(defpackage :lispostory
  (:use :cl :alexandria :serapeum)
  (:export :main :create-exe-and-die))

(in-package :lispostory)

(defun http-get-json (url)
  (multiple-value-bind (body status) (drakma:http-request url)
    (if (/= status 200)
        nil
        (let ((body-str (flexi-streams:octets-to-string body)))
          (shasht:read-json body-str)))))

(defun alist (&rest pairs)
  (loop for (key value) on pairs by #'cddr
        collect (cons key value)))

(defun map-vector (func vec)
  (map 'vector func vec))

(defun string-to-hash-table-key (s)
  (string-replace " " s ""))

(defun update-hash (hm key f)
  (setf (@ hm key) (funcall f (@ hm key))))

(defun string->bool (s)
  (if (string-equal (string-downcase s) "true") t nil))

(defun find-string (str seq)
  (sequence:find str seq :test #'string-equal))

(defclass data-source ()
  ((cache :initform nil :accessor cache)
   (file-path :initarg :file-path :accessor file-path)))

(defun maybe-pass (func arg)
  "Pass ARG to FUNC if arg is not nil."
  (if (fnil)arg
      (funcall func arg)
      (funcall func)))

(defmacro define-data-source (singular-name)
  (let* ((class-name (symbolicate singular-name '-data-source))
         (constructor-name (symbolicate 'make- singular-name '-data-source))
         (plural-name (concat (symbol-name singular-name) "s"))
         (file-name (concat (string-downcase plural-name) ".json")))
    `(progn
       (defclass ,class-name (data-source) ())

       (defun ,constructor-name (&optional (file-path ,file-name))
         (make-instance ',class-name :file-path file-path)))))

(defgeneric data (data-source))
(defmethod data ((ds data-source))
  (or (cache ds)
      (reload ds)))

(defgeneric reload (data-source))
(defmethod reload ((ds data-source))
  (if (uiop:file-exists-p (file-path ds))
      (let ((data (shasht:read-json (uiop:read-file-string (file-path ds)))))
        (setf (cache ds) data)
        data)))

(defgeneric refresh (data-source))