use crate::*;
use std::sync::atomic::Ordering;

//pub trait MaybeHas<T>: Send + Sync {
    //fn get (&self) -> Option<&T>;
//}

pub trait HasN<T>: Send + Sync {
    fn get_nth     (&self,     key: usize) -> &T;
    fn get_nth_mut (&mut self, key: usize) -> &mut T;
}

pub trait Gettable<T> {
    /// Returns current value
    fn get (&self) -> T;
}

pub trait Mutable<T>: Gettable<T> {
    /// Sets new value, returns old
    fn set (&mut self, value: T) -> T;
}

pub trait InteriorMutable<T>: Gettable<T> {
    /// Sets new value, returns old
    fn set (&self, value: T) -> T;
}

pub trait NotePoint {
    fn note_len (&self) -> &AtomicUsize;
    /// Get the current length of the note cursor.
    fn get_note_len (&self) -> usize {
        self.note_len().load(Relaxed)
    }
    /// Set the length of the note cursor, returning the previous value.
    fn set_note_len (&self, x: usize) -> usize {
        self.note_len().swap(x, Relaxed)
    }

    fn note_pos (&self) -> &AtomicUsize;
    /// Get the current pitch of the note cursor.
    fn get_note_pos (&self) -> usize {
        self.note_pos().load(Relaxed).min(127)
    }
    /// Set the current pitch fo the note cursor, returning the previous value.
    fn set_note_pos (&self, x: usize) -> usize {
        self.note_pos().swap(x.min(127), Relaxed)
    }
}

pub trait TimePoint {
    fn time_pos (&self) -> &AtomicUsize;
    /// Get the current time position of the note cursor.
    fn get_time_pos (&self) -> usize {
        self.time_pos().load(Relaxed)
    }
    /// Set the current time position of the note cursor, returning the previous value.
    fn set_time_pos (&self, x: usize) -> usize {
        self.time_pos().swap(x, Relaxed)
    }
}

pub trait MidiPoint: NotePoint + TimePoint {
    /// Get the current end of the note cursor.
    fn get_note_end (&self) -> usize {
        self.get_time_pos() + self.get_note_len()
    }
}

pub trait TimeRange {
    fn time_len (&self) -> &AtomicUsize;
    fn get_time_len (&self) -> usize {
        self.time_len().load(Ordering::Relaxed)
    }
    fn time_zoom (&self) -> &AtomicUsize;
    fn get_time_zoom (&self) -> usize {
        self.time_zoom().load(Ordering::Relaxed)
    }
    fn set_time_zoom (&self, value: usize) -> usize {
        self.time_zoom().swap(value, Ordering::Relaxed)
    }
    fn time_lock (&self) -> &AtomicBool;
    fn get_time_lock (&self) -> bool {
        self.time_lock().load(Ordering::Relaxed)
    }
    fn set_time_lock (&self, value: bool) -> bool {
        self.time_lock().swap(value, Ordering::Relaxed)
    }
    fn time_start (&self) -> &AtomicUsize;
    fn get_time_start (&self) -> usize {
        self.time_start().load(Ordering::Relaxed)
    }
    fn set_time_start (&self, value: usize) -> usize {
        self.time_start().swap(value, Ordering::Relaxed)
    }
    fn time_axis (&self) -> &AtomicUsize;
    fn get_time_axis (&self) -> usize {
        self.time_axis().load(Ordering::Relaxed)
    }
    fn get_time_end (&self) -> usize {
        self.time_start().get() + self.time_axis().get() * self.time_zoom().get()
    }
}

pub trait NoteRange {
    fn note_lo (&self) -> &AtomicUsize;
    fn get_note_lo (&self) -> usize {
        self.note_lo().load(Ordering::Relaxed)
    }
    fn set_note_lo (&self, x: usize) -> usize {
        self.note_lo().swap(x, Ordering::Relaxed)
    }
    fn note_axis (&self) -> &AtomicUsize;
    fn get_note_axis (&self) -> usize {
        self.note_axis().load(Ordering::Relaxed)
    }
    fn get_note_hi (&self) -> usize {
        (self.note_lo().get() + self.note_axis().get().saturating_sub(1)).min(127)
    }
}

pub trait MidiRange: TimeRange + NoteRange {}

/// A unit of time, represented as an atomic 64-bit float.
///
/// According to https://stackoverflow.com/a/873367, as per IEEE754,
/// every integer between 1 and 2^53 can be represented exactly.
/// This should mean that, even at 192kHz sampling rate, over 1 year of audio
/// can be clocked in microseconds with f64 without losing precision.
pub trait TimeUnit: InteriorMutable<f64> {}