using Godot;
using System;
using System.Collections.Generic;

public class RunningProgramGraphBuilder
{
	private readonly Dictionary<ProgramNode, PackedScene> dslNodes;
	private readonly Action<NodeDisplay> addNode;
	private readonly Action<StringName, int, StringName, int> connectNodes;

	public RunningProgramGraphBuilder(
        Dictionary<ProgramNode, PackedScene> dslNodes,
		Action<NodeDisplay> addNode,
		Action<StringName, int, StringName, int> connectNodes
	)
	{
		this.dslNodes = dslNodes;
		this.addNode = addNode;
		this.connectNodes = connectNodes;
	}

	public void Load(ProgramNode startNode)
	{
        Dictionary<ProgramNode, NodeDisplay> loadedNodes =
			new Dictionary<ProgramNode, NodeDisplay>();
		LoadNode(startNode, loadedNodes);
	}

	private NodeDisplay LoadNode(
		ProgramNode programNode,
        Dictionary<ProgramNode, NodeDisplay> loadedNodes
	)
	{
		if (programNode == null) return null;
		if (loadedNodes.ContainsKey(programNode)) return loadedNodes[programNode];

		NodeDisplay nodeDisplay = NodeDisplay.Load(
			programNode.DisplayText,
			programNode.Save(),
			dslNodes
		);
		if (nodeDisplay == null) return null;
		if (programNode.EditorNodeId != null && programNode.EditorNodeId.Length > 0)
		{
			nodeDisplay.Name = programNode.EditorNodeId;
		}

		addNode(nodeDisplay);
		loadedNodes.Add(programNode, nodeDisplay);

		ConnectNode(nodeDisplay, 0, programNode.nextNode, loadedNodes);
		ConnectNode(nodeDisplay, 1, programNode.NegativeNode, loadedNodes);

		return nodeDisplay;
	}

	private void ConnectNode(
		NodeDisplay fromDisplay,
		int fromPort,
		ProgramNode targetNode,
        Dictionary<ProgramNode, NodeDisplay> loadedNodes
	)
	{
		NodeDisplay toDisplay = LoadNode(targetNode, loadedNodes);
		if (toDisplay == null) return;

		connectNodes(fromDisplay.Name, fromPort, toDisplay.Name, 0);
	}
}