;;; evil-leap.el --- Evil's answer to Neovim's answer to the mouse -*- lexical-binding: t; -*-
;;
;; Copyright (C) 2024 Madeleine Sydney
;;
;; Author: Madeleine Sydney <lomiskiam@gmail.com>
;; Maintainer: Madeleine Sydney <lomiskiam@gmail.com>
;; Created: October 06, 2024
;; Modified: October 06, 2024
;; Version: 0.0.1
;; Keywords: evil movement
;; Homepage: https://github.com/crumbtoo/leap.el
;; Package-Requires: ((emacs "24.3"))
;;
;; This file is not part of GNU Emacs.
;;
;;; Commentary:
;;
;;
;;
;;; Code:

(defcustom evil-leap-safe-labels
  (string-to-list "sfnut/SFNLHMUGTZ?")
  "TODO A list of characters that you will never use immediately after an evil-leap
jump."
  :group 'evil-leap
  :type "List of characters")

(defcustom evil-leap-labels
  (string-to-list "sfnjklhodweimbuyvrgtaqpcxz/SFNJKLHODWEIMBUYVRGTAQPCXZ?")
  ;; (append evil-leap-safe-labels
  ;;         (string-to-list "jklhodweimbyvrgaqpcxzJKODWEIBYVRAQPCX"))
  "TODO A list of characters to use as labels."
  :group 'evil-leap
  :type "List of characters")

;; (defun evil-leap--collect-keys (&optional forward?)
;;   (let ((collected-keys nil))
;;     (dolist (i '(0 1) collected-keys)
;;       (let ((prompt (format ">%s" (mapconcat #'char-to-string collected-keys))))
;;         (appendq! collected-keys (list (evil-read-key prompt)))))))

(defcustom evil-leap-character-aspect-ratio
  0.3
  "TODO"
  :group 'evil-leap
  :type "Number")

(defcustom evil-leap-equivalence-classes '((?\s ?\n ?\t ?\r))
  "TODO"
  :group 'evil-leap
  :type "List of lists of characters")

(defun evil-leap--gather-targets-forward (regexp)
  (let ((end-of-visible (window-end))
        targets)
    (save-excursion
      (while (re-search-forward regexp end-of-visible t)
        (save-excursion
          (goto-char (match-beginning 0))
          (push (list (point) (current-column) (line-number-at-pos))
                targets))))
    (reverse targets)))

(defun evil-leap--euclidean-distance (x1 y1 x2 y2)
  (let* ((width (abs (- x1 x2)))
         (height (* (abs (- y1 y2))
                    evil-leap-character-aspect-ratio))
         (hypotenuse (sqrt (+ (* width width)
                              (* height height)))))
    hypotenuse))

(defun evil-leap--sort-by-euclidean-distance-from-point (targets)
  (let ((point-x (current-column))
        (point-y (line-number-at-pos)))
    (sort targets
          :lessp
          (lambda (pos1 pos2)
            (pcase-let ((`(,_ ,pos1-x ,pos1-y) pos1)
                        (`(,_ ,pos2-x ,pos2-y) pos2))
              (< (evil-leap--euclidean-distance point-x point-y pos1-x pos1-y)
                 (evil-leap--euclidean-distance point-x point-y pos2-x pos2-y)))))))

;; (defun evil-leap--label-targets (targets)
;;   (let ((ht (make-hash-table :test 'equal)))
;;     (dolist (c ))))

;; define-inline?
(defun evil-leap-jump-to (target)
  (goto-char (car target)))

(defun evil-leap (&rest args)
  "TODO Something something something.

Keyword arguments
  :backward-p BOOL
  :action     ACTION
  :targets    TARGETS  A list of targets, or a Lisp procedure returning such a
                       list.  Each target should be a list of form
                       (POS LINE COLUMN . XS)."
  (let ((backward-p (plist-get args :backward-p))
        (action (or (plist-get args :action) #'evil-leap-jump-to))
        (targets (plist-get args :targets)))
    ))

(evil-define-motion evil-leap-s (count keys)
  "TODO"
  :jump t
  :type 'exclusive
  (interactive)
  (evil-leap--collect-keys))

(provide 'evil-leap)
;;; evil-leap.el ends here