Add Danbooru::Http client.

This is a wrapper around the http.rb gem that provides caching.

app/logical/danbooru/http.rb

@@ -0,0 +1,62 @@
+module Danbooru
+  class Http
+    attr_accessor :cache, :http
+
+    class << self
+      delegate :get, :post, :cache, :auth, :basic_auth, :headers, to: :new
+    end
+
+    def get(url, **options)
+      request(:get, url, **options)
+    end
+
+    def post(url, **options)
+      request(:post, url, **options)
+    end
+
+    def cache(expiry)
+      dup.tap { |o| o.cache = expiry.to_i }
+    end
+
+    def auth(*args)
+      dup.tap { |o| o.http = o.http.auth(*args) }
+    end
+
+    def basic_auth(*args)
+      dup.tap { |o| o.http = o.http.basic_auth(*args) }
+    end
+
+    def headers(*args)
+      dup.tap { |o| o.http = o.http.headers(*args) }
+    end
+
+    protected
+
+    def request(method, url, **options)
+      if @cache.present?
+        cached_request(method, url, **options)
+      else
+        raw_request(method, url, **options)
+      end
+    end
+
+    def cached_request(method, url, **options)
+      key = Cache.hash({ method: method, url: url, **options }.to_json)
+
+      cached_response = Cache.get(key, @cache) do
+        response = raw_request(method, url, **options)
+        { status: response.status, body: response.to_s, headers: response.headers.to_h, version: "1.1" }
+      end
+
+      ::HTTP::Response.new(**cached_response)
+    end
+
+    def raw_request(method, url, **options)
+      http.send(method, url, **options)
+    end
+
+    def http
+      @http ||= ::HTTP.use(:auto_inflate).headers(Danbooru.config.http_headers).headers("Accept-Encoding" => "gzip")
+    end
+  end
+end