"(post_id = :post_id AND NOT reflection) OR (link_post_id = :post_id AND reflection)",
post_id: post.id
)
.delete_all
end
end
end
# Crawl a link's title after it's saved
def crawl_link_title
Jobs.enqueue(:crawl_topic_link, topic_link_id: id)
end
def self.duplicate_lookup(topic)
results = TopicLink
.includes(:post, :user)
.joins(:post, :user)
.where("posts.id IS NOT NULL AND users.id IS NOT NULL")
.where(topic_id: topic.id, reflection: false)
.last(200)
lookup = {}
results.each do |tl|
normalized = tl.url.downcase.sub(/^https?:\/\//, '').sub(/\/$/, '')
lookup[normalized] = { domain: tl.domain,
username: tl.user.username_lower,
posted_at: tl.post.created_at,
post_number: tl.post.post_number }
end
lookup
end
end
# == Schema Information
#
# Table name: topic_links
#
# id :integer not null, primary key
# topic_id :integer not null
# post_id :integer
# user_id :integer not null
# url :string(500) not null
# domain :string(100) not null
# internal :boolean default(FALSE), not null
# link_topic_id :integer
# created_at :datetime not null
# updated_at :datetime not null
# reflection :boolean default(FALSE)
# clicks :integer default(0), not null
# link_post_id :integer
# title :string
# crawled_at :datetime
# quote :boolean default(FALSE), not null
# extension :string(10)
#
# Indexes
#
# index_topic_links_on_extension (extension)
# index_topic_links_on_link_post_id_and_reflection (link_post_id,reflection)
# index_topic_links_on_post_id (post_id)
# index_topic_links_on_topic_id (topic_id)
# unique_post_links (topic_id,post_id,url) UNIQUE
#