;;; erc-nicks-tests.el --- Tests for erc-nicks  -*- lexical-binding:t -*-

;; Copyright (C) 2023 Free Software Foundation, Inc.

;; This file is part of GNU Emacs.

;; GNU Emacs 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.

;; GNU Emacs 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 GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.

;;; Commentary:

;; Unlike most of ERC's tests, the ones in this file can be run
;; interactively in the same session.

;; TODO:
;;
;; * Add mock session (or scenario) with buffer snapshots, like those
;;   in erc-fill-tests.el.  (Should probably move helpers to a common
;;   library under ./resources.)

;;; Code:

(require 'ert)
(require 'erc-nicks)

;; This function replicates the behavior of older "invert" strategy
;; implementations from EmacsWiki, etc.  The values for the lower and
;; upper bounds (0.33 and 0.66) are likewise inherited.  See
;; `erc-nicks--invert-classic--dark' below for one reason its results
;; may not be plainly obvious.
(defun erc-nicks-tests--invert-classic (color)
  (if (pcase (erc-nicks--bg-mode)
        ('dark (< (erc-nicks--get-luminance color) (/ 1 3.0)))
        ('light (> (erc-nicks--get-luminance color) (/ 2 3.0))))
      (list (- 1.0 (nth 0 color)) (- 1.0 (nth 1 color)) (- 1.0 (nth 2 color)))
    color))


(ert-deftest erc-nicks--get-luminance ()
  (should (eql 0.0 (erc-nicks--get-luminance "black")))
  (should (eql 1.0 (erc-nicks--get-luminance "white")))
  (should (eql 21.0 (/ (+ 0.05 1.0) (+ 0.05 0.0))))

  ;; RGB floats from a `display-graphic-p' session.
  (let ((a (erc-nicks--get-luminance ; #9439ad
            '(0.5803921568627451 0.2235294117647059 0.6784313725490196)))
        (b (erc-nicks--get-luminance ; #ae54c7
            '(0.6823529411764706 0.32941176470588235 0.7803921568627451)))
        (c (erc-nicks--get-luminance ; #d19ddf
            '(0.8196078431372549 0.615686274509804 0.8745098039215686)))
        (d (erc-nicks--get-luminance ; #f5e8f8
            '(0.9607843137254902 0.9098039215686274 0.9725490196078431))))
    ;; Low, med, high contrast comparisons against known values from
    ;; an external source.
    (should (eql 1.42 (/ (round (* 100 (/ (+ 0.05 b) (+ 0.05 a)))) 100.0)))
    (should (eql 2.78 (/ (round (* 100 (/ (+ 0.05 c) (+ 0.05 a)))) 100.0)))
    (should (eql 5.16 (/ (round (* 100 (/ (+ 0.05 d) (+ 0.05 a)))) 100.0)))))

(ert-deftest erc-nicks-invert--classic ()
  (let ((convert (lambda (n) (apply #'color-rgb-to-hex
                                    (erc-nicks-tests--invert-classic
                                     (color-name-to-rgb n))))))
    (let ((erc-nicks--bg-mode-value 'dark))
      (should (equal (funcall convert "white") "#ffffffffffff"))
      (should (equal (funcall convert "black") "#ffffffffffff"))
      (should (equal (funcall convert "green") "#0000ffff0000")))
    (let ((erc-nicks--bg-mode-value 'light))
      (should (equal (funcall convert "white") "#000000000000"))
      (should (equal (funcall convert "black") "#000000000000"))
      (should (equal (funcall convert "green") "#ffff0000ffff")))))

(ert-deftest erc-nicks--get-contrast ()
  (should (= 21.0 (erc-nicks--get-contrast "white" "black")))
  (should (= 21.0 (erc-nicks--get-contrast "black" "white")))
  (should (= 1.0 (erc-nicks--get-contrast "black" "black")))
  (should (= 1.0 (erc-nicks--get-contrast "white" "white"))))

(defun erc-nicks-tests--print-contrast (fn color)
  (let* ((erc-nicks-color-adjustments (list fn))
         (result (erc-nicks--reduce color))
         (start (point)))
    (insert (format "%16s%-16s%16s%-16s\n"
                    (concat color "-")
                    (concat ">" result)
                    (concat color " ")
                    (concat " " result)))
    (put-text-property (+ start 32) (+ start 48) 'face
                       (list :background color :foreground result))
    (put-text-property (+ start 48) (+ start 64) 'face
                       (list :background result :foreground color))
    result))

