//!

//! # Overview

//!

//! This crate is part of

//! [Arti](https://gitlab.torproject.org/tpo/core/arti/), a project to

//! implement [Tor](https://www.torproject.org/) in Rust.

//! It provides safe wrappers for primitive numeric wrappers used in

//! other parts of Arti.

//! In particular, it provides:

//!   * a bounded i32 with both checked and clamping constructors,

//!   * an integer milliseconds wrapper with conversion to [`Duration`]

//!   * an integer seconds wrapper with conversion to [`Duration`]

//!   * a percentage wrapper, to prevent accidental failure

//!     to divide by 100.

//!   * a SendMeVersion which can be compared only.

#![deny(missing_docs)]

#![warn(noop_method_call)]

#![deny(unreachable_pub)]

#![warn(clippy::all)]

#![deny(clippy::await_holding_lock)]

#![deny(clippy::cargo_common_metadata)]

#![deny(clippy::cast_lossless)]

#![deny(clippy::checked_conversions)]

#![warn(clippy::cognitive_complexity)]

#![deny(clippy::debug_assert_with_mut_call)]

#![deny(clippy::exhaustive_enums)]

#![deny(clippy::exhaustive_structs)]

#![deny(clippy::expl_impl_clone_on_copy)]

#![deny(clippy::fallible_impl_from)]

#![deny(clippy::implicit_clone)]

#![deny(clippy::large_stack_arrays)]

#![warn(clippy::manual_ok_or)]

#![deny(clippy::missing_docs_in_private_items)]

#![deny(clippy::missing_panics_doc)]

#![warn(clippy::needless_borrow)]

#![warn(clippy::needless_pass_by_value)]

#![warn(clippy::option_option)]

#![warn(clippy::rc_buffer)]

#![deny(clippy::ref_option_ref)]

#![warn(clippy::semicolon_if_nothing_returned)]

#![warn(clippy::trait_duplication_in_bounds)]

#![deny(clippy::unnecessary_wraps)]

#![warn(clippy::unseparated_literal_suffix)]

#![deny(clippy::unwrap_used)]

use derive_more::{Add, Display, Div, From, FromStr, Mul};

use std::convert::{TryFrom, TryInto};

use std::time::Duration;

use thiserror::Error;

/// Conversion errors from converting a value into a [`BoundedInt32`].

#[non_exhaustive]

pub enum Error {

    /// A passed value was below the lower bound for the type.

    #[error("Value {0} was below the lower bound {1} for this type.")]

    BelowLowerBound(i32, i32),

    /// A passed value was above the upper bound for the type.

    #[error("Value {0} was above the lower bound {1} for this type.")]

    AboveUpperBound(i32, i32),

    /// Tried to convert a negative value to an unsigned type.

    #[error("Tried to convert a negative value to an unsigned type")]

    Negative,

    /// Tried to parse a value that was not representable as the

    /// underlying type.

    #[error("Value could not be represented as an i32")]

    Unrepresentable,

    /// We encountered some kind of integer overflow when converting a number.

    #[error("Integer overflow")]

    Overflow,

    /// Tried to instantiate an uninhabited type.

    #[error("No value is valid for this type")]

    Uninhabited,

}

/// A 32-bit signed integer with a restricted range.

///

/// This type holds an i32 value such that `LOWER` <= value <= `UPPER`

///

/// # Limitations

///

/// If you try to instantiate this type with LOWER > UPPER, you will

/// get an uninhabitable type.  It would be better if we could check that at

/// compile time, and prevent such types from being named.

//

// [TODO: If you need a Bounded* for some type other than i32, ask nickm:

// he has an implementation kicking around.]

pub struct BoundedInt32<const LOWER: i32, const UPPER: i32> {

    /// Interior Value

    value: i32,

}

impl<const LOWER: i32, const UPPER: i32> BoundedInt32<LOWER, UPPER> {

    /// Lower bound

    pub const LOWER: i32 = LOWER;

    /// Upper bound

    pub const UPPER: i32 = UPPER;

    /// Private constructor function for this type.

