#include "src/fs.h"
#include "src/gdt.h"
#include "src/idt.h"
#include "src/keyboard.h"
#include "src/memory.h"
#include "src/panic.h"
#include "src/path.h"
#include "src/pic.h"
#include "src/process.h"
#include "src/syscall.h"
#include "src/util.h"
#include "src/vga.h"

__attribute__((interrupt)) void isr_divide_by_zero(__attribute__((unused)) struct interrupt_frame *frame) {
  vga_set_string(VGA_HEIGHT - 1, 0, "EXCEPTION: divide by zero", 0x4F);
  while (1)
    ;
}

__attribute__((interrupt)) void isr_page_fault(__attribute__((unused)) struct interrupt_frame *frame) {
  vga_set_string(VGA_HEIGHT - 1, 0, "EXCEPTION: page fault", 0x4F);
  while (1)
    ;
}

__attribute__((interrupt)) void isr_general_violation(__attribute__((unused)) struct interrupt_frame *frame) {
  vga_set_string(VGA_HEIGHT - 1, 0, "EXCEPTION: general violation", 0x4F);
  while (1)
    ;
}

__attribute__((interrupt)) void isr_ata_primary(__attribute__((unused)) struct interrupt_frame *frame) {
  outb(0x20, 0x20);
  outb(0xA0, 0x20);
}

void kernel_main() {
  pic_init();
  idt_init();
  outb(0x21, inb(0x21) | 0x01); // mask out timer interrupt
  idt_set_entry(0, isr_divide_by_zero, 0x8E);
  idt_set_entry(0x0E, isr_page_fault, 0x8E);
  idt_set_entry(0x0D, isr_general_violation, 0x8E);
  idt_set_entry(46, isr_ata_primary, 0x8E);
  __asm__ volatile("sti");

  gdt_init();
  syscall_init();

  memory_init();

  process_t *kp = memory_allocate(sizeof(process_t));
  kp->root = fs_mount();
  kp->cwd = memory_allocate(sizeof(path_t));
  kp->stdin = keyboard_init();
  kp->stdout = vga_init();

  fs_node_t *hello = fs_open_by(kp->root, "HELLO.BIN");

  ASSERT(hello, "kernel: hello.bin not found");

  uint8_t *hello_code = memory_allocate(hello->size);
  fs_read(hello, 0, hello->size, hello_code);

  process_t *proc = process_create(kp, hello_code, hello->size);

  memory_free(hello_code);
  fs_close(hello);

  process_run(proc);

  while (1);

  fs_unmount(kp->root);

  outw(0x604, 0x2000); // TODO: parse ACPI tables for real hardware
  __asm__ volatile("cli; hlt");
}