// This Source Code Form is subject to the terms of the Mozilla Public

// License, v. 2.0. If a copy of the MPL was not distributed with this

// file, You can obtain one at https://mozilla.org/MPL/2.0/.

use crate::day_count::BoundedDayCount;

use crate::day_count::Fixed;

use crate::day_count::FromFixed;

use crate::day_cycle::BoundedCycle;

use crate::day_cycle::OnOrBefore;

#[allow(unused_imports)] //FromPrimitive is needed for derive

use num_traits::FromPrimitive;

/// Represents a day in the common week cycle

///

/// Note that some calendars such as the ISO calendar assign different numbers to each day.

/// See `ISO` for details about that.

///

/// Additionally, some calendars use different week cycles than the common week cycle. Some

/// calendars have seperate data types representing their weekdays, such as `FrenchRevArith`

/// which has a ten-day week. Other calendars which use the same names for their weekdays

/// re-use the `Weekday` struct such as `Cotsworth`. Monday in the common week cycle does

/// not necessarily correspond to Monday in the Cotsworth calendar.

#[derive(Debug, PartialEq, PartialOrd, Clone, Copy, FromPrimitive, ToPrimitive)]

pub enum Weekday {

    //LISTING 1.53-1.59 (*Calendrical Calculations: The Ultimate Edition* by Reingold & Dershowitz.)

    Sunday = 0,

    Monday,

    Tuesday,

    Wednesday,

    Thursday,

    Friday,

    Saturday,

}

impl BoundedCycle<7, 0> for Weekday {}

impl FromFixed for Weekday {

    fn from_fixed(t: Fixed) -> Weekday {

        //LISTING 1.60 (*Calendrical Calculations: The Ultimate Edition* by Reingold & Dershowitz.)

        //Modified to remove superfluous terms, modulus is in BoundedCycle

        Weekday::from_unbounded(t.get_day_i())

    }

}

impl OnOrBefore<7, 0> for Weekday {

    fn raw_on_or_before(self, date: i64) -> Fixed {

        //LISTING 1.62 (*Calendrical Calculations: The Ultimate Edition* by Reingold & Dershowitz.)

        let k = self.to_unbounded();

        Fixed::cast_new(date - (Weekday::from_unbounded(date - k) as i64))

    }

}

#[cfg(test)]

mod tests {

    use super::*;

    use crate::day_count::FIXED_MAX;

    use crate::day_count::FIXED_MIN;

    use proptest::proptest;

    proptest! {

        #[test]

        fn day_of_week_sequence(x in (FIXED_MIN+14.0)..(FIXED_MAX - 14.0)) {

            let w = Weekday::Sunday;

            let d0 = w.on_or_before(Fixed::new(x));

            let d1 = Fixed::new(d0.get() + 1.0);

            let d2 = Fixed::new(d0.get() + 2.0);

            let d3 = Fixed::new(d0.get() + 3.0);

            let d4 = Fixed::new(d0.get() + 4.0);

            let d5 = Fixed::new(d0.get() + 5.0);

            let d6 = Fixed::new(d0.get() + 6.0);

            assert_eq!(Weekday::from_fixed(d0), Weekday::Sunday);

            assert_eq!(Weekday::from_fixed(d1), Weekday::Monday);

            assert_eq!(Weekday::from_fixed(d2), Weekday::Tuesday);

            assert_eq!(Weekday::from_fixed(d3), Weekday::Wednesday);

            assert_eq!(Weekday::from_fixed(d4), Weekday::Thursday);

            assert_eq!(Weekday::from_fixed(d5), Weekday::Friday);

            assert_eq!(Weekday::from_fixed(d6), Weekday::Saturday);

        }

    }

}