flux-tui 0.5.0

pub(crate) mod event_queue;
pub(crate) mod handler;
pub(crate) mod helper;

use as_any::AsAny;
use singlevec::SingleVec;
use uid::IdU64;
use vector2d::Vector2D;

use crate::canvas::{BorderCanvas, Canvas};
use crate::common::*;
use std::cell::RefCell;
use std::rc::*;

pub use event_queue::*;
pub use handler::WindowHandler;
pub use helper::*;


/// Defines border decoration
#[derive(Clone, Copy, Debug, PartialEq, Default)]
pub enum BorderKind {
	#[default]
	Solid,
	Thick,
	Dashed,
}

impl BorderKind {
	/// Top Left, Top Right, Bottom Left, Bottom Right
	pub const fn corner_style(&self) -> [Grapheme; 4] {
		match self {
			BorderKind::Solid => [
				Grapheme::new_unchecked("┌", GlyphWidth::Half),
				Grapheme::new_unchecked("┐", GlyphWidth::Half),
				Grapheme::new_unchecked("└", GlyphWidth::Half),
				Grapheme::new_unchecked("┘", GlyphWidth::Half),
			],
			BorderKind::Dashed => [
				Grapheme::new_unchecked("╔", GlyphWidth::Half),
				Grapheme::new_unchecked("╗", GlyphWidth::Half),
				Grapheme::new_unchecked("╚", GlyphWidth::Half),
				Grapheme::new_unchecked("╝", GlyphWidth::Half),
			],
			BorderKind::Thick => [
				Grapheme::new_unchecked("┏", GlyphWidth::Half),
				Grapheme::new_unchecked("┓", GlyphWidth::Half),
				Grapheme::new_unchecked("┗", GlyphWidth::Half),
				Grapheme::new_unchecked("┛", GlyphWidth::Half),
			],
		}
	}

	/// Default cross
	pub const fn cross_style(&self) -> Grapheme {
		match self {
			BorderKind::Solid => Grapheme::new_unchecked("┼", GlyphWidth::Half),
			BorderKind::Dashed => Grapheme::new_unchecked("╬", GlyphWidth::Half),
			BorderKind::Thick => Grapheme::new_unchecked("╋", GlyphWidth::Half),
		}
	}

	/// Non-connected side: Left, Right, Top, Bottom
	pub const fn connector_style(&self) -> [Grapheme; 4] {
		match self {
			BorderKind::Solid => [
				Grapheme::new_unchecked("├", GlyphWidth::Half),
				Grapheme::new_unchecked("┤", GlyphWidth::Half),
				Grapheme::new_unchecked("┬", GlyphWidth::Half),
				Grapheme::new_unchecked("┴", GlyphWidth::Half),
			],
			BorderKind::Dashed => [
				Grapheme::new_unchecked("╠", GlyphWidth::Half),
				Grapheme::new_unchecked("╣", GlyphWidth::Half),
				Grapheme::new_unchecked("╦", GlyphWidth::Half),
				Grapheme::new_unchecked("╩", GlyphWidth::Half),
			],
			BorderKind::Thick => [
				Grapheme::new_unchecked("┣", GlyphWidth::Half),
				Grapheme::new_unchecked("┫", GlyphWidth::Half),
				Grapheme::new_unchecked("┳", GlyphWidth::Half),
				Grapheme::new_unchecked("┻", GlyphWidth::Half),
			],
		}
	}

	/// Horizontal line, Vertical line
	pub const fn line_style(&self) -> [Grapheme; 2] {
		match self {
			BorderKind::Solid => [
				Grapheme::new_unchecked("─", GlyphWidth::Half),
				Grapheme::new_unchecked("│", GlyphWidth::Half),
			],
			BorderKind::Dashed => [
				Grapheme::new_unchecked("═", GlyphWidth::Half),
				Grapheme::new_unchecked("║", GlyphWidth::Half),
			],
			BorderKind::Thick => [
				Grapheme::new_unchecked("━", GlyphWidth::Half),
				Grapheme::new_unchecked("┃", GlyphWidth::Half),
			],
		}
	}
}

/// The given [Window] is the instance which returned BorderStyle
pub type CustomStyleFn = fn(&dyn Window, BorderCanvas);

