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//! Implementations of standard operators:  `Add`, `Sub`, `Mul`, `Div`

use crate::Currency;
use std::ops::{Add, Div, Mul, Sub};

/// Overloads the '+' operator for Currency objects.
///
/// # Panics
/// Panics if the two addends are different types of currency, as denoted by the Currency's symbol.
impl Add for Currency {
    type Output = Currency;

    #[inline]
    fn add(self, rhs: Currency) -> Currency {
        if self.symbol == rhs.symbol || self.symbol.is_none() {
            Currency {
                symbol: rhs.symbol,
                value: self.value + rhs.value,
            }
        } else {
            panic!(
                "Cannot add two different types of currency!\n{:?} vs {:?}",
                self.symbol, rhs.symbol
            );
        }
    }
}

/// Overloads the '-' operator for Currency objects.
///
/// # Panics
/// Panics if the minuend and subtrahend are two different types of currency, as denoted by the
/// Currency's symbol.
impl Sub for Currency {
    type Output = Currency;

    #[inline]
    fn sub(self, rhs: Currency) -> Currency {
        if self.symbol == rhs.symbol {
            Currency {
                symbol: self.symbol,
                value: self.value - rhs.value,
            }
        } else {
            panic!("Cannot subtract two different types of currency!");
        }
    }
}

/// Overloads the '*' operator for Currency objects.
///
/// Allows a Currency to be multiplied by an i64.
impl Mul<i64> for Currency {
    type Output = Currency;

    #[inline]
    fn mul(self, rhs: i64) -> Currency {
        Currency {
            symbol: self.symbol,
            value: self.value * rhs,
        }
    }
}

/// Overloads the '*' operator for i64.
///
/// Allows an i64 to be multiplied by a Currency.
/// Completes the commutative property for i64 multiplied by Currency.
impl Mul<Currency> for i64 {
    type Output = Currency;

    #[inline]
    fn mul(self, rhs: Currency) -> Currency {
        Currency {
            symbol: rhs.symbol,
            value: rhs.value * self,
        }
    }
}

/// Multiplies with float, probably not a good idea, help appreciated.
impl Mul<f64> for Currency {
    type Output = Currency;

    #[inline]
    fn mul(self, rhs: f64) -> Currency {
        Currency {
            symbol: self.symbol,
            value: (self.value as f64 * rhs).round() as i64,
        }
    }
}

impl Mul<Currency> for f64 {
    type Output = Currency;

    #[inline]
    fn mul(self, rhs: Currency) -> Currency {
        rhs * self
    }
}

/// Overloads the '/' operator for Currency objects.
///
/// Allows a Currency to be divided by an i64.
impl Div<i64> for Currency {
    type Output = Currency;

    #[inline]
    fn div(self, rhs: i64) -> Currency {
        Currency {
            symbol: self.symbol,
            value: self.value / rhs,
        }
    }
}