[AI-3] Add the LLM connection administration page

app/components/llm_connections/form_component.html.erb

@@ -0,0 +1,26 @@
+<%=
+  component_wrapper(tag: "turbo-frame", **wrapper_options) do
+    concat(
+      settings_primer_form_with(**form_options) do |f|
+        render(LlmConnections::ConnectionForm.new(f))
+      end
+    )
+
+    concat(
+      render(
+        Primer::Beta::Text.new(
+          tag: :div,
+          mt: 3,
+          hidden: true,
+          display: :flex,
+          align_items: :center,
+          color: :muted,
+          data: { "admin--llm-connection-form-target": "progressBanner" }
+        )
+      ) do
+        concat(render(Primer::Beta::Spinner.new(size: :small, mr: 2)))
+        concat(t("admin.llm_connections.form.label_connecting"))
+      end
+    )
+  end
+%>

app/components/llm_connections/form_component.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 LlmConnections
+  class FormComponent < ApplicationComponent
+    include ApplicationHelper
+    include OpPrimer::ComponentHelpers
+    include OpTurbo::Streamable
+
+    def self.wrapper_key = :llm_connection_form
+
+    alias_method :connection, :model
+
+    private
+
+    def wrapper_options
+      {
+        data: {
+          controller: "admin--llm-connection-form",
+          test_selector: "llm-connection--form"
+        }
+      }
+    end
+
+    def form_options
+      {
+        model: connection,
+        url: llm_connection_path,
+        method: :patch
+      }
+    end
+  end
+end

app/contracts/llm_connections/base_contract.rb

@@ -0,0 +1,65 @@
+# 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 LlmConnections
+  # Validations that hold for every write, including provisioning from the
+  # environment. Deliberately makes no network request -- see UpdateContract.
+  class BaseContract < ModelContract
+    attribute :enabled
+    attribute :api_format
+    attribute :base_url
+    attribute :api_key
+    attribute :default_chat_model_id
+    attribute :default_embedding_model_id
+
+    validates :base_url, presence: true
+    validates :api_format, inclusion: { in: Llm::Adapters::FORMATS }
+    # Bedrock and Vertex AI can be discovered against, but not called: they need
+    # a secret key and region, or a project and location, and there is one
+    # api_key column. Offering them would only fail at request time.
+    validates :api_format, exclusion: { in: Llm::Session::UNSUPPORTED_FORMATS, message: :not_supported },
+                           unless: -> { api_format.blank? }
+    # Resolves to the validate_url gem, which defaults to http and https. Plain
+    # http is deliberately allowed: an on-premise LLM server on an internal
+    # network commonly terminates TLS elsewhere, or not at all.
+    validates :base_url, url: { message: :invalid_url }, unless: -> { base_url.blank? }
+
+    validate :enabled_requires_connection
+
+    private
+
+    def enabled_requires_connection
+      return unless model.enabled?
+      return if model.base_url.present?
+
+      errors.add :enabled, :requires_connection
+    end
+  end
+end

app/contracts/llm_connections/update_contract.rb

@@ -0,0 +1,45 @@
+# 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 LlmConnections
+  # The contract used when an administrator saves the form.
+  #
+  # This is the only contract that talks to the remote server, so that a failed
+  # probe persists nothing. It must NOT move to BaseContract: provisioning from
+  # the environment reuses that base, and a validates line cannot be un-declared
+  # by a subclass -- an outbound request during seeding would fail the boot of a
+  # container whose LLM server has not started yet.
+  #
+  # The probe itself is guarded on changed attributes, so toggling +enabled+ or
+  # picking a default model contacts nothing.
+  class UpdateContract < BaseContract
+    validates :base_url, llm_server: true, unless: -> { errors.include?(:base_url) }
+  end
+end

app/controllers/admin/llm_connections_controller.rb

@@ -0,0 +1,102 @@
+# 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 Admin
+  class LlmConnectionsController < ApplicationController
+    include OpTurbo::ComponentStream
+    include PaginationHelper
+
+    layout "admin"
+    menu_item :llm_connection
+
+    before_action :require_feature
+    before_action :require_admin
+    before_action :set_connection
+
+    def show; end
+
+    def update
+      result = ::LlmConnections::UpdateService
+                 .new(user: current_user, model: @connection)
+                 .call(**llm_connection_params)
+
+      result.on_success { redirect_after_save }
+      result.on_failure { render_form_with_errors }
+    end
+
+    private
+
+    def set_connection
+      @connection = LlmConnection.instance
+    end
+
+    # The flag gates the endpoints, not only the menu entry: an unfinished page
+    # must not accept writes just because somebody knows the URL.
+    def require_feature
+      render_404 unless OpenProject::FeatureDecisions.llm_connection_active?
+    end
+
+    def redirect_after_save
+      redirect_with_notice(t(".success"))
+    end
+
+    def render_form_with_errors
+      update_via_turbo_stream(component: ::LlmConnections::FormComponent.new(@connection))
+      # The HTML fallback re-renders the whole page, which needs everything the
+      # show action assigns -- not just the form that failed.
+      respond_with_turbo_streams do |format|
+        format.html do
+          show
+          render :show
+        end
+      end
+    end
+
+    def redirect_with_notice(message)
+      flash[:notice] = message
+      redirect_to llm_connection_path, status: :see_other
+    end
+
+    def redirect_with_error(message)
+      flash[:error] = message
+      redirect_to llm_connection_path, status: :see_other
+    end
+
+    # A blank API key means "keep the stored one": the form never renders the
+    # saved value, so submitting it unchanged posts an empty string.
+    def llm_connection_params
+      permitted = params.expect(
+        llm_connection: %i[enabled api_format base_url api_key]
+      )
+      permitted.delete(:api_key) if permitted[:api_key].blank?
+      permitted.to_h.symbolize_keys
+    end
+  end
+end