use x86_64::structures::idt::{InterruptStackFrame, PageFaultErrorCode};

macro_rules! exception_default {
    ($stack_frame: expr) => {
        format_args!("instruction addr: 0x{:08x}\nstack addr: 0x{:08x}\nflags: 0x{:x}",
                    $stack_frame.instruction_pointer.as_u64(),
                    $stack_frame.cpu_flags,
                    $stack_frame.stack_pointer.as_u64()
             )
    }
}

pub extern "x86-interrupt" fn breakpoint_handler(stack_frame: &mut InterruptStackFrame) {
    panic!(
        "BREAKPOINT exception thrown\n\n{}",
        exception_default!(stack_frame)
    );
}

pub extern "x86-interrupt" fn page_fault_handler(
    stack_frame: &mut InterruptStackFrame,
    error_code: PageFaultErrorCode,
) {
    use x86_64::registers::control::Cr2;

    panic!(
        "PAGE FAULT while accessing address: 0x{:08x}\nerror code: {:?}(0x{:x})\n{}",
        Cr2::read().as_u64(),
        error_code,
        error_code.bits(),
        exception_default!(stack_frame)
    );
}

pub extern "x86-interrupt" fn segment_not_present_handler(
    stack_frame: &mut InterruptStackFrame,
    error_code: u64,
) {
    panic!(
        "SEGMENT NOT PRESENT exception\nerror code: 0x{:x}\n{}",
        error_code,
        exception_default!(stack_frame)
    );
}

pub extern "x86-interrupt" fn double_fault_handler(
    stack_frame: &mut InterruptStackFrame,
    _error_code: u64, // code is always zero
) {
    panic!(
        "DOUBLE FAULT\nthis is a fatal exception\n{}",
        exception_default!(stack_frame)
    );
}