ai tags: add autotagger API client.

Add API client for https://github.com/danbooru/autotagger service.

app/controllers/mock_services_controller.rb

@@ -38,6 +38,14 @@ class MockServicesController < ApplicationController
     render json: @data
   end
 
+  def autotagger_evaluate
+    limit = params.fetch(:limit, 50)
+    predictions = tags(limit).pluck(:name).map { |name| [name, rand(0.0..1.0)] }.to_h
+    data = { filename: "test.jpg", tags: predictions }
+
+    render json: data
+  end
+
   private
 
   def posts(limit = 10)

app/logical/autotagger_client.rb

@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+# API client for the Danbooru Autotagger service. Used for the AI tagging feature.
+#
+# @see https://autotagger.donmai.us
+# @see https://github.com/danbooru/autotagger
+class AutotaggerClient
+  attr_reader :autotagger_url, :http
+
+  def initialize(autotagger_url: Danbooru.config.autotagger_url.to_s, http: Danbooru::Http.new)
+    @autotagger_url = autotagger_url.chomp("/")
+    @http = http
+  end
+
+  def evaluate(file, limit: 50, confidence: 0.01)
+    return {} if autotagger_url.blank?
+
+    response = http.post("#{autotagger_url}/evaluate", form: { file: HTTP::FormData::File.new(file), threshold: confidence, format: "json" })
+    return {} if !response.status.success?
+
+    tag_names_with_scores = response.parse.first["tags"]
+    tags = Tag.where(name: tag_names_with_scores.keys).index_by(&:name)
+    tag_names_with_scores.transform_keys(&tags)
+  end
+end

config/danbooru_default_config.rb

@@ -542,6 +542,16 @@ module Danbooru
       # "http://localhost:3000/mock/iqdb"
     end
 
+    # The URL for the Danbooru Autotagger service (https://github.com/danbooru/autotagger). Optional.
+    #
+    # Used for the AI tagging feature. Set this to http://localhost:3000/mock/autotagger
+    # to enable a fake server for development purposes, or do
+    # `docker run --rm -p 5000:5000 ghcr.io/danbooru/autotagger` to run a real server.
+    def autotagger_url
+      # "http://localhost:3000/mock/autotagger"
+      # "http://localhost:5000"
+    end
+
     def aws_credentials
       Aws::Credentials.new(Danbooru.config.aws_access_key_id, Danbooru.config.aws_secret_access_key)
     end

config/routes.rb

@@ -365,6 +365,7 @@ Rails.application.routes.draw do
   get "/mock/reportbooru/post_views/rank" => "mock_services#reportbooru_post_views", as: "mock_reportbooru_post_views"
   get "/mock/iqdb/query" => "mock_services#iqdb_query", as: "mock_iqdb_query"
   post "/mock/iqdb/query" => "mock_services#iqdb_query"
+  get "/mock/autotagger/evaluate" => "mock_services#autotagger_evaluate", as: "mock_autotagger_evaluate"
 
   match "*other", to: "static#not_found", via: :all
 end