#include "type.h"
#include "hal/mem.h"
#include "hal/cpu.h"
#include "lib/salloc.h"
#include "hal/intr.h"
#include "status.h"

static uint8_t _gdts[HAL_CORE_COUNT][GDT_ENTRY_NUM * GDT_ENTRY_SIZE];
static hal_gdt_ptr_t _gdt_ptrs[HAL_CORE_COUNT];

#define KERNEL_HEAP_SIZE 8192

char kernel_heap[KERNEL_HEAP_SIZE];

/**
 * helper for boot.asm, not open to C headers
 * @param k_start kernel start paddr
 * @param k_end kernel end paddr
 * @param multiboot_info multibootinfo paddr
 * @param pt_base page table base paddr
 * @param pt_end page table entry paddr
 */
status_t KABI hal_write_initial_page_table(void* multiboot_info)
{
	UNREFERENCED(multiboot_info);

	/*
	// still identity mapping
    uint32_t pt_num = 0;
    uint32_t pd_num = 0;
    uint32_t pdpt_num = 0;
    uint32_t pml4_num = 0;

    // calculate the number of page tables required:
    uint64_t k_size = (uintptr_t)KERNEL_IMAGE_END_VADDR - (uintptr_t)KERNEL_IMAGE_VADDR;
    // see multiboot boot info header
    uint32_t m_size = *(uint32_t *)multiboot_info;

	// how many pages do we need to hold the entries
    // 512 page table entries per 4k page
	pt_num = (1 + (uint32_t)((k_size + m_size - 1) / KERNEL_PAGE_SIZE)) / 512;
	pd_num = 1 + (pt_num - 1) / 512;
	pdpt_num = 1 + (pd_num - 1) / 512;
	pml4_num = 1 + (pdpt_num - 1) / 512;

	// calculate the # of page tables
    if ((((uintptr_t)(pt_end) - (uintptr_t)(pt_base)) / KERNEL_PAGE_SIZE) < (pt_num + pd_num + pdpt_num + pml4_num))
    {
        return STATUS_FAIL;
    }

	// map kernel first
	KERNEL_IMAGE_VADDR = ;

	// map kernel dynamic
	KERNEL_DYNAMIC_SIZE = ;

    // map recursive page tables
	hal_write_pml4(pt_base, (uintptr_t)pt_base, PML4_PRESENT | PML4_WRITE);
	 */

	return STATUS_SUCCESS;
}


void KABI hal_write_pt(void *const base, uintptr_t const p_addr, uint64_t const attr)
{
    if (base == NULL)
        return;
    uint64_t entry = (p_addr & 0xFFFFFFFFFF000) | attr;
    ((uint8_t *) base)[0] = (uint8_t) (entry & 0xFF);
    ((uint8_t *) base)[1] = (uint8_t) ((entry >> 8) & 0xFF);
    ((uint8_t *) base)[2] = (uint8_t) ((entry >> 16) & 0xFF);
    ((uint8_t *) base)[3] = (uint8_t) ((entry >> 24) & 0xFF);
    ((uint8_t *) base)[4] = (uint8_t) ((entry >> 32) & 0xFF);
    ((uint8_t *) base)[5] = (uint8_t) ((entry >> 40) & 0xFF);
    ((uint8_t *) base)[6] = (uint8_t) ((entry >> 48) & 0xFF);
    ((uint8_t *) base)[7] = (uint8_t) ((entry >> 56) & 0xFF);
    return;
}

void KABI hal_write_pd(void *const base, uintptr_t const pt_addr, uint64_t const attr)
{
    if (base == NULL)
        return;
    uint64_t entry = (pt_addr & 0xFFFFFFFFFF000) | attr;
    ((uint8_t *) base)[0] = (uint8_t) (entry & 0xFF);
    ((uint8_t *) base)[1] = (uint8_t) ((entry >> 8) & 0xFF);
    ((uint8_t *) base)[2] = (uint8_t) ((entry >> 16) & 0xFF);
    ((uint8_t *) base)[3] = (uint8_t) ((entry >> 24) & 0xFF);
    ((uint8_t *) base)[4] = (uint8_t) ((entry >> 32) & 0xFF);
    ((uint8_t *) base)[5] = (uint8_t) ((entry >> 40) & 0xFF);
    ((uint8_t *) base)[6] = (uint8_t) ((entry >> 48) & 0xFF);
    ((uint8_t *) base)[7] = (uint8_t) ((entry >> 56) & 0xFF);
    return;
}

void KABI hal_write_pdpt(void *const base, uintptr_t const pd_addr, uint64_t const attr)
{
    if (base == NULL)
        return;
    uint64_t entry = (pd_addr & 0xFFFFFFFFFF000) | attr;
    ((uint8_t *) base)[0] = (uint8_t) (entry & 0xFF);
    ((uint8_t *) base)[1] = (uint8_t) ((entry >> 8) & 0xFF);
    ((uint8_t *) base)[2] = (uint8_t) ((entry >> 16) & 0xFF);
    ((uint8_t *) base)[3] = (uint8_t) ((entry >> 24) & 0xFF);
    ((uint8_t *) base)[4] = (uint8_t) ((entry >> 32) & 0xFF);
    ((uint8_t *) base)[5] = (uint8_t) ((entry >> 40) & 0xFF);
    ((uint8_t *) base)[6] = (uint8_t) ((entry >> 48) & 0xFF);
    ((uint8_t *) base)[7] = (uint8_t) ((entry >> 56) & 0xFF);
    return;
}

void KABI hal_write_pml4(void *const base, uintptr_t const pdpt_addr, uint64_t const attr)
{
    if (base == NULL)
        return;
    uint64_t const entry = (pdpt_addr & 0xFFFFFFFFFF000) | attr;
    ((uint8_t *) base)[0] = (uint8_t) (entry & 0xFF);
    ((uint8_t *) base)[1] = (uint8_t) ((entry >> 8) & 0xFF);
    ((uint8_t *) base)[2] = (uint8_t) ((entry >> 16) & 0xFF);
    ((uint8_t *) base)[3] = (uint8_t) ((entry >> 24) & 0xFF);
    ((uint8_t *) base)[4] = (uint8_t) ((entry >> 32) & 0xFF);
    ((uint8_t *) base)[5] = (uint8_t) ((entry >> 40) & 0xFF);
    ((uint8_t *) base)[6] = (uint8_t) ((entry >> 48) & 0xFF);
    ((uint8_t *) base)[7] = (uint8_t) ((entry >> 56) & 0xFF);
    return;
}

void KABI hal_write_segment_descriptor(void *const gdt, uint32_t const base, uint32_t const limit,
                                       uint64_t const attr)
{
    if (gdt == NULL)
        return;
    uint64_t const seg_desc = (((uint64_t) base & 0xFFFF) << 16) | ((((uint64_t) base >> 16) & 0xFF) << 32) |
                              ((((uint64_t) base >> 24) & 0xFF) << 56) | ((uint64_t) limit & 0xFFFF) |
                              ((((uint64_t) limit >> 16) & 0xF) << 48) | attr;
    ((uint8_t *) gdt)[0] = (uint8_t) (seg_desc & 0xFF);
    ((uint8_t *) gdt)[1] = (uint8_t) ((seg_desc >> 8) & 0xFF);
    ((uint8_t *) gdt)[2] = (uint8_t) ((seg_desc >> 16) & 0xFF);
    ((uint8_t *) gdt)[3] = (uint8_t) ((seg_desc >> 24) & 0xFF);
    ((uint8_t *) gdt)[4] = (uint8_t) ((seg_desc >> 32) & 0xFF);
    ((uint8_t *) gdt)[5] = (uint8_t) ((seg_desc >> 40) & 0xFF);
    ((uint8_t *) gdt)[6] = (uint8_t) ((seg_desc >> 48) & 0xFF);
    ((uint8_t *) gdt)[7] = (uint8_t) ((seg_desc >> 56) & 0xFF);
    return;
}

void *KABI halloc(uint32_t size)
{
    return lb_salloc(kernel_heap, size);
}

void KABI hfree(void *ptr)
{
    lb_sfree(kernel_heap, ptr);
    return;
}

static void KABI _hal_init_gdt(void)
{
    uint32_t coreid = hal_get_core_id();
    // get gdt ready
    hal_write_segment_descriptor((void *) &_gdts[coreid][0], 0, 0, 0);
    hal_write_segment_descriptor((void *) &_gdts[coreid][8], 0, 0,
                                 SEG_DPL_0 | SEG_CODE_DATA | SEG_PRESENT | SEG_LONG | SEG_TYPE_CODE_X);
    hal_write_segment_descriptor((void *) &_gdts[coreid][16], 0, 0,
                                 SEG_DPL_0 | SEG_CODE_DATA | SEG_PRESENT | SEG_LONG | SEG_TYPE_DATA_RW);
    hal_write_segment_descriptor((void *) &_gdts[coreid][24], 0, 0,
                                 SEG_DPL_3 | SEG_CODE_DATA | SEG_PRESENT | SEG_LONG | SEG_TYPE_CODE_X);
    hal_write_segment_descriptor((void *) &_gdts[coreid][32], 0, 0,
                                 SEG_DPL_3 | SEG_CODE_DATA | SEG_PRESENT | SEG_LONG | SEG_TYPE_DATA_RW);

    hal_write_segment_descriptor((void *) &_gdts[coreid][40], 0, 0xFFFFF,
                                 SEG_DPL_0 | SEG_GRANULARITY | SEG_CODE_DATA | SEG_PRESENT | SEG_32_BITS |
                                 SEG_TYPE_CODE_X);
    hal_write_segment_descriptor((void *) &_gdts[coreid][48], 0, 0xFFFFF,
                                 SEG_DPL_0 | SEG_GRANULARITY | SEG_CODE_DATA | SEG_PRESENT | SEG_32_BITS |
                                 SEG_TYPE_DATA_RW);
    hal_write_segment_descriptor((void *) &_gdts[coreid][56], 0, 0xFFFFF,
                                 SEG_DPL_3 | SEG_GRANULARITY | SEG_CODE_DATA | SEG_PRESENT | SEG_32_BITS |
                                 SEG_TYPE_CODE_X);
    hal_write_segment_descriptor((void *) &_gdts[coreid][64], 0, 0xFFFFF,
                                 SEG_DPL_3 | SEG_GRANULARITY | SEG_CODE_DATA | SEG_PRESENT | SEG_32_BITS |
                                 SEG_TYPE_DATA_RW);
    _gdt_ptrs[coreid].base = (uint64_t) &_gdts[coreid];
    _gdt_ptrs[coreid].limit = GDT_ENTRY_NUM * GDT_ENTRY_SIZE - 1;
    hal_flush_gdt(&_gdt_ptrs[coreid], seg_selector(1, 0), seg_selector(2, 0));
}

void KABI hal_mem_init()
{
    _hal_init_gdt();
    lb_salloc_init(kernel_heap, KERNEL_HEAP_SIZE);
    return;
}