#include "liballoc.h"

#include <heap/heap.h>
#include <mango/handle.h>
#include <mango/log.h>
#include <mango/status.h>
#include <mango/task.h>
#include <mango/vm.h>
#include <stdio.h>

#define HEAP_REGION_SIZE      0x40000000
#define HEAP_EXPAND_INCREMENT 0x100000

void *heap_alloc(heap_t *heap, size_t sz)
{
	return _lbmalloc(heap, sz);
}

void *heap_realloc(heap_t *heap, void *p, size_t sz)
{
	return _lbrealloc(heap, p, sz);
}

void *heap_calloc(heap_t *heap, size_t num, size_t itemsz)
{
	return _lbcalloc(heap, num, itemsz);
}

void heap_free(heap_t *heap, void *p)
{
	_lbfree(heap, p);
}

static kern_status_t init_heap_region(heap_t *heap)
{
	kern_handle_t self, address_space;
	task_self(&self);
	task_get_address_space(self, &address_space);
	kern_handle_close(self);

	kern_status_t status = vm_region_create(
		address_space,
		"libc-heap",
		9,
		VM_REGION_ANY_OFFSET,
		HEAP_REGION_SIZE,
		VM_PROT_READ | VM_PROT_WRITE | VM_PROT_USER,
		&heap->heap_region,
		&heap->heap_base);

	kern_handle_close(address_space);

	if (status != KERN_OK) {
		return status;
	}

	return KERN_OK;
}

static kern_status_t expand_heap(heap_t *heap)
{
	kern_handle_t vmo;
	kern_status_t status = vm_object_create(
		"libc-heap-data",
		14,
		HEAP_EXPAND_INCREMENT,
		VM_PROT_READ | VM_PROT_WRITE | VM_PROT_USER,
		&vmo);
	if (status != KERN_OK) {
		return status;
	}

	virt_addr_t base = 0;

	status = vm_region_map_relative(
		heap->heap_region,
		heap->heap_sys_alloc,
		vmo,
		0,
		HEAP_EXPAND_INCREMENT,
		VM_PROT_READ | VM_PROT_WRITE | VM_PROT_USER,
		&base);

	kern_handle_close(vmo);

	heap->heap_sys_alloc += HEAP_EXPAND_INCREMENT;
	return status;
}

void *heap_expand(heap_t *heap, size_t size)
{
	kern_status_t status = KERN_OK;
	if (heap->heap_region == KERN_HANDLE_INVALID) {
		status = init_heap_region(heap);
	}

	if (status != KERN_OK) {
		return NULL;
	}

	while (heap->heap_req_alloc + size > heap->heap_sys_alloc) {
		status = expand_heap(heap);
		if (status != KERN_OK) {
			return NULL;
		}
	}

	void *p = (void *)(heap->heap_base + heap->heap_req_alloc);
	heap->heap_req_alloc += size;

	return p;
}