use std::collections::HashMap;

#[derive(Default, Clone)]
pub struct Template {
    pub(crate) template_str: String,
    pub(crate) params: HashMap<String, String>,
    pub(crate) impl_params: HashMap<String, Vec<HashMap<String, String>>>,
}

impl Template {
    /// Add a parameter
    pub fn insert_param(&mut self, name: String, value: String) {
        self.params.insert(name, value);
    }

    /// Add an implementation block and return a HashMap to set its parameters
    pub fn add_impl(&mut self, impl_name: String) -> &mut Vec<HashMap<String, String>> {
        self.impl_params
            .entry(impl_name)
            .or_insert_with(|| Vec::<HashMap<String, String>>::new())
    }
}

impl From<String> for Template {
    fn from(s: String) -> Self {
        Template {
            template_str: s,
            ..Default::default()
        }
    }
}

impl std::fmt::Display for Template {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        let cloned = self.clone();
        write!(f, "{}", cloned.expand().unwrap_or_default())
    }
}