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emacs/lisp/ledger-mode/ledger-schedule.el
2025-11-25 19:52:03 +01:00

333 lines
14 KiB
EmacsLisp

;;; ledger-schedule.el --- Helper code for use with the "ledger" command-line tool -*- lexical-binding: t; -*-
;; Copyright (C) 2013 Craig Earls (enderw88 at gmail dot com)
;; This file is not part of GNU Emacs.
;; This 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 2, or (at your option)
;; any later version.
;;
;; This 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; see the file COPYING. If not, write to the
;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
;; MA 02110-1301 USA.
;;; Commentary:
;;
;; This module provides for automatically adding transactions to a
;; ledger buffer on a periodic basis. Recurrence expressions are
;; inspired by Martin Fowler's "Recurring Events for Calendars",
;; martinfowler.com/apsupp/recurring.pdf
;; use (fset 'VARNAME (macro args)) to put the macro definition in the
;; function slot of the symbol VARNAME. Then use VARNAME as the
;; function without have to use funcall.
(require 'ledger-init)
(require 'cl-lib)
(declare-function ledger-mode "ledger-mode")
;;; Code:
(defgroup ledger-schedule nil
"Support for automatically recommendation transactions."
:group 'ledger)
(defcustom ledger-schedule-buffer-name "*Ledger Schedule*"
"Name for the schedule buffer."
:type 'string
:group 'ledger-schedule)
(defcustom ledger-schedule-look-backward 7
"Number of days to look back in time for transactions."
:type 'integer
:group 'ledger-schedule)
(defcustom ledger-schedule-look-forward 14
"Number of days auto look forward to recommend transactions."
:type 'integer
:group 'ledger-schedule)
(defcustom ledger-schedule-file "~/ledger-schedule.ledger"
"File to find scheduled transactions."
:type 'file
:group 'ledger-schedule)
(defcustom ledger-schedule-week-days '(("Mo" 1)
("Tu" 2)
("We" 3)
("Th" 4)
("Fr" 5)
("Sa" 6)
("Su" 0))
"List of weekday abbreviations.
There must be exactly seven entries each with a two character
abbreviation for a day and the number of that day in the week."
:type '(alist :key-type string :value-type (group integer))
:group 'ledger-schedule)
(defsubst ledger-between (val low high)
"Return TRUE if VAL >= LOW and <= HIGH."
(declare (obsolete <= "Ledger-mode v4.0.1"))
(<= low val high))
(defun ledger-schedule-days-in-month (month year)
"Return number of days in the MONTH, MONTH is from 1 to 12.
If YEAR is nil, assume it is not a leap year"
(if (<= 1 month 12)
(if (and year (date-leap-year-p year) (= 2 month))
29
(nth (1- month) '(31 28 31 30 31 30 31 31 30 31 30 31)))
(error "Month out of range, MONTH=%S" month)))
(defun ledger-schedule-encode-day-of-week (day-string)
"Return the numerical day of week corresponding to DAY-STRING."
(cadr (assoc day-string ledger-schedule-week-days)))
;; Macros to handle date expressions
(defun ledger-schedule-constrain-day-in-month (count day-of-week)
"Return a form that returns TRUE for the the COUNT DAY-OF-WEEK.
For example, return true if date is the 3rd Thursday of the
month. Negative COUNT starts from the end of the month. (EQ
COUNT 0) means EVERY day-of-week (eg. every Saturday)"
(if (and (<= -6 count 6) (<= 0 day-of-week 6))
(cond ((zerop count) ;; Return true if day-of-week matches
`(eq (nth 6 (decode-time date)) ,day-of-week))
((> count 0) ;; Positive count
(let ((decoded (gensym)))
`(let ((,decoded (decode-time date)))
(and (eq (nth 6 ,decoded) ,day-of-week)
(<= ,(* (1- count) 7)
(nth 3 ,decoded)
,(* count 7))))))
((< count 0)
(let ((days-in-month (gensym))
(decoded (gensym)))
`(let* ((,decoded (decode-time date))
(,days-in-month (ledger-schedule-days-in-month
(nth 4 ,decoded)
(nth 5 ,decoded))))
(and (eq (nth 6 ,decoded) ,day-of-week)
(<= (+ ,days-in-month ,(* count 7))
(nth 3 ,decoded)
(+ ,days-in-month ,(* (1+ count) 7)))))))
(t
(error "COUNT out of range, COUNT=%S" count)))
(error "Invalid argument to ledger-schedule-day-in-month-macro %S %S"
count
day-of-week)))
(defun ledger-schedule-constrain-every-count-day (day-of-week skip start-date)
"Return a form that is true for every DAY-OF-WEEK.
