//! Structures for tracing the execution flow of [Monad]s.

mod rendered;
mod rendered_display;
mod trace;
mod traceable;
mod traced;

use crate::rcore::*;

use super::*;

pub use self::rendered::{
    RenderedAny, RenderedCommon, RenderedLong, RenderedWide, WithLengthAndWidth,
};
use self::trace::*;
pub use self::traceable::Traceable;
pub use self::traced::Traced;

/// [`Diagnostic`] for [Traced] objects.
///
/// [`Diagnostic::after`]/[`Diagnostic::before`] are represented in [`RenderedCommon::Event`].
/// [`Diagnostic::wrapped`] is represented in [`RenderedCommon::Action`].
pub struct TracedDiagnostic;

/// Implementation of [`Monad`] for [Traced] objects.
pub type TracedInstance = instances::effect::EffectInstance<TraceBox>;

impl instances::effect::Effect for TraceBox {
    fn e_pure() -> Self {
        TraceBox::pure()
    }

    fn e_seq(el: Self, er: Self) -> Self {
        TraceBox::parallel(el, er)
    }

    fn e_after(self, effect: Self) -> Self {
        self.after(effect)
    }
}

trait WithTrace: Sized {
    fn with_trace(self, t: TraceBox) -> Traced<Self>;
}

impl<A> WithTrace for A {
    fn with_trace(self, t: TraceBox) -> Traced<Self> {
        Traced {
            value: self,
            effect: t,
        }
    }
}

impl<A> Traced<A> {
    fn wrapped(self, event: String) -> Self {
        Traced {
            value: self.value,
            effect: self.effect.wrapped(event),
        }
    }

    pub fn after_resolution(self) -> Self {
        self.after(TraceBox::resolution())
    }

    fn after(self, t: TraceBox) -> Self {
        Traced {
            value: self.value,
            effect: self.effect.after(t),
        }
    }

    fn before(self, t: TraceBox) -> Self {
        Traced {
            value: self.value,
            effect: self.effect.before(t),
        }
    }

    pub fn length(&self) -> usize {
        self.effect.length()
    }

    pub fn width(&self) -> usize {
        self.effect.width()
    }
}

impl<'a> Diagnostic<'a, TracedInstance> for TracedDiagnostic {
    fn after<'b, A>(fa: Traced<A>, event: impl FnOnce() -> String) -> Traced<A>
    where
        'a: 'b,
    {
        fa.after(TraceBox::event(event()))
    }

    fn before<'b, A>(fa: Traced<A>, event: impl FnOnce() -> String) -> Traced<A>
    where
        'a: 'b,
    {
        fa.before(TraceBox::event(event()))
    }

    fn wrapped<'b, A>(fa: Traced<A>, event: impl FnOnce() -> String) -> Traced<A>
    where
        'a: 'b,
    {
        fa.wrapped(event())
    }
}