1 files changed, 122 insertions, 0 deletions
diff --git a/lib/bitbucket_server/connection.rb b/lib/bitbucket_server/connection.rb
new file mode 100644
index 00000000000..45a437844bd
--- /dev/null
+++ b/lib/bitbucket_server/connection.rb
@@ -0,0 +1,122 @@
+# frozen_string_literal: true
+
+module BitbucketServer
+  class Connection
+    include ActionView::Helpers::SanitizeHelper
+
+    DEFAULT_API_VERSION = '1.0'
+    SEPARATOR = '/'
+
+    attr_reader :api_version, :base_uri, :username, :token
+
+    ConnectionError = Class.new(StandardError)
+
+    def initialize(options = {})
+      @api_version = options.fetch(:api_version, DEFAULT_API_VERSION)
+      @base_uri = options[:base_uri]
+      @username = options[:user]
+      @token = options[:password]
+    end
+
+    def get(path, extra_query = {})
+      response = Gitlab::HTTP.get(build_url(path),
+                                  basic_auth: auth,
+                                  headers: accept_headers,
+                                  query: extra_query)
+
+      check_errors!(response)
+
+      response.parsed_response
+    end
+
+    def post(path, body)
+      response = Gitlab::HTTP.post(build_url(path),
+                                   basic_auth: auth,
+                                   headers: post_headers,
+                                   body: body)
+
+      check_errors!(response)
+
+      response.parsed_response
+    end
+
+    # We need to support two different APIs for deletion:
+    #
+    # /rest/api/1.0/projects/{projectKey}/repos/{repositorySlug}/branches/default
+    # /rest/branch-utils/1.0/projects/{projectKey}/repos/{repositorySlug}/branches
+    def delete(resource, path, body)
+      url = delete_url(resource, path)
+
+      response = Gitlab::HTTP.delete(url,
+                                     basic_auth: auth,
+                                     headers: post_headers,
+                                     body: body)
+
+      check_errors!(response)
+
+      response.parsed_response
+    end
+
+    private
+
+    def check_errors!(response)
+      raise ConnectionError, "Response is not valid JSON" unless response.parsed_response.is_a?(Hash)
+
+      return if response.code >= 200 && response.code < 300
+
+      details = sanitize(response.parsed_response.dig('errors', 0, 'message'))
+      message = "Error #{response.code}"
+      message += ": #{details}" if details
+
+      raise ConnectionError, message
+    rescue JSON::ParserError
+      raise ConnectionError, "Unable to parse the server response as JSON"
+    end
+
+    def auth
+      @auth ||= { username: username, password: token }
+    end
+
+    def accept_headers
+      @accept_headers ||= { 'Accept' => 'application/json' }
+    end
+
+    def post_headers
+      @post_headers ||= accept_headers.merge({ 'Content-Type' => 'application/json' })
+    end
+
+    def build_url(path)
+      return path if path.starts_with?(root_url)
+
+      url_join_paths(root_url, path)
+    end
+
+    def root_url
+      url_join_paths(base_uri, "/rest/api/#{api_version}")
+    end
+
+    def delete_url(resource, path)
+      if resource == :branches
+        url_join_paths(base_uri, "/rest/branch-utils/#{api_version}#{path}")
+      else
+        build_url(path)
+      end
+    end
+
+    # URI.join is stupid in that slashes are important:
+    #
+    # # URI.join('http://example.com/subpath', 'hello')
+    # => http://example.com/hello
+    #
+    # We really want http://example.com/subpath/hello
+    #
+    def url_join_paths(*paths)
+      paths.map { |path| strip_slashes(path) }.join(SEPARATOR)
+    end
+
+    def strip_slashes(path)
+      path = path[1..-1] if path.starts_with?(SEPARATOR)
+      path.chomp(SEPARATOR)
+    end
+  end
+end