#include <kernel/init.h>
#include <math.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <sys/io.h>
#include "gdt.h"

int tss[16][2];

int test_libc(void) {
  int failed = 0;

  printf("==Testing stdio.h==\n");

  printf("printf(\"%%d\", 10): %d (expected 10)\n", 10);
  printf("printf(\"%%o\", 14): %o (expected 16)\n", 14);
  printf("printf(\"%%u\", 10): %u (expected 10)\n", 10);
  printf("printf(\"%%x\", 26): %x (expected 1a)\n", 26);
  printf("printf(\"%%X\", 0xC9A): %x (expected C9A)\n", 0xC9A);
  printf("printf(\"%%p\", &i): %p (expected 0x[hex])\n", &failed);
  printf("printf(\"%%n\"): %n (expected 14)\n");
  
  printf("==Testing math.h==\n");
  if(cos(0) == 1.0) {
    printf("[");
    /* I want the status to be coloured. How do I do that? */
    printf("OK");
    printf("] cos()\n");
  }
  else {
    printf("[");
    printf("FAIL");
    printf("] cos()\n");
    failed++;
  }

  if(fabs(-2.3) == 2.3) {
    printf("[");
    printf("OK");
    printf("] fabs()\n");
  }
  else {
    printf("[");
    printf("FAIL");
    printf("] fabs()\n");
    failed++;
  }

  printf("==Testing time.h==\n");
  printf("time(0): Current UNIX time: %d\n", time(0));

  printf("==Testing stdlib.h==\n");

  if(abs(-5) == 5) {
    printf("[");
    printf("OK");
    printf("] abs()\n");
  }
  else {
    printf("[");
    printf("FAIL");
    printf("] abs(); expected 5, got %d\n", abs(-5));
    failed++;
  }

  srand(time(0));
  int rand_test = rand();
  printf("rand() output with seed time(0): %d\n", rand_test);

  printf("==Testing string.h==\n");

  if(strcmp("Hi", "Hi") == 0 && strcmp("Hi", "Hello") != 0) {
    printf("[");
    printf("OK");
    printf("] strcmp()\n");
  }
  else {
    printf("[");
    printf("FAIL");
    printf("] strcmp()\n");
    failed++;
  }

  if(strcspn("Hello!", "!e") == 1) {
    printf("[");
    printf("OK");
    printf("] strcspn()\n");
  }
  else {
    printf("[");
    printf("FAIL");
    printf("] strcspn(); expected 1, got %d\n", strcspn("Hello!", "!e"));
    failed++;
  }

  printf("Tests failed: %d\n", failed);

  return failed;
}

void NMI_disable(void) {
  outb(0x70, inb(0x70) | 0x80);
}

void NMI_enable(void) {
  outb(0x70, inb(0x70) & 0x7F);
}

void A20_enable(void) {
  unsigned short int a = inb(0x92);
  if((a & 2) != 0) {
    return;
  }
  a |= 2;
  outb(a, 0x92);
}

void setup_gdt(void) {
  struct GDT gdt[4];

  gdt[0].base = 0; gdt[0].limit = 0; gdt[0].type = 0;
  gdt[1].base = 0; gdt[1].limit = 0xFFFFFFFF; gdt[1].type = 0x9A;
  gdt[2].base = 0; gdt[2].limit = 0xFFFFFFFF; gdt[2].type = 0x92;
  gdt[3].base = (unsigned int) tss; gdt[3].limit=sizeof(tss); gdt[3].type = 0x89;

  unsigned short int GDT[4];
  encode_gdt_entry(&GDT[0], gdt[0]);
  encode_gdt_entry(&GDT[1], gdt[1]);
  encode_gdt_entry(&GDT[2], gdt[2]);
  encode_gdt_entry(&GDT[3], gdt[3]);

  set_gdt(GDT, sizeof(GDT));
}

int init(void) {
  NMI_disable();
  A20_enable();
  setup_gdt();
  printf("Fenix Dev Pre-release v0.0.3\n");
  return test_libc();
}