    /// Return the underlying i32 value.

    ///

    /// This value will always be between [`Self::LOWER`] and [`Self::UPPER`],

    /// inclusive.

    /// If `val` is within range, return a new `BoundedInt32` wrapping

    /// it; otherwise, clamp it to the upper or lower bound as

    /// appropriate.

    /// If `val` is an acceptable value inside the range for this type,

    /// return a new [`BoundedInt32`].  Otherwise return an error.

        } else {

        }

    /// This private function clamps an input to the acceptable range.

    /// Convert from the underlying type, clamping to the upper or

    /// lower bound if needed.

    ///

    /// # Panics

    ///

    /// This function will panic if UPPER < LOWER.

    /// Convert from a string, clamping to the upper or lower bound if needed.

    ///

    /// # Limitations

    ///

    /// If the input is a number that cannot be represented as an i32,

    /// then we return an error instead of clamping it.

            // The compiler should optimize this block out at compile time.

}

impl<const L: i32, const U: i32> std::fmt::Display for BoundedInt32<L, U> {

}

impl<const L: i32, const U: i32> From<BoundedInt32<L, U>> for i32 {

}

impl<const L: i32, const U: i32> From<BoundedInt32<L, U>> for f64 {

}

impl<const L: i32, const H: i32> TryFrom<i32> for BoundedInt32<L, H> {

    type Error = Error;

}

impl<const L: i32, const H: i32> std::str::FromStr for BoundedInt32<L, H> {

    type Err = Error;

}

impl From<BoundedInt32<0, 1>> for bool {

}

impl From<BoundedInt32<0, 255>> for u8 {

}

impl<const H: i32> From<BoundedInt32<0, H>> for u32 {

}

impl<const H: i32> From<BoundedInt32<1, H>> for u32 {

}

impl<const L: i32, const H: i32> TryFrom<BoundedInt32<L, H>> for u64 {

    type Error = Error;

        } else {

        }

}

impl<const L: i32, const H: i32> TryFrom<BoundedInt32<L, H>> for usize {

    type Error = Error;

        } else {

        }

}

/// A percentage value represented as a number.

///

/// This type wraps an underlying numeric type, and ensures that callers

/// are clear whether they want a _fraction_, or a _percentage_.

pub struct Percentage<T: Copy + Into<f64>> {

    /// The underlying percentage value.

    value: T,

}

impl<T: Copy + Into<f64>> Percentage<T> {

    /// Create a new `IntPercentage` from the underlying percentage.

    /// Return this value as a (possibly improper) fraction.

    ///

    /// ```

    /// use tor_units::Percentage;

    /// let pct_200 = Percentage::<u8>::new(200);

    /// let pct_100 = Percentage::<u8>::new(100);

    /// let pct_50 = Percentage::<u8>::new(50);

    ///

    /// assert_eq!(pct_200.as_fraction(), 2.0);

    /// assert_eq!(pct_100.as_fraction(), 1.0);

    /// assert_eq!(pct_50.as_fraction(), 0.5);

    /// // Note: don't actually compare f64 with ==.

    /// ```

    /// Return this value as a percentage.

    ///

    /// ```

    /// use tor_units::Percentage;

    /// let pct_200 = Percentage::<u8>::new(200);

    /// let pct_100 = Percentage::<u8>::new(100);

    /// let pct_50 = Percentage::<u8>::new(50);

    ///

    /// assert_eq!(pct_200.as_percent(), 200);

    /// assert_eq!(pct_100.as_percent(), 100);

    /// assert_eq!(pct_50.as_percent(), 50);

    /// ```

}

impl<const H: i32, const L: i32> TryFrom<i32> for Percentage<BoundedInt32<H, L>> {

    type Error = Error;

}

#[derive(

)]

/// This type represents an integer number of milliseconds.

