;;; test-pearl-title-sync.el --- Tests for title sync-back -*- 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 explicit title sync-back, a separate path from the description
;; sync that shares the `pearl--sync-decision' gate.  Covers the title
;; extractor, the title fetch and update helpers (stubbed at the HTTP
;; boundary), the command's no-op / push / conflict branches, and the
;; deliberate bracket-stripping lossiness: a bracketed remote title renders
;; with its stored hash matching the stripped heading, so a no-op sync makes
;; no API call and never clobbers the brackets on Linear.

;;; Code:

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

(defmacro test-pearl--in-org (content &rest body)
  "Run BODY in an org-mode temp buffer holding CONTENT, default mapping bound."
  (declare (indent 1))
  `(let ((pearl-state-to-todo-mapping
          '(("Todo" . "TODO") ("In Progress" . "IN-PROGRESS") ("Done" . "DONE")))
         (org-todo-keywords '((sequence "TODO" "IN-PROGRESS" "|" "DONE"))))
     (with-temp-buffer
       (insert ,content)
       (org-mode)
       (goto-char (point-min))
       ,@body)))

;;; --issue-title-at-point

(ert-deftest test-pearl-issue-title-strips-keyword-and-cookie ()
  "The title extractor returns the heading text without TODO, priority, tags."
  (test-pearl--in-org
      "*** TODO [#B] My issue title :tag:\n:PROPERTIES:\n:LINEAR-ID: a\n:END:\n"
    (should (string= "My issue title" (pearl--issue-title-at-point)))))

;;; network helpers

(ert-deftest test-pearl-fetch-issue-title-parses-payload ()
  "The title fetch returns the remote title and timestamp."
  (testutil-linear-with-response
      '((data (issue (title . "Remote title") (updatedAt . "2026-05-23T00:00:00.000Z"))))
    (let (result)
      (pearl--fetch-issue-title-async "a" (lambda (r) (setq result r)))
      (should (string= "Remote title" (plist-get result :title)))
      (should (string= "2026-05-23T00:00:00.000Z" (plist-get result :updated-at))))))

(ert-deftest test-pearl-update-issue-title-success ()
  "A successful title issueUpdate reports success."
  (testutil-linear-with-response
      '((data (issueUpdate (success . t)
                           (issue (id . "a") (updatedAt . "2026-05-23T01:00:00.000Z")))))
    (let (result)
      (pearl--update-issue-title-async "a" "New" (lambda (r) (setq result r)))
      (should (eq t (plist-get result :success))))))

(ert-deftest test-pearl-update-issue-title-soft-fail ()
  "A non-success title issueUpdate reports failure rather than erroring."
  (testutil-linear-with-response
      '((data (issueUpdate (success . :json-false) (issue . nil))))
    (let ((called nil) result)
      (pearl--update-issue-title-async "a" "New" (lambda (r) (setq called t result r)))
      (should called)
      (should-not (plist-get result :success)))))

;;; command branches

(defmacro test-pearl--with-title-stubs (remote-title update-spy &rest body)
  "Run BODY with the title fetch/update helpers stubbed.
REMOTE-TITLE is the plist the fetch hands its callback.  UPDATE-SPY collects
the titles pushed to the update helper, which reports success."
  (declare (indent 2))
  `(cl-letf (((symbol-function 'pearl--fetch-issue-title-async)
              (lambda (_id cb) (funcall cb ,remote-title)))
             ((symbol-function 'pearl--update-issue-title-async)
              (lambda (_id title cb)
                (push title ,update-spy)
                (funcall cb '(:success t :updated-at "2026-05-23T02:00:00.000Z")))))
     ,@body))

(ert-deftest test-pearl-sync-title-noop-skips-network ()
  "No title edit: neither the fetch nor the update helper is called."
  (let ((fetched nil) (updates nil))
    (test-pearl--in-org
        (format "*** TODO [#B] Same Title\n:PROPERTIES:\n:LINEAR-ID: a\n:LINEAR-TITLE-SHA256: %s\n:END:\n"
                (secure-hash 'sha256 "Same Title"))
      (cl-letf (((symbol-function 'pearl--fetch-issue-title-async)
                 (lambda (&rest _) (setq fetched t)))
                ((symbol-function 'pearl--update-issue-title-async)
                 (lambda (&rest _) (push 'called updates))))
        (pearl-sync-current-issue-title)
        (should-not fetched)
        (should-not updates)))))

(ert-deftest test-pearl-sync-title-push-advances-provenance ()
  "An edited title against an unchanged remote pushes and advances the hash."
  (let ((updates nil))
    (test-pearl--in-org
        (format "*** TODO [#B] Edited Title\n:PROPERTIES:\n:LINEAR-ID: a\n:LINEAR-TITLE-SHA256: %s\n:END:\n"
                (secure-hash 'sha256 "Old Title"))
      (test-pearl--with-title-stubs '(:title "Old Title" :updated-at "t0") updates
        (pearl-sync-current-issue-title)
        (should (equal '("Edited Title") updates))
        (should (string= (secure-hash 'sha256 "Edited Title")
                         (org-entry-get nil "LINEAR-TITLE-SHA256")))))))

(ert-deftest test-pearl-sync-title-conflict-refuses ()
  "Title edited locally and changed on the remote too: refuse, do not push."
  (let ((updates nil)
        (stored (secure-hash 'sha256 "Old Title")))
    (test-pearl--in-org
        (format "*** TODO [#B] Edited Title\n:PROPERTIES:\n:LINEAR-ID: a\n:LINEAR-TITLE-SHA256: %s\n:END:\n"
                stored)
      (test-pearl--with-title-stubs '(:title "Remote Changed Title" :updated-at "t1") updates
        ;; On conflict the command now prompts; cancel keeps the old behavior.
        (cl-letf (((symbol-function 'pearl--read-conflict-resolution)
                   (lambda (_label) 'cancel)))
          (pearl-sync-current-issue-title)
          (should-not updates)
          (should (string= stored (org-entry-get nil "LINEAR-TITLE-SHA256"))))))))

(ert-deftest test-pearl-sync-title-bracketed-remote-is-noop ()
  "A bracketed remote title renders stripped; a no-op sync makes no API call.
This is the deliberate bracket-stripping lossiness: the stored hash is of the
stripped heading, so an unedited bracketed title is never clobbered on Linear."
  (let ((fetched nil) (updates nil))
    (test-pearl--in-org
        ;; remote title "Fix [URGENT] bug" renders to heading "Fix URGENT bug";
        ;; the stored hash is of the stripped form.
        (format "*** TODO [#B] Fix URGENT bug\n:PROPERTIES:\n:LINEAR-ID: a\n:LINEAR-TITLE-SHA256: %s\n:END:\n"
                (secure-hash 'sha256 "Fix URGENT bug"))
      (cl-letf (((symbol-function 'pearl--fetch-issue-title-async)
                 (lambda (&rest _) (setq fetched t)))
                ((symbol-function 'pearl--update-issue-title-async)
                 (lambda (&rest _) (push 'called updates))))
        (pearl-sync-current-issue-title)
        (should-not fetched)
        (should-not updates)))))

(ert-deftest test-pearl-sync-title-not-on-issue-errors ()
  "Running the command outside a Linear issue heading signals a user error."
  (test-pearl--in-org "* Plain heading\nno id\n"
    (should-error (pearl-sync-current-issue-title) :type 'user-error)))

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