open Types

let ansi_filter s =
  s |> function
  | Ansi a ->
      Types.Ansi
        (List.filter
           (function Types.Fg _ | Types.Bg _ -> false | _ -> true)
           a)
  | n -> n

let permute order a = Array.mapi (fun i _ -> a.(order.(i))) a

(* TODO: implement this so cli can use a dsl to specify colourising patterns *)
type culr = { colours : colour array; sz : int; mutable current : int }

module Culriser = struct
  type filter = (colour -> bool) list
  type sort = int array

  let run_filters (f : filter) el =
    List.fold_left (fun res filt -> if not (filt el) then false else res) true f

  let create s f c =
    let ( @ ) = Array.append in
    let colours =
      c |> permute s |> fun c ->
      if List.length f > 0 then
        Array.fold_left
          (fun acc el -> if run_filters f el then acc @ [| el |] else acc)
          [||] c
      else c
    in
    { colours; sz = Array.length colours; current = 0 }

  let next t =
    let ret = t.current and nv = t.current + 1 in
    if nv >= t.sz then t.current <- 0 else t.current <- nv;
    t.colours.(ret)

  let reset t = t.current <- 0

  let serialise_with_colour t serialiser chunk =
    (match chunk with
    | Separator _ -> Emitter.serialise serialiser (Ansi [ Fg (next t) ])
    | Delimiter _ ->
        reset t;
        Emitter.serialise serialiser (Ansi [ Fg (next t) ])
    | _ -> ());
    Emitter.serialise serialiser chunk
end