dust-lang 0.4.2

use std::fmt::{self, Display, Formatter};

use serde::{Deserialize, Serialize};

use crate::{
    built_in_functions::Callable, BuiltInFunction, Format, FunctionNode, Identifier, Type,
};

#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Serialize, Deserialize)]
pub enum Function {
    BuiltIn(BuiltInFunction),
    ContextDefined(FunctionNode),
}

impl Function {
    pub fn r#type(&self) -> Type {
        match self {
            Function::BuiltIn(built_in_function) => built_in_function.r#type(),
            Function::ContextDefined(context_defined_function) => {
                context_defined_function.r#type().clone()
            }
        }
    }

    pub fn parameters(&self) -> Option<&Vec<Identifier>> {
        if let Function::ContextDefined(function) = self {
            Some(function.parameters())
        } else {
            None
        }
    }
}

impl Format for Function {
    fn format(&self, output: &mut String, indent_level: u8) {
        match self {
            Function::BuiltIn(built_in_function) => built_in_function.format(output, indent_level),
            Function::ContextDefined(function_node) => function_node.format(output, indent_level),
        }
    }
}

impl Display for Function {
    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
        match self {
            Function::BuiltIn(built_in_function) => write!(f, "{built_in_function}"),
            Function::ContextDefined(function_node) => write!(f, "{function_node}"),
        }
    }
}