vertigo-cmark 0.1.4

// Based on https://github.com/pulldown-cmark/pulldown-cmark/blob/master/pulldown-cmark/src/html.rs

use pulldown_cmark::{Alignment, CowStr, Event};
use std::{
    collections::{HashMap, VecDeque},
    rc::Rc,
};
use vertigo::{Css, DomElement, DomNode, log};

use crate::{policy::HtmlPolicy, styling::CMarkStyle};

pub(super) enum TableState {
    Head,
    Body,
}

pub(super) struct VertigoWriter<'a, I> {
    /// Iterator supplying events.
    pub(super) iter: I,

    /// Whether if inside a metadata block (text should not be written)
    pub(super) in_non_writing_block: bool,

    pub(super) table_state: TableState,
    pub(super) table_alignments: Vec<Alignment>,
    pub(super) table_cell_index: usize,
    pub(super) numbers: HashMap<CowStr<'a>, usize>,

    // Stack of nested nodes
    pub(super) soc: VecDeque<DomNode>,

    /// Elements opened by raw HTML and not closed yet, with the stack depth right after each
    /// one was pushed. Raw HTML closes only its own elements, and a markdown element closes
    /// raw HTML left open inside it, so a stray or missing end tag can't break the tree.
    #[cfg(feature = "html")]
    pub(super) html_open: Vec<(String, usize)>,

    /// Inside an element of raw HTML removed with its content: its name and how many elements
    /// of the same name opened inside it. Nothing but the structure of the document gets out
    /// until its end tag.
    #[cfg(feature = "html")]
    pub(super) removing: Option<(String, usize)>,

    pub(super) styling: Rc<CMarkStyle>,

    /// What of raw HTML and link destinations gets into the tree.
    pub(super) policy: &'a dyn HtmlPolicy,

    #[cfg(feature = "syntect")]
    pub(super) in_code_block: Option<CowStr<'a>>,
}

impl<'a, I> VertigoWriter<'a, I>
where
    I: Iterator<Item = Event<'a>>,
{
    pub fn new(iter: I, styling: CMarkStyle, policy: &'a dyn HtmlPolicy) -> Self {
        Self {
            iter,
            in_non_writing_block: false,
            table_state: TableState::Head,
            table_alignments: vec![],
            table_cell_index: 0,
            numbers: HashMap::new(),
            soc: VecDeque::new(),
            #[cfg(feature = "html")]
            html_open: vec![],
            #[cfg(feature = "html")]
            removing: None,
            styling: Rc::new(styling),
            policy,
            #[cfg(feature = "syntect")]
            in_code_block: None,
        }
    }

    /// Whether the content of an element removed by the policy is going on.
    pub(super) fn removing(&self) -> bool {
        #[cfg(feature = "html")]
        return self.removing.is_some();
        #[cfg(not(feature = "html"))]
        false
    }

    pub(super) fn push_node(&mut self, node: impl Into<DomNode>) {
        self.soc.push_front(node.into());
    }

    pub(super) fn push_element_styled(&mut self, element: DomElement, css: &Css) {
        let mut element = element;
        if !css.groups.is_empty() {
            element = element.css(css)
        }
        self.soc.push_front(element.into());
    }

    pub(super) fn push_elname(&mut self, name: impl Into<String>, css: &Css) {
        let name = name.into();
        let mut element = DomElement::new(name);
        if !css.groups.is_empty() {
            element = element.css(css)
        }
        self.push_node(element);
    }

    pub(super) fn pop_node(&mut self) -> Option<DomNode> {
        if let Some(child) = self.soc.pop_front() {
            match self.soc.front_mut() {
                Some(parent) => {
                    match parent {
                        DomNode::Node { node } => node.add_child(child),
                        _ => {
                            unreachable!("Can't push children to non-element node");
                        }
                    }
                    return None;
                }
                None => return Some(child),
            }
        }
        None
    }

    /// Pops node pushed for a markdown element, closing first raw HTML left open inside it.
    pub(super) fn pop_markdown_node(&mut self) -> Option<DomNode> {
        #[cfg(feature = "html")]
        while self
            .html_open
            .last()
            .is_some_and(|(_, depth)| *depth == self.soc.len())
        {
            self.html_open.pop();
            self.pop_node();
        }
        self.pop_node()
    }

    pub(super) fn add_child(&mut self, child: impl Into<DomNode>) {
        if let Some(parent) = self.soc.front_mut() {
            match parent {
                DomNode::Node { node } => node.add_child(child),
                _ => log::error!("Can't push child to non-element node (2)"),
            }
        } else {
            log::error!("Can't add child without parent node")
        }
    }

    pub(super) fn add_child_name(&mut self, child_name: impl Into<String>) {
        self.add_child(DomElement::new(child_name.into()));
    }
}