[AI-3] Register AI features and resolve their models at runtime

app/components/llm_connections/default_models_component.rb

@@ -29,7 +29,7 @@
 #++
 
 module LlmConnections
-  # The "Default models" section of the LLMs page.
+  # The "Default models" section of the LLMs tab.
   class DefaultModelsComponent < ApplicationComponent
     include ApplicationHelper
     include OpPrimer::ComponentHelpers

app/components/llm_connections/delete_model_dialog_component.rb

@@ -41,11 +41,17 @@ def form_arguments
       { action: url_helpers.llm_model_path(llm_model), method: :delete }
     end
 
-    # Named so the message says what is actually at stake. The connection
-    # defaults count as bindings here -- deleting their model breaks every
-    # feature that inherits them.
+    # Named so the message says what is actually at stake: features bound to this
+    # model stop resolving, rather than silently falling back to another one.
+    # The connection defaults count as bindings here -- deleting their model
+    # breaks every feature that inherits them.
     def bound_features
-      affected_defaults
+      bindings = llm_model.llm_connection
+                          .feature_bindings
+                          .where(model_id: llm_model.external_id)
+                          .filter_map { |binding| binding.feature&.label }
+
+      bindings + affected_defaults
     end
 
     def affected_defaults

app/components/llm_connections/disconnect_dialog_component.html.erb

@@ -21,7 +21,13 @@
             safe_join(
               [
                 content_tag(:li, t("admin.llm_connections.disconnect.keeps_settings")),
-                content_tag(:li, t("admin.llm_connections.disconnect.keeps_models"))
+                content_tag(:li, t("admin.llm_connections.disconnect.keeps_models")),
+                if bound_features.any?
+                  content_tag(
+                    :li,
+                    t("admin.llm_connections.disconnect.keeps_bindings", features: bound_features.to_sentence)
+                  )
+                end
               ].compact
             )
           end

app/components/llm_connections/disconnect_dialog_component.rb

@@ -46,5 +46,9 @@ class DisconnectDialogComponent < ApplicationComponent
     def form_arguments
       { action: url_helpers.disconnect_llm_connection_path, method: :post }
     end
+
+    def bound_features
+      connection.feature_bindings.filter_map { |binding| binding.feature&.label if binding.model_id.present? }
+    end
   end
 end

app/components/llm_connections/feature_binding_component.html.erb

@@ -0,0 +1,53 @@
+<%= render(Primer::Box.new(border: true, border_radius: 2, p: 3, mb: 3)) do %>
+  <%= render(Primer::Beta::Text.new(tag: :h3, font_size: 4, font_weight: :bold, mb: 1)) { feature.label } %>
+
+  <% if feature.caption.present? %>
+    <%= render(Primer::Beta::Text.new(tag: :p, color: :muted, mb: 2)) { feature.caption } %>
+  <% end %>
+
+  <% if dangling? %>
+    <%= render(Primer::Alpha::Banner.new(scheme: :warning, mb: 2, icon: :alert)) do %>
+      <%= t("admin.llm_feature_bindings.dangling", model: binding.resolved_model_id) %>
+    <% end %>
+  <% end %>
+
+  <% if deactivated? %>
+    <%= render(Primer::Alpha::Banner.new(scheme: :warning, mb: 2, icon: :alert)) do %>
+      <%= t("admin.llm_feature_bindings.deactivated", model: binding.resolved_model_id) %>
+    <% end %>
+  <% end %>
+
+  <% if locked? %>
+    <%= render(Primer::Alpha::Banner.new(scheme: :warning, mb: 2, icon: :lock)) do %>
+      <%= t("admin.llm_feature_bindings.locked", model: binding.model_id) %>
+    <% end %>
+  <% end %>
+
+  <%= primer_form_with(model: form_model, url: form_url, method: :patch, scope: :llm_feature_binding) do |f| %>
+    <%= render(
+          LlmConnections::FeatureBindingForm.new(
+            f,
+            options: model_options,
+            inherit_label:,
+            feature_key: feature.key,
+            locked: locked?,
+            embedding: feature.embedding?,
+            selected_model_id: binding&.model_id,
+            dimensions_hint: probed_dimensions
+          )
+        ) %>
+  <% end %>
+
+  <% if locked? && feature.embedding? %>
+    <%# Rendered as text rather than disabled inputs: a disabled input submits
+        nothing, so the values would arrive blank and wipe the columns. %>
+    <%= render(Primer::Beta::Text.new(tag: :p, font_weight: :bold, mt: 2, mb: 1)) do %>
+      <%= t("admin.llm_feature_bindings.locked_values_heading") %>
+    <% end %>
+    <% locked_values.each do |label, value| %>
+      <%= render(Primer::Beta::Text.new(tag: :p, color: :muted, mb: 0)) do %>
+        <%= "#{label}: #{value}" %>
+      <% end %>
+    <% end %>
+  <% end %>
+<% end %>

