;;; test-pearl-mapping.el --- Tests for pearl mapping helpers -*- 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:

;; Unit tests for the pure mapping helpers in pearl.el:
;; Linear state <-> org keyword, the cached TODO-states regex, and
;; Linear priority -> org cookie / readable name.

;;; Code:

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

;; A small, explicit mapping used across the state tests so cases don't
;; depend on the package default.
(defmacro test-pearl--with-mapping (mapping &rest body)
  "Run BODY with the state mapping bound to MAPPING and the cache cleared."
  (declare (indent 1))
  `(let ((pearl-state-to-todo-mapping ,mapping)
         (pearl-todo-states-pattern nil)
         (pearl--todo-states-pattern-source nil))
     ,@body))

;;; pearl--map-linear-state-to-org

(ert-deftest test-pearl-map-linear-state-to-org-mapped-returns-keyword ()
  "A Linear state present in the mapping returns its org keyword."
  (test-pearl--with-mapping '(("Todo" . "TODO") ("In Progress" . "DOING"))
    (should (string-equal "DOING" (pearl--map-linear-state-to-org "In Progress")))))

(ert-deftest test-pearl-map-linear-state-to-org-unmapped-defaults-todo ()
  "An unmapped Linear state falls back to TODO."
  (test-pearl--with-mapping '(("Todo" . "TODO") ("Done" . "DONE"))
    (should (string-equal "TODO" (pearl--map-linear-state-to-org "Triage")))))

(ert-deftest test-pearl-map-linear-state-to-org-nil-defaults-todo ()
  "A nil state falls back to TODO rather than erroring."
  (test-pearl--with-mapping '(("Todo" . "TODO"))
    (should (string-equal "TODO" (pearl--map-linear-state-to-org nil)))))

;;; pearl--map-org-state-to-linear

(ert-deftest test-pearl-map-org-state-to-linear-mapped-returns-state ()
  "An org keyword present in the mapping returns its Linear state."
  (test-pearl--with-mapping '(("Todo" . "TODO") ("In Progress" . "DOING"))
    (should (string-equal "In Progress" (pearl--map-org-state-to-linear "DOING")))))

(ert-deftest test-pearl-map-org-state-to-linear-unmapped-returns-nil ()
  "An org keyword not in the mapping returns nil."
  (test-pearl--with-mapping '(("Todo" . "TODO") ("Done" . "DONE"))
    (should (null (pearl--map-org-state-to-linear "WAITING")))))

(ert-deftest test-pearl-map-org-state-to-linear-nil-returns-nil ()
  "A nil org keyword returns nil."
  (test-pearl--with-mapping '(("Todo" . "TODO"))
    (should (null (pearl--map-org-state-to-linear nil)))))

;;; pearl--get-todo-states-pattern

(ert-deftest test-pearl-get-todo-states-pattern-builds-alternation ()
  "The pattern is the org keywords joined with regex alternation."
  (test-pearl--with-mapping '(("Todo" . "TODO") ("In Progress" . "IN-PROGRESS") ("Done" . "DONE"))
    (should (string-equal "TODO\\|IN-PROGRESS\\|DONE"
                          (pearl--get-todo-states-pattern)))))

(ert-deftest test-pearl-get-todo-states-pattern-empty-mapping ()
  "An empty mapping yields an empty pattern string."
  (test-pearl--with-mapping '()
    (should (string-equal "" (pearl--get-todo-states-pattern)))))

(ert-deftest test-pearl-get-todo-states-pattern-recomputes-after-mapping-change ()
  "The cached pattern is recomputed when the mapping changes mid-session.

Regression for the stale-cache bug: a once-populated pattern must not
outlive a change to `pearl-state-to-todo-mapping'."
  (test-pearl--with-mapping '(("Todo" . "TODO") ("Done" . "DONE"))
    (should (string-equal "TODO\\|DONE" (pearl--get-todo-states-pattern)))
    ;; Change the mapping after the pattern has been cached.
    (setq pearl-state-to-todo-mapping
          '(("Todo" . "TODO") ("In Progress" . "DOING") ("Done" . "DONE")))
    (should (string-equal "TODO\\|DOING\\|DONE"
                          (pearl--get-todo-states-pattern)))))

;;; pearl--map-linear-priority-to-org

(ert-deftest test-pearl-map-linear-priority-to-org-known-values ()
  "Linear priorities 1-4 map to org cookies A-D."
  (should (string-equal "[#A]" (pearl--map-linear-priority-to-org 1)))
  (should (string-equal "[#B]" (pearl--map-linear-priority-to-org 2)))
  (should (string-equal "[#C]" (pearl--map-linear-priority-to-org 3)))
  (should (string-equal "[#D]" (pearl--map-linear-priority-to-org 4))))

(ert-deftest test-pearl-map-linear-priority-to-org-zero-defaults-c ()
  "Priority 0 (No priority) falls back to [#C]."
  (should (string-equal "[#C]" (pearl--map-linear-priority-to-org 0))))

(ert-deftest test-pearl-map-linear-priority-to-org-nil-and-unknown-default-c ()
  "A nil or out-of-range priority falls back to [#C]."
  (should (string-equal "[#C]" (pearl--map-linear-priority-to-org nil)))
  (should (string-equal "[#C]" (pearl--map-linear-priority-to-org 99))))

;;; pearl--get-linear-priority-name

(ert-deftest test-pearl-get-linear-priority-name-known-values ()
  "Linear priorities 1-4 have readable names."
  (should (string-equal "Urgent" (pearl--get-linear-priority-name 1)))
  (should (string-equal "High"   (pearl--get-linear-priority-name 2)))
  (should (string-equal "Medium" (pearl--get-linear-priority-name 3)))
  (should (string-equal "Low"    (pearl--get-linear-priority-name 4))))

(ert-deftest test-pearl-get-linear-priority-name-nil-and-unknown-default-medium ()
  "A nil, zero, or out-of-range priority falls back to Medium."
  (should (string-equal "Medium" (pearl--get-linear-priority-name 0)))
  (should (string-equal "Medium" (pearl--get-linear-priority-name nil)))
  (should (string-equal "Medium" (pearl--get-linear-priority-name 99))))

;;; pearl-get-priorities

(ert-deftest test-pearl-get-priorities-returns-fixed-alist ()
  "The priority list maps the five Linear priority names to their integers."
  (let ((priorities (pearl-get-priorities)))
    (should (equal 0 (cdr (assoc "No priority" priorities))))
    (should (equal 1 (cdr (assoc "Urgent" priorities))))
    (should (equal 2 (cdr (assoc "High" priorities))))
    (should (equal 3 (cdr (assoc "Medium" priorities))))
    (should (equal 4 (cdr (assoc "Low" priorities))))))

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