///

/// The underlying type should implement TryInto<u64>.

pub struct IntegerMilliseconds<T> {

    /// Interior Value. Should Implement TryInto<u64> to be useful.

    value: T,

}

impl<T: TryInto<u64>> IntegerMilliseconds<T> {

    /// Public Constructor

}

impl<T: TryInto<u64>> TryFrom<IntegerMilliseconds<T>> for Duration {

    type Error = <T as TryInto<u64>>::Error;

}

impl<const H: i32, const L: i32> TryFrom<i32> for IntegerMilliseconds<BoundedInt32<H, L>> {

    type Error = Error;

}

#[derive(

)]

/// This type represents an integer number of seconds.

///

/// The underlying type should implement TryInto<u64>.

pub struct IntegerSeconds<T> {

    /// Interior Value. Should Implement TryInto<u64> to be useful.

    value: T,

}

impl<T: TryInto<u64>> IntegerSeconds<T> {

    /// Public Constructor

}

impl<T: TryInto<u64>> TryFrom<IntegerSeconds<T>> for Duration {

    type Error = <T as TryInto<u64>>::Error;

}

impl<const H: i32, const L: i32> TryFrom<i32> for IntegerSeconds<BoundedInt32<H, L>> {

    type Error = Error;

}

/// This type represents an integer number of days.

///

/// The underlying type should implement TryInto<u64>.

pub struct IntegerDays<T> {

    /// Interior Value. Should Implement TryInto<u64> to be useful.

    value: T,

}

impl<T> IntegerDays<T> {

    /// Public Constructor

}

impl<T: TryInto<u64>> TryFrom<IntegerDays<T>> for Duration {

    type Error = Error;

        /// Number of seconds in a single day.

        const SECONDS_PER_DAY: u64 = 86400;

}

impl<const H: i32, const L: i32> TryFrom<i32> for IntegerDays<BoundedInt32<H, L>> {

    type Error = Error;

}

/// A SendMe Version

///

/// DOCDOC: Explain why this needs to have its own type, or remove it.

pub struct SendMeVersion(u8);

impl SendMeVersion {

    /// Public Constructor

    /// Helper

}

impl TryFrom<i32> for SendMeVersion {

    type Error = Error;

}

#[cfg(test)]

mod tests {

    #![allow(clippy::unwrap_used)]

    use float_cmp::assert_approx_eq;

    use super::*;

    use std::convert::TryInto;

    type TestFoo = BoundedInt32<1, 5>;

    type TestBar = BoundedInt32<-45, 17>;

    //make_parameter_type! {TestFoo(3,)}

    #[test]

    fn entire_range_parsed() {

        let x: TestFoo = "1".parse().unwrap();

        assert!(x.get() == 1);

        let x: TestFoo = "2".parse().unwrap();

        assert!(x.get() == 2);

        let x: TestFoo = "3".parse().unwrap();

        assert!(x.get() == 3);

        let x: TestFoo = "4".parse().unwrap();

        assert!(x.get() == 4);

        let x: TestFoo = "5".parse().unwrap();

        assert!(x.get() == 5);

    }

    #[test]

    fn saturating() {

        let x: TestFoo = TestFoo::saturating_new(1000);

        let x_val: i32 = x.into();

        assert!(x_val == TestFoo::UPPER);

        let x: TestFoo = TestFoo::saturating_new(0);

        let x_val: i32 = x.into();

        assert!(x_val == TestFoo::LOWER);

    }

    #[test]

    fn saturating_string() {

        let x: TestFoo = TestFoo::saturating_from_str("1000").unwrap();

        let x_val: i32 = x.into();

        assert!(x_val == TestFoo::UPPER);

        let x: TestFoo = TestFoo::saturating_from_str("0").unwrap();

        let x_val: i32 = x.into();

        assert!(x_val == TestFoo::LOWER);

    }

    #[test]

    #[should_panic]

    fn uninhabited_saturating_new() {

        // This value should be uncreatable.

        let _: BoundedInt32<10, 5> = BoundedInt32::saturating_new(7);

    }

    #[test]

    fn uninhabited_from_string() {

        let v: Result<BoundedInt32<10, 5>, Error> = BoundedInt32::saturating_from_str("7");

        assert!(matches!(v, Err(Error::Uninhabited)));

