open Ast
open Trav
open Stringify

let rec var_init node =
    let move_inits body =
        let rec trav inits = function
            (* local declarations: collect initialisations *)
            | VarDec (ctype, name, Some init) :: t ->
                VarDec (ctype, name, None) :: (trav (inits @ [Assign (name, init)]) t)
            | (VarDec (_, _, None) as h) :: t
            | (FunDef (_, _, _, _, _) as h) :: t ->
                 h :: (trav inits t)

            (* rest of function body: recurse *)
            | rest -> inits @ (List.map var_init rest)
        in trav [] body
    in
    match node with
    | FunDef (export, ret_type, name, params, body) ->
        FunDef (export, ret_type, name, params, move_inits body)
    | _ -> transform var_init node

let rec phase repr =
    let _ = print_endline "- Var init" in
    match repr with
        | Node (node, verbose) ->
            Node (var_init node, verbose)
        | _ -> failwith "invalid input for this phase"