zeyn 0.0.3

//! Layout containers: `Row`, `Stack`, `Panel`, `Card`, `Tabs` and `Split`. Each holds other nodes,
//! so grids, forms and other containers can be placed inside.

use super::{dom_id, render_child};
use crate::i18n::Text;
use crate::render::{Render, slug};
use crate::screen::{Component, Node, Toolbar};
use serde_json::{Value as Json, json};

/// Implements `From<T> for Node` for components of this library.
macro_rules! into_node {
    ($($t:ty),* $(,)?) => {
        $(impl From<$t> for Node {
            fn from(c: $t) -> Self {
                Node::new(c)
            }
        })*
    };
}
pub(crate) use into_node;

into_node!(Row, Stack, Panel, Card, Tabs, Split);

fn children_schema(nodes: &[Node]) -> Vec<Json> {
    nodes.iter().map(Node::schema).collect()
}

/// Columns side by side. Each column takes a share of the width by its weight; on narrow screens
/// the columns stack.
///
/// ```ignore
/// Row::new().col(customer_form).weight(2).col(order_totals)
/// ```
#[derive(Default)]
pub struct Row {
    nodes: Vec<Node>,
    weights: Vec<u8>,
    compact: bool,
}

impl Row {
    pub fn new() -> Self {
        Self::default()
    }

    /// Adds a column with weight 1.
    pub fn col(mut self, node: impl Into<Node>) -> Self {
        self.nodes.push(node.into());
        self.weights.push(1);
        self
    }

    /// Columns as wide as their content, wrapping when there is no room: for badges and buttons.
    pub fn compact(mut self) -> Self {
        self.compact = true;
        self
    }

    /// Weight of the last column, 1 to 12. A column of weight 2 is twice as wide as one of weight 1.
    pub fn weight(mut self, weight: u8) -> Self {
        if let Some(w) = self.weights.last_mut() {
            *w = weight.clamp(1, 12);
        }
        self
    }
}

impl Component for Row {
    fn render(&self, out: &mut String, r: &Render) {
        out.push_str(if self.compact { r#"<div class="z-row z-row-compact">"# } else { r#"<div class="z-row">"# });
        for (i, node) in self.nodes.iter().enumerate() {
            out.push_str(&format!(r#"<div class="z-col" style="--z-flex:{}">"#, self.weights[i]));
            render_child(out, r, i, node);
            out.push_str("</div>");
        }
        out.push_str("</div>");
    }

    fn schema(&self) -> Json {
        let columns: Vec<Json> =
            self.nodes.iter().zip(&self.weights).map(|(n, w)| json!({ "weight": w, "node": n.schema() })).collect();
        json!({ "type": "row", "columns": columns })
    }

    fn children(&self) -> &[Node] {
        &self.nodes
    }
}

/// Nodes one under the other with a gap.
#[derive(Default)]
pub struct Stack {
    nodes: Vec<Node>,
    gap: u8,
}

impl Stack {
    pub fn new() -> Self {
        Self { nodes: Vec::new(), gap: 3 }
    }

    pub fn add(mut self, node: impl Into<Node>) -> Self {
        self.nodes.push(node.into());
        self
    }

    /// Gap in spacing units (4 px at regular density), 0 to 12. The default is 3.
    pub fn gap(mut self, units: u8) -> Self {
        self.gap = units.min(12);
        self
    }
}

impl Component for Stack {
    fn render(&self, out: &mut String, r: &Render) {
        out.push_str(&format!(r#"<div class="z-stack" style="--z-stack-gap:{}">"#, self.gap));
        for (i, node) in self.nodes.iter().enumerate() {
            render_child(out, r, i, node);
        }
        out.push_str("</div>");
    }

    fn schema(&self) -> Json {
        json!({ "type": "stack", "gap": self.gap, "children": children_schema(&self.nodes) })
    }

    fn children(&self) -> &[Node] {
        &self.nodes
    }
}

/// A titled section with an optional toolbar. It can collapse when `collapsible` is set.
pub struct Panel {
    title: Text,
    nodes: Vec<Node>,
    toolbar: Option<Toolbar>,
    collapsible: bool,
    collapsed: bool,
}

impl Panel {
    pub fn new(title: impl Into<Text>) -> Self {
        Self { title: title.into(), nodes: Vec::new(), toolbar: None, collapsible: false, collapsed: false }
    }

    pub fn add(mut self, node: impl Into<Node>) -> Self {
        self.nodes.push(node.into());
        self
    }