    }

    #[test]

    fn errors_correct() {

        let x: Result<TestBar, Error> = "1000".parse();

        assert!(x.unwrap_err() == Error::AboveUpperBound(1000, TestBar::UPPER));

        let x: Result<TestBar, Error> = "-1000".parse();

        assert!(x.unwrap_err() == Error::BelowLowerBound(-1000, TestBar::LOWER));

        let x: Result<TestBar, Error> = "xyz".parse();

        assert!(x.unwrap_err() == Error::Unrepresentable);

    }

    #[test]

    fn display() {

        let v = BoundedInt32::<99, 1000>::checked_new(345).unwrap();

        assert_eq!(v.to_string(), "345".to_string());

    }

    #[test]

    #[should_panic]

    fn checked_too_high() {

        let _: TestBar = "1000".parse().unwrap();

    }

    #[test]

    #[should_panic]

    fn checked_too_low() {

        let _: TestBar = "-46".parse().unwrap();

    }

    #[test]

    fn bounded_to_u64() {

        let b: BoundedInt32<-100, 100> = BoundedInt32::checked_new(77).unwrap();

        let u: u64 = b.try_into().unwrap();

        assert_eq!(u, 77);

        let b: BoundedInt32<-100, 100> = BoundedInt32::checked_new(-77).unwrap();

        let u: Result<u64, Error> = b.try_into();

        assert!(u.is_err());

    }

    #[test]

    fn bounded_to_f64() {

        let x: BoundedInt32<-100, 100> = BoundedInt32::checked_new(77).unwrap();

        let f: f64 = x.into();

        assert_approx_eq!(f64, f, 77.0);

    }

    #[test]

    fn bounded_from_i32() {

        let x: Result<BoundedInt32<-100, 100>, _> = 50.try_into();

        let y: i32 = x.unwrap().into();

        assert_eq!(y, 50);

        let x: Result<BoundedInt32<-100, 100>, _> = 1000.try_into();

        assert!(x.is_err());

    }

    #[test]

    fn into_bool() {

        let zero: BoundedInt32<0, 1> = BoundedInt32::saturating_from(0);

        let one: BoundedInt32<0, 1> = BoundedInt32::saturating_from(1);

        let f: bool = zero.into();

        let t: bool = one.into();

        assert!(!f);

        assert!(t);

    }

    #[test]

    fn into_u8() {

        let zero: BoundedInt32<0, 255> = BoundedInt32::saturating_from(0);

        let one: BoundedInt32<0, 255> = BoundedInt32::saturating_from(1);

        let ninety: BoundedInt32<0, 255> = BoundedInt32::saturating_from(90);

        let max: BoundedInt32<0, 255> = BoundedInt32::saturating_from(1000);

        let a: u8 = zero.into();

        let b: u8 = one.into();

        let c: u8 = ninety.into();

        let d: u8 = max.into();

        assert_eq!(a, 0);

        assert_eq!(b, 1);

        assert_eq!(c, 90);

        assert_eq!(d, 255);

    }

    #[test]

    fn into_u32() {

        let zero: BoundedInt32<0, 1000> = BoundedInt32::saturating_from(0);

        let one: BoundedInt32<0, 1000> = BoundedInt32::saturating_from(1);

        let ninety: BoundedInt32<0, 1000> = BoundedInt32::saturating_from(90);

        let max: BoundedInt32<0, 1000> = BoundedInt32::saturating_from(1000);

        assert_eq!(u32::from(zero), 0);

        assert_eq!(u32::from(one), 1);

        assert_eq!(u32::from(ninety), 90);

        assert_eq!(u32::from(max), 1000);

        let zero: BoundedInt32<1, 1000> = BoundedInt32::saturating_from(0);

        let one: BoundedInt32<1, 1000> = BoundedInt32::saturating_from(1);

        let ninety: BoundedInt32<1, 1000> = BoundedInt32::saturating_from(90);

        let max: BoundedInt32<1, 1000> = BoundedInt32::saturating_from(1000);

        assert_eq!(u32::from(zero), 1);

        assert_eq!(u32::from(one), 1);

        assert_eq!(u32::from(ninety), 90);

        assert_eq!(u32::from(max), 1000);

