init.el

;; Theme Management
(use-package heaven-and-hell
  :ensure t
  :init
  (setq heaven-and-hell-themes
	'((light . doom-sakura-light)
	  (dark . doom-sakura-dark)))
  (setq heaven-and-hell-load-theme-no-confirm t)
  :hook (after-init . heaven-and-hell-init-hook))

(defun sakura/toggle-tab-line-theme ()
  "Check the current theme type and load the corresponding tab-line theme."
  (interactive)
  (if (eq heaven-and-hell-theme-type 'dark)
      (sakura/tab-line-dark-theme)
    (sakura/tab-line-light-theme)))

(defun sakura/toggle-theme ()
  (interactive)
  (call-interactively 'heaven-and-hell-toggle-theme)
  (call-interactively 'sakura/toggle-tab-line-theme))

;; Powerline
(use-package powerline)
(require 'powerline)
(defvar sakura/tab-height 22)
(defvar sakura/tab-left (powerline-wave-right 'tab-line nil sakura/tab-height))
(defvar sakura/tab-right (powerline-wave-left nil 'tab-line sakura/tab-height))

;; Tab-Line-Mode
(defun sakura/tab-line-tab-name-buffer (buffer &optional _buffers)
  (powerline-render (list sakura/tab-left
			  (format " %s  " (buffer-name buffer))
			  sakura/tab-right)))

(setq tab-line-tab-name-function #'sakura/tab-line-tab-name-buffer)
(setq tab-line-new-button-show nil)
(setq tab-line-close-button-show nil)

(defun sakura/tab-line-dark-theme ()
  (global-tab-line-mode)
  (setq sakura/tab-left (powerline-wave-right 'tab-line nil sakura/tab-height))
  (setq sakura/tab-right (powerline-wave-left nil 'tab-line sakura/tab-height))
  (sakura/dark-theme-tab-line)
  (global-tab-line-mode))

(defun sakura/tab-line-light-theme ()
  (global-tab-line-mode)
  (setq sakura/tab-left (powerline-wave-right 'tab-line nil sakura/tab-height))
  (setq sakura/tab-right (powerline-wave-left nil 'tab-line sakura/tab-height))
  (sakura/light-theme-tab-line)
  (global-tab-line-mode))