#!/usr/bin/env bash
set -eo pipefail

user=$(whoami)

if [ "x$HOME" = "x" ]; then
	echo "HOME must be set"
	exit 1
fi

function is_sudo() {
	if [ "x$SUDO_UID" != "x" ]; then
		echo "Please run without sudo"
		exit 1
	fi
}

function detect_os() {
	# Adapted from https://unix.stackexchange.com/a/6348
	if [ -f /etc/os-release ]; then
		# freedesktop.org and systemd
		. /etc/os-release
		OS=Arch
		VER=$VERSION_ID
	elif type lsb_release >/dev/null 2>&1; then
		# linuxbase.org
		OS=$(lsb_release -si)
		VER=$(lsb_release -sr)
	elif [ -f /etc/lsb-release ]; then
		# For some versions of Debian/Ubuntu without lsb_release command
		. /etc/lsb-release
		OS=$DISTRIB_ID
		VER=$DISTRIB_RELEASE
	elif [ -f /etc/debian_version ]; then
		# Older Debian/Ubuntu/etc.
		OS=Debian
		VER=$(cat /etc/debian_version)
	else
		# Fall back to uname, e.g. "Linux <version>", also works for BSD, etc.
		OS=$(uname -s)
		VER=$(uname -r)
	fi

	OS=$(echo "$OS" | tr '[:upper:]' '[:lower:]')
