#!/bin/sh
#
# Installs this dotfiles repo by:
#   - cloning Oh My Zsh into $ZSH
#   - symlinking the managed config files from this repository
#   - installing the tmux plugin manager and bundled tmux plugins
#   - cloning the powerlevel10k theme
#
# Run it from a checked out copy of this repository:
#   sh .config/dotfiles/install.sh
#
# You can tweak the install behavior by setting variables when running the script:
#   ZSH=~/.zsh sh .config/dotfiles/install.sh
#
# Respects the following environment variables:
#   ZSH     - path to the Oh My Zsh installation (default: $HOME/.oh-my-zsh)
#   REPO    - Oh My Zsh GitHub repo name (default: robbyrussell/oh-my-zsh)
#   REMOTE  - full remote URL of the Oh My Zsh git repo
#   BRANCH  - Oh My Zsh branch to check out immediately after install
#
# Other options:
#   CHSH    - 'no' means the installer will not change the default shell (default: yes)
#   RUNZSH  - 'no' means the installer will not run zsh after the install (default: yes)
#
# You can also pass some arguments to the install script to set some of these options:
#   --skip-chsh: has the same behavior as setting CHSH to 'no'
#   --unattended: sets both CHSH and RUNZSH to 'no'
# For example:
#   sh .config/dotfiles/install.sh --unattended
#
set -e

# Default settings
ZSH=${ZSH:-~/.oh-my-zsh}
REPO=${REPO:-ohmyzsh/ohmyzsh}
REMOTE=${REMOTE:-https://github.com/${REPO}.git}
BRANCH=${BRANCH:-master}

# Other options
CHSH=${CHSH:-yes}
RUNZSH=${RUNZSH:-yes}
DOTFILES_DIR=$(CDPATH= cd -- "$(dirname -- "$0")" && pwd)
TMUX_PLUGIN_DIR="${XDG_DATA_HOME:-$HOME/.local/share}/tmux/plugins"
TMUX_RESURRECT_DIR="${XDG_STATE_HOME:-$HOME/.local/state}/tmux/resurrect"
P10K_REMOTE=${P10K_REMOTE:-https://github.com/romkatv/powerlevel10k.git}


command_exists() {
	command -v "$@" >/dev/null 2>&1
}

require_command() {
	command_name=$1

	if ! command_exists "$command_name"; then
		error "$command_name is required but not installed. Install it first via your package manager."
		exit 1
	fi
}

error() {
	echo ${RED}"Error: $@"${RESET} >&2
}

skip() {
	echo "${YELLOW}Skipping $1${RESET}"
}

setup_color() {
	# Only use colors if connected to a terminal
	if [ -t 1 ]; then
		RED=$(printf '\033[31m')
		GREEN=$(printf '\033[32m')
		YELLOW=$(printf '\033[33m')
		BLUE=$(printf '\033[34m')
		BOLD=$(printf '\033[1m')
		RESET=$(printf '\033[m')
	else
		RED=""
		GREEN=""
		YELLOW=""
		BLUE=""
		BOLD=""
		RESET=""
	fi
}

apply_dotfiles() {
	echo "${BLUE}Applying dotfiles...${RESET}"

	require_command lsd
	require_command tmux
	require_command nvim
	require_command rg

	remove_legacy_dotfile "$HOME/.vimrc"
	link_dotfile "$DOTFILES_DIR/.zshrc" "$HOME/.zshrc"
	link_dotfile "$DOTFILES_DIR/.zprofile" "$HOME/.zprofile"
	link_dotfile "$DOTFILES_DIR/.gitconfig" "$HOME/.gitconfig"
	link_dotfile "$DOTFILES_DIR/.p10k.zsh" "$HOME/.p10k.zsh"
	mkdir -p "$HOME/.config"
	link_dotfile "$DOTFILES_DIR/kitty" "$HOME/.config/kitty"
	link_dotfile "$DOTFILES_DIR/nvim" "$HOME/.config/nvim"
	link_dotfile "$DOTFILES_DIR/tmux" "$HOME/.config/tmux"
	if [ "$(uname -s)" = "Darwin" ]; then
		install_karabiner_config
	fi
	install_kitty_icon
	install_tmux_plugins
	install_powerlevel10k

	echo
}

remove_legacy_dotfile() {
	target_path=$1

	if [ -L "$target_path" ] || [ -e "$target_path" ]; then
		echo "${YELLOW}Removing legacy $target_path${RESET}"
		rm -rf "$target_path"
	fi
}

