#ifndef SOCKS_KEXT_H_
#define SOCKS_KEXT_H_

#include <socks/status.h>
#include <socks/compiler.h>
#include <socks/btree.h>

#define KERNEL_KEXT_ID "net.doorstuck.socks-kernel"
#define KEXT_IDENT_MAX 80
#define KEXT_NO_DEPENDENCIES NULL

#define __KEXT_INFO_VARNAME_2(a, b) a ## b
#define __KEXT_INFO_VARNAME_1(a, b) __KEXT_INFO_VARNAME_2(a, b)

#ifdef SOCKS_INTERNAL
#define __KEXT_INFO_LINKAGE static
#define __KEXT_INFO_VARNAME() __KEXT_INFO_VARNAME_1(__kext_info, __LINE__)
#define __KEXT_INFO_DEPNAME() __KEXT_INFO_VARNAME_1(__kext_deps, __LINE__)
#define __KEXT_INFO_FLAGS KEXT_INTERNAL
#define __KEXT_INFO_ALIGNMENT 0x80
#else
#define __KEXT_INFO_LINKAGE
#define __KEXT_INFO_VARNAME() __kext_info
#define __KEXT_INFO_DEPNAME() __kext_deps
#define __KEXT_INFO_FLAGS KEXT_NONE
#define __KEXT_INFO_ALIGNMENT 0x80
#endif

#ifdef __cplusplus
#define DEFINE_KEXT(ident, online, offline, ...) \
	static const char *__KEXT_INFO_DEPNAME()[] = { \
		__VA_ARGS__, NULL \
	}; \
	static struct kext_info __section(".kextinfo") __aligned(__KEXT_INFO_ALIGNMENT) __used __KEXT_INFO_VARNAME() = { \
		__KEXT_INFO_FLAGS, \
		ident, \
		online, \
		offline, \
		__KEXT_INFO_DEPNAME(), \
	}
#else
#define DEFINE_KEXT(ident, online, offline, ...) \
	static const char *__KEXT_INFO_DEPNAME()[] = { \
		__VA_ARGS__, NULL \
	}; \
	static struct kext_info __section(".kextinfo") __aligned(__KEXT_INFO_ALIGNMENT) __used  __KEXT_INFO_VARNAME() = { \
		.k_flags = __KEXT_INFO_FLAGS, \
		.k_ident = ident, \
		.k_online = online, \
		.k_offline = offline, \
		.k_dependencies = __KEXT_INFO_DEPNAME(), \
	}
#endif

struct kext;

enum kext_flags {
	KEXT_NONE = 0x00u,
	KEXT_INTERNAL = 0x01u,
	KEXT_ONLINE = 0x02u,
};

struct kext_info {
	enum kext_flags k_flags;
	char k_ident[KEXT_IDENT_MAX];
	kern_status_t(*k_online)(struct kext *);
	kern_status_t(*k_offline)(struct kext *);
	const char **k_dependencies;
};

struct kext {
	enum kext_flags k_flags;
	char k_ident[KEXT_IDENT_MAX];
	uint64_t k_ident_hash;
	btree_node_t k_node;

	kern_status_t(*k_online)(struct kext *);
	kern_status_t(*k_offline)(struct kext *);

	unsigned int k_nr_dependencies;
	struct kext **k_dependencies;
};

extern kern_status_t scan_internal_kexts(void);
extern kern_status_t bring_internal_kexts_online(void);

extern kern_status_t kext_cache_init(void);
extern struct kext *kext_alloc(void);
extern void kext_release(struct kext *kext);
extern kern_status_t kext_register(struct kext *kext);
extern struct kext *kext_get_by_id(const char *ident);
extern kern_status_t kext_bring_online(struct kext *kext);

#endif