using System;
using System.Diagnostics;

namespace NTERA.Engine.Compiler
{
	[DebuggerDisplay("{Name} ({Parameters.Length})")]
	public class FunctionDefinition
	{
		public string Name { get; }

		public FunctionParameter[] Parameters { get; }

		public FunctionVariable[] Variables { get; }

		public bool IsReturnFunction { get; }

		public string Filename { get; }

		public Marker Position { get; }

		public FunctionDefinition(string name, FunctionParameter[] parameters, FunctionVariable[] methodVariables, bool isReturnFunction, string filename, Marker position = default(Marker))
		{
			Name = name;
			Parameters = parameters;
			Variables = methodVariables;
			IsReturnFunction = isReturnFunction;
			Filename = filename;
			Position = position;
		}
	}

	[Flags]
	public enum VariableType
	{
		None = 0,
		Constant = 1,
		Reference = 2,
		Dynamic = 4,
		SaveData = 8,
		CharaData = 16,
		Global = 32,
	}

	public class FunctionVariable
	{
		public string Name { get; }

		public ValueType ValueType { get; }

		public VariableType VariableType { get; }

		public Value? DefaultValue { get; }

		public Value CalculatedValue => DefaultValue.HasValue ? DefaultValue.Value : ValueType == ValueType.String ? new Value("") : new Value(0d); //for some reason, this can't be null coalesce (??), as it disregards the value

		public FunctionVariable(string name, ValueType valueType, VariableType variableType = VariableType.None, Value? defaultValue = null)
		{
			Name = name;
			ValueType = valueType;
			VariableType = variableType;
			DefaultValue = defaultValue;
		}
	}

	public class FunctionParameter
	{
		public string Name { get; }

		public string[] Indices { get; }

		public bool IsArrayParameter { get; }

		public Value? DefaultValue { get; }

		public FunctionParameter(string name, string[] indices, Value? defaultValue = null, bool isArrayParameter = false)
		{
			Name = name;
			Indices = indices;
			DefaultValue = defaultValue;
			IsArrayParameter = isArrayParameter;
		}
	}
}