Skips SKIP, and starts on START-DATE.
For example every second Friday, regardless of month."
(let ((start-day (nth 6 (decode-time start-date))))
(if (eq start-day day-of-week) ;; good, can proceed
`(zerop (mod (- (time-to-days date) ,(time-to-days start-date)) ,(* skip 7)))
(error "START-DATE day of week doesn't match DAY-OF-WEEK"))))
(defun ledger-schedule-constrain-date-range (month1 day1 month2 day2)
"Return a form of DATE that is true if DATE falls between two dates.
The dates are given by the pairs MONTH1 DAY1 and MONTH2 DAY2."
(let ((decoded (gensym))
(target-month (gensym))
(target-day (gensym)))
`(let* ((,decoded (decode-time date))
(,target-month (nth 4 decoded))
(,target-day (nth 3 decoded)))
(and (and (> ,target-month ,month1)
(< ,target-month ,month2))
(and (> ,target-day ,day1)
(< ,target-day ,day2))))))
(defun ledger-schedule-scan-transactions (schedule-file)
"Scan SCHEDULE-FILE and return a list of transactions with date predicates.
The car of each item is a function of date that returns true if
the transaction should be logged for that day."
(interactive "fFile name: ")
(let ((xact-list (list)))
(with-current-buffer
(find-file-noselect schedule-file)
(goto-char (point-min))
(while (re-search-forward "^\\[\\(.*\\)\\] " nil t)
(let ((date-descriptor "")
(transaction nil)
(xact-start (match-end 0)))
(setq date-descriptor
(ledger-schedule-read-descriptor-tree
(buffer-substring-no-properties
(match-beginning 0)
(match-end 0))))
(forward-paragraph)
(setq transaction (list date-descriptor
(buffer-substring-no-properties
xact-start
(point))))
(setq xact-list (cons transaction xact-list))))
xact-list)))
(defun ledger-schedule-read-descriptor-tree (descriptor-string)
"Read DESCRIPTOR-STRING and return a form that evaluates dates."
(ledger-schedule-transform-auto-tree
(split-string
(substring descriptor-string 1 (string-match "]" descriptor-string)) " ")))
(defun ledger-schedule-transform-auto-tree (descriptor-string-list)
"Take DESCRIPTOR-STRING-LIST, and return a string with a lambda function of date."
;; use funcall to use the lambda function spit out here
(if (consp descriptor-string-list)
(let (result)
(while (consp descriptor-string-list)
(let ((newcar (car descriptor-string-list)))
(if (consp newcar)
(setq newcar (ledger-schedule-transform-auto-tree (car descriptor-string-list))))
;; newcar may be a cons now, after ledger-schedule-transfrom-auto-tree
(if (consp newcar)
(push newcar result)
;; this is where we actually turn the string descriptor into useful lisp
(push (ledger-schedule-compile-constraints newcar) result)) )
(setq descriptor-string-list (cdr descriptor-string-list)))
;; tie up all the clauses in a big or lambda, and return
;; the lambda function as list to be executed by funcall
`(lambda (date)
,(nconc (list 'or) (nreverse result) descriptor-string-list)))))
(defun ledger-schedule-compile-constraints (descriptor-string)
"Return a list with the year, month and day fields split."
(let ((fields (split-string descriptor-string "[/\\-]" t)))
(list 'and
(ledger-schedule-constrain-day (nth 0 fields) (nth 1 fields) (nth 2 fields))
(ledger-schedule-constrain-year (nth 0 fields) (nth 1 fields) (nth 2 fields))
(ledger-schedule-constrain-month (nth 0 fields) (nth 1 fields) (nth 2 fields)))))
(defun ledger-schedule-constrain-year (year-desc month-desc day-desc)
"Return a form that constrains the year.
YEAR-DESC, MONTH-DESC, and DAY-DESC are the string portions of the
date descriptor."
(cond
((string-match "[A-Za-z]" day-desc) t) ; there is an advanced day descriptor which overrides the year
((string= year-desc "*") t)
((/= 0 (string-to-number year-desc))
`(memq (nth 5 (decode-time date)) ',(mapcar 'string-to-number (split-string year-desc ","))))
(t
(error "Improperly specified year constraint: %s %s %s" year-desc month-desc day-desc))))
(defun ledger-schedule-constrain-month (year-desc month-desc day-desc)
"Return a form that constrains the month.
YEAR-DESC, MONTH-DESC, and DAY-DESC are the string portions of the
date descriptor."