#[derive(Copy, Clone, Debug, Default)]
pub enum BorderStyle {
	#[default]
	None,
	Preset {
		kind: BorderKind,
		bg: Option<Color>,
		fg: Option<Color>,
	},
	Custom(CustomStyleFn, Thickness),
}

impl PartialEq for BorderStyle {
	fn eq(&self, other: &Self) -> bool {
		match self {
			Self::None => matches!(other, Self::None),
			Self::Preset {
				kind: kind0,
				bg: bg0,
				fg: fg0,
			} => match other {
				Self::Preset { kind, bg, fg } => kind0 == kind && bg0 == bg && fg0 == fg,
				_ => false,
			},
			Self::Custom(_, _) => false,
		}
	}
}

impl BorderStyle {
	pub const fn new(kind: BorderKind, bg: Option<Color>, fg: Option<Color>) -> Self {
		Self::Preset { kind, bg, fg }
	}

	/// Use a custom callback to render the border
	pub const fn custom(f: CustomStyleFn, thickness: Thickness) -> Self {
		Self::Custom(f, thickness)
	}

	pub const fn thickness(&self) -> Thickness {
		match *self {
			BorderStyle::None => Thickness::from(0),
			BorderStyle::Custom(_, tn) => tn,
			_ => Thickness::from(1),
		}
	}

	pub const fn get_borderkind(&self) -> Option<BorderKind> {
		match self {
			BorderStyle::Preset { kind, .. } => Some(*kind),
			_ => None,
		}
	}
}

#[derive(Default, Clone, Copy, Debug, PartialEq)]
pub struct Thickness {
	pub top: TSize,
	pub left: TSize,
	pub right: TSize,
	pub bottom: TSize,
}

impl Thickness {
	pub const fn from(size: TSize) -> Self {
		Self {
			top: size,
			left: size,
			right: size,
			bottom: size,
		}
	}

	pub const fn new(top: TSize, left: TSize, right: TSize, bottom: TSize) -> Self {
		Self {
			top,
			left,
			right,
			bottom,
		}
	}

	pub const fn width(&self) -> TSize {
		self.left + self.right
	}

	pub const fn height(&self) -> TSize {
		self.top + self.bottom
	}
}

impl From<CustomStyleFn> for BorderStyle {
	fn from(value: CustomStyleFn) -> Self {
		Self::Custom(value, Thickness::from(1))
	}
}

impl From<BorderKind> for BorderStyle {
	fn from(value: BorderKind) -> Self {
		Self::Preset {
			kind: value,
			bg: None,
			fg: None,
		}
	}
}

#[derive(Copy, Clone, Debug, Default)]
pub struct RectsOverlapping {}

pub struct SubWindowBuilder {
	base_rect: Rect,
	children: SingleVec<WindowRef>,
	rects: SingleVec<Rect>,
	overlapping: bool,
}

impl SubWindowBuilder {
	pub(crate) fn from(base_rect: Rect) -> Self {
		Self {
			base_rect,
			children: SingleVec::new(),
			rects: SingleVec::new(),
			overlapping: true,
		}
	}

	/// Allows overlapping sub-windows
	/// Enabled by default
	pub fn enable_overlapping(&mut self) {
		self.overlapping = true;
	}

	/// Disallows overlapping sub-windows
	pub fn disable_overlapping(&mut self) {
		self.overlapping = false;
	}

	/// Adds only a new children into the buffer
	pub fn add_child(&mut self, child: WindowRef) {
		self.children.push(child);
	}

	/// Returns [Err] when rects overlap (if overlapping is disabled)
	pub fn add_rect(&mut self, rect: Rect) -> Result<(), RectsOverlapping> {
		if self.check_overlapping(rect) {
			return Err(RectsOverlapping::default());
		}
		self.rects.push(rect);
		Ok(())
	}

	/// If `rect` is None then [Self::base_rect] will be used
	/// Returns [Err] when rects overlap (if overlapping is disabled)
	pub fn add_pair(
		&mut self,
		child: WindowRef,
		rect: Option<Rect>,
	) -> Result<(), RectsOverlapping> {
		let rect = rect.unwrap_or(self.base_rect);
		if self.check_overlapping(rect) {
			return Err(RectsOverlapping::default());
		}

		self.children.push(child);
		self.rects.push(rect);
		Ok(())
	}

	#[inline(always)]
	pub fn base_rect(&self) -> Rect {
		self.base_rect
	}

	/// Builds children and their corresponding rects together
	/// Children and their rects have to be in the same order
	/// Returns `None` when the children and rects length are unequal
	pub fn build(self) -> Option<SubWindows> {
		if self.children.len() != self.rects.len() {
			return None;
		}