app/components/llm_connections/feature_binding_component.rb

@@ -0,0 +1,107 @@
+# 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
+  # One feature's row on the model assignment page.
+  class FeatureBindingComponent < ApplicationComponent
+    include ApplicationHelper
+    include OpPrimer::ComponentHelpers
+
+    def initialize(feature:, connection:, binding: nil)
+      super(feature)
+      @feature = feature
+      @connection = connection
+      @binding = binding
+    end
+
+    # The record the select binds to. A feature without a stored binding still
+    # needs one so the form has a model_id to read.
+    def form_model
+      binding || connection.feature_bindings.new(feature_key: feature.key.to_s)
+    end
+
+    # Not named +options+: ApplicationComponent already owns that name and
+    # initialises it to an empty hash, which silently swallowed the memoisation.
+    def model_options
+      @model_options ||= SelectableModelsQuery.new(connection, feature).call
+    end
+
+    def inherit_label
+      if default_model_id.present?
+        I18n.t("admin.llm_feature_bindings.inherit_with_default", model: default_model_id)
+      else
+        I18n.t("admin.llm_feature_bindings.inherit_without_default")
+      end
+    end
+
+    def locked? = binding&.locked?
+
+    def dangling? = binding&.dangling?
+
+    # What the embeddings probe last saw, offered as information. Never filled
+    # into the field: the server decides the vector size at index time.
+    def probed_dimensions
+      return unless feature.embedding?
+
+      model_id = binding&.resolved_model_id
+      return if model_id.blank?
+
+      connection.capability_verdicts.for_model(model_id).for_capability(:embeddings).first&.dimensions
+    end
+
+    def locked_values
+      [
+        [LlmFeatureBinding.human_attribute_name(:model_id), binding.model_id],
+        [LlmFeatureBinding.human_attribute_name(:dimensions), binding.dimensions || "—"]
+      ]
+    end
+
+    # Still resolvable, so not dangling -- but an administrator has hidden it
+    # from the pickers, so say so rather than let the choice look unremarkable.
+    def deactivated?
+      model_id = binding&.resolved_model_id
+      return false if model_id.blank?
+
+      connection.models.deactivated.exists?(external_id: model_id)
+    end
+
+    private
+
+    attr_reader :feature, :connection, :binding
+
+    def default_model_id
+      feature.embedding? ? connection.default_embedding_model_id : connection.default_chat_model_id
+    end
+
+    def form_url
+      url_helpers.llm_feature_binding_path(feature.key)
+    end
+  end
+end

app/contracts/llm_connections/base_contract.rb

@@ -54,6 +54,7 @@ class BaseContract < ModelContract
     validate :features_require_connection
     validate :default_models_offered_by_server
     validate :default_chat_model_can_chat
+    validate :default_embedding_model_can_embed
     validate :not_configured_from_env
 
     def not_configured_from_env
@@ -64,13 +65,25 @@ def not_configured_from_env
 
     private
 
+    # Only a model the server has ruled out is refused. "We could not tell" is the
+    # normal state on a self-hosted server, and an environment-provisioned default
+    # would otherwise fail on a catalogue row nothing has probed yet. The picker
+    # still offers confirmed models only.
+    def default_embedding_model_can_embed
+      llm_model = model.default_embedding_model
+      return if llm_model.blank?
+      return unless model.changed_attributes.include?("default_embedding_model_id")
+
+      errors.add(:default_embedding_model_id, :cannot_embed) if llm_model.verdict_for(:embeddings)&.blocking?
+    end
+
     # A model the server identifies as an embedding model is not a chat candidate.
     def default_chat_model_can_chat
       llm_model = model.default_chat_model
       return if llm_model.blank?
       return unless model.changed_attributes.include?("default_chat_model_id")
 