(cond
((string-match "[A-Za-z]" day-desc) t) ; there is an advanced day descriptor which overrides the month
((string= month-desc "*")
t) ;; always match
((string= month-desc "E") ;; Even
`(cl-evenp (nth 4 (decode-time date))))
((string= month-desc "O") ;; Odd
`(cl-oddp (nth 4 (decode-time date))))
((/= 0 (string-to-number month-desc)) ;; Starts with number
`(memq (nth 4 (decode-time date)) ',(mapcar 'string-to-number (split-string month-desc ","))))
(t
(error "Improperly specified month constraint: %s %s %s" year-desc month-desc day-desc))))
(defun ledger-schedule-constrain-day (year-desc month-desc day-desc)
"Return a form that constrains the day.
YEAR-DESC, MONTH-DESC, and DAY-DESC are the string portions of the
date descriptor."
(cond ((string= day-desc "*")
t)
((string= day-desc "L")
`(= (nth 3 (decode-time date)) (ledger-schedule-days-in-month (nth 4 (decode-time date)) (nth 5 (decode-time date)))))
((string-match "[A-Za-z]" day-desc) ;; There is something other than digits and commas
(ledger-schedule-parse-complex-date year-desc month-desc day-desc))
((/= 0 (string-to-number day-desc))
`(memq (nth 3 (decode-time date)) ',(mapcar 'string-to-number (split-string day-desc ","))))
(t
(error "Improperly specified day constraint: %s %s %s" year-desc month-desc day-desc))))
(defun ledger-schedule-parse-complex-date (year-desc month-desc day-desc)
"Parse day descriptors that have repeats."
(let ((years (mapcar 'string-to-number (split-string year-desc ",")))
(months (mapcar 'string-to-number (split-string month-desc ",")))
(day-parts (split-string day-desc "\\+"))
(every-nth (string-match "\\+" day-desc)))
(if every-nth
(let ((base-day (string-to-number (car day-parts)))
(increment (string-to-number (substring (cadr day-parts) 0
(string-match "[A-Za-z]" (cadr day-parts)))))
(day-of-week (ledger-schedule-encode-day-of-week
(substring (cadr day-parts) (string-match "[A-Za-z]" (cadr day-parts))))))
(ledger-schedule-constrain-every-count-day day-of-week increment (encode-time 0 0 0 base-day (car months) (car years))))
(let ((count (string-to-number (substring (car day-parts) 0 1)))
(day-of-week (ledger-schedule-encode-day-of-week
(substring (car day-parts) (string-match "[A-Za-z]" (car day-parts))))))
(ledger-schedule-constrain-day-in-month count day-of-week)))))
(defun ledger-schedule-list-upcoming-xacts (candidate-items early horizon)
"Search CANDIDATE-ITEMS for xacts that occur within the given period.
The period runs from (today - EARLY) to (today + HORIZON)."
(let ((start-date (time-subtract (current-time) (days-to-time early)))
test-date items)
(cl-loop for day from 0 to (+ early horizon) by 1 do
(setq test-date (time-add start-date (days-to-time day)))
(dolist (candidate candidate-items items)
(if (funcall (car candidate) test-date)
(setq items (append items (list (list test-date (cadr candidate))))))))
items))
(defun ledger-schedule-create-auto-buffer (candidate-items early horizon)
"Format CANDIDATE-ITEMS for display."
(let ((candidates (ledger-schedule-list-upcoming-xacts candidate-items early horizon))
(schedule-buf (get-buffer-create ledger-schedule-buffer-name)))
(with-current-buffer schedule-buf
(erase-buffer)
(dolist (candidate candidates)
(insert (ledger-format-date (car candidate) ) " " (cadr candidate) "\n"))
(ledger-mode))
(length candidates)))
(defun ledger-schedule-upcoming (file look-backward look-forward)
"Generate upcoming transactions.
FILE is the file containing the scheduled transaction,
default to `ledger-schedule-file'.
LOOK-BACKWARD is the number of days in the past to look at
default to `ledger-schedule-look-backward'
LOOK-FORWARD is the number of days in the future to look at
default to `ledger-schedule-look-forward'
Use a prefix arg to change the default value"
(interactive (if current-prefix-arg
(list (read-file-name "Schedule File: " () ledger-schedule-file t)
(read-number "Look backward: " ledger-schedule-look-backward)
(read-number "Look forward: " ledger-schedule-look-forward))
(list ledger-schedule-file ledger-schedule-look-backward ledger-schedule-look-forward)))
(unless (and file (file-exists-p file))
(error "Could not find ledger schedule file at %s" file))
(ledger-schedule-create-auto-buffer
(ledger-schedule-scan-transactions file)
look-backward
look-forward)
(pop-to-buffer ledger-schedule-buffer-name))
(provide 'ledger-schedule)
;;; ledger-schedule.el ends here