;; --- FUNCTIONS ---
(defun load-if-exists (filename)
  (when (file-exists-p filename) (load-file filename)))

;; --- BUG WORKAROUNDS ---

;; https://debbugs.gnu.org/cgi/bugreport.cgi?bug=34341
;; Affects ability to use the gnu package repository on gnutls 3.6.
;; Should recheck when emacs >26 is out.
(setq gnutls-algorithm-priority "NORMAL:-VERS-TLS1.3")

;; https://stackoverflow.com/questions/26108655/
;; https://lists.gnu.org/archive/html/bug-gnu-emacs/2014-12/msg00781.html
;; Apparently the gnu package repository has had unverifiable
;; signatures since 2014 and nobody cares ¯\_(ツ)_/¯
(setq package-check-signature nil)

;; --- TERMINAL SUPPORT ---
(add-to-list 'term-file-aliases '("st-256color" . "tmux-256color"))

;; --- PACKAGE REPOSITORIES ---
(require 'package)
(setq package-archives
    '(("gnu"   . "https://elpa.gnu.org/packages/")
      ("melpa" . "https://melpa.org/packages/")))

(package-initialize)

(require 'use-package)

(require 'whitespace)
(require 'yasnippet)
(require 'evil)

;; --- GLOBAL MODES ---
(evil-mode 1)               ;; Make emacs usable
(global-hl-line-mode 1)     ;; Highlight the line containing the cursor
(global-whitespace-mode 1)  ;; Display whitespace, highlight trailing whitespace
(show-paren-mode 1)         ;; Highlight matching parenthesis

(use-package ivy
  :config
  (setq ivy-use-virtual-buffers t
        enable-recursive-minibuffers t)
  (ivy-mode 1))

;; --- ORG MODE ---
(use-package org-ql
  :demand t
  :mode
  (("\\.org$" . org-mode))
  :init
  (add-to-list 'auto-mode-alist `(,(expand-file-name "~/org/") . org-mode))
  :bind
  (("C-c a" . org-agenda))
  :config
  (org-super-agenda-mode 1)
  (load-file "~/.emacs.d/org-mode.el"))

;; --- PROJECTS ---
(use-package projectile
  :demand t
  :config
  (setq projectile-completion-system 'ivy)
  (projectile-mode 1)
  :bind-keymap
  ("C-c p" . projectile-command-map))

(use-package counsel-projectile
  :config (counsel-projectile-mode 1)
  :after (ivy projectile))

;; --- TABS ---
(use-package all-the-icons)
(use-package centaur-tabs
  :demand
  :config
  (setq centaur-tabs-set-bar 'over
        centaur-tabs-set-icons t
        centaur-tabs-modified-marker t
        centaur-tabs-height 32
        centaur-tabs-icon-v-adjust -0.15)
  (centaur-tabs-change-fonts "Iosevka Regular" 120)
  (centaur-tabs-mode t)
  :bind
  ("C-<prior>" . centaur-tabs-backward)
  ("C-<next>" . centaur-tabs-forward))

;; --- FILE TREE ---
(use-package neotree
  :config
  (setq neo-theme (if (display-graphic-p) 'icons 'arrow))
  :bind
  ("<f8>" . neotree-toggle))

;; --- AUTO-COMPLETE ---
(use-package company
  :config
  (global-company-mode)
  (require 'color)
  (let ((bg "midnight blue"))
    (set-face-attribute 'company-tooltip      nil :background bg)
    (set-face-attribute 'company-scrollbar-bg nil :background (color-lighten-name bg 20))
    (set-face-attribute 'company-scrollbar-fg nil :background (color-lighten-name bg 40)))
  )

(use-package company-posframe
  :after company
  :config
  (setq company-posframe-show-indicator nil
        company-posframe-quickhelp-delay nil)
  (company-posframe-mode 1)
  )

(use-package company-c-headers
  :after company
  :config (push 'company-c-headers company-backends))

(use-package company-lsp
  :after company
  :config (push 'company-lsp company-backends))

;; --- LANGUAGE SERVERS ---
(use-package lsp-mode
  :hook (typescript-mode . lsp-deferred)
  :commands (lsp lsp-deferred))

(use-package lsp-ui
  :hook (lsp-mode . lsp-ui-mode))

(use-package company-lsp
  :commands company-lsp)

;; --- TODO ---
;;(require 'undo-tree)

;; --- POWERLINE ---
(require 'telephone-line)
(telephone-line-mode 1)

;; --- INDENTATION ---
;; Two callable functions for enabling/disabling tabs in Emacs
(defun disable-tabs () (setq indent-tabs-mode nil))
(defun enable-tabs  ()
  (local-set-key (kbd "TAB") 'tab-to-tab-stop)
  (setq indent-tabs-mode t))

;; Hooks to Enable Tabs
(add-hook 'prog-mode-hook 'enable-tabs)
;; Hooks to Disable Tabs
;; Using tabs in lisp just leads to mixing tabs and spaces, which is yucky
(add-hook 'lisp-mode-hook 'disable-tabs)
(add-hook 'emacs-lisp-mode-hook 'disable-tabs)

;; --- GENERAL PREFERENCES ---
(setq-default
 ;; --- THEME CONFIGURATION ---
 dracula-enlarge-headings nil

 ;; -- TABS AND INDENTATION --
 ;; Set tab stops to every four spaces
 tab-width 4
 ;; Tab key indents if cursor at start of line, otherwise inserts tab character
 tab-always-indent nil
 ;; Backspace deletes one whole tab character
 backward-delete-char-untabify-method nil

 ;; --- MOUSE ---
 ;; Don't speed up during continued mouse wheel scrolling
 mouse-wheel-progressive-speed nil

 ;; -- C LANGUAGE --
 ;; Overall tab and brace placement style
 c-default-style "linux"
 ;; Indent width
 c-basic-offset 4

 ;; -- LISP --
 inferior-lisp-program "sbcl"

 ;; -- WHITESPACE --
 ;; Clean up trailing whitespace automatically on save
 whitespace-action '(auto-cleanup)
 ;; Configure what to highlight.
 ;; Main difference from default is that for overlong lines,
 ;; we only highlight the overlong tail, not the whole line
 whitespace-style
    '(face trailing tabs spaces lines-tail empty indentation space-after-tab
      space-before-tab space-mark tab-mark)

 ;; -- MISC --
 ;; Display line numbers, relative to the current line
 display-line-numbers 'relative
 ;; Don't show the emacs startup screen
 inhibit-startup-screen t
 )

(let ((fg "RoyalBlue4")
      (bg 'unspecified)
      (faces '(whitespace-hspace whitespace-newline whitespace-space whitespace-tab)))
  (dolist (face faces)
    (set-face-attribute face nil :foreground fg :background bg)))

(load-if-exists "~/.emacs.d/local.el")

(setq custom-file "~/.emacs.d/custom.el")
(load-file custom-file)