(ert-deftest erc-nicks--invert-classic--light ()
  (let ((erc-nicks--bg-luminance 1.0)
        (erc-nicks--bg-mode-value 'light)
        (show (lambda (c) (erc-nicks-tests--print-contrast
                           #'erc-nicks-tests--invert-classic c))))

    (with-current-buffer (get-buffer-create
                          "*erc-nicks--invert-classic--light*")
      (should (equal "#000000000000" (funcall show "white")))
      (should (equal "#000000000000" (funcall show "black")))
      (should (equal "#ffff00000000" (funcall show "red")))
      (should (equal "#ffff0000ffff" (funcall show "green"))) ; magenta
      (should (equal "#00000000ffff" (funcall show "blue")))

      (unless noninteractive
        (should (equal "#bbbbbbbbbbbb" (funcall show "#bbbbbbbbbbbb")))
        (should (equal "#cccccccccccc" (funcall show "#cccccccccccc")))
        (should (equal "#222122212221" (funcall show "#dddddddddddd")))
        (should (equal "#111011101110" (funcall show "#eeeeeeeeeeee"))))

      (when noninteractive
        (kill-buffer)))))

;; This shows that the output can be darker (have less contrast) than
;; the input.
(ert-deftest erc-nicks--invert-classic--dark ()
  (let ((erc-nicks--bg-luminance 0.0)
        (erc-nicks--bg-mode-value 'dark)
        (show (lambda (c) (erc-nicks-tests--print-contrast
                           #'erc-nicks-tests--invert-classic c))))

    (with-current-buffer (get-buffer-create
                          "*erc-nicks--invert-classic--dark*")
      (should (equal "#ffffffffffff" (funcall show "white")))
      (should (equal "#ffffffffffff" (funcall show "black")))
      (should (equal "#0000ffffffff" (funcall show "red"))) ; cyan
      (should (equal "#0000ffff0000" (funcall show "green")))
      (should (equal "#ffffffff0000" (funcall show "blue"))) ; yellow

      (unless noninteractive
        (should (equal "#aaaaaaaaaaaa" (funcall show "#555555555555")))
        (should (equal "#999999999999" (funcall show "#666666666666")))
        (should (equal "#888888888888" (funcall show "#777777777777")))
        (should (equal "#777777777777" (funcall show "#888888888888")))
        (should (equal "#666666666666" (funcall show "#999999999999")))
        (should (equal "#aaaaaaaaaaaa" (funcall show "#aaaaaaaaaaaa"))))

      (when noninteractive
        (kill-buffer)))))

;; These are the same as the legacy version but work in terms of
;; contrast ratios.  Converting the original bounds to contrast ratios
;; (assuming pure white and black backgrounds) gives:
;;
;;   min-lum of 0.33 ~~> 1.465
;;   max-lum of 0.66 ~~> 7.666
;;
(ert-deftest erc-nicks-invert--light ()
  (let ((erc-nicks--bg-luminance 1.0)
        (erc-nicks--bg-mode-value 'light)
        (erc-nicks-contrast-range '(1.465))
        (show (lambda (c) (erc-nicks-tests--print-contrast
                           #'erc-nicks-invert c))))

    (with-current-buffer (get-buffer-create
                          "*erc-nicks--invert-classic--light*")
      (should (equal "#000000000000" (funcall show "white")))
      (should (equal "#000000000000" (funcall show "black")))
      (should (equal "#ffff00000000" (funcall show "red")))
      (should (equal "#ffff0000ffff" (funcall show "green"))) ; magenta
      (should (equal "#00000000ffff" (funcall show "blue")))

      (unless noninteractive
        (should (equal "#bbbbbbbbbbbb" (funcall show "#bbbbbbbbbbbb")))
        (should (equal "#cccccccccccc" (funcall show "#cccccccccccc")))
        (should (equal "#222122212221" (funcall show "#dddddddddddd")))
        (should (equal "#111011101110" (funcall show "#eeeeeeeeeeee"))))

      (when noninteractive
        (kill-buffer)))))

