use super::TextNode;
use crate::library::prelude::*;
use crate::util::EcoString;

/// Link text and other elements to an URL.
#[derive(Debug, Hash)]
pub struct LinkNode {
    /// The url the link points to.
    pub url: EcoString,
    /// How the link is represented.
    pub body: Option<Content>,
}

#[node(showable)]
impl LinkNode {
    /// The fill color of text in the link. Just the surrounding text color
    /// if `auto`.
    pub const FILL: Smart<Paint> = Smart::Auto;
    /// Whether to underline link.
    pub const UNDERLINE: bool = true;

    fn construct(_: &mut Context, args: &mut Args) -> TypResult<Content> {
        Ok(Content::show(Self {
            url: args.expect::<EcoString>("url")?,
            body: args.find()?,
        }))
    }
}

impl Show for LinkNode {
    fn show(&self, ctx: &mut Context, styles: StyleChain) -> TypResult<Content> {
        let args = [Value::Str(self.url.clone()), match &self.body {
            Some(body) => Value::Content(body.clone()),
            None => Value::None,
        }];

        let mut body = styles
            .show::<Self, _>(ctx, args)?
            .or_else(|| self.body.clone())
            .unwrap_or_else(|| {
                let url = &self.url;
                let mut text = url.as_str();
                for prefix in ["mailto:", "tel:"] {
                    text = text.trim_start_matches(prefix);
                }
                let shorter = text.len() < url.len();
                Content::Text(if shorter { text.into() } else { url.clone() })
            });

        let mut map = StyleMap::new();
        map.set(TextNode::LINK, Some(self.url.clone()));

        if let Smart::Custom(fill) = styles.get(Self::FILL) {
            map.set(TextNode::FILL, fill);
        }

        if styles.get(Self::UNDERLINE) {
            body = body.underlined();
        }

        Ok(body.styled_with_map(map))
    }
}