dom_query 0.29.0

use std::cell::Ref;

use html5ever::local_name;

use crate::NodeId;
use crate::node::{NodeData, TreeNode, descendant_nodes};

use super::super::ctx::FormatOpts;
use super::super::serializer::MDSerializer;
use super::super::text_utils::{
    escape_trailing_bang, push_md_url, push_normalized_text, push_title,
};

impl MDSerializer<'_> {
    pub(in crate::serializing::md) fn write_link(&self, text: &mut String, link_node: &TreeNode) {
        let Some(el) = link_node.as_element() else {
            return;
        };

        let default_opts = FormatOpts::new();

        let Some(href) = el.attr("href") else {
            // no href: fallback to serializing node contents
            self.write(text, link_node.id, default_opts);
            return;
        };

        let mut link_text = String::new();
        let has_img = self.has_descendant_img(&link_node.id);

        let mut is_md_body = false;
        // try to collect plain text if there is no image
        if !has_img {
            let link_opts = FormatOpts::new().include_node().skip_escape();
            self.write_text(&mut link_text, link_node.id, link_opts);
        }
        // a link with only whitespace to show still separates the words around it
        if !link_text.is_empty() && link_text.trim_ascii().is_empty() {
            push_normalized_text(text, &link_text, default_opts);
            return;
        }
        // serialize as markdown if body contains images or non-text elements
        if has_img || link_text.is_empty() {
            let body_opts = if has_img {
                default_opts.link_body()
            } else {
                default_opts
            };
            self.write(&mut link_text, link_node.id, body_opts);
            is_md_body = true;
        }

        if link_text.is_empty() {
            return;
        }

        // an unescaped trailing `!` would turn `[x](u)` into image syntax
        escape_trailing_bang(text);
        text.push('[');
        if is_md_body {
            text.push_str(&link_text);
        } else {
            push_normalized_text(text, &link_text, default_opts);
        }

        text.push_str("](");
        push_md_url(text, &href);

        if let Some(title) = el.attr_ref(local_name!("title")) {
            push_title(text, title);
        }

        text.push(')');
    }

    fn has_descendant_img(&self, id: &NodeId) -> bool {
        descendant_nodes(Ref::clone(&self.nodes), id).any(|child_id| {
            matches!(
                &self.nodes[child_id.value()].data,
                NodeData::Element(e) if e.name.local == local_name!("img")
            )
        })
    }
}