;;; zero-input-table.el --- a demo table based input method based on zero.el -*- no-byte-compile: t; lexical-binding: t -*-

;; Licensed under the Apache License, Version 2.0 (the "License");
;; you may not use this file except in compliance with the License.
;; You may obtain a copy of the License at
;;
;;     http://www.apache.org/licenses/LICENSE-2.0
;;
;; Unless required by applicable law or agreed to in writing, software
;; distributed under the License is distributed on an "AS IS" BASIS,
;; WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
;; See the License for the specific language governing permissions and
;; limitations under the License.

;;; Commentary:

;; when you type the key in `zero-input-table-table', IM will insert the
;; corresponding value.
;;
;; To use this demo IM,
;;   (add-to-list 'load-path "~/fromsource/zero")
;;   (require 'zero-input-table)
;;   (zero-input-set-default-im 'zero-input-table) ; set as default IM
;;   or (zero-input-set-im 'zero-input-table)      ; set as current buffer's IM

;;; Code:

;;==============
;; dependencies
;;==============

(require 'zero-input-framework)

;;===============================
;; basic data and emacs facility
;;===============================

(defvar zero-input-table-table nil
  "The table used by zero-input-table input method, map string to string.")
(defvar zero-input-table-sequence-initials nil
  "Used in `zero-input-table-can-start-sequence'.")

;;=====================
;; key logic functions
;;=====================

(defun zero-input-table-sort-key (lhs rhs)
  "A predicate function to sort candidates.  Return t if LHS should sort before RHS."
  (string< (car lhs) (car rhs)))

(defun zero-input-table-build-candidates (preedit-str &optional _fetch-size)
  "Build candidates by looking up PREEDIT-STR in `zero-input-table-table'."
  (mapcar 'cdr (sort (cl-remove-if-not #'(lambda (pair) (string-prefix-p preedit-str (car pair))) zero-input-table-table) 'zero-input-table-sort-key)))

;; (defun zero-input-table-build-candidates-async (preedit-str)
;;   "build candidate list, when done show it via `zero-input-table-show-candidates'"
;;   (zero-input-table-debug "building candidate list\n")
;;   (let ((candidates (zero-input-table-build-candidates preedit-str)))
;;     ;; update cache to make SPC and digit key selection possible.
;;     (setq zero-input-table-candidates candidates)
;;     (zero-input-table-show-candidates candidates)))

(defun zero-input-table-can-start-sequence (ch)
  "Return t if char CH can start a preedit sequence."
  (member (make-string 1 ch) zero-input-table-sequence-initials))

;;===============================
;; register IM to zero framework
;;===============================

(zero-input-register-im
 "zero-input-table"
 '((:build-candidates . zero-input-table-build-candidates)
   (:can-start-sequence . zero-input-table-can-start-sequence)))

;;============
;; public API
;;============

(defun zero-input-table-set-table (alist)
  "Set the conversion table.

the ALIST should be a list of (key . value) pairs.  when user type
\(part of) key, the IM will show all matching value.

To use demo data, you can call:
\(zero-input-table-set-table
 \\='((\"phone\" . \"18612345678\")
   (\"mail\" . \"foo@example.com\")
   (\"map\" . \"https://ditu.amap.com/\")
   (\"m\" . \"https://msdn.microsoft.com/en-us\")
   (\"address\" . \"123 Happy Street\")))"
  (setq zero-input-table-table alist)
  (setq zero-input-table-sequence-initials
	(delete-dups (mapcar #'(lambda (pair) (substring (car pair) 0 1))
			     zero-input-table-table))))

(provide 'zero-input-table)

;;; zero-input-table.el ends here