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

public partial class CodingWindow : PanelContainer
{
	private Robot robot;

	[Export] VBoxContainer codeBlocks;
	[Export] GraphEdit editorWindow;
	[Export] OptionButton availableScripts;
	[Export] LineEdit scriptName;
	[Export] LineEdit nameInput;
	[Export] NodeTooltip nodeTooltip;

	public System.Collections.Generic.Dictionary<ProgramNode, PackedScene> DSLNodes;
	public NodeDisplay selectedNode;

	public override void _Ready()
	{
		DSLNodes = ResourceLoader.LoadDSLNodes();
		GenerateCodingBlocks();
	}

	public override void _Notification(int id)
	{
		if (id == NotificationVisibilityChanged)
		{
			if (Visible) LoadWindow();
		}
	}

    public override void _Process(double delta)
	{
		if (Input.IsActionJustPressed("delete_node"))
		{
			Control focused = GetViewport().GuiGetFocusOwner();

			if (focused is LineEdit || focused is TextEdit) return;
			if (selectedNode == null) return;
			editorWindow.RemoveChild(selectedNode);
			selectedNode.QueueFree();
		}
	}

	public void OnNodeSelect(NodeDisplay node)
	{
		selectedNode = node;
	}

	public void OnNodeDeselect(NodeDisplay node)
	{
		selectedNode = null;
	}

	private void LoadWindow()
	{
		if (robot == null) return;

		nameInput.Text = robot.Name;
		SetupScriptOptions();
		ClearWindow();
		LoadTemporaryProgram();
	}

	private void SetupScriptOptions()
	{
		availableScripts.Clear();
		availableScripts.AddItem("Select script to load...");

		List<string> scripts = FileHandler.LoadProgramNames();
		scripts.Sort((a, b) => a.CompareTo(b));
		foreach (string script in scripts)
		{
			availableScripts.AddItem(script);
		}
	}

	public void SaveRobotName()
	{
		if (robot == null) return;

		robot.Name = nameInput.Text;
	}

	public void CloseWindow()
	{
		Hide();
	}

	public void GenerateCodingBlocks()
	{
		foreach (ProgramNode nodeTemplate in DSLNodes.Keys)
		{
			Button nodeListButton = new Button
			{
				Name = nodeTemplate.DisplayText,
				Text = nodeTemplate.DisplayText
			};
			nodeListButton.Pressed += () =>
			{
				AddEditorNode(nodeTemplate);
			};
			nodeListButton.MouseEntered += () =>
			{
				nodeTooltip.ShowTooltip(nodeTemplate.DisplayText, nodeTemplate.DisplayText, nodeListButton);
			};
			nodeListButton.MouseExited += () =>
			{
				nodeTooltip.HideTooltip();
			};
			codeBlocks.AddChild(nodeListButton);
		}
	}

	private void AddEditorNode(ProgramNode node)
	{
		NodeDisplay editorDisplay = DSLNodes[node].Instantiate<NodeDisplay>();
		editorDisplay.PositionOffset = GetVisibleGraphCenter() - editorDisplay.Size / 2f;
		editorWindow.AddChild(editorDisplay);
	}

	private Vector2 GetVisibleGraphCenter()
	{
		return (editorWindow.ScrollOffset + editorWindow.Size / 2f) / editorWindow.Zoom;
	}

	public void ClearWindow()
	{
		DisconnectAllNodes();
		RemoveEditorNodes();
		scriptName.Text = "";
	}

	private void DisconnectAllNodes()
	{
		foreach (Dictionary connection in editorWindow.GetConnectionList())
		{
			editorWindow.DisconnectNode(
				connection["from_node"].AsStringName(),
				(int)connection["from_port"],
				connection["to_node"].AsStringName(),
				(int)connection["to_port"]
			);
		}
	}

	private void RemoveEditorNodes()
	{
		foreach (Node child in editorWindow.GetChildren())
		{
			if (child is not GraphNode) continue;

			editorWindow.RemoveChild(child);
			child.QueueFree();
		}
	}

	public void CompileProgram()
	{
		if (robot == null) return;

		ScriptGraphCompiler compiler = new ScriptGraphCompiler(editorWindow);
		string errorMessage;
		List<ProgramNode> nodes = compiler.BuildProgram(out errorMessage);
		if (errorMessage.Length > 0)
		{
			robot.StopExecution(errorMessage);
			return;
		}

		if (nodes.Count > 0) robot.SetupExecution(nodes);
		robot.currentProgram = GetCurrentScriptName();
	}

	private string GetCurrentScriptName()
	{
		if (scriptName.Text.Length > 0) return scriptName.Text;

		return $"Script{availableScripts.ItemCount}";
	}

	public void SetRobot(Robot robot)
	{
		this.robot = robot;
	}

	public void LoadProgram(int index)
	{
		if (index <= 0) return;

		ClearWindow();
		string scriptContent = FileHandler.LoadProgram(availableScripts.GetItemText(index));
		CreateSerializer().Load(scriptContent);
		scriptName.Text = availableScripts.GetItemText(index);
		availableScripts.Select(0);
	}

	private void AddLoadedNode(NodeDisplay nodeDisplay)
	{
		editorWindow.AddChild(nodeDisplay);
	}

	public void LoadTemporaryProgram()
	{
		if (robot == null) return;
		if (robot.currentNode == null) return;

		RunningProgramGraphBuilder builder = new RunningProgramGraphBuilder(
			DSLNodes,
			AddLoadedNode,
			ConnectNodes
		);
		builder.Load(robot.currentNode);

		scriptName.Text = robot.currentProgram ?? "";
	}

	public void DeleteProgram()
	{
		string filename = scriptName.Text;
		int selectedIndex = availableScripts.GetSelectedId();
		if (selectedIndex > 0)
		{
			filename = availableScripts.GetItemText(selectedIndex);
		}

		if (filename.Length <= 0) return;
		if (!FileHandler.DeleteProgram(filename)) return;

		ClearWindow();
		SetupScriptOptions();
	}

	public void SaveProgram()
	{
		string result = CreateSerializer().Save();
		if (result.Length <= 0) return;

		FileHandler.SaveProgram(GetCurrentScriptName(), result);
		SetupScriptOptions();
	}

	public void OnNodeConnect(StringName from, int fromPort, StringName to, int toPort)
	{
		if (to == from) return;

		ConnectNodes(from, fromPort, to, toPort);
	}

	private void ConnectNodes(StringName from, int fromPort, StringName to, int toPort)
	{
		if (HasOutputConnection(from, fromPort)) return;

		editorWindow.ConnectNode(from, fromPort, to, toPort);
	}

	private bool HasOutputConnection(StringName from, int fromPort)
	{
		foreach (Dictionary connection in editorWindow.GetConnectionList())
		{
			if (connection["from_node"].AsStringName() != from) continue;
			if ((int)connection["from_port"] != fromPort) continue;

			return true;
		}

		return false;
	}

	private ScriptGraphSerializer CreateSerializer()
	{
		return new ScriptGraphSerializer(
			editorWindow,
			DSLNodes,
			AddLoadedNode,
			ConnectNodes
		);
	}

	public void OnNodeDisconnect(StringName from, int fromPort, StringName to, int toPort)
	{
		editorWindow.DisconnectNode(from, fromPort, to, toPort);
	}
}