use core::fmt::*;
use core::hash::*;
use core::iter::*;
use core::num::*;
use core::ops::*;

#[inline(always)]
pub fn align_up(addr: usize, align: usize) -> usize {
    (addr + align - 1) & !(align - 1)
}

#[inline(always)]
pub fn align_down(addr: usize, align: usize) -> usize {
    addr & !(align - 1)
}

#[inline(always)]
pub fn is_aligned(addr: usize, align: usize) -> bool {
    if align.is_power_of_two() {
        addr & (align - 1) == 0
    } else {
        false
    }
}

#[derive(Copy, Clone, Default, Eq, Ord, PartialOrd, PartialEq)]
pub struct PhysAddr(pub usize);

#[derive(Copy, Clone, Default, Eq, Ord, PartialOrd, PartialEq)]
pub struct VirtAddr(pub usize);

pub trait AddressOps: Copy + Clone + Default + Eq + Ord + PartialOrd + PartialEq {
    fn as_mut_ptr<T>(&self) -> *mut T {
        self.as_usize() as *mut T
    }
    fn as_const_ptr<T>(&self) -> *const T {
        self.as_usize() as *const T
    }
    fn as_u32(&self) -> u32;
    fn as_u64(&self) -> u64;
    fn as_usize(&self) -> usize;
    fn as_non_zero_usize(&self) -> Option<NonZeroUsize>;
    fn align_up<T>(&self, align: T) -> Self
    where T: Into<usize>;
    fn align_down<T>(&self, align: T) -> Self
    where T: Into<usize>;
    fn is_aligned<T>(&self, align: T) -> bool
    where T: Into<usize> + Copy {
        is_aligned(self.as_usize(), align.into())
    }
}

impl AddressOps for PhysAddr {
    fn as_u32(&self) -> u32 {
        self.0 as u32
    }

    fn as_u64(&self) -> u64 {
        self.0 as u64
    }

    fn as_usize(&self) -> usize {
        self.0
    }

    fn as_non_zero_usize(&self) -> Option<NonZeroUsize> {
        NonZeroUsize::new(self.0)
    }

    fn align_up<T>(&self, align: T) -> Self
    where T: Into<usize> {
        PhysAddr(align_up(self.0, align.into()))
    }

    fn align_down<T>(&self, align: T) -> Self
    where T: Into<usize> {
        PhysAddr(align_down(self.0, align.into()))
    }
}

impl AddressOps for VirtAddr {
    fn as_u32(&self) -> u32 {
        self.0 as u32
    }

    fn as_u64(&self) -> u64 {
        self.0 as u64
    }

    fn as_usize(&self) -> usize {
        self.0
    }

    fn as_non_zero_usize(&self) -> Option<NonZeroUsize> {
        NonZeroUsize::new(self.0)
    }

    fn align_up<T>(&self, align: T) -> Self
    where T: Into<usize> {
        VirtAddr(align_up(self.0, align.into()))
    }

    fn align_down<T>(&self, align: T) -> Self
    where T: Into<usize> {
        VirtAddr(align_down(self.0, align.into()))
    }
}

impl Add<usize> for PhysAddr {
    type Output = Self;

    fn add(self, rhs: usize) -> Self::Output {
        Self(self.0 + rhs)
    }
}

impl Add<PhysAddr> for PhysAddr {
    type Output = Self;

    fn add(self, rhs: PhysAddr) -> Self::Output {
        Self(self.0 + rhs.0)
    }
}

impl AddAssign<usize> for PhysAddr {
    fn add_assign(&mut self, rhs: usize) {
        *self = PhysAddr::from(self.0 + rhs);
    }
}

impl AddAssign<PhysAddr> for PhysAddr {
    fn add_assign(&mut self, rhs: PhysAddr) {
        *self = PhysAddr::from(self.0 + rhs.0);
    }
}

impl Sub<usize> for PhysAddr {
    type Output = Self;

    fn sub(self, rhs: usize) -> Self::Output {
        PhysAddr(self.0 - rhs)
    }
}

