Add OpenProject Gitea integration plugin

Implements a Gitea integration for OpenProject following the same
patterns as the bundled GitHub and GitLab integrations.

- Webhook endpoint at /webhooks/gitea with HMAC-SHA256 verification
- Handles pull_request and issue_comment events
- Links Gitea PRs to work packages via OP# references or URLs
- Posts journal comments on WPs for PR lifecycle events
- Gitea tab on the work package split view
- V3 API endpoint: GET /api/v3/work_packages/:id/gitea_pull_requests
- Admin settings UI for bot user and webhook secret
- Nightly cron job to clean up unlinked PR records

lib/open_project/gitea_integration/services/params_helper.rb

@@ -0,0 +1,50 @@
+# frozen_string_literal: true
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See COPYRIGHT and LICENSE files for more details.
+#++
+
+module OpenProject
+  module GiteaIntegration
+    module Services
+      module ParamsHelper
+        private
+
+        EMPTY_AVATAR_URL = "https://www.gravatar.com/avatar/?d=mp"
+        EMPTY_DESCRIPTION = "No description provided"
+
+        def avatar_url(raw_url)
+          raw_url.presence || EMPTY_AVATAR_URL
+        end
+
+        def description(raw_description)
+          raw_description.presence || EMPTY_DESCRIPTION
+        end
+      end
+    end
+  end
+end

lib/open_project/gitea_integration/services/upsert_gitea_user.rb

@@ -0,0 +1,60 @@
+# frozen_string_literal: true
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See COPYRIGHT and LICENSE files for more details.
+#++
+
+module OpenProject
+  module GiteaIntegration
+    module Services
+      ##
+      # Takes user data from a Gitea webhook payload and stores it as a GiteaUser.
+      # If the GiteaUser already exists, it is updated.
+      class UpsertGiteaUser
+        include ParamsHelper
+
+        def call(payload)
+          GiteaUser.find_or_initialize_by(gitea_id: payload.id)
+                   .tap do |gitea_user|
+                     gitea_user.update!(extract_params(payload))
+                   end
+        end
+
+        private
+
+        def extract_params(payload)
+          {
+            gitea_id: payload.id,
+            gitea_name: payload.full_name.presence || payload.login,
+            gitea_login: payload.login,
+            gitea_avatar_url: avatar_url(payload.avatar_url)
+          }
+        end
+      end
+    end
+  end
+end

lib/open_project/gitea_integration/services/upsert_pull_request.rb

@@ -0,0 +1,93 @@
+# frozen_string_literal: true
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See COPYRIGHT and LICENSE files for more details.
+#++
+
+module OpenProject
+  module GiteaIntegration
+    module Services
+      class UpsertPullRequest
+        include ParamsHelper
+
+        def call(payload, work_packages: [])
+          find_or_initialize(payload).tap do |pr|
+            pr.update!(work_packages: pr.work_packages | work_packages, **extract_params(payload))
+          end
+        end
+
+        private
+
+        def find_or_initialize(payload)
+          GiteaPullRequest.find_by_gitea_identifiers(
+            id: payload.pull_request.number,
+            url: payload.pull_request.html_url,
+            initialize: true
+          )
+        end
+
+        # rubocop:disable Metrics/AbcSize
+        def extract_params(payload)
+          merged = payload.pull_request.merged?
+          {
+            gitea_id: payload.pull_request.number,
+            gitea_user: gitea_user_record(payload.pull_request.user),
+            number: payload.pull_request.number,
+            gitea_html_url: payload.pull_request.html_url,
+            gitea_updated_at: payload.pull_request.updated_at,
+            state: pr_state(payload),
+            title: payload.pull_request.title,
+            body: description(payload.pull_request.body),
+            repository: payload.repository.full_name,
+            draft: payload.pull_request.draft?,
+            merged:,
+            merged_by: merged ? gitea_user_record(payload.pull_request.merged_by?) : nil,
+            merged_at: merged ? payload.pull_request.merged_at? : nil,
+            labels: Array(payload.pull_request.labels?).map { |l| extract_label(l) }
+          }
+        end
+        # rubocop:enable Metrics/AbcSize
+
+        def pr_state(payload)
+          return "merged" if payload.pull_request.merged?
+
+          payload.pull_request.state
+        end
+
+        def extract_label(label)
+          { "name" => label["name"], "color" => "##{label["color"]}" }
+        end
+
+        def gitea_user_record(payload)
+          return if payload.blank?
+
+          ::OpenProject::GiteaIntegration::Services::UpsertGiteaUser.new.call(payload)
+        end
+      end
+    end
+  end
+end