use protobuf::descriptor::{FileDescriptorProto, source_code_info::Location};

pub struct SourceContext<'a> {
    location_map: std::collections::HashMap<Vec<i32>, &'a Location>,
}

impl<'a> SourceContext<'a> {
    pub fn new(file: &'a FileDescriptorProto) -> Self {
        let mut map = std::collections::HashMap::new();
        for loc in &file.source_code_info.location {
            map.insert(loc.path.clone(), loc);
        }
        Self { location_map: map }
    }

    pub fn get_message_loc(&self, msg_index: usize) -> Option<&Location> {
        self.location_map.get(&vec![4, msg_index as i32]).copied()
    }

    #[expect(unused)]
    pub fn get_nested_loc(&self, parent_path: &[i32], nested_index: usize) -> Option<&Location> {
        let mut path = parent_path.to_vec();
        path.push(3);
        path.push(nested_index as i32);
        self.location_map.get(&path).copied()
    }
}