impl Sub<PhysAddr> for PhysAddr {
    type Output = Self;

    fn sub(self, rhs: PhysAddr) -> Self::Output {
        PhysAddr(self.0 - rhs.0)
    }
}

impl SubAssign<usize> for PhysAddr {
    fn sub_assign(&mut self, rhs: usize) {
        *self = PhysAddr::from(self.0 - rhs);
    }
}

impl SubAssign<PhysAddr> for PhysAddr {
    fn sub_assign(&mut self, rhs: PhysAddr) {
        *self = PhysAddr::from(self.0 - rhs.0);
    }
}

impl Add<usize> for VirtAddr {
    type Output = Self;

    fn add(self, rhs: usize) -> Self::Output {
        Self(self.0 + rhs)
    }
}

impl Add<VirtAddr> for VirtAddr {
    type Output = Self;

    fn add(self, rhs: VirtAddr) -> Self::Output {
        Self(self.0 + rhs.0)
    }
}

impl AddAssign<usize> for VirtAddr {
    fn add_assign(&mut self, rhs: usize) {
        *self = VirtAddr::from(self.0 + rhs);
    }
}

impl AddAssign<VirtAddr> for VirtAddr {
    fn add_assign(&mut self, rhs: VirtAddr) {
        *self = VirtAddr::from(self.0 + rhs.0);
    }
}

impl Sub<usize> for VirtAddr {
    type Output = VirtAddr;

    fn sub(self, rhs: usize) -> Self::Output {
        VirtAddr(self.0 - rhs)
    }
}

impl Sub<VirtAddr> for VirtAddr {
    type Output = Self;

    fn sub(self, rhs: VirtAddr) -> Self::Output {
        VirtAddr(self.0 - rhs.0)
    }
}

impl SubAssign<usize> for VirtAddr {
    fn sub_assign(&mut self, rhs: usize) {
        *self = VirtAddr::from(self.0 - rhs);
    }
}

impl SubAssign<VirtAddr> for VirtAddr {
    fn sub_assign(&mut self, rhs: VirtAddr) {
        *self = VirtAddr::from(self.0 - rhs.0);
    }
}

impl From<usize> for PhysAddr {
    fn from(addr: usize) -> Self {
        PhysAddr(addr)
    }
}

impl From<u32> for PhysAddr {
    fn from(addr: u32) -> Self {
        PhysAddr(addr as usize)
    }
}

#[cfg(target_pointer_width = "64")]
impl From<u64> for PhysAddr {
    fn from(addr: u64) -> Self {
        PhysAddr(addr as usize)
    }
}

impl From<NonZeroUsize> for PhysAddr {
    fn from(addr: NonZeroUsize) -> Self {
        PhysAddr(addr.get())
    }
}

impl<T> From<*mut T> for PhysAddr {
    fn from(addr: *mut T) -> Self {
        PhysAddr(addr as usize)
    }
}

impl<T> From<*const T> for PhysAddr {
    fn from(addr: *const T) -> Self {
        PhysAddr(addr as usize)
    }
}

impl From<PhysAddr> for usize {
    fn from(addr: PhysAddr) -> Self {
        addr.0
    }
}

impl From<PhysAddr> for NonZeroUsize {
    fn from(addr: PhysAddr) -> Self {
        NonZeroUsize::new(addr.0).unwrap()
    }
}

impl<T> From<PhysAddr> for *mut T {
    fn from(addr: PhysAddr) -> Self {
        addr.0 as *mut T
    }
}

impl From<usize> for VirtAddr {
    fn from(addr: usize) -> Self {
        VirtAddr(addr)
    }
}

impl From<u32> for VirtAddr {
    fn from(addr: u32) -> Self {
        VirtAddr(addr as usize)
    }
}

