(*---------------------------------------------------------------------------
   Copyright (c) 2025 Thomas Gazagnaire. All rights reserved.
   SPDX-License-Identifier: ISC
  ---------------------------------------------------------------------------*)

(** Unit tests for {!E2e} — pure logic only, no VMs. *)

(* ---------------------------------------------------------------------------
   Helpers
   --------------------------------------------------------------------------- *)

let result_testable =
  Alcotest.testable E2e.pp_result (fun a b ->
      match (a, b) with
      | E2e.Pass a, E2e.Pass b -> String.equal a b
      | Fail a, Fail b -> String.equal a b
      | _ -> false)

let pass msg = E2e.Pass msg
let fail msg = E2e.Fail msg
let contains pat s = Re.execp (Re.Pcre.re pat |> Re.compile) s

(* ---------------------------------------------------------------------------
   Tests
   --------------------------------------------------------------------------- *)

let test_default_config () =
  let c = E2e.default_config in
  Alcotest.(check int) "min_frames" 10 c.min_frames;
  Alcotest.(check (float 0.1)) "timeout" 60. c.timeout;
  Alcotest.(check (option string)) "build_file" None c.build_file;
  Alcotest.(check (option string)) "run_file" None c.run_file;
  Alcotest.(check (option string)) "kernel" None c.kernel;
  Alcotest.(check (option string)) "output" None c.output

let test_is_pass () =
  Alcotest.(check bool) "pass is pass" true (E2e.is_pass (pass "ok"));
  Alcotest.(check bool) "fail is not pass" false (E2e.is_pass (fail "bad"))

let test_exit_code_all_pass () =
  let results = [ pass "a"; pass "b"; pass "c" ] in
  Alcotest.(check int) "all pass" 0 (E2e.exit_code results)

let test_exit_code_one_fail () =
  let results = [ pass "a"; fail "b"; pass "c" ] in
  Alcotest.(check int) "one fail" 1 (E2e.exit_code results)

let test_exit_code_empty () = Alcotest.(check int) "empty" 0 (E2e.exit_code [])

let test_check_frames_pass () =
  let r = E2e.check_frames ~received:15 ~target:10 in
  Alcotest.(check bool) "enough frames" true (E2e.is_pass r)

let test_check_frames_exact () =
  let r = E2e.check_frames ~received:10 ~target:10 in
  Alcotest.(check bool) "exact frames" true (E2e.is_pass r)

let test_check_frames_fail () =
  let r = E2e.check_frames ~received:3 ~target:10 in
  Alcotest.(check bool) "not enough frames" false (E2e.is_pass r)

let test_check_frames_zero () =
  let r = E2e.check_frames ~received:0 ~target:10 in
  Alcotest.(check bool) "zero frames" false (E2e.is_pass r)

let test_check_exit_code_clean () =
  let r = E2e.check_exit_code 0 in
  Alcotest.(check result_testable)
    "clean"
    (pass "clean shutdown (exit code 0)")
    r

let test_check_exit_code_crash () =
  let r = E2e.check_exit_code 1 in
  Alcotest.(check bool) "crash" false (E2e.is_pass r)

let test_check_exit_code_signal () =
  let r = E2e.check_exit_code 137 in
  Alcotest.(check bool) "signal" false (E2e.is_pass r)

let test_pp_result_pass () =
  let s = Fmt.str "%a" E2e.pp_result (pass "ok") in
  Alcotest.(check bool) "has PASS" true (contains "PASS" s)

let test_pp_result_fail () =
  let s = Fmt.str "%a" E2e.pp_result (fail "bad") in
  Alcotest.(check bool) "has FAIL" true (contains "FAIL" s)

let test_report_all_pass () =
  (* report prints to stdout but returns exit code *)
  let code = E2e.report [ pass "a"; pass "b" ] in
  Alcotest.(check int) "exit 0" 0 code

let test_report_with_failure () =
  let code = E2e.report [ pass "a"; fail "b" ] in
  Alcotest.(check int) "exit 1" 1 code

let test_report_empty () =
  let code = E2e.report [] in
  Alcotest.(check int) "exit 0" 0 code

(* ---------------------------------------------------------------------------
   Suite
   --------------------------------------------------------------------------- *)

let suite =
  ( "e2e",
    [
      Alcotest.test_case "config defaults" `Quick test_default_config;
      Alcotest.test_case "is_pass" `Quick test_is_pass;
      Alcotest.test_case "exit_code all pass" `Quick test_exit_code_all_pass;
      Alcotest.test_case "exit_code one fail" `Quick test_exit_code_one_fail;
      Alcotest.test_case "exit_code empty" `Quick test_exit_code_empty;
      Alcotest.test_case "check_frames enough" `Quick test_check_frames_pass;
      Alcotest.test_case "check_frames exact" `Quick test_check_frames_exact;
      Alcotest.test_case "check_frames not enough" `Quick test_check_frames_fail;
      Alcotest.test_case "check_frames zero" `Quick test_check_frames_zero;
      Alcotest.test_case "check_exit clean" `Quick test_check_exit_code_clean;
      Alcotest.test_case "check_exit crash" `Quick test_check_exit_code_crash;
      Alcotest.test_case "check_exit signal" `Quick test_check_exit_code_signal;
      Alcotest.test_case "pp_result pass" `Quick test_pp_result_pass;
      Alcotest.test_case "pp_result fail" `Quick test_pp_result_fail;
      Alcotest.test_case "report all pass" `Quick test_report_all_pass;
      Alcotest.test_case "report with failure" `Quick test_report_with_failure;
      Alcotest.test_case "report empty" `Quick test_report_empty;
    ] )