defmodule GenAI.Thread.Standard do
  @moduledoc """
  This module defines the chat struct used to manage conversations with generative AI models.
  """

  @vsn 1.0

  defstruct [
    state: %GenAI.Thread.State{},
    graph: %GenAI.Graph{},
    vsn: @vsn
  ]


  defimpl GenAI.ThreadProtocol do
    @moduledoc """
    This allows chat contexts to be used for configuring and running GenAI interactions.
    """
    #alias GenAI.Graph.Node
    alias GenAI.Graph.ModelNode
    alias GenAI.Graph.MessageNode
    alias GenAI.Graph.SettingNode
    alias GenAI.Graph.ProviderSettingNode
    alias GenAI.Graph.ToolNode

    defp append_node(context, node) do
      context
      |> update_in([Access.key(:graph)], & GenAI.Graph.append_node(&1, node))
    end

    def with_model(context, model) do
      context
      |> append_node(%ModelNode{content: model})
    end

    def with_tool(context, tool) do
      context
      |> append_node(%ToolNode{content: tool})
    end
    def with_tools(context, tools) do
      Enum.reduce(tools, context, fn(tool, context) ->
        with_tool(context, tool)
      end)
    end

    def with_api_key(context, provider, api_key) do
      context
      |> append_node(%ProviderSettingNode{provider: provider, setting: :api_key, value: api_key})
    end

    def with_api_org(context, provider, api_org) do
      context
      |> append_node(%ProviderSettingNode{provider: provider, setting: :api_org, value: api_org})
    end

    def with_setting(context, setting, value) do
      context
      |> append_node(%SettingNode{setting: setting, value: value})
    end

    def with_safety_setting(context, safety_setting, threshold) do
      context
      |> append_node(%SettingNode{setting: {:__multi__, :safety_setting}, value: %{category: safety_setting, threshold: threshold}})
    end


    def with_message(context, message,_) do
      context
      |> append_node(%MessageNode{content: message})
    end

    def with_messages(context, messages, options) do
      Enum.reduce(messages, context, fn(message, context) ->
        with_message(context, message, options)
      end)
    end

    def stream(_context, _handler) do
      {:ok, :nyi}
    end

    @doc """
    Runs inference on the chat context.

    This function determines the final settings and model, prepares the messages, and then delegates the actual inference execution to the selected provider's `chat/3` function.
    """
    def run(context) do
      with {:prepare_state, {:ok, state}} <-
             GenAi.Graph.NodeProtocol.apply(context.graph, context.state)
             |> label(:prepare_state),
           {:effective_model, {:ok, model, state}} <-
             GenAI.Thread.StateProtocol.model(state)
             |> label(:effective_model) do
        GenAI.ProviderBehaviour.run(model, state)
      end
    end

    defp label(response, title) do
      {title, response}
    end

  end
end