(ert-deftest erc-nicks-invert--dark ()
  (let ((erc-nicks--bg-luminance 0.0)
        (erc-nicks--bg-mode-value 'dark)
        (erc-nicks-contrast-range '(7.666))
        (show (lambda (c) (erc-nicks-tests--print-contrast
                           #'erc-nicks-invert c))))

    (with-current-buffer (get-buffer-create "*erc-nicks-invert--dark*")
      (should (equal "#ffffffffffff" (funcall show "white")))
      (should (equal "#ffffffffffff" (funcall show "black")))
      (should (equal "#0000ffffffff" (funcall show "red"))) ; cyan
      (should (equal "#0000ffff0000" (funcall show "green")))
      (should (equal "#ffffffff0000" (funcall show "blue"))) ; yellow

      (unless noninteractive
        (should (equal "#aaaaaaaaaaaa" (funcall show "#555555555555")))
        (should (equal "#999999999999" (funcall show "#666666666666")))
        (should (equal "#888888888888" (funcall show "#777777777777")))
        (should (equal "#888888888888" (funcall show "#888888888888")))
        (should (equal "#999999999999" (funcall show "#999999999999"))))

      (when noninteractive
        (kill-buffer)))))

(ert-deftest erc-nicks-add-contrast ()
  (let ((erc-nicks--bg-luminance 1.0)
        (erc-nicks--bg-mode-value 'light)
        (erc-nicks-contrast-range '(3.5))
        (show (lambda (c) (erc-nicks-tests--print-contrast
                           #'erc-nicks-add-contrast c))))

    (with-current-buffer (get-buffer-create "*erc-nicks-add-contrast*")
      (should (equal "#893a893a893a" (funcall show "white")))
      (should (equal "#893a893a893a" (funcall show "#893a893a893a")))
      (should (equal "#000000000000" (funcall show "black")))
      (should (equal "#ffff00000000" (funcall show "red")))
      (should (equal "#0000a12e0000" (funcall show "green")))
      (should (equal "#00000000ffff" (funcall show "blue")))

      ;; When the input is already near the desired ratio, the result
      ;; may not be in bounds, only close.  But the difference is
      ;; usually imperceptible.
      (unless noninteractive
        ;; Well inside (light slate gray)
        (should (equal "#777788889999" (funcall show "#777788889999")))
        ;; Slightly outside -> just outside
        (should (equal "#7c498bd39b5c" (funcall show "#88889999aaaa")))
        ;; Just outside -> just inside
        (should (equal "#7bcc8b479ac0" (funcall show "#7c498bd39b5c")))
        ;; Just inside
        (should (equal "#7bcc8b479ac0" (funcall show "#7bcc8b479ac0"))))

      (when noninteractive
        (kill-buffer)))))

(ert-deftest erc-nicks-cap-contrast ()
  (should (= 12.5 (cdr erc-nicks-contrast-range)))
  (let ((erc-nicks--bg-luminance 1.0)
        (erc-nicks--bg-mode-value 'light)
        (show (lambda (c) (erc-nicks-tests--print-contrast
                           #'erc-nicks-cap-contrast c))))

    (with-current-buffer (get-buffer-create "*erc-nicks-remove-contrast*")
      (should (equal (funcall show "black") "#34e534e534e5" )) ; 21.0 -> 12.14
      (should ; 12.32 -> 12.32 (same)
       (equal (funcall show "#34e534e534e5") "#34e534e534e5"))
      (should (equal (funcall show "white") "#ffffffffffff"))

      (unless noninteractive
        (should (equal (funcall show "DarkRed") "#8b8b00000000"))
        (should (equal (funcall show "DarkGreen") "#000064640000"))
        ;; 15.29 -> 12.38
        (should (equal (funcall show "DarkBlue") "#1cf11cf198b5"))

        ;; 12.50 -> 12.22
        (should (equal (funcall show "#33e033e033e0") "#34ab34ab34ab"))
        ;; 12.57 -> 12.28
        (should (equal (funcall show "#338033803380") "#344c344c344c"))
        ;; 12.67 -> 12.37
        (should (equal (funcall show "#330033003300") "#33cc33cc33cc")))

      (when noninteractive
        (kill-buffer)))))

;; Here is an example of how filters can steer us wrong (don't always
;; DTRT).  Two keys with similar names hash to very different values:
;;
;;   1) "awbLibera.Chat" -> #x1e3b5ca4edbc ; deep blue
;;   2) "twbLibera.Chat" -> #xdeb4c26934af ; yellow/orange
;;
;; But on a dark bg, (1) falls below `erc-nicks-invert's min threshold
;; and thus gets treated, becoming #xe1c4a35b1243, which is quite
;; close to and thus easily confused with (2).