    }

    #[test]

    fn try_into_usize() {

        let b0: BoundedInt32<-10, 300> = BoundedInt32::saturating_from(0);

        let b100: BoundedInt32<-10, 300> = BoundedInt32::saturating_from(100);

        let bn5: BoundedInt32<-10, 300> = BoundedInt32::saturating_from(-5);

        assert_eq!(usize::try_from(b0), Ok(0_usize));

        assert_eq!(usize::try_from(b100), Ok(100_usize));

        assert_eq!(usize::try_from(bn5), Err(Error::Negative));

    }

    #[test]

    fn percents() {

        type Pct = Percentage<u8>;

        let p = Pct::new(100);

        assert_eq!(p.as_percent(), 100);

        assert_approx_eq!(f64, p.as_fraction(), 1.0);

        let p = Pct::new(0);

        assert_eq!(p.as_percent(), 0);

        assert_approx_eq!(f64, p.as_fraction(), 0.0);

        let p = Pct::new(25);

        assert_eq!(p.as_percent(), 25);

        assert_eq!(p.clone(), p);

        assert_approx_eq!(f64, p.as_fraction(), 0.25);

        type BPct = Percentage<BoundedInt32<0, 100>>;

        assert_eq!(BPct::try_from(99).unwrap().as_percent().get(), 99);

    }

    #[test]

    fn milliseconds() {

        type Msec = IntegerMilliseconds<i32>;

        let ms = Msec::new(500);

        let d: Result<Duration, _> = ms.try_into();

        assert_eq!(d.unwrap(), Duration::from_millis(500));

        assert_eq!(Duration::try_from(ms * 2).unwrap(), Duration::from_secs(1));

        let ms = Msec::new(-100);

        let d: Result<Duration, _> = ms.try_into();

        assert!(d.is_err());

        type BMSec = IntegerMilliseconds<BoundedInt32<0, 1000>>;

        let half_sec = BMSec::try_from(500).unwrap();

        assert_eq!(

            Duration::try_from(half_sec).unwrap(),

            Duration::from_millis(500)

        );

        assert!(BMSec::try_from(1001).is_err());

    }

    #[test]

    fn seconds() {

        type Sec = IntegerSeconds<i32>;

        let ms = Sec::new(500);

        let d: Result<Duration, _> = ms.try_into();

        assert_eq!(d.unwrap(), Duration::from_secs(500));

        let ms = Sec::new(-100);

        let d: Result<Duration, _> = ms.try_into();

        assert!(d.is_err());

        type BSec = IntegerSeconds<BoundedInt32<0, 3600>>;

        let half_hour = BSec::try_from(1800).unwrap();

        assert_eq!(

            Duration::try_from(half_hour).unwrap(),

            Duration::from_secs(1800)

        );

        assert!(BSec::try_from(9999).is_err());

        assert_eq!(half_hour.clone(), half_hour);

    }

    #[test]

    fn days() {

        type Days = IntegerDays<i32>;

        let t = Days::new(500);

        let d: Duration = t.try_into().unwrap();

        assert_eq!(d, Duration::from_secs(500 * 86400));

        let t = Days::new(-100);

        let d: Result<Duration, _> = t.try_into();

        assert_eq!(d, Err(Error::Overflow));

        let t = IntegerDays::<u64>::new(u64::MAX);

        let d: Result<Duration, _> = t.try_into();

        assert_eq!(d, Err(Error::Overflow));

        type BDays = IntegerDays<BoundedInt32<10, 30>>;

        assert_eq!(

            BDays::new(17_i32.try_into().unwrap()),

            BDays::try_from(17).unwrap()

        );

    }

    #[test]

    fn sendme() {

        let smv = SendMeVersion::new(5);

        assert_eq!(smv.get(), 5);

        assert_eq!(smv.clone().get(), 5);

        assert_eq!(smv, SendMeVersion::try_from(5).unwrap());

    }

}