//
//  RQEXTRuntimeExtensions.h
//  RQCommon
//
//  Created by 张嵘 on 2018/11/16.
//  Copyright © 2018 张嵘. All rights reserved.
//

#import <objc/runtime.h>

/**
 * Describes the memory management policy of a property.
 */
typedef enum {
	/**
	 * The value is assigned.
	 */
	rq_propertyMemoryManagementPolicyAssign = 0,
	
	/**
	 * The value is retained.
	 */
	rq_propertyMemoryManagementPolicyRetain,
	
	/**
	 * The value is copied.
	 */
	rq_propertyMemoryManagementPolicyCopy
} rq_propertyMemoryManagementPolicy;

/**
 * Describes the attributes and type information of a property.
 */
typedef struct {
	/**
	 * Whether this property was declared with the \c readonly attribute.
	 */
	BOOL readonly;
	
	/**
	 * Whether this property was declared with the \c nonatomic attribute.
	 */
	BOOL nonatomic;
	
	/**
	 * Whether the property is a weak reference.
	 */
	BOOL weak;
	
	/**
	 * Whether the property is eligible for garbage collection.
	 */
	BOOL canBeCollected;
	
	/**
	 * Whether this property is defined with \c \@dynamic.
	 */
	BOOL dynamic;
	
	/**
	 * The memory management policy for this property. This will always be
	 * #rq_propertyMemoryManagementPolicyAssign if #readonly is \c YES.
	 */
	rq_propertyMemoryManagementPolicy memoryManagementPolicy;
	
	/**
	 * The selector for the getter of this property. This will reflect any
	 * custom \c getter= attribute provided in the property declaration, or the
	 * inferred getter name otherwise.
	 */
	SEL getter;
	
	/**
	 * The selector for the setter of this property. This will reflect any
	 * custom \c setter= attribute provided in the property declaration, or the
	 * inferred setter name otherwise.
	 *
	 * @note If #readonly is \c YES, this value will represent what the setter
	 * \e would be, if the property were writable.
	 */
	SEL setter;
	
	/**
	 * The backing instance variable for this property, or \c NULL if \c
	 * \c @synthesize was not used, and therefore no instance variable exists. This
	 * would also be the case if the property is implemented dynamically.
	 */
	const char *ivar;
	
	/**
	 * If this property is defined as being an instance of a specific class,
	 * this will be the class object representing it.
	 *
	 * This will be \c nil if the property was defined as type \c id, if the
	 * property is not of an object type, or if the class could not be found at
	 * runtime.
	 */
	Class objectClass;
	
	/**
	 * The type encoding for the value of this property. This is the type as it
	 * would be returned by the \c \@encode() directive.
	 */
	char type[];
} rq_propertyAttributes;

/**
 * Returns a pointer to a structure containing information about \a property.
 * You must \c free() the returned pointer. Returns \c NULL if there is an error
 * obtaining information from \a property.
 */
rq_propertyAttributes *rq_copyPropertyAttributes (objc_property_t property);