using System;
using System.Linq.Expressions;
using System.Reflection;
using Vintagestory.API.Common;

namespace OrekiWoofsBees.Common;

public static class CompatibilityUtil
{
	private const string fruiting_bush_behavior_name = "BEBehaviorFruitingBush";
	private const string b_state_field_name = "BState";
	private const string growthstate_property_name = "Growthstate";
	private const int flowering_growth_state_value = 2;

	private static System.Func<BlockEntityBehavior, bool>? is_fruiting_bush_flowering_check;

	public static bool IsFruitingBushFlowering(this BlockEntityBehavior behavior)
	{
		var behaviorType = behavior.GetType();
		if (!IsFruitingBushBehaviorType(behaviorType))
			return false;

		var check = is_fruiting_bush_flowering_check ??= BuildIsFruitingBushFloweringCheck(behaviorType);
		return check(behavior);
	}

	private static bool IsFruitingBushBehaviorType(Type behaviorType)
	{
		for (var type = behaviorType; type is not null; type = type.BaseType)
		{
			if (type.Name == fruiting_bush_behavior_name)
				return true;
		}

		return false;
	}

	private static System.Func<BlockEntityBehavior, bool> BuildIsFruitingBushFloweringCheck(Type behaviorType)
	{
		var bStateField = behaviorType.GetField(b_state_field_name, BindingFlags.Instance | BindingFlags.Public)!;
		var growthStateProperty = bStateField.FieldType.GetProperty(growthstate_property_name, BindingFlags.Instance | BindingFlags.Public)!;

		var behaviorParameter = Expression.Parameter(typeof(BlockEntityBehavior), "behavior");
		var typedBehavior = Expression.Convert(behaviorParameter, behaviorType);
		var bState = Expression.Field(typedBehavior, bStateField);
		var growthState = Expression.Property(bState, growthStateProperty);

		var comparison = Expression.Equal(
			Expression.Convert(growthState, typeof(int)),
			Expression.Constant(flowering_growth_state_value));

		return Expression.Lambda<System.Func<BlockEntityBehavior, bool>>(comparison, behaviorParameter).Compile();
	}
}