(use-package company
  :config
  (progn
    (global-company-mode 1)
    (setq company-idle-delay nil
          company-minimum-prefix-length 1
          company-show-numbers nil
          company-tooltip-limit 20
          company-dabbrev-downcase nil
          company-dabbrev-ignore-case nil
          company-tooltip-align-annotations t
          company-require-match 'never
          company-global-modes
          '(not eshell-mode comint-mode org-mode erc-mode message-mode help-mode))

    (require 'color)
    (let ((bg (face-attribute 'default :background)))
      (custom-set-faces
       `(company-tooltip ((t (:inherit default :background ,(color-lighten-name bg 9)))))
       `(company-scrollbar-bg ((t (:background ,(color-lighten-name bg 15)))))
       `(company-scrollbar-fg ((t (:background ,(color-lighten-name bg 5)))))
       `(company-search ((t (:background ,(color-lighten-name bg 15)))))
       `(company-tooltip-selection ((t (:inherit font-lock-function-name-face))))
       `(company-tooltip-common ((t (:inherit font-lock-constant-face))))))

    ;; Sort candidates by
    (add-to-list 'company-transformers 'company-sort-by-occurrence)
    ;; (add-to-list 'company-transformers 'company-sort-by-backend-importance)
    (use-package company-statistics
      :config
      (progn
        (setq company-statistics-file (expand-file-name "company-statistics-cache.el" my-tmp-dir))
        (company-statistics-mode)))

    (progn ; frontends
      (setq-default company-frontends '(company-pseudo-tooltip-unless-just-one-frontend
                                        company-echo-metadata-frontend
                                        company-preview-if-just-one-frontend)))

    (progn ; backends
      (setq-default company-backends '((company-capf company-yasnippet) (company-dictionary company-keywords)))

      (defun company--backend-on (hook &rest backends)
        (add-hook hook
                  `(lambda()
                     (set (make-local-variable 'company-backends)
                          (append '((,@backends company-semantic)) company-backends)))))

      (company--backend-on 'nxml-mode-hook 'company-nxml 'company-yasnippet)
      (company--backend-on 'emacs-lisp-mode-hook 'company-elisp 'company-yasnippet)

      ;; Rewrite evil-complete to use company-dabbrev
      (setq company-dabbrev-code-other-buffers t)
      (setq company-dabbrev-code-buffers nil)
      (setq evil-complete-next-func
            (lambda(arg)
              (call-interactively 'company-dabbrev)
              (if (eq company-candidates-length 1)
                (company-complete))))
      (setq evil-complete-previous-func
            (lambda (arg)
              (let ((company-selection-wrap-around t))
                (call-interactively 'company-dabbrev)
                (if (eq company-candidates-length 1)
                    (company-complete)
                  (call-interactively 'company-select-previous)))))

      ;; Simulates ac-source-dictionary (without global dictionary)
      (defconst my-dicts-dir (concat my-dir "dict/"))
      (defvar company-dictionary-alist '())
      (defvar company-dictionary-major-minor-modes '())
      (defun company-dictionary-active-minor-modes ()
        (-filter (lambda (mode) (symbol-value mode)) company-dictionary-major-minor-modes))
      (defun company-dictionary-assemble ()
        (let ((minor-modes (company-dictionary-active-minor-modes))
              (dicts (cdr (assq major-mode company-dictionary-alist))))
          (dolist (mode minor-modes)
            (setq dicts (append dicts (cdr (assq mode company-dictionary-alist)))))
          dicts))
      (defun company-dictionary-init ()
        (dolist (file (f-files my-dicts-dir))
          (add-to-list 'company-dictionary-alist `(,(intern (f-base file)) ,@(s-split "\n" (f-read file) t)))))
      (defun company-dictionary (command &optional arg &rest ignored)
        "`company-mode' back-end for user-provided dictionaries."
        (interactive (list 'interactive))
        (unless company-dictionary-alist (company-dictionary-init))
        (let ((dict (company-dictionary-assemble)))
          (cl-case command
            (interactive (company-begin-backend 'company-dictionary))
            (prefix (and dict (or (company-grab-symbol) 'stop)))
            (candidates
             (let ((completion-ignore-case nil)
                   (symbols dict))
               (all-completions arg symbols)))
            (sorted t))))

    (progn ; keybinds
      (bind 'insert company-mode-map
            "C-SPC"     'company-complete-common
            "C-x C-k"   'company-dictionary
            "C-x C-f"   'company-files
            "C-x C-]"   'company-etags
            "C-x s"     'company-ispell
            "C-x C-s"   'company-yasnippet
            "C-x C-o"   'company-semantic
            "C-x C-n"   'company-dabbrev-code
            "C-x C-p"   (λ (let ((company-selection-wrap-around t))
                             (call-interactively 'company-dabbrev-code)
                             (company-select-previous-or-abort))))

      (define-key company-active-map "C-w" nil)
      (bind company-active-map
            "C-o"        'company-search-kill-others
            "C-n"        'company-select-next-or-abort
            "C-p"        'company-select-previous-or-abort
            "C-h"        'company-show-doc-buffer
            "C-S-h"      'company-show-location
            "C-S-s"      'company-search-candidates
            "C-s"        'company-filter-candidates
            "C-SPC"      'company-complete-common
            [tab]        'company-complete
            "<backtab>"  'company-select-previous
            [escape]     'company-abort)

      (bind company-search-map
            "C-n"        'company-search-repeat-forward
            "C-p"        'company-search-repeat-backward
            [escape]     'company-abort)

      (bind company-mode-map   "<C-return>" 'helm-company)
      (bind company-active-map "<C-return>" 'helm-company)))))


(provide 'init-company)
;;; init-company.el ends here