replace_dir() {
	source_path=$1
	target_path=$2

	if [ -e "$target_path" ] || [ -L "$target_path" ]; then
		rm -rf "$target_path"
	fi

	mv "$source_path" "$target_path"
}

link_dotfile() {
	source_path=$1
	target_path=$2

	if [ -L "$target_path" ]; then
		current_target=$(readlink "$target_path")
		if [ "$current_target" = "$source_path" ]; then
			echo "${GREEN}$target_path already linked.${RESET}"
			return
		fi
		rm -f "$target_path"
	elif [ -e "$target_path" ]; then
		echo "${YELLOW}Removing existing $target_path${RESET}"
		rm -rf "$target_path"
	fi

	ln -s "$source_path" "$target_path"
	echo "${GREEN}Linked $target_path -> $source_path${RESET}"
}

install_karabiner_config() {
	mkdir -p "$HOME/.config/karabiner"
	link_dotfile "$DOTFILES_DIR/karabiner/karabiner.json" "$HOME/.config/karabiner/karabiner.json"
	link_dotfile "$DOTFILES_DIR/karabiner/assets" "$HOME/.config/karabiner/assets"
}

install_kitty_icon() {
	icon_path="$DOTFILES_DIR/kitty/kitty.app.png"

	if [ "$(uname -s)" != "Darwin" ]; then
		return
	fi

	if ! command_exists kitty; then
		skip "kitty icon setup: kitty is not installed."
		return
	fi

	if [ ! -d /Applications/kitty.app ]; then
		skip "kitty icon setup: /Applications/kitty.app was not found."
		return
	fi

	if [ ! -f "$icon_path" ]; then
		skip "kitty icon setup: $icon_path was not found."
		return
	fi

	echo "${BLUE}Applying custom kitty icon...${RESET}"

	kitty +runpy 'from kitty.fast_data_types import cocoa_set_app_icon; import sys; cocoa_set_app_icon(*sys.argv[1:]); print("OK")' \
		"$icon_path" /Applications/kitty.app

	echo
}

install_tmux_plugins() {
	echo "${BLUE}Installing tmux plugins...${RESET}"

	rm -rf "$TMUX_PLUGIN_DIR"
	mkdir -p "$TMUX_PLUGIN_DIR" "$TMUX_RESURRECT_DIR"

	git clone --depth=1 https://github.com/tmux-plugins/tpm \
		"$TMUX_PLUGIN_DIR/tpm"
	git clone --depth=1 https://github.com/tmux-plugins/tmux-resurrect \
		"$TMUX_PLUGIN_DIR/tmux-resurrect"
	git clone --depth=1 https://github.com/tmux-plugins/tmux-continuum \
		"$TMUX_PLUGIN_DIR/tmux-continuum"

	echo
}

setup_ohmyzsh() {
	# Prevent the cloned repository from having insecure permissions. Failing to do
	# so causes compinit() calls to fail with "command not found: compdef" errors
	# for users with insecure umasks (e.g., "002", allowing group writability). Note
	# that this will be ignored under Cygwin by default, as Windows ACLs take
	# precedence over umasks except for filesystems mounted with option "noacl".
	umask g-w,o-w

	echo "${BLUE}Cloning Oh My Zsh...${RESET}"

	command_exists git || {
		error "git is not installed"
		exit 1
	}

	if [ "$OSTYPE" = cygwin ] && git --version | grep -q msysgit; then
		error "Windows/MSYS Git is not supported on Cygwin"
		error "Make sure the Cygwin git package is installed and is first on the \$PATH"
		exit 1
	fi

	zsh_parent=$(dirname "$ZSH")
	mkdir -p "$zsh_parent"
	zsh_stage=$(mktemp -d "${zsh_parent%/}/.oh-my-zsh.XXXXXX")

	git clone -c core.eol=lf -c core.autocrlf=false \
		-c fsck.zeroPaddedFilemode=ignore \
		-c fetch.fsck.zeroPaddedFilemode=ignore \
		-c receive.fsck.zeroPaddedFilemode=ignore \
		--depth=1 --branch "$BRANCH" "$REMOTE" "$zsh_stage" || {
		rm -rf "$zsh_stage"
		error "git clone of oh-my-zsh repo failed"
		exit 1
	}

	replace_dir "$zsh_stage" "$ZSH"

	echo
}

install_powerlevel10k() {
	theme_dir="${ZSH_CUSTOM:-$HOME/.oh-my-zsh/custom}/themes/powerlevel10k"
	theme_parent=$(dirname "$theme_dir")
	mkdir -p "$theme_parent"
	theme_stage=$(mktemp -d "${theme_parent%/}/.powerlevel10k.XXXXXX")

	echo "${BLUE}Installing powerlevel10k...${RESET}"

	git clone --depth=1 "$P10K_REMOTE" "$theme_stage" || {
		rm -rf "$theme_stage"
		error "git clone of powerlevel10k repo failed"
		exit 1
	}

	replace_dir "$theme_stage" "$theme_dir"

	echo
}

setup_shell() {
	# Skip setup if the user wants or stdin is closed (not running interactively).
	if [ $CHSH = no ]; then
		return
	fi

