;;; yekneb-debug.el --- Debug utility functions for GNU Emacs.

;; Copyright © 2021 - 2025 Ben Key

;; This file is part of the yekneb package.
;;
;; The yekneb package 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.
;;
;; The yekneb package 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
;; the yekneb package. If not, see <http://www.gnu.org/licenses/>.

(require 'cl-lib)

(defconst yekneb-log-always -1)
(defconst yekneb-log-min 0)
(defconst yekneb-log-severe 0)
(defconst yekneb-log-error 1)
(defconst yekneb-log-warning 2)
(defconst yekneb-log-info 3)
(defconst yekneb-log-entry 4)
(defconst yekneb-log-param 5)
(defconst yekneb-log-debug 6)
(defconst yekneb-log-hidebug 7)
(defconst yekneb-log-all 7)
(defconst yekneb-log-max 7)
(defconst yekneb-log-level-names `("severe" "error" "warning" "info" "entry" "param" "debug" "hidebug"))

(defvar yekneb-debug-level yekneb-log-error
  "The currently enabled debug level.")

(defun yekneb-get-log-file-name ()
  "Gets the path to the file that log messages will be written to."
  (expand-file-name "debug.log" user-emacs-directory)
  )

(defun yekneb-validate-debug-level (value low high)
  (cond
   ((or (< value low) (> value high))
    low
    )
   (t
    value
    )
   )
  )

(defun yekneb-get-debug-level-name (level)
  "Gets the name for the specified debug level."
  (cond
   ((or (< level yekneb-log-min) (> level yekneb-log-max))
    (format "Unknown level %d" level)
    )
   (t
    (nth level yekneb-log-level-names)
    )
   )
  )

(defun yekneb-set-debug-level (level)
  "Sets `yekneb-debug-level', with validation."
  (setq yekneb-debug-level (yekneb-validate-debug-level level yekneb-log-min yekneb-log-max))
  (message "yekneb-debug-level set to %s" (yekneb-get-debug-level-name yekneb-debug-level))
  )

(defun yekneb-update-debug-level ()
  "Sets `yekneb-debug-level' to one more than the current value."
  (interactive)
  (yekneb-set-debug-level (+ yekneb-debug-level 1))
  )

(defun yekneb-log (level log-message &rest format-params)
  "Log message."
  (when (<= level yekneb-debug-level)
    (setq log-message (eval (append '(format log-message) format-params)))
    (message "%s" log-message)
    (let ((save-silently t))
      (write-region (format "%s\n" log-message) nil (yekneb-get-log-file-name) t 'quite)
      )
    )
  )

(provide 'yekneb-debug)