;;;; main.lisp -- oneliners.cli entrypoint

(defpackage oneliners.cli
  (:use :cl)
  (:local-nicknames (#:api #:oneliners.api-client)))

(in-package :oneliners.cli)

;;; CONFIG AND RESULTS FILE LOCATIONS

(defvar *config* nil
  "A configuration plist")

(defun make-config (&key host api-token)
  (append (when host (list :host host))
          (when api-token (list :api-token api-token))))

(defun valid-config-p (config)
  (and (listp config)
       (evenp (length config))
       (stringp (getf config :host))
       t))

(defun write-default-config-to-disk ()
  (let ((conf-file (config-file)))
    (ensure-directories-exist conf-file)
    (with-open-file (out conf-file :direction :output)
      (print (make-config :host "https://oneliners.wiki") out))))

(defun fetch-config-from-disk ()
  (let ((conf
          (uiop:with-safe-io-syntax ()
            (uiop:read-file-form (config-file)))))
    (assert (valid-config-p conf) () "Invalid configuration file")
    (setf *config* conf)))

(defun ensure-config ()
  (unless (uiop:file-exists-p (config-file))
    (write-default-config-to-disk))
  (fetch-config-from-disk))

(defun host () (getf *config* :host))
(defun api-token () (getf *config* :api-token))

(defun config-file ()
  (merge-pathnames ".config/oneliners.config" (user-homedir-pathname)))

(defun last-search-file ()
  (merge-pathnames ".last_oneliners_search" (user-homedir-pathname)))

(defun fetch-nth-oneliner (n)
  "Returns nil if there is no nth oneliner from the search history."
  (when (uiop:file-exists-p (last-search-file))
    (nth n (uiop:read-file-form (last-search-file)))))

;;; SEARCHNG THE WIKI

(defun search-for-oneliners (terms limit not-flagged-p)
  (assert (loop for term in terms never (find #\, term) ))
  (handler-case
      (api:request-with
          (:host (host))
          (api:get--search :tags (str:join ",")
                           :limit limit
                           :notflagged (if not-flagged-p "true" "false")))
    (dex:http-request-failed (e)
      (format *error-output* "~a -- ~a"
              (dex:response-status e)
              (dex:response-body e)))))

;;; RUNNING COMMANDS

(defun parent-process-name ()
  "Prints the name of the parent process of the current process."
  (let ((ppidfile (format nil "/proc/~a/status" (osicat-posix:getppid))))
    (first (last 
            (ppcre:split "\\s" 
                         (with-open-file (input ppidfile)
                           (read-line input)))))))

(defmacro wait-until ((&key (timeout 1) (poll-every 0.01)) &body check)
  "Run CHECK every POLL-EVERY seconds until either TIMEOUT seconds
have passed or CHECK returns non-nil."
  (let ((clockvar (gensym))
        (var (gensym)))
    `(loop
       for ,clockvar from 0 by ,poll-every to ,timeout
       for ,var = (progn ,@check)
       when ,var
         return ,var
       do (sleep ,poll-every))))

(defun run-with-shell
    (command
     &key
       (shell-name (parent-process-name))
       (await-output-p 0.8)
       (output-stream *standard-output*))
  "run COMMAND, a string, in a fresh shell environment, initialized
with SHELL-NAME. The output from the command read line by line and is
printed to OUTPUT-STREAM. "
  (let ((shell
          (uiop:launch-program shell-name :input :stream :output :stream)))
    (symbol-macrolet ((shell-input (uiop:process-info-input shell))
                      (shell-output (uiop:process-info-output shell)))
      (write-line command shell-input)
      (finish-output shell-input)
      (when await-output-p
        (wait-until (:timeout await-output-p :poll-every 0.005)
          (listen shell-output))
        (loop while (listen shell-output)
              do (princ (read-line shell-output) output-stream)
                 (terpri output-stream))))))