;;; syd-keybinds.el -*- lexical-binding: t; -*-
;;; Universal keybindings, not /too/ tied to any particular packages.

(use-package general
  :custom (general-use-package-emit-autoloads t))

(require 'general)

(defvar syd-leader-key "SPC"
  "A prefix key akin to Vim's <Leader>.")

(defvar syd-localleader-key "SPC m"
  "A prefix key akin to Vim's <LocalLeader>.")

(defvar syd-alt-leader-key "M-SPC"
  "`syd-leader', but for the states specified in `syd-alt-leader-key-states'.

Often, your \"usual\" leader key will be something unavailable in the Insert
state.  This key exists as a fallback for when you need your Leader, but must
remain in the Insert state.  Substitute \"Insert state\" for your states of
choice with `syd-alt-leader-key-states'.")

(defvar syd-alt-localleader-key "M-SPC m"
  "`syd-localleader', but for the states specified in `syd-alt-leader-key-states'.

See `syd-alt-leader-key' for rationale.")

(defvar syd-leader-key-states '(normal visual motion)
  "States for which the Leader keys (`syd-leader-key', `syd-localleader-key')
are active.")

(defvar syd-alt-leader-key-states '(emacs insert)
  "States for which the alternative Leader keys are active.  See
`syd-alt-leader-key' and `syd-alt-localleader-key'.")

(defvar-keymap syd-leader-map
  :doc "Leader-prefixed commands")

(defvar-keymap syd-leader-window-map
  :doc "Window commands")

(defun syd--initialise-leader ()
  "Set up the (empty) keymap associated with `syd-leader-key',
`syd-localleader-key', `syd-alt-leader-key', and `syd-alt-localleader-key'."
  ;; Define `syd/leader' as a command corresponding to the prefix map
  ;; `syd-leader-map'.
  (define-prefix-command 'syd/leader 'syd-leader-map)
  ;; This should help make the Leader key close to universally available.
  ;; Ideally, *nothing* takes precedence over Leader — it's an incredibly
  ;; important key!
  ;; https://github.com/noctuid/evil-guide?tab=readme-ov-file#undoprevent-overridingintercept-maps
  ;; Really, we do this because Doom does.  I'm honestly not entirely sure what
  ;; it does.  I can't find anything useful online.
  (define-key syd-leader-map [override-state] 'all)
  ;; Finally, we shall bind the damned keys. }:)
  (let ((map general-override-mode-map))
    (require 'evil)
    (evil-define-key* syd-leader-key-states map (kbd syd-leader-key) 'syd/leader)
    (evil-define-key* syd-alt-leader-key-states map (kbd syd-leader-key) 'syd/leader))
  (general-override-mode 1))

(defun syd-keybinds-initialise ()
  (syd--initialise-leader)
  (general-define-key
   :keymaps 'syd-leader-map
   "." #'find-file))

(syd-keybinds-initialise)

;; Show possible completions for a partially-entered key sequence.
(use-package which-key
  :hook (on-first-input . which-key-mode)
  :custom ((which-key-allow-evil-operators t)
           (which-key-show-operator-state-maps t)))

(provide 'syd-keybinds)