    /// Lets the user collapse the panel with a button in its title.
    pub fn collapsible(mut self) -> Self {
        self.collapsible = true;
        self
    }

    /// Starts collapsed. Implies `collapsible`.
    pub fn collapsed(mut self) -> Self {
        self.collapsible = true;
        self.collapsed = true;
        self
    }

    pub fn toolbar<F, R>(mut self, build: F) -> Self
    where
        F: FnOnce(Toolbar) -> R,
        R: Into<Toolbar>,
    {
        self.toolbar = Some(build(Toolbar::default()).into());
        self
    }
}

impl Component for Panel {
    fn render(&self, out: &mut String, r: &Render) {
        let id = dom_id(r, "panel");
        let title = r.text(&self.title);
        out.push_str(&format!(
            r#"<section class="z-panel" aria-labelledby="{id}-title"><header class="z-panel-head">"#
        ));
        if self.collapsible {
            out.push_str(&format!(
                r#"<h2 class="z-panel-title" id="{id}-title"><button type="button" class="z-panel-toggle" data-zeyn-toggle aria-expanded="{}" aria-controls="{id}-body" data-testid="{}.panel.{}"><span class="z-chevron" aria-hidden="true"></span>{title}</button></h2>"#,
                !self.collapsed,
                r.scope,
                slug(&self.title.english())
            ));
        } else {
            out.push_str(&format!(r#"<h2 class="z-panel-title" id="{id}-title">{title}</h2>"#));
        }
        if let Some(t) = &self.toolbar {
            t.render(out, r, &title);
        }
        let hidden = if self.collapsed { " hidden" } else { "" };
        out.push_str(&format!(r#"</header><div class="z-panel-body" id="{id}-body"{hidden}>"#));
        for (i, node) in self.nodes.iter().enumerate() {
            render_child(out, r, i, node);
        }
        out.push_str("</div></section>");
    }

    fn schema(&self) -> Json {
        json!({
            "type": "panel",
            "title": self.title,
            "collapsible": self.collapsible,
            "collapsed": self.collapsed,
            "toolbar": self.toolbar.as_ref().map(Toolbar::schema),
            "children": children_schema(&self.nodes),
        })
    }

    fn children(&self) -> &[Node] {
        &self.nodes
    }
}

/// A raised box that groups related content, with an optional title.
#[derive(Default)]
pub struct Card {
    title: Option<Text>,
    nodes: Vec<Node>,
}

impl Card {
    pub fn new() -> Self {
        Self::default()
    }

    pub fn title(mut self, title: impl Into<Text>) -> Self {
        self.title = Some(title.into());
        self
    }

    pub fn add(mut self, node: impl Into<Node>) -> Self {
        self.nodes.push(node.into());
        self
    }
}

impl Component for Card {
    fn render(&self, out: &mut String, r: &Render) {
        match &self.title {
            Some(t) => {
                let id = dom_id(r, "card");
                out.push_str(&format!(
                    r#"<article class="z-card" aria-labelledby="{id}-title"><h3 class="z-card-title" id="{id}-title">{}</h3>"#,
                    r.text(t)
                ));
            }
            None => out.push_str(r#"<article class="z-card">"#),
        }
        for (i, node) in self.nodes.iter().enumerate() {
            render_child(out, r, i, node);
        }
        out.push_str("</article>");
    }

    fn schema(&self) -> Json {
        json!({ "type": "card", "title": self.title, "children": children_schema(&self.nodes) })
    }

    fn children(&self) -> &[Node] {
        &self.nodes
    }
}

/// Tabs. Only the first tab is rendered with the page; the others load from the server the first
/// time they open. The open tab is kept in the URL hash, so reloads and shared links keep it.
///
/// Keyboard (ARIA tabs pattern): Left and Right move between tabs and open them, Home and End go
/// to the first and last tab, Tab moves into the open panel.
pub struct Tabs {
    label: Text,
    titles: Vec<Text>,
    nodes: Vec<Node>,
}

impl Tabs {
    /// Tabs with an accessible name for the tab list, such as "Order details".
    pub fn new(label: impl Into<Text>) -> Self {
        Self { label: label.into(), titles: Vec::new(), nodes: Vec::new() }
    }

    pub fn tab(mut self, title: impl Into<Text>, node: impl Into<Node>) -> Self {
        self.titles.push(title.into());
        self.nodes.push(node.into());
        self
    }
}