#[cfg(target_pointer_width = "64")]
impl From<u64> for VirtAddr {
    fn from(addr: u64) -> Self {
        VirtAddr(addr as usize)
    }
}

impl From<NonZeroUsize> for VirtAddr {
    fn from(addr: NonZeroUsize) -> Self {
        VirtAddr(addr.get())
    }
}

impl<T> From<*mut T> for VirtAddr {
    fn from(addr: *mut T) -> Self {
        VirtAddr(addr as usize)
    }
}

impl<T> From<*const T> for VirtAddr {
    fn from(addr: *const T) -> Self {
        VirtAddr(addr as usize)
    }
}

impl From<VirtAddr> for usize {
    fn from(addr: VirtAddr) -> Self {
        addr.0
    }
}

impl From<VirtAddr> for NonZeroUsize {
    fn from(addr: VirtAddr) -> Self {
        NonZeroUsize::new(addr.0).unwrap()
    }
}

impl<T> From<VirtAddr> for *mut T {
    fn from(addr: VirtAddr) -> Self {
        addr.0 as *mut T
    }
}

impl Debug for PhysAddr {
    fn fmt(&self, f: &mut Formatter) -> Result {
        write!(f, "PhysAddr({:#x})", self.0)
    }
}

impl Display for PhysAddr {
    fn fmt(&self, f: &mut Formatter) -> Result {
        write!(f, "{:#x}", self.0)
    }
}

impl LowerHex for PhysAddr {
    fn fmt(&self, f: &mut Formatter) -> Result {
        write!(f, "{:#x}", self.0)
    }
}

impl UpperHex for PhysAddr {
    fn fmt(&self, f: &mut Formatter) -> Result {
        write!(f, "{:#X}", self.0)
    }
}

impl Debug for VirtAddr {
    fn fmt(&self, f: &mut Formatter) -> Result {
        write!(f, "VirtAddr({:#x})", self.0)
    }
}

impl Display for VirtAddr {
    fn fmt(&self, f: &mut Formatter) -> Result {
        write!(f, "{:#x}", self.0)
    }
}

impl LowerHex for VirtAddr {
    fn fmt(&self, f: &mut Formatter) -> Result {
        write!(f, "{:#x}", self.0)
    }
}

impl UpperHex for VirtAddr {
    fn fmt(&self, f: &mut Formatter) -> Result {
        write!(f, "{:#X}", self.0)
    }
}

impl Hash for PhysAddr {
    fn hash<H: core::hash::Hasher>(&self, state: &mut H) {
        self.0.hash(state);
    }
}

impl Hash for VirtAddr {
    fn hash<H: core::hash::Hasher>(&self, state: &mut H) {
        self.0.hash(state);
    }
}

impl Step for PhysAddr {
    fn steps_between(start: &Self, end: &Self) -> Option<usize> {
        if end.0 >= start.0 {
            Some(end.0 - start.0)
        } else {
            None
        }
    }

    fn forward_checked(start: Self, count: usize) -> Option<Self> {
        start.as_usize().checked_add(count).map(PhysAddr)
    }

    fn backward_checked(start: Self, count: usize) -> Option<Self> {
        start.as_usize().checked_sub(count).map(PhysAddr)
    }
}

impl Step for VirtAddr {
    fn steps_between(start: &Self, end: &Self) -> Option<usize> {
        if end.0 >= start.0 {
            Some(end.0 - start.0)
        } else {
            None
        }
    }

    fn forward_checked(start: Self, count: usize) -> Option<Self> {
        start.as_usize().checked_add(count).map(VirtAddr)
    }

    fn backward_checked(start: Self, count: usize) -> Option<Self> {
        start.as_usize().checked_sub(count).map(VirtAddr)
    }
}

impl PhysAddr {
    /// # Safety
    /// Only provided for the sake of completeness. Use `{mmap, kernel}_phys_to_virt` instead.
    pub unsafe fn to_virt_addr(&self) -> VirtAddr {
        VirtAddr(self.0)
    }
}

impl VirtAddr {
    /// # Safety
    /// Only provided for the sake of completeness. Use `{mmap, kernel}_virt_to_phys` instead.
    pub unsafe fn to_phys_addr(&self) -> PhysAddr {
        PhysAddr(self.0)
    }
}