#!/usr/bin/env bash
# exwm-arch install script
# arch + exwm + daviwil emacs-from-scratch dotfiles (https://github.com/daviwil/emacs-from-scratch)

set -euo pipefail

RED='\033[0;31m'; GREEN='\033[0;32m'; YELLOW='\033[1;33m'; NC='\033[0m'
info()    { echo -e "${GREEN}[info]${NC} $*"; }
warn()    { echo -e "${YELLOW}[warn]${NC} $*"; }
error()   { echo -e "${RED}[error]${NC} $*"; exit 1; }

[[ $EUID -eq 0 ]] && error "do not run as root. run as your sudo user."
command -v pacman &>/dev/null || error "this script is for arch linux only."

# base tools 
info "installing xorg and base tools..."
sudo pacman -S --noconfirm --needed \
    xorg-server xorg-xinit \
    emacs \
    dmenu \
    git \
    zsh \
    rxvt-unicode \
    tmux \
    xterm \
    nano

# daviwil emacs-from-scratch dotfiles
if [[ -d "$HOME/.emacs.d" ]]; then
    warn "~/.emacs.d already exists — backing up to ~/.emacs.d-old"
    mv "$HOME/.emacs.d" "$HOME/.emacs.d-old"
fi

info "cloning daviwil emacs-from-scratch..."
git clone https://github.com/daviwil/emacs-from-scratch "$HOME/.emacs.d"

#.xinitrc
info "writing ~/.xinitrc..."
cat > "$HOME/.xinitrc" << 'EOF'
exec emacs
EOF

# pipewire audio 
info "installing pipewire audio stack..."
sudo pacman -S --noconfirm --needed \
    pipewire \
    pipewire-pulse \
    wireplumber

info "enabling pipewire user services..."
systemctl --user enable --now pipewire pipewire-pulse wireplumber

# installing applications 
info "installing applications and fonts..."
sudo pacman -S --noconfirm --needed \
    firefox \
    ttf-dejavu \
    noto-fonts \
    xclip \
    scrot \
    xf86-video-qxl       # proxmox/qemu display driver

# .emacs config 
info "writing ~/.emacs..."
cat > "$HOME/.emacs" << 'EOF'
;;; -*- lexical-binding: t -*-

;; package manager setup
(require 'package)
(add-to-list 'package-archives '("melpa" . "https://melpa.org/packages/") t)
(package-initialize)

;; ensure exwm is installed (if not already)
(unless (package-installed-p 'exwm)
  (package-refresh-contents)
  (package-install 'exwm))

;; ensure doom-themes is installed (if not already)
(unless (package-installed-p 'doom-themes)
  (package-refresh-contents)
  (package-install 'doom-themes))

;; load exwm and disable clunky gui elements
(require 'exwm)
(menu-bar-mode -1)
(tool-bar-mode -1)
(scroll-bar-mode -1)
(column-number-mode 1)
(show-paren-mode 1)

;; theme
(use-package doom-themes
  :ensure t
  :config
  (load-theme 'doom-moonlight t))

;; rename buffer to match application name
(defun efs/exwm-update-class ()
  (exwm-workspace-rename-buffer exwm-class-name))
(add-hook 'exwm-update-class-hook #'efs/exwm-update-class)

;; cua: better copy/paste keybinds. C-x C-c copy, C-v to paste
(cua-selection-mode t)

;; keys that must passthrough to emacs regardless of focused window
(setq exwm-input-prefix-keys
      '(?\C-x
        ?\C-u
        ?\C-h
        ?\M-x
        ?\M-:
        ?\C-\ ))

;; C-q passes the next key directly to the application
(define-key exwm-mode-map [?\C-q] 'exwm-input-send-next-key)

;; global keybinds
;; note: super (win) key passes through to host when running in a vm via browser.
;; use meta (alt) keybinds instead when in a vm. super binds work on bare metal.
(setq exwm-input-global-keys
      `(;; reset window to line mode
        ([?\s-r] . exwm-reset)

        ;; move between emacs windows
        ([s-left] . windmove-left)
        ([s-right] . windmove-right)
        ([s-up] . windmove-up)
        ([s-down] . windmove-down)

        ;; launch application by shell command
        ([?\s-&] . (lambda (command)
                     (interactive (list (read-shell-command "$ ")))
                     (start-process-shell-command command nil command)))

        ;; open terminal
        ([s-return] . (lambda ()
                        (interactive)
                        (start-process "" nil "urxvt")))

        ;; switch workspace interactively
        ([?\s-w] . exwm-workspace-switch)

        ;; s-0 through s-9 switch workspaces
        ,@(mapcar (lambda (i)
                    `(,(kbd (format "s-%d" i)) .
                      (lambda ()
                        (interactive)
                        (exwm-workspace-switch-create ,i))))
                  (number-sequence 0 9))))

;; start exwm
(exwm-wm-mode)
EOF

# install emacs packages via batch emacs
info "installing emacs packages (exwm + doom-themes) via batch mode..."
emacs --batch \
    --eval "(require 'package)" \
    --eval "(add-to-list 'package-archives '(\"melpa\" . \"https://melpa.org/packages/\") t)" \
    --eval "(package-initialize)" \
    --eval "(unless (package-installed-p 'exwm) (package-refresh-contents) (package-install 'exwm))" \
    --eval "(unless (package-installed-p 'doom-themes) (package-refresh-contents) (package-install 'doom-themes))" \
    2>&1 | tail -5

echo ""
info "all done! launch with: startx"
echo ""
echo ""
echo "  quick reference:"
echo "    s-Return       open urxvt terminal"
echo "    s-0 .. s-9     switch/create workspace"
echo "    s-w            interactive workspace switcher"
echo "    s-r            reset/refresh window"
echo "    s-arrows       move between emacs splits"
echo "    s-&            launch app by shell command"
echo "    C-x C-f        open/find file"
echo "    C-x C-c        quit emacs (closes everything)"
echo ""