impl Component for Tabs {
    fn render(&self, out: &mut String, r: &Render) {
        let id = dom_id(r, "tabs");
        out.push_str(&format!(
            r#"<div class="z-tabs" data-zeyn-tabs="{id}" data-zeyn-loading="{}" data-zeyn-failed="{}"><div class="z-tablist" role="tablist" aria-label="{}">"#,
            r.text(&Text::key("zeyn.ui.loading")),
            r.text(&Text::key("zeyn.ui.load_failed")),
            r.text(&self.label)
        ));
        for (i, title) in self.titles.iter().enumerate() {
            let selected = i == 0;
            out.push_str(&format!(
                r#"<button type="button" role="tab" class="z-tab" id="{id}-tab-{i}" aria-selected="{selected}" aria-controls="{id}-panel-{i}" tabindex="{}" data-zeyn-tab="{}" data-testid="{}.tab.{}">{}</button>"#,
                if selected { 0 } else { -1 },
                slug(&title.english()),
                r.scope,
                slug(&title.english()),
                r.text(title)
            ));
        }
        out.push_str("</div>");
        for (i, node) in self.nodes.iter().enumerate() {
            let path = if r.path.is_empty() { i.to_string() } else { format!("{}.{i}", r.path) };
            if i == 0 {
                out.push_str(&format!(r#"<div class="z-tabpanel" role="tabpanel" id="{id}-panel-{i}" aria-labelledby="{id}-tab-{i}" tabindex="0">"#));
                render_child(out, r, i, node);
            } else {
                out.push_str(&format!(
                    r#"<div class="z-tabpanel" role="tabpanel" id="{id}-panel-{i}" aria-labelledby="{id}-tab-{i}" tabindex="0" hidden data-zeyn-lazy="{path}">"#
                ));
            }
            out.push_str("</div>");
        }
        out.push_str("</div>");
    }

    fn schema(&self) -> Json {
        let tabs: Vec<Json> =
            self.titles.iter().zip(&self.nodes).map(|(t, n)| json!({ "title": t, "node": n.schema() })).collect();
        json!({ "type": "tabs", "label": self.label, "tabs": tabs })
    }

    fn children(&self) -> &[Node] {
        &self.nodes
    }

    fn eager_children(&self) -> &[Node] {
        &self.nodes[..self.nodes.len().min(1)]
    }
}

/// Two panes with a divider the user can drag, or move with the arrow keys when it has focus.
/// The panes stack on narrow screens.
pub struct Split {
    nodes: Vec<Node>,
    ratio: u8,
    vertical: bool,
}

impl Split {
    /// Two panes side by side; the first takes 40 percent.
    pub fn new(first: impl Into<Node>, second: impl Into<Node>) -> Self {
        Self { nodes: vec![first.into(), second.into()], ratio: 40, vertical: false }
    }

    /// Share of the first pane in percent, 10 to 90.
    pub fn ratio(mut self, percent: u8) -> Self {
        self.ratio = percent.clamp(10, 90);
        self
    }

    /// Puts the panes one above the other.
    pub fn vertical(mut self) -> Self {
        self.vertical = true;
        self
    }
}

impl Component for Split {
    fn render(&self, out: &mut String, r: &Render) {
        let id = dom_id(r, "split");
        let (class, orientation) =
            if self.vertical { ("z-split z-split-v", "horizontal") } else { ("z-split", "vertical") };
        out.push_str(&format!(r#"<div class="{class}" data-zeyn-split style="--z-split:{}%">"#, self.ratio));
        out.push_str(&format!(r#"<div class="z-split-pane" id="{id}-first">"#));
        render_child(out, r, 0, &self.nodes[0]);
        out.push_str(&format!(
            r#"</div><div class="z-split-bar" role="separator" tabindex="0" aria-orientation="{orientation}" aria-controls="{id}-first" aria-valuenow="{}" aria-valuemin="10" aria-valuemax="90" aria-label="{}" data-testid="{}.split"></div><div class="z-split-pane">"#,
            self.ratio,
            r.text(&Text::key("zeyn.ui.resize")),
            r.scope
        ));
        render_child(out, r, 1, &self.nodes[1]);
        out.push_str("</div></div>");
    }

    fn schema(&self) -> Json {
        json!({ "type": "split", "ratio": self.ratio, "vertical": self.vertical, "children": children_schema(&self.nodes) })
    }

    fn children(&self) -> &[Node] {
        &self.nodes
    }
}