;;; livie.el --- Livie is Video in Emacs -*- lexical-binding: t; -*-

;; Copyright (C) 2018

;;; Authors:

;; Charlie Ritter <chewzerita@posteo.net>
;; Jesus E. <heckyel@hyperbola.info>

;;; Commentary:

;; livie grabs a list of youtube videos based on a search.  the user
;; can then select a video to watch through `livie-player'

;;; Code:

(require 'f)

(defgroup livie '()
  "Livie is Video in Emacs"
  :prefix "livie-"
  :group 'livie)

(defcustom livie-player "mpv"
  "Default video player to use with livie."
  :group 'livie
  :type 'string)

(defcustom livie-player-args '()
  "Command line arguments for `livie-player'."
  :group 'livie
  :type '(list)
  :tag "Livie Player Arguments")

(defcustom livie-python-name "python3"
  "Name of the python executable."
  :group 'livie
  :type 'string)

(defcustom livie-script-path nil
  "Full path of livie.py."
  :group 'livie
  :type 'file)

(defcustom livie-buffer-name "*livie*"
  "Name of the buffer to show results."
  :group 'livie
  :type 'string)

(defvar livie-youtube-regexp "https://www.youtube.com/watch\\?v=[A-Za-z0-9_\\-]\\{11\\}")

(define-derived-mode livie-mode
  special-mode "livie"
  "Major mode for livie.")

(defun livie-close-window ()
  "Close the livie window and bury the buffer."
  (interactive)
  (bury-buffer)
  (delete-window)
  (message nil))

(defun livie-next-video ()
  "Goto the next video in the buffer."
  (interactive)
  (forward-line 1)
  (search-forward-regexp livie-youtube-regexp)
  (livie-prev-video))

(defun livie-prev-video ()
  "Goto the previous video in the buffer."
  (interactive)
  (search-backward-regexp livie-youtube-regexp))

(defun livie-this-video ()
  "Go to the start of the current video."
  (interactive)
  (move-beginning-of-line nil)
  (ignore-errors (forward-line -1))
  (livie-next-video))

(defun livie-copy-video ()
  "Copy the currently selected video into the kill ring."
  (interactive)
  (livie-this-video)
  (push-mark)
  (move-end-of-line nil)
  (kill-ring-save nil nil t)
  (livie-this-video))

(defun livie-watch-this-video ()
  "Watch video under the cursor."
  (interactive)
  (livie-copy-video)
  (livie-watch (car kill-ring))
  (delete-other-windows))

(defun livie-watch (url)
  "Watch video at URL using `livie-player' and `livie-player-args'."
  (interactive "sURL: ")
  (apply 'start-process
         (cl-concatenate
          'list
          (list "livie"
                nil
                livie-player)
          livie-player-args
          (list url)))
  (message "Loading video..."))

(defun livie (query)
  "Livie is Video in Emacs.

Livie will prompt the user for a QUERY.  This is fed into a
python script that scrapes youtube.com for search results.  The
results are displayed in an Emacs buffer.

See also: `livie-mode'."
  (interactive "sSearch: ")
  (unless livie-script-path
    (error "Please set `livie-script-path'"))
  (if (equal (buffer-name) livie-buffer-name)
      (progn
        (read-only-mode -1)
        (erase-buffer))
    (progn
      (select-window (split-window))
      (ignore-errors (kill-buffer livie-buffer-name))
      (switch-to-buffer (generate-new-buffer livie-buffer-name))))
  (call-process livie-python-name
                nil t t
                livie-script-path
                query)
  (livie-mode)
  (font-lock-ensure)
  (goto-char (point-min))
  (message (concat "Results for: " query)))

(font-lock-add-keywords
 'livie-mode
 `((,livie-youtube-regexp . 'link)
   ("title: \\(.*\\)" 1 'bold)
   ("channel: \\(.*\\)" 1 'italic)
   ("^ +[a-zA-Z]+:" . 'shadow)))

(define-key livie-mode-map "s" 'livie)
(define-key livie-mode-map "q" 'livie-close-window)
(define-key livie-mode-map (kbd "<tab>") 'livie-next-video)
(define-key livie-mode-map (kbd "<backtab>") 'livie-prev-video)
(define-key livie-mode-map "n" 'livie-next-video)
(define-key livie-mode-map "p" 'livie-prev-video)
(define-key livie-mode-map (kbd "<return>") 'livie-watch-this-video)

(provide 'livie)

;;; livie.el ends here