	# If this user's login shell is already "zsh", do not attempt to switch.
	if [ "$(basename "$SHELL")" = "zsh" ]; then
		return
	fi

	# If this platform doesn't provide a "chsh" command, bail out.
	if ! command_exists chsh; then
		cat <<-EOF
			I can't change your shell automatically because this system does not have chsh.
			${BLUE}Please manually change your default shell to zsh${RESET}
		EOF
		return
	fi

	echo "${BLUE}Time to change your default shell to zsh:${RESET}"

	# Prompt for user choice on changing the default login shell
	printf "${YELLOW}Do you want to change your default shell to zsh? [Y/n]${RESET} "
	read opt
	case $opt in
		y*|Y*|"") echo "Changing the shell..." ;;
		n*|N*) echo "Shell change skipped."; return ;;
		*) echo "Invalid choice. Shell change skipped."; return ;;
	esac

	# Check if we're running on Termux
	case "$PREFIX" in
		*com.termux*) termux=true; zsh=zsh ;;
		*) termux=false ;;
	esac

	if [ "$termux" != true ]; then
		# Test for the right location of the "shells" file
		if [ -f /etc/shells ]; then
			shells_file=/etc/shells
		elif [ -f /usr/share/defaults/etc/shells ]; then # Solus OS
			shells_file=/usr/share/defaults/etc/shells
		else
			error "could not find /etc/shells file. Change your default shell manually."
			return
		fi

		# Get the path to the right zsh binary
		# 1. Use the most preceding one based on $PATH, then check that it's in the shells file
		# 2. If that fails, get a zsh path from the shells file, then check it actually exists
		if ! zsh=$(which zsh) || ! grep -qx "$zsh" "$shells_file"; then
			if ! zsh=$(grep '^/.*/zsh$' "$shells_file" | tail -1) || [ ! -f "$zsh" ]; then
				error "no zsh binary found or not present in '$shells_file'"
				error "change your default shell manually."
				return
			fi
		fi
	fi

	# We're going to change the default shell, so back up the current one
	if [ -n "$SHELL" ]; then
		echo $SHELL > ~/.shell.pre-oh-my-zsh
	else
		grep "^$USER:" /etc/passwd | awk -F: '{print $7}' > ~/.shell.pre-oh-my-zsh
	fi

	# Actually change the default shell to zsh
	if ! chsh -s "$zsh"; then
		error "chsh command unsuccessful. Change your default shell manually."
	else
		export SHELL="$zsh"
		echo "${GREEN}Shell successfully changed to '$zsh'.${RESET}"
	fi

	echo
}

main() {
	# Run as unattended if stdin is closed
	if [ ! -t 0 ]; then
		RUNZSH=no
		CHSH=no
	fi

	# Parse arguments
	while [ $# -gt 0 ]; do
		case $1 in
			--unattended) RUNZSH=no; CHSH=no ;;
			--skip-chsh) CHSH=no ;;
		esac
		shift
	done

	setup_color

	if ! command_exists zsh; then
		echo "${YELLOW}Zsh is not installed.${RESET} Please install zsh first."
		exit 1
	fi

	setup_ohmyzsh
	setup_shell

	apply_dotfiles

	printf "$GREEN"
	cat <<-'EOF'
		         __                                     __
		  ____  / /_     ____ ___  __  __   ____  _____/ /_
		 / __ \/ __ \   / __ `__ \/ / / /  /_  / / ___/ __ \
		/ /_/ / / / /  / / / / / / /_/ /    / /_(__  ) / / /
		\____/_/ /_/  /_/ /_/ /_/\__, /    /___/____/_/ /_/
		                        /____/                       ....is now installed!


		Your dotfiles have been installed to your home directory.

	EOF
	printf "$RESET"

	if [ $RUNZSH = no ]; then
		echo "${YELLOW}Run zsh to try it out.${RESET}"
		exit
	fi

	exec zsh -l
}

main "$@"