(ql:quickload "cl-store")
(ql:quickload "cl-ppcre")

;;;; Reimplementation of my bills tracker in Lisp
(defun reload ()
  (load "~/Repos/fin-lisp/fin-lisp.lisp"))

;;; All records exist in this data structure
;;; nil on start and loaded in from file
;;; *records* represents as hash of months,
;;; where the key is the month stamp, eg 20210701
;;; and the value is the monthly expenses hash
(defvar *records* (make-hash-table :test 'equalp))

(defun reset-records ()
  (setf *records* (make-hash-table :test 'equalp)))
  
;; Called like: (add-month '202107)
(defun add-month (month-key)
  (setf (gethash month-key *records*) (make-hash-table :test 'equalp))
  month-key)

;;; Taken from practical common lisp
(defun prompt-read (prompt)
  (format *query-io* "~a: " prompt)
  (force-output *query-io*)
  (read-line *query-io*))

(defun prompt-for-expense ()
  (list
   (prompt-read "Enter expense name")
   (parse-integer
    (prompt-read "Enter expense value"))))

(defun add-expense-to-month (month)
  (if (gethash month *records*)
      (let ((innerhash (gethash month *records*))
	    (exp-l (prompt-for-expense)))
	(setf (gethash (first exp-l) innerhash) (second exp-l)))
      ;;NIL))
      (add-expense-to-month (add-month month))))

;;; Given key for *records* hash,
;;; print expenses/values for month
(defun dump-month (month-key)
  (format t "~a~C" month-key #\linefeed)
  (let ((month-hash)
	(exp-keys))
    (setf month-hash (gethash month-key *records*))
    (setf exp-keys (loop for key being the hash-keys of month-hash collect key))
    (dolist (exp-key exp-keys)
      (format t "~a : ~a~C" exp-key (gethash exp-key month-hash) #\linefeed))))

;;; Dump all records.
;;; This will also be used for data serialization at some point
(defun dump-records ()
  (let ((record-key-list (loop for key being the hash-keys of *records* collect key)))
    (dolist (month-key record-key-list) (dump-month month-key))))

(defun serialize-records (filename)
  (cl-store:store *records* filename))

(defun deserialize-records (filename)
  ;(setf *records* (cl-store:restore (pathname filename))))
  (setf *records* (cl-store:restore filename)))

;; Import records from old perl version (plaintext file)
(defun import-records (filename)
  (let ((old-file-lines
	  (with-open-file (stream filename)
	    (loop for line = (read-line stream nil)
		  while line
		  collect line)))
	(mre (ppcre:create-scanner "^(.*)[0-9]{4}$"))
	(ere (ppcre:create-scanner "^([A-Z].*)\ -\ \\\$([0-9]{1,4}) - PAID"))
	(cur-mon)
	(cur-exp))
    (loop for line in old-file-lines
	  do (progn
	       (if (ppcre:scan mre line) (setf cur-mon line))
	       (if (ppcre:scan ere line)
		   (progn
		     (setf cur-exp (ppcre:register-groups-bind (first second) (ere line) :sharedp t (list first second)))
		     (print cur-exp)
		     (if (gethash cur-mon *records*)
			 (let ((innerhash (gethash cur-mon *records*)))
			   (setf (gethash (first cur-exp) innerhash) (second cur-exp))))
		     (if (not (gethash cur-mon *records*))
			 (progn
			   (add-month cur-mon)
			   (let ((innerhash (gethash cur-mon *records*)))
			     (setf (gethash (first cur-exp) innerhash) (second cur-exp)))))))))))
 

(defmacro generic-handler (form error-string)
  `(handler-case ,form
    (error (e)
      (format t "Invalid input: ~a ~%" ,error-string)
      (values 0 e))))

;; Util screen clearer
(defun cls()
  (format t "~A[H~@*~A[J" #\escape))

;; Entry point
(defun main ()
  (format t "~%")
  (format t "Available options:~%")
  (format t "1. Enter expense~%")
  (format t "2. Display month~%")
  (format t "3. Write records~%")
  (format t "4. Read records~%")
  (format t "5. Quit~%")
  (format t "6. Import Records~%")
  (let
      ((answer (prompt-read "Select an option")))
    (if (string= answer "1")
	(generic-handler
	 (add-expense-to-month (prompt-read "Enter month"))
	 "Invalid Input"))
    (if (string= answer "2")
	(generic-handler
	 (dump-month (prompt-read "Enter month"))
	 "Invalid month"))
    (if (string= answer "3")
	(generic-handler
	 (serialize-records (prompt-read "Enter filename"))
	 "Serialization error or invalid filename"))
    (if (string= answer "4")
	(generic-handler
	 (deserialize-records (prompt-read "Enter filename"))
	 "Deserialization error or invalid filename"))
    (if (string= answer "5")
	(quit))
    (if (string= answer "6")
	(generic-handler
	 (import-records (prompt-read "Enter filename"))
	 "Parsing error or invalid filename"))
  (main)))