use super::Reflect;

pub trait Array: Reflect {
    /// Get a borrow to the element at `idx` in the array.
    fn get(&self, idx: usize) -> Option<&dyn Reflect>;

    /// Get a mutable borrow to the element at `idx` in the array.
    fn get_mut(&mut self, idx: usize) -> Option<&mut dyn Reflect>;

    /// Returns the length of the array
    fn len(&self) -> usize;
}

impl<T: Clone + Reflect, const N: usize> Array for [T; N] {
    fn get(&self, idx: usize) -> Option<&dyn Reflect> {
        if idx < self.len() {
            Some(&self[idx])
        } else {
            None
        }
    }

    fn get_mut(&mut self, idx: usize) -> Option<&mut dyn Reflect> {
        if idx < self.len() {
            Some(&mut self[idx])
        } else {
            None
        }
    }

    fn len(&self) -> usize {
        N
    }
}

#[cfg(test)]
mod tests {
    use crate::{Reflect, ReflectRef};

    #[test]
    fn simple() {
        let mut arr = [0; 4];
        arr[0] = 340;
        arr[1] = 275;
        arr[2] = 5;
        arr[3] = 93;

        let arr = Box::new(arr) as Box<dyn Reflect>;
        
        if let ReflectRef::Array(arr) = arr.reflect_ref() {
            let zero = arr.get(0).unwrap().as_any().downcast_ref::<i32>().unwrap();
            assert_eq!(*zero, 340);

            let one = arr.get(1).unwrap().as_any().downcast_ref::<i32>().unwrap();
            assert_eq!(*one, 275);

            let two = arr.get(2).unwrap().as_any().downcast_ref::<i32>().unwrap();
            assert_eq!(*two, 5);

            let three = arr.get(3).unwrap().as_any().downcast_ref::<i32>().unwrap();
            assert_eq!(*three, 93);
        }
    }
}