use convert_case::{Case, Casing};
use once_cell::sync::Lazy;
use regex::{Captures, Regex};

static C_PTR_RE: Lazy<Regex> =
    Lazy::new(|| Regex::new(r"(const )?([a-zA-Z0-9_]+)\s?\*(.*)").unwrap());

static REST_C_PTR_RE: Lazy<Regex> = Lazy::new(|| Regex::new(r"(const)?\s?\*").unwrap());

pub fn clean_param_name(param_name: &str) -> String
{
    match param_name {
        "ref" => "reference",
        "type" => "ty",
        "in" => "inside",
        "box" => "a_box",
        name => name,
    }
    .to_case(Case::Snake)
}

pub fn fix_type(ty: &str) -> String
{
    let ty = ty.replace("struct", "");

    let ty = c_ptr_to_rust_ptr(&ty);

    ty.replace("void", "std::ffi::c_void")
}

pub fn c_ptr_to_rust_ptr(c_ptr: &str) -> String
{
    C_PTR_RE
        .replace(c_ptr, |captures: &Captures| {
            let const_or_mut = captures.get(1).map_or_else(|| "mut", |_| "const");

            let type_name = captures.get(2).unwrap().as_str();

            let rest = captures.get(3).unwrap();

            let rest_ptr_matches = REST_C_PTR_RE.captures_iter(rest.as_str());

            let rest_ptrs = rest_ptr_matches
                .map(|capts| {
                    let const_or_mut = capts.get(1).map_or_else(|| "mut", |_| "const");

                    format!("*{const_or_mut} ")
                })
                .collect::<Vec<_>>();

            format!("{}*{const_or_mut} {type_name}", rest_ptrs.join(" "))
        })
        .to_string()
}