		Some(SubWindows {
			children: self.children,
			rects: self.rects,
		})
	}

	fn check_overlapping(&self, rect: Rect) -> bool {
		if !self.overlapping {
			for rt in self.rects.iter() {
				if rt.overlaps(&rect) {
					return true;
				}
			}
		}
		false
	}
}

//Instead SingleVec<SubWindow>
#[derive(Default)]
pub struct SubWindows {
	children: SingleVec<WindowRef>,
	rects: SingleVec<Rect>,
}

impl SubWindows {
	/// Returns the children/sub-windows of the current window
	pub fn children(&self) -> &[WindowRef] {
		&self.children
	}

	/// This returns the childrens associated rectangles
	/// The rectangles define the inner area for rendering
	pub fn rects(&self) -> &[Rect] {
		&self.rects
	}
}

pub type WindowRef = Rc<RefCell<dyn Window>>;
pub type WindowWeakRef = Weak<RefCell<dyn Window>>;

/// Main trait for any window
pub trait Window: WindowLayout + HasWindowUID + AsAny {
	/// The events are forwarded from [crossterm] with the only exception of Resize
	/// which will have the same dimensions as the resulting canvas
	/// If a event's handled attributed is set to true it will stop bubbling
	/// otherwise it will keep bubbling until another Window marks it as handled
	/// Except for:
	/// - [Event::FocusGained] and [Event::FocusLost] indicate focus for the specific Window
	/// - [Event::Resize] is broadcasted
	fn handle_event(&mut self, event: &mut WindowEvent) {
		let _ = event;
	}

	/// Returns all children windows (and layouting [Rect]s)
	/// Note: When changing the children make sure to also adjust the focus
	fn children(&mut self, builder: SubWindowBuilder) -> SubWindows {
		let _ = builder;
		SubWindows::default()
	}

	/// Allows [self] to draw into its own [Canvas]
	/// The canvas size depends on other properties set and the terminal size itself
	/// It is guarenteed that the size of the [Canvas] is atleast 1x1
	fn render(&self, canvas: &mut Canvas);


	/// Which child of the window has focus
	/// Is there is None, then ´self´ has focus
	fn focus(&self) -> Option<WindowRef> {
		None
	}

	/// Is [self] enabled?
	/// Indicated whether or not to handle input and if its focusable
	/// When `false`, [Window] is still eligible to receive events
	fn is_enabled(&self) -> bool {
		true
	}
}


/// Properties which define how the window is drawn
pub trait WindowLayout {
	/// Aligns [self] within its parent [Window]
	fn alignment(&self) -> (HorizontalAlignment, VerticalAlignment) {
		(HorizontalAlignment::default(), VerticalAlignment::default())
	}

	/// This is similar to desired_size but will not return anything and can mutably change [self]
	/// This is executed *before* [WindowLayout::desired_size]
	/// Only implement if actually necessary
	fn desired_size_pre_hook(&mut self, available_size: TPoint) {
		_ = available_size;
	}

	/// Parents call this to get the desired size of the child
	/// This must not exceed `available_size` on any axis
	/// When the result's product is equal to 0, this window wont be drawn
	fn desired_size(&self, available_size: TPoint) -> TPoint {
		available_size
	}

	fn margin(&self) -> Thickness {
		Thickness::default()
	}

	fn border(&self) -> BorderStyle {
		BorderStyle::default()
	}

	fn is_visible(&self) -> bool {
		true
	}
}


pub trait HasWindowUID {
	/// Must be static and unique for each object implementing [Window].
	/// Generate once per instance using [WindowUID::new].
	fn uid(&self) -> WindowUID;
}

/// Helper struct for generating the UID
#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct WindowUID(u64);

impl std::fmt::Display for WindowUID {
	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
		write!(f, "{}", self.0)
	}
}

impl Default for WindowUID {
	fn default() -> Self {
		Self::new()
	}
}

impl WindowUID {
	/// Generates a new [Window]'s UID
	pub fn new() -> Self {
		Self(IdU64::<Self>::new().get())
	}
}