(** Cache entry information *)

type t = {
  key : string;
  size : int64;
  mtime : float;
  ttl : float option;
  flags : Flags.t;
}

let create ~key ~size ~mtime ~ttl ~flags =
  { key; size; mtime; ttl; flags }

let key t = t.key
let size t = t.size
let mtime t = t.mtime
let ttl t = t.ttl
let flags t = t.flags

let is_expired t =
  match t.ttl with
  | None -> false
  | Some expiry -> Unix.time () > expiry

let is_pinned t =
  Flags.is_pinned t.flags

let is_stale t =
  Flags.is_stale t.flags

let is_temporary t =
  Flags.is_temporary t.flags

let compare_by_mtime a b =
  Float.compare a.mtime b.mtime

let compare_by_size a b =
  Int64.compare a.size b.size

let pp fmt t =
  Format.fprintf fmt "Entry{key=%s, size=%Ld, mtime=%.1f, ttl=%s, flags=%a}"
    t.key
    t.size
    t.mtime
    (match t.ttl with
     | None -> "never"
     | Some exp -> Printf.sprintf "%.1f" exp)
    Flags.pp t.flags

(* Jsont support *)

(* Helper codec for int64 *)
let int64_jsont =
  let kind = "Int64" in
  let doc = "64-bit integer as number" in
  let dec n = Int64.of_float n in
  let enc i = Int64.to_float i in
  Jsont.map ~kind ~doc ~dec ~enc Jsont.number

let jsont =
  let kind = "Entry" in
  let doc = "A cache entry" in
  let make key size mtime ttl flags = { key; size; mtime; ttl; flags } in
  Jsont.Object.map ~kind ~doc make
  |> Jsont.Object.mem "key" Jsont.string ~enc:key
  |> Jsont.Object.mem "size" int64_jsont ~enc:size
  |> Jsont.Object.mem "mtime" Jsont.number ~enc:mtime
  |> Jsont.Object.opt_mem "ttl" Jsont.number ~enc:ttl
  |> Jsont.Object.mem "flags" Flags.jsont ~enc:flags
  |> Jsont.Object.finish