-      errors.add(:default_chat_model_id, :cannot_chat) if model.default_chat_model&.embedding?
+      errors.add(:default_chat_model_id, :cannot_chat) if llm_model.embedding?
     end
 
     def features_require_connection

app/controllers/admin/llm_feature_bindings_controller.rb

@@ -0,0 +1,130 @@
+# 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
+  # Assigns a model to each registered AI feature.
+  class LlmFeatureBindingsController < ApplicationController
+    layout "admin"
+    menu_item :llm_connection
+
+    before_action :require_feature
+    before_action :require_admin
+    before_action :set_connection
+    before_action :require_enabled_connection
+
+    def index
+      @features = OpenProject::Llm::Features.available
+      @bindings = bindings_by_feature_key
+    end
+
+    def update
+      feature = OpenProject::Llm::Features[params[:id]]
+      assign(feature)
+
+      redirect_to llm_feature_bindings_path, status: :see_other
+    rescue OpenProject::Llm::UnknownFeature
+      render_404
+    end
+
+    private
+
+    def set_connection
+      @connection = LlmConnection.active_connection
+    end
+
+    def require_enabled_connection
+      return if Setting.llm_features_enabled? && @connection.configured?
+
+      flash[:notice] = t("admin.llm_connections.disabled_notice")
+      redirect_to llm_connection_path, status: :see_other
+    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 bindings_by_feature_key
+      @connection.feature_bindings.index_by(&:feature_key)
+    end
+
+    def binding_for(feature)
+      @connection.feature_bindings.find_or_initialize_by(feature_key: feature.key.to_s)
+    end
+
+    def assign(feature)
+      binding = build_binding(feature)
+
+      unless binding.save
+        flash[:error] = binding.errors.full_messages.join(", ")
+        return
+      end
+
+      confirm_assignment(feature, probe_capabilities(feature, binding))
+    end
+
+    # The probe may just have proven the chosen model cannot do what the feature
+    # requires; confirming that save would report a working configuration that
+    # Llm::Runtime immediately resolves as incapable.
+    def confirm_assignment(feature, verdict)
+      if verdict&.blocking?
+        flash[:error] = t("admin.llm_feature_bindings.update.model_incapable",
+                          feature: feature.label,
+                          capability: Llm::Capabilities.label(:embeddings))
+      else
+        flash[:notice] = t("admin.llm_feature_bindings.update.success", feature: feature.label)
+      end
+    end
+
+    def build_binding(feature)
+      binding = binding_for(feature)
+      binding.model_id = params.dig(:llm_feature_binding, :model_id).presence
+
+      # Only ever accepted for the kind of feature it describes; the model
+      # rejects it elsewhere, and it is not read at all for a chat feature.
+      assign_embedding_settings(binding) if feature.embedding?
+
+      binding
+    end
+
+    def assign_embedding_settings(binding)
+      binding.dimensions = params.dig(:llm_feature_binding, :dimensions).presence
+    end
+
+    # The verdict that actually matters is the one for the model an administrator
+    # just chose, so it is fetched now rather than left unknown until first use.
+    def probe_capabilities(feature, binding)
+      return if feature.requires.empty? || binding.model_id.blank?
+
+      LlmConnections::DetectCapabilitiesService.new(@connection).detect(binding.model_id).result
+    end
+  end
+end

app/controllers/admin/llm_models_controller.rb

@@ -155,7 +155,7 @@ def toggle
     private
 
     def default_model_params
-      params.expect(llm_connection: %i[default_chat_model_id]).to_h.symbolize_keys
+      params.expect(llm_connection: %i[default_chat_model_id default_embedding_model_id]).to_h.symbolize_keys
     end
 
     def set_connection