// This file is part of "haussmann"
// Under the MIT License
// Copyright (c) 2023 Antonin Hérault

//! Widgets are items to be placed on a drawable surface and managed by layouts.

use crate::{
    graphics::{Shape, Size},
    ToAny,
};

mod button;
mod container;
mod image;
mod label;
mod layout;
mod toolbar;

pub use button::Button;
pub use container::Container;
pub use image::Image;
pub use label::Label;
pub use layout::Layout;
pub use toolbar::ToolBar;

/// The simplest functionalities and property getters of any widget.
pub trait Widget: DebugWidget + ToAny {
    /// Returns the widget as a shape of `size`. If it's a widget containing
    /// other widgets, it does not return its children but only itself as a
    /// shape.
    ///
    /// If the size is `None`, the widget has to define its own size.
    fn shape(&self, size: Option<Size>) -> Shape;
}

/// Automatically implemented by the macro [`dynamic_widget`](crate::dynamic_widget).
pub trait DebugWidget: std::fmt::Debug {
    /// Should not be overridden
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(f, "{:?}", self)
    }
}

/// Implements what it is needed to make a widget a clean `dyn Widget` to be
/// inserted in layouts etc...
///
/// The `t` argument is the type of the widget. It can be a [`Button`], a
/// [`Label`], ...
///
/// To use this trait, the [`ToAny`], [`Widget`] and [`DebugWidget`] traits must
/// be imported in the usage context.
#[macro_export]
macro_rules! dynamic_widget {
    ($t:ty) => {
        impl ToAny for $t {
            fn as_any(&self) -> &dyn std::any::Any {
                self
            }
        }

        impl From<$t> for Box<dyn Widget> {
            fn from(value: $t) -> Self {
                Box::new(value)
            }
        }

        impl DebugWidget for $t {}
    };
}

/// Same as [`dynamic_widget`](crate::dynamic_widget) but for controller 
/// widgets since controllers have a generic parameters as following : 
/// `<'a, T: Widget + 'static>`.
/// 
/// Also, the [`ToAny`] trait implementation returns the widget as 
/// [`std::any::Any`] and not the controller itself.
#[macro_export]
macro_rules! dynamic_controller {
    ($t:ty) => {
        impl<'a, T: Widget + 'static> ToAny for $t {
            fn as_any(&self) -> &dyn std::any::Any {
                self.widget.as_any()
            }
        }
        
        impl<'a, T: Widget + 'static> From<$t> for Box<dyn Widget> {
            fn from(value: $t) -> Self {
                Box::new(value)
            }
        }
        
        impl<'a, T: Widget> DebugWidget for $t {}        
    };
}



/// Creates a vector of dynamic widgets from a series of widgets, no matter
/// their type as long as they implement the [`Widget`] trait.
///
/// To use this trait, the [`Widget`] trait must be imported in the usage
/// context.
#[macro_export]
macro_rules! widgets {
    () => {
        vec![]
    };

    ($first:expr $(, $widget:expr) *,) => {
        widgets![$first, $($widget),*]
    };

    ($first:expr $(, $widget:expr) *) => {
        // Code block returning a vector of boxes of dynamic widget.
        {
            // The type annotation here is very important. It transforms the
            // widget boxes into boxes of dynamic widget.
            let widgets: Vec<Box<dyn Widget>> = vec![
                $first.into(),
                $($widget.into()),*
            ];
            widgets
        }
    };
}