chore: next god module down (AI)

Co-authored-by: Copilot <copilot@github.com>

lib/bds/ai/runtime.ex

@@ -0,0 +1,100 @@
+defmodule BDS.AI.Runtime do
+  @moduledoc false
+
+  alias BDS.AI
+  alias BDS.AI.Catalog
+  alias BDS.AI.SecretBackend
+
+  @model_preference_keys %{
+    default: "ai.model.default",
+    chat: "ai.model.chat",
+    title: "ai.model.title",
+    image_analysis: "ai.model.image_analysis",
+    airplane_chat: "ai.airplane.model.chat",
+    airplane_title: "ai.airplane.model.title",
+    airplane_image_analysis: "ai.airplane.model.image_analysis"
+  }
+
+  @spec model_preference_keys() :: %{atom() => String.t()}
+  def model_preference_keys, do: @model_preference_keys
+
+  @spec resolve_target(atom(), keyword()) ::
+          {:ok, map(), String.t(), :airplane | :online} | {:error, term()}
+  def resolve_target(operation, extra) do
+    mode = if AI.airplane_mode?(), do: :airplane, else: :online
+    secret_backend = Keyword.get(extra, :secret_backend, SecretBackend)
+
+    with {:ok, endpoint} <- fetch_endpoint_for_mode(mode, secret_backend),
+         {:ok, model} <- resolve_model_for_operation(operation, mode, endpoint, extra) do
+      {:ok, endpoint, model, mode}
+    end
+  end
+
+  @spec validate_target(atom(), String.t(), :airplane | :online) :: :ok | {:error, term()}
+  def validate_target(:analyze_image, model, _mode) do
+    if Catalog.model_capabilities(model).supports_attachment do
+      :ok
+    else
+      {:error, %{kind: :model_capability_missing, capability: :supports_attachment, model: model}}
+    end
+  end
+
+  def validate_target(_operation, _model, _mode), do: :ok
+
+  @spec endpoint_with_model(map(), String.t()) :: map()
+  def endpoint_with_model(endpoint, model), do: Map.put(endpoint, :model, model)
+
+  @spec model_preference_value(atom()) :: String.t() | nil
+  def model_preference_value(key) do
+    case AI.get_model_preference(key) do
+      {:ok, value} -> value
+      _other -> nil
+    end
+  end
+
+  defp resolve_model_for_operation(:chat, :airplane, endpoint, _extra) do
+    {:ok, model_preference_value(:airplane_chat) || endpoint.model}
+  end
+
+  defp resolve_model_for_operation(:chat, :online, endpoint, conversation: conversation) do
+    {:ok, conversation.model || model_preference_value(:chat) || endpoint.model}
+  end
+
+  defp resolve_model_for_operation(:chat, :online, endpoint, _extra) do
+    {:ok, model_preference_value(:chat) || endpoint.model}
+  end
+
+  defp resolve_model_for_operation(:analyze_image, :airplane, endpoint, extra) do
+    {:ok, Keyword.get(extra, :model) || model_preference_value(:airplane_image_analysis) || endpoint.model}
+  end
+
+  defp resolve_model_for_operation(:analyze_image, :online, endpoint, extra) do
+    {:ok, Keyword.get(extra, :model) || model_preference_value(:image_analysis) || endpoint.model}
+  end
+
+  defp resolve_model_for_operation(_operation, :airplane, endpoint, extra) do
+    {:ok, Keyword.get(extra, :model) || model_preference_value(:airplane_title) || endpoint.model}
+  end
+
+  defp resolve_model_for_operation(_operation, :online, endpoint, extra) do
+    {:ok, Keyword.get(extra, :model) || model_preference_value(:title) || endpoint.model}
+  end
+
+  defp fetch_endpoint_for_mode(mode, secret_backend) do
+    with {:ok, endpoint} <- AI.get_endpoint(mode, secret_backend: secret_backend) do
+      case endpoint do
+        %{url: url, model: model} = loaded when is_binary(url) and url != "" and is_binary(model) and model != "" ->
+          if mode == :online and blank?(loaded.api_key) do
+            {:error, %{kind: :endpoint_not_configured, endpoint: mode}}
+          else
+            {:ok, loaded}
+          end
+
+        _other ->
+          {:error, %{kind: :endpoint_not_configured, endpoint: mode}}
+      end
+    end
+  end
+
+  defp blank?(value), do: value in [nil, ""]
+end