use std::path::PathBuf;
use swc_common::errors::{ColorConfig, Handler};
use swc_common::sync::Lrc;
use swc_common::{FileName, SourceFile, SourceMap, Span};
use swc_css::visit::{Visit, VisitWith};
use swc_css::{ast::Rule, parser::parse_file};
pub struct ClassName {
pub value: cnls::Str,
pub span: Span,
}
pub struct ClassNamesCollector {
class_names: Vec<ClassName>,
last_rule_span: Option<Span>,
}
impl ClassNamesCollector {
pub fn new() -> Self {
ClassNamesCollector {
last_rule_span: None,
class_names: vec![],
}
}
pub fn find_class_name_by_value(&self, value: &str) -> Option<&ClassName> {
self.class_names.iter().find(|c| &c.value == value)
}
pub fn parse(css_file: PathBuf) -> anyhow::Result<Self> {
let options = swc_css::parser::parser::ParserConfig::default();
let (cssfile, cm) = css_source_file_from(css_file)?;
let handler = Handler::with_tty_emitter(ColorConfig::Auto, true, false, Some(cm.clone()));
let mut errors = vec![];
let c = parse_file::<Vec<Rule>>(&cssfile, None, options, &mut errors).unwrap();
for e in errors {
e.to_diagnostics(&handler).emit();
}
let mut ccns = ClassNamesCollector::new();
c.visit_with(&mut ccns);
Ok(ccns)
}
}
impl Visit for ClassNamesCollector {
fn visit_qualified_rule(&mut self, n: &swc_css::ast::QualifiedRule) {
self.last_rule_span = Some(n.span);
n.visit_children_with(self)
}
fn visit_compound_selector(&mut self, n: &swc_css::ast::CompoundSelector) {
let selectors = &n.subclass_selectors;
selectors
.iter()
.filter_map(|s| match s {
swc_css::ast::SubclassSelector::Class(selector) => Some(selector),
_ => None,
})
.for_each(|s| {
if s.text.value.contains(':') {
let cn = s.text.value.split(':').last().expect("should have at least one value after split, since empty selectors aren't allowed");
self.class_names.push(ClassName {
value: cn.into(),
span: self.last_rule_span.unwrap_or_default()
});
} else {
self.class_names.push(ClassName { value: s.text.value.as_str().into(), span: self.last_rule_span.unwrap_or_default()});
}
});
}
}
pub fn css_source_file_from(
css_file: PathBuf,
) -> anyhow::Result<(Lrc<SourceFile>, Lrc<SourceMap>)> {
let code = std::fs::read_to_string(&css_file)?;
let cm: Lrc<SourceMap> = Default::default();
let filename = FileName::Real(css_file);
Ok((cm.new_source_file(filename, code), cm))
}