(ert-deftest erc-nicks--hash ()
  (with-current-buffer (get-buffer-create "*erc-nicks--hash*")
    ;; Here, we're just using `erc-nicks-tests--show-contrast' for show.
    (let ((show (lambda (c) (erc-nicks-tests--print-contrast #'identity c))))

      ;; Similar nicks yielding similar colors is likely undesirable.
      (should (= (erc-nicks--hash "00000000") #xe4deaa6df385))
      (should (= (erc-nicks--hash "00000001") #xe4deaa6df386))
      (funcall show "#e4deaa6df385")
      (funcall show "#e4deaa6df386")

      ;; So we currently pad from the right to avoid this.
      (should (= (erc-nicks--hash "0Libera.Chat") #x32fdc0d63a92))
      (should (= (erc-nicks--hash "1Libera.Chat") #xc2c4f1c997f3))
      (funcall show "#32fdc0d63a92")
      (funcall show "#c2c4f1c997f3")

      (should (= (erc-nicks--hash "0       OFTC") #x6805b7521261))
      (should (= (erc-nicks--hash "1       OFTC") #xf7cce8456fc2))
      (funcall show "#6805b7521261")
      (funcall show "#f7cce8456fc2"))

    (when noninteractive
      (kill-buffer))))

(ert-deftest erc-nicks--skip-p ()
  ;; Baseline
  (should-not (erc-nicks--skip-p 'bold nil 10000000))
  (should-not (erc-nicks--skip-p '(bold) nil 10000000))
  (should-not (erc-nicks--skip-p nil '(bold) 10000000))
  (should-not (erc-nicks--skip-p 'bold '(bold) 0))
  (should-not (erc-nicks--skip-p '(bold) '(bold) 0))
  (should-not (erc-nicks--skip-p 'bold '(foo bold) 0))
  (should-not (erc-nicks--skip-p '((:inherit bold)) '(bold) 1))
  (should (erc-nicks--skip-p 'bold '(bold) 1))
  (should (erc-nicks--skip-p 'bold '(fake bold) 1))
  (should (erc-nicks--skip-p 'bold '(foo bar bold) 1))
  (should (erc-nicks--skip-p '(bold) '(bold) 1))
  (should (erc-nicks--skip-p '((bold)) '(bold) 1))
  (should (erc-nicks--skip-p '((((bold)))) '(bold) 1))
  (should (erc-nicks--skip-p '(bold) '(foo bold) 1))
  (should (erc-nicks--skip-p '(:inherit bold) '((:inherit bold)) 1))
  (should (erc-nicks--skip-p '((:inherit bold)) '((:inherit bold)) 1))
  (should (erc-nicks--skip-p '(((:inherit bold))) '((:inherit bold)) 1))

  ;; Composed
  (should-not (erc-nicks--skip-p '(italic bold) '(bold) 1))
  (should-not (erc-nicks--skip-p '((italic) bold) '(bold) 1))
  (should-not (erc-nicks--skip-p '(italic (bold)) '(bold) 1))
  (should (erc-nicks--skip-p '(italic bold) '(bold) 2))
  (should (erc-nicks--skip-p '((italic) bold) '(bold) 2))
  (should (erc-nicks--skip-p '(italic (bold)) '(bold) 2))

  (should-not (erc-nicks--skip-p '(italic default bold) '(bold) 2))
  (should-not (erc-nicks--skip-p '((default italic) bold) '(bold) 2))
  (should-not (erc-nicks--skip-p '(italic (default bold)) '(bold) 2))
  (should-not (erc-nicks--skip-p '((default italic) (bold shadow)) '(bold) 2))
  (should (erc-nicks--skip-p '((default italic) bold) '(bold) 3))
  (should (erc-nicks--skip-p '(italic (default bold)) '(bold) 3))
  (should (erc-nicks--skip-p '((default italic) (bold shadow)) '(bold) 3))
  (should (erc-nicks--skip-p '(italic (default (bold shadow))) '(bold) 3)))

;;; erc-nicks-tests.el ends here