#ifndef MEMBLOCK_H_
#define MEMBLOCK_H_

#include <stddef.h>
#include <limits.h>
#include <socks/types.h>

#define MEMBLOCK_INIT_MEMORY_REGION_COUNT 128
#define MEMBLOCK_INIT_RESERVED_REGION_COUNT 128

#define __for_each_mem_range(i, type_a, type_b, p_start, p_end) \
	for ((i)->__idx = 0, __next_memory_region(i, type_a, type_b, p_start, p_end); \
			(i)->__idx != ULLONG_MAX; \
			__next_memory_region(i, type_a, type_b, p_start, p_end))

#define for_each_mem_range(i, p_start, p_end) \
	__for_each_mem_range(i, &memblock.memory, NULL, p_start, p_end)

#define for_each_reserved_mem_range(i, p_start, p_end) \
	__for_each_mem_range(i, &memblock.reserved, NULL, p_start, p_end)

#define for_each_free_mem_range(i, p_start, p_end) \
	__for_each_mem_range(i, &memblock.memory, &memblock.reserved, p_start, p_end)

typedef uint64_t memblock_index_t;

typedef enum memblock_region_status {
	/* Used in memblock.memory regions, indicates that the memory region exists */
	MEMBLOCK_MEMORY = 0,
	/* Used in memblock.reserved regions, indicates that the memory region was reserved
	 * by a call to memblock_alloc() */
	MEMBLOCK_ALLOC,
	/* Used in memblock.reserved regions, indicates that the memory region was reserved
	 * by a call to memblock_reserve() */
	MEMBLOCK_RESERVED,
} memblock_region_status_t;

typedef struct memblock_region {
	/* the status of the memory region (free, reserved, allocated, etc) */
	memblock_region_status_t status;
	/* the address of the first byte that makes up the region */
	phys_addr_t base;
	/* the address of the last byte that makes up the region */
	phys_addr_t limit;
} memblock_region_t;

typedef struct memblock_type {
	struct memblock_region *regions;
	unsigned int count;
	unsigned int max;
	const char *name;
} memblock_type_t;

typedef struct memblock {
	/* bounds of the memory region that can be used by memblock_alloc()
	   both of these are virtual addresses */
	uintptr_t m_alloc_start, m_alloc_end;
	/* memblock assumes that all memory in the alloc zone is contiguously mapped
	   (if paging is enabled). m_voffset is the offset that needs to be added to
	   a given physical address to get the corresponding virtual address */
	uintptr_t m_voffset;

	struct memblock_type memory;
	struct memblock_type reserved;
} memblock_t;

typedef struct memblock_iter {
	memblock_index_t __idx;
	phys_addr_t it_base;
	phys_addr_t it_limit;
	memblock_region_status_t it_status;
} memblock_iter_t;

extern memblock_t memblock;

extern int __next_mem_range(memblock_iter_t *it);

extern int memblock_init(uintptr_t alloc_start, uintptr_t alloc_end, uintptr_t voffset);

extern int memblock_add(phys_addr_t base, size_t size);
extern int memblock_reserve(phys_addr_t base, size_t size);

extern void *memblock_alloc(size_t size);
extern phys_addr_t memblock_alloc_phys(size_t size);

extern int memblock_free(void *addr, size_t size);
extern int memblock_free_phys(phys_addr_t addr, size_t size);

extern void __next_memory_region(memblock_iter_t *it, \
		memblock_type_t *type_a, memblock_type_t *type_b,
		phys_addr_t start, phys_addr_t end);

#endif