use either::Either;
use syntax::{
    ast::{self, AstNode},
    SyntaxKind,
};

use crate::{InlayHint, InlayHintsConfig, InlayKind, InlayTooltip, LifetimeElisionHints};

pub(super) fn hints(
    acc: &mut Vec<InlayHint>,
    config: &InlayHintsConfig,
    statik_or_const: Either<ast::Static, ast::Const>,
) -> Option<()> {
    if config.lifetime_elision_hints != LifetimeElisionHints::Always {
        return None;
    }

    if let Either::Right(it) = &statik_or_const {
        if ast::AssocItemList::can_cast(
            it.syntax().parent().map_or(SyntaxKind::EOF, |it| it.kind()),
        ) {
            return None;
        }
    }

    if let Some(ast::Type::RefType(ty)) = statik_or_const.either(|it| it.ty(), |it| it.ty()) {
        if ty.lifetime().is_none() {
            let t = ty.amp_token()?;
            acc.push(InlayHint {
                range: t.text_range(),
                kind: InlayKind::LifetimeHint,
                label: "'static".to_owned().into(),
                tooltip: Some(InlayTooltip::String("Elided static lifetime".into())),
            });
        }
    }

    Some(())
}