#include "drivers/uart.h"
#include "kernel/pmm.h"
#include "kernel/mm.h"
#include "kernel/trap.h"
#include "kernel/proc.h"
#include "kernel/timer.h"

void delay()
{
    for(volatile int i = 0; i < 1000000; i++)
    {

    }
}

void task_a()
{
    while(1)
    {
        Drivers::uart_putc('A');
        delay();
        ProcManager::yield();
    }
}

void task_b()
{
    while (1)
    {
        Drivers::uart_putc('B');
        delay();
        ProcManager::yield();
    }
    
}

extern "C" void kernel_main()
{

    Drivers::uart_init();
    Drivers::uart_puts("\n[Modern DOS Kernel] Booted in S-Mode.\n");
    Drivers::uart_puts("2025 Richard Qin\n");
    Drivers::uart_puts("\n");
    Drivers::uart_puts("\n[Boot] Kernel started.\n");

    PMM::init();
    Drivers::uart_puts("[Boot] PMM initialized.\n");

    VM::kvminit();
    Drivers::uart_puts("[Boot] Kernel page table created.\n");

    VM::kvminithart();
    Drivers::uart_puts("[Boot] MMU ENABLED! We are now using virtual addresses.\n");

    Trap::init();
    Drivers::uart_puts("[Boot] Trap Handler Installed.\n");

    Timer::init();
    Drivers::uart_puts("[Boot] Timer Interrupt Enabled.\n");

    // Drivers::uart_puts("\n[Test] Triggering Page Fault by reading 0x0...\n");
    // volatile int *p = (int *)0x0;
    // int crash = *p;
    // (void)crash;

    // Drivers::uart_puts("[Test Failed] Shuold not reach here.\n");

    // Drivers::uart_puts("\n[Test] Triggering Store Fault on Text Segment...\n");
    // *(int*)0x80000000 = 1234;

    ProcManager::init();
    Drivers::uart_puts("[Boot] Process Manager initialized.\n");

    ProcManager::create_kernel_thread(task_a, "Task A");
    ProcManager::create_kernel_thread(task_b, "Task B");

    ProcManager::scheduler();

    while (1)
    {

    }
}