#![no_main]
#![feature(compiler_builtins_lib)]
#![feature(custom_test_frameworks)]
#![feature(abi_x86_interrupt)]
#![feature(panic_info_message)]
#![test_runner(crate::test_runner)]
#![reexport_test_harness_main = "test_main"]
#![no_std]

mod interrupts;
mod io;

use core::fmt::Write;
use io::vga_text::OStream;
use io::{qemu, serial, vga_text};

#[cfg(test)]
pub fn test_runner(tests: &[&dyn Fn(&mut OStream)]) {
    let mut stdout = OStream::new();
    stdout.clear();
    write!(&mut stdout, "running {} tests\n", tests.len()).unwrap();
    for test in tests {
        test(&mut stdout)
    }
}

#[no_mangle]
pub extern "C" fn _start() -> ! {
    interrupts::gdt::init();
    interrupts::table::init();
    if cfg!(test) {
        #[cfg(test)]
        test_main();
        qemu::exit_qemu(qemu::QemuExitCode::Success);
    }

    fn _loop(i: u64) -> u64 {
        if i > 0b1010101001101101 {
             return i;
        }
        let n = i;
        let mut stdout = OStream::new();
        write!(&mut stdout, "{:x}", &n as *const u64 as u64).unwrap();
        _loop(i + 1)
    }
    _loop(0);
    x86_64::instructions::interrupts::int3();

    let stdout = OStream::new();
    stdout.clear();
    panic!("panic! at the disco");

    /// TODO: write test
    ///fn _loop(i: u64) -> u64 {
    ///    if i > 0b1010101001101101 {
    ///         return i;
    ///    }
    ///    let n = i;
    ///    let mut stdout = OStream::new();
    ///    write!(&mut stdout, "{:x}", &n as *const u64 as u64).unwrap();
    ///    _loop(i + 1)
    ///}
    ///_loop(0);
    /// TODO: write test
    ///x86_64::instructions::interrupts::int3();
    loop {}
}

#[panic_handler]
#[no_mangle]
pub extern "C" fn panic_handler(info: &core::panic::PanicInfo) -> ! {
    io::panic_screen::show(info.message());

    if cfg!(test) {
        write!(serial::SerialStream::new(), "Testing failed\n").unwrap();
        qemu::exit_qemu(qemu::QemuExitCode::Failed);
    }
    loop {}
}