// vim: ft=c
#include <ttest.h>

#include "multiboot.c"

#include <string.h>
#include <stdarg.h>

#define MAGIC 0x36D76289

struct tag_st
{
  uint32_t type;
  uint32_t size;
  uint8_t data[];
}__attribute__((packed));
struct header
{
  uint32_t size;
  uint32_t _;
}__attribute__((packed));


struct tag_st *generate_tag(uint32_t type, void *data, uint32_t data_size)
{
  struct tag_st *tag = calloc(1, sizeof(struct tag_st) + data_size);
  tag->type = type;
  tag->size = sizeof(struct tag_st) + data_size;
  if(data_size)
    memcpy(tag->data, data, data_size);
  return tag;
}

#define padded_size(tag) (tag->size + ((tag->size%8)?(8-(tag->size%8)):0))

struct header *generate_taglist(int num, ...)
{
  va_list args;
  va_start(args, num);
  uint32_t total_size = sizeof(struct header);
  struct tag_st **tags = calloc(num, sizeof(struct tag_st *));
  for(int i = 0; i < num; i++)
  {
    tags[i] = va_arg(args, struct tag_st *);
    total_size += padded_size(tags[i]);
  }

  struct header *taglist = calloc(1, total_size);
  taglist->size = total_size;

  int pos = 8;
  uint8_t *p = (uint8_t *)taglist;
  for(int i = 0; i < num; i++)
  {
    memcpy(&p[pos], tags[i], tags[i]->size);
    pos += padded_size(tags[i]);
    free(tags[i]);
  }
  va_end(args);

  return taglist;
}

TEST(correctly_identifies_multiboot2_magic)
{
  uint32_t tags[] = {16, 0, 0, 8};
  multiboot_init(MAGIC, tags);
  ASSERT_EQ_INT(kernel_boot_data.multiboot_version, 2);
}

TEST(reads_boot_loader_name)
{
  char *name = "ttest";
  void *tags = generate_taglist(2,
    generate_tag(2, name, strlen(name) + 1),
    generate_tag(0,0,0));

  multiboot_init(MAGIC, tags);
  ASSERT_EQ_STR(kernel_boot_data.bootloader, name, strlen(name));
  free(tags);
}
TEST(reads_kernel_commandline)
{
  char *cmd = "mittos64-kern boot";
  void *tags = generate_taglist(2,
    generate_tag(1, cmd, strlen(cmd) + 1),
    generate_tag(0,0,0));

  multiboot_init(MAGIC, tags);
  ASSERT_EQ_STR(kernel_boot_data.commandline, cmd, strlen(cmd));
  free(tags);
}
// Here are four very similar tests
// The difference is what values are checked and the order of the tags
// Their existence is based on experience - helped me actually find a bug
TEST(reads_multiple_tags_1)
{
  char *cmd = "mittos64-kern boot";
  char *name = "ttest";
  void *tags = generate_taglist(3,
    generate_tag(1, cmd, strlen(cmd) + 1),
    generate_tag(2, name, strlen(name) + 1),
    generate_tag(0,0,0)
  );

  multiboot_init(MAGIC, tags);
  ASSERT_EQ_STR(kernel_boot_data.commandline, cmd, strlen(cmd));
  free(tags);
}
TEST(reads_multiple_tags_2)
{
  char *cmd = "mittos64-kern boot";
  char *name = "ttest";
  void *tags = generate_taglist(3,
    generate_tag(1, cmd, strlen(cmd) + 1),
    generate_tag(2, name, strlen(name) + 1),
    generate_tag(0,0,0)
  );

  multiboot_init(MAGIC, tags);
  ASSERT_EQ_STR(kernel_boot_data.bootloader, name, strlen(name));
  free(tags);
}
TEST(reads_multiple_tags_3)
{
  char *cmd = "mittos64-kern boot";
  char *name = "ttest";
  void *tags = generate_taglist(3,
    generate_tag(2, name, strlen(name) + 1),
    generate_tag(1, cmd, strlen(cmd) + 1),
    generate_tag(0,0,0)
  );

  multiboot_init(MAGIC, tags);
  ASSERT_EQ_STR(kernel_boot_data.commandline, cmd, strlen(cmd));
  free(tags);
}
TEST(reads_multiple_tags_4)
{
  char *cmd = "mittos64-kern boot";
  char *name = "ttest";
  void *tags = generate_taglist(3,
    generate_tag(2, name, strlen(name) + 1),
    generate_tag(1, cmd, strlen(cmd) + 1),
    generate_tag(0,0,0)
  );

  multiboot_init(MAGIC, tags);
  ASSERT_EQ_STR(kernel_boot_data.bootloader, name, strlen(name));
  free(tags);
}

TEST(reads_mmap_tag)
{
  uint32_t mmap[] = {24, 0,
  0x90ABCDEF, 0x12345678, 0x00010000, 0x00000000, 0x1, 0x0
  };
  void *tags = generate_taglist(2,
    generate_tag(6, mmap, 32),
    generate_tag(0,0,0)
  );
  multiboot_init(MAGIC, tags);

  ASSERT_EQ_INT(kernel_boot_data.mmap_size, 1);
  free(tags);
}
void setup_memory_areas()
{
  uint32_t mmap[] = {24, 0,
  0x90ABCDEF, 0x12345678, 0x00010000, 0x00000000, 0x1, 0x0,
  0x0ABCDEF1, 0x23456789, 0x00010000, 0x00000000, 0x1, 0x0
  };
  void *tags = generate_taglist(2,
    generate_tag(6, mmap, 56),
    generate_tag(0,0,0)
  );
  multiboot_init(MAGIC, tags);
}
TEST(reads_multiple_mmap_tags)
{
  setup_memory_areas();
  ASSERT_EQ_INT(kernel_boot_data.mmap_size, 2);
}
TEST(returns_memory_area_start)
{
  setup_memory_areas();
  uintptr_t start, end;
  uint32_t type;
  multiboot_get_memory_area(0, &start, &end, &type);
  ASSERT_EQ_PTR(start, 0x1234567890ABCDEF);
}
TEST(returns_memory_area_end)
{
  setup_memory_areas();
  uintptr_t start, end;
  uint32_t type;
  multiboot_get_memory_area(0, &start, &end, &type);
  ASSERT_EQ_PTR(end, 0x1234567890ACCDEF);
}
TEST(returns_memory_area_type)
{
  setup_memory_areas();
  uintptr_t start, end;
  uint32_t type;
  multiboot_get_memory_area(0, &start, &end, &type);
  ASSERT_EQ_INT(type, 1);
}
TEST(returns_second_memory_area_start)
{
  setup_memory_areas();
  uintptr_t start, end;
  uint32_t type;
  multiboot_get_memory_area(1, &start, &end, &type);
  ASSERT_EQ_PTR(start, 0x234567890ABCDEF1);
}
TEST(does_not_return_too_many_areas)
{
  setup_memory_areas();
  uintptr_t start, end;
  uint32_t type;
  int retval = multiboot_get_memory_area(2, &start, &end, &type);
  ASSERT_NEQ_INT(retval, 0);
}