(*---------------------------------------------------------------------------
  Copyright (c) 2025 Anil Madhavapeddy <anil@recoil.org>. All rights reserved.
  SPDX-License-Identifier: ISC
 ---------------------------------------------------------------------------*)

(** Tests for Cache module - HTTP response caching per RFC 9111 *)

module Headers = Requests.Headers

(** Run a test inside the Eio event loop (needed for Eio.Mutex) *)
let run f () = Eio_main.run @@ fun _env -> f ()

(** {1 Memory.create and Memory.size Tests} *)

let test_create_size () =
  let c = Cache.Memory.create () in
  Alcotest.(check int) "fresh cache size is 0" 0 (Cache.Memory.size c)

(** {1 Memory.stats Tests} *)

let test_create_stats () =
  let c = Cache.Memory.create () in
  let hits, misses, stores = Cache.Memory.stats c in
  Alcotest.(check int) "hits" 0 hits;
  Alcotest.(check int) "misses" 0 misses;
  Alcotest.(check int) "stores" 0 stores

(** {1 Memory.clear Tests} *)

let test_clear_empty () =
  let c = Cache.Memory.create () in
  Cache.Memory.clear c;
  Alcotest.(check int) "size after clear" 0 (Cache.Memory.size c)

(** {1 parse_vary Tests} *)

let test_parse_vary () =
  let result = Cache.parse_vary "Accept, Accept-Language" in
  Alcotest.(check (list string))
    "parsed vary"
    [ "accept"; "accept-language" ]
    result

(** {1 is_not_modified Tests} *)

let test_is_not_modified_304 () =
  Alcotest.(check bool)
    "304 is not modified" true
    (Cache.is_not_modified ~status:304)

let test_is_not_modified_200 () =
  Alcotest.(check bool)
    "200 is modified" false
    (Cache.is_not_modified ~status:200)

(** {1 vary_matches Tests} *)

let test_vary_matches () =
  let request_headers =
    Headers.empty |> Headers.add_string "accept" "text/html"
  in
  let cached_vary = [ ("accept", "text/html") ] in
  Alcotest.(check bool)
    "matching vary" true
    (Cache.vary_matches ~cached_vary ~request_headers)

let test_vary_no_match () =
  let request_headers =
    Headers.empty |> Headers.add_string "accept" "application/json"
  in
  let cached_vary = [ ("accept", "text/html") ] in
  Alcotest.(check bool)
    "non-matching vary" false
    (Cache.vary_matches ~cached_vary ~request_headers)

(** {1 Test Suite} *)

let suite =
  ( "cache",
    [
      Alcotest.test_case "create size 0" `Quick (run test_create_size);
      Alcotest.test_case "create stats zeros" `Quick (run test_create_stats);
      Alcotest.test_case "clear empty" `Quick (run test_clear_empty);
      Alcotest.test_case "parse_vary" `Quick test_parse_vary;
      Alcotest.test_case "is_not_modified 304" `Quick test_is_not_modified_304;
      Alcotest.test_case "is_not_modified 200" `Quick test_is_not_modified_200;
      Alcotest.test_case "vary matches" `Quick test_vary_matches;
      Alcotest.test_case "vary no match" `Quick test_vary_no_match;
    ] )