;;; ui.el --- Configure user interfaces. -*- lexical-binding: t; -*-

;; Time-stamp: <2020-02-19T15:08:04+0100>

;;; Commentary:
;; * treemacs
;; * ivy + counsel.

;;; Code:

;; Directory tree.
(use-package treemacs
  :pin melpa                            ; We need > 2.6 for lsp-treemacs.
  :demand t
  :after (display-line-numbers)

  :custom
  (treemacs-project-follow-cleanup t)   ; Collapse projects when leaving.
  (treemacs-silent-refresh t)           ; No log message on refresh.

  :bind
  ("<f8>" . treemacs-select-window)                     ; Focus treemacs.
  ("C-<f8>" . treemacs)                                 ; Toggle treemacs.
  ("M-<f8>" . treemacs-add-and-display-current-project) ; Add current project.
  (:map treemacs-mode-map
        ("<mouse-1>" . treemacs-single-click-expand-action))

  :hook
  (treemacs-mode . my/disable-line-numbers)
  )

(use-package treemacs-projectile
  :after (treemacs projectile)
  )

(use-package treemacs-magit
  :after (treemacs magit)
  )

;; Completion in many Emacs commands.
(use-package ivy
  :demand t
  :diminish ivy-mode

  :custom
  (ivy-use-virtual-buffers t)
  (ivy-count-format "[%d/%d] ")
  (ivy-wrap t)

  :config
  (ivy-mode 1)

  :bind
  ("C-c C-r" . ivy-resume)
  (:map ivy-minibuffer-map
        ("M-<up>" . ivy-previous-history-element)
        ("M-<down>" . ivy-next-history-element)
        ("S-<return>" . ivy-immediate-done) ; Ignore completion.
        )
  )

;; Extensions for ivy
(use-package counsel
  :after (ivy)
  :demand t

  :bind
  ("C-x C-f" . counsel-find-file)
  ("M-x" . counsel-M-x)
  )

;; Use icons in ivy.
(use-package all-the-icons-ivy
  :after (all-the-icons counsel)

  :config
  (all-the-icons-ivy-setup)
  )

;; More information in ivy mini-buffers.
(use-package ivy-rich
  ;; all-the-icons-ivy would override the ivy-rich switch-buffer improvements.
  :after (all-the-icons-ivy counsel)
  :functions (ivy-format-function-line)

  :config
  (defun my/ivy-rich-switch-buffer-icon (candidate)
    "Return icon for `candidate'."
    (with-current-buffer
        (get-buffer candidate)
      (let ((icon (all-the-icons-icon-for-mode major-mode)))
        (if (symbolp icon)
            (all-the-icons-icon-for-mode 'fundamental-mode)
          icon))))

  ;; Add icons to buffer switcher.
  ;; <https://github.com/Yevgnen/ivy-rich/issues/37#issuecomment-583033211>
  (setq ivy-rich-display-transformers-list
        (plist-put ivy-rich-display-transformers-list 'ivy-switch-buffer
                   '(:columns
                     ((my/ivy-rich-switch-buffer-icon (:width 1))
                      (ivy-rich-candidate (:width 0.25))
                      (ivy-rich-switch-buffer-size (:width 0.05 :face font-lock-comment-face))
                      (ivy-rich-switch-buffer-indicators (:width 0.05 :face error :align right))
                      (ivy-rich-switch-buffer-major-mode (:width 0.1 :face font-lock-function-name-face))
                      (ivy-rich-switch-buffer-project (:width 0.15 :face success))
                      (ivy-rich-switch-buffer-path (:width (lambda (x) (ivy-rich-switch-buffer-shorten-path x (ivy-rich-minibuffer-width 0.4))) :face font-lock-keyword-face)))
                     :predicate
                     (lambda (cand) (get-buffer cand))
                     :delimiter "\t"
                     )))

  (ivy-rich-mode 1)
  (setcdr (assq t ivy-format-functions-alist) #'ivy-format-function-line)
  )

(use-package ivy-purpose
  :after (window-purpose)

  :config
  (ivy-purpose-setup)

  :bind
  (:map purpose-mode-map
        ("C-x b" . ivy-switch-buffer)
        ;; ("C-x b" . ivy-purpose-switch-buffer-without-purpose)
        )
  )

(use-package counsel-projectile
  :after (projectile)

  :custom
  (counsel-projectile-mode t)  ; Turn on projectile-mode and enable keybindings.
  (projectile-switch-project-action 'my/switch-project)

  :config
  (defun my/counsel-projectile-switch-project-action (project)
    "Call `my/switch-project'."
    (let ((projectile-switch-project-action 'my/switch-project))
      (counsel-projectile-switch-project-by-name project)))

  (counsel-projectile-modify-action
   'counsel-projectile-switch-project-action
   '((add ("Y" my/counsel-projectile-switch-project-action
           "open project in treemacs") 1)))
  )

;; Switch between named persistent window configurations.
(when (>= emacs-major-version 27)
  (use-package tab-bar
    :bind
    ("C-<prior>" . tab-bar-switch-to-prev-tab)
    ("C-<next>" . tab-bar-switch-to-next-tab)
    ))

;; Shows tabs of all visible buffers per window.
(when (>= emacs-major-version 27)
  (use-package tab-line
    :custom-face
    (tab-line ((t (:inherit ruler-mode-default))))
    (tab-line-tab ((t (:inherit ruler-mode-default))))
    (tab-line-tab-inactive ((t (:inherit tab-line-tab))))
    (tab-line-tab-current ((t (:inherit tab-line-tab
                                        :background "grey10"
                                        :foreground "grey70"))))
    (tab-line-highlight ((t (:inherit tab-line-tab-current
                                      :foreground "white"))))
    ))

(provide 'basics/ui)
;;; ui.el ends here