;;; test-pearl-api.el --- Tests for pearl core API layer -*- lexical-binding: t; -*-

;; Copyright (C) 2026 Craig Jennings

;; Author: Craig Jennings <c@cjennings.net>

;; This program is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.

;; This program is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with this program.  If not, see <http://www.gnu.org/licenses/>.

;;; Commentary:

;; Tests for the GraphQL request layer with `request' stubbed at the HTTP
;; boundary: the async entry point routes to success/error correctly and
;; balances the active-request counter; the sync wrapper returns data or nil.

;;; Code:

(require 'test-bootstrap (expand-file-name "test-bootstrap.el"))
(require 'testutil-request (expand-file-name "testutil-request.el"))

(ert-deftest test-pearl-graphql-request-async-success-routes-to-success-fn ()
  "A successful response is passed to the success function."
  (let ((got nil))
    (testutil-linear-with-response '((data (viewer (name . "Me"))))
      (pearl--graphql-request-async
       "query" nil
       (lambda (data) (setq got data))
       (lambda (&rest _) (setq got 'error))))
    (should (equal '((data (viewer (name . "Me")))) got))))

(ert-deftest test-pearl-graphql-request-async-error-routes-to-error-fn ()
  "A transport error is passed to the error function."
  (let ((got nil))
    (testutil-linear-with-error "boom"
      (pearl--graphql-request-async
       "query" nil
       (lambda (_d) (setq got 'success))
       (lambda (err _r _d) (setq got err))))
    (should (equal "boom" got))))

(ert-deftest test-pearl-graphql-request-async-balances-active-counter-on-success ()
  "The active-request counter returns to its starting value after success."
  (let ((pearl--active-requests 0))
    (testutil-linear-with-response '((data))
      (pearl--graphql-request-async "q" nil #'ignore #'ignore))
    (should (= 0 pearl--active-requests))))

(ert-deftest test-pearl-graphql-request-async-nil-response-does-not-error ()
  "A transport error with a nil response routes to error-fn without throwing.

The error handler logs the response status code; that read must be guarded
so a nil response (some transport failures) doesn't crash inside the handler."
  (let ((pearl-api-key "test-key") (got nil))
    (cl-letf (((symbol-function 'request)
               (lambda (_url &rest args)
                 (funcall (plist-get args :error)
                          :error-thrown "boom" :response nil :data nil))))
      (pearl--graphql-request-async
       "q" nil #'ignore (lambda (err _r _d) (setq got err))))
    (should (equal "boom" got))))

(ert-deftest test-pearl-graphql-request-async-balances-active-counter-on-error ()
  "The active-request counter returns to its starting value after an error."
  (let ((pearl--active-requests 0))
    (testutil-linear-with-error "boom"
      (pearl--graphql-request-async "q" nil #'ignore #'ignore))
    (should (= 0 pearl--active-requests))))

(ert-deftest test-pearl-graphql-request-sync-returns-data ()
  "The synchronous wrapper returns the parsed response."
  (testutil-linear-with-response '((data (x . 1)))
    (should (equal '((data (x . 1))) (pearl--graphql-request "q")))))

(ert-deftest test-pearl-graphql-request-sync-error-returns-nil ()
  "The synchronous wrapper returns nil on a transport error."
  (testutil-linear-with-error "boom"
    (should (null (pearl--graphql-request "q")))))

(provide 'test-pearl-api)
;;; test-pearl-api.el ends here