#include "panic.h"
#include "arch.h"
#include <arch/i686/paging.h>
#include <stdbool.h>
#include <stdint.h>
#include <string.h>
#include <print.h>

extern struct page_directory_t page_directory[1024];
extern struct page_table_t     page_tables[1024][1024];
// static uintptr_t KERNEL_MAPPING = 0xC0000000;

void setup_pgdir(struct page_directory_t pgdir[1024]) {
    for(int i = 0; i < 1024; i++) {
        pgdir[i].present    = 0;
        pgdir[i].rw_flag    = 1;
        pgdir[i].access_lvl = 0;
    }
}

void paging_ident(struct page_table_t tbl[1024]) {
    size_t size = 1024;
    for(size_t i = 0; i < size; i++) {
        tbl[i].rw_flag    = 1;
        tbl[i].access_lvl = 0;
        tbl[i].phys_addr  = i;
        tbl[i].present    = 1;
    }
}

void map_page(struct page_table_t tbl[1024], void *addr) {
    uintptr_t ptr = (uintptr_t) addr;
    ptr &= 0xfffff000;
    ptr >>= 16;
    for(size_t i = 0; i < 4096; i++) {
        tbl[i].rw_flag    = 1;
        tbl[i].access_lvl = 0;
        tbl[i].phys_addr  = ptr / 4096 + i;
        tbl[i].present    = 1;
    }
}

void unmap_page(struct page_table_t tbl[1024]) {
    for(size_t i = 0; i < 4096; i++) {
        tbl[i].rw_flag    = 1;
        tbl[i].access_lvl = 0;
        tbl[i].phys_addr  = 0;
        tbl[i].present    = 0;
    }
}

void ident_map_addr(void *addr, size_t len) {
    uintptr_t ptr = (uintptr_t) addr;
    int i = ptr / 0x400000;
    // int c = len / 0x1000 + (len % 0x1000 ? 1 : 0);
    // for (; c > 0; c--, i++) {
    //     paging_ident(page_tables[i]);
    // }
    paging_ident(page_tables[i]);
}

void ident_unmap_addr(void *addr, size_t len) {
    uintptr_t ptr = (uintptr_t) addr;
    int i = ptr / 0x1000;
    int c = len / 0x1000 + (len % 0x1000 ? 1 : 0);
    for (; c > 0; c--, i++) {
        page_tables[i / 1024][i % 1024].present = 0;    
        page_tables[i / 1024][i % 1024].rw_flag = 1;   
        page_tables[i / 1024][i % 1024].access_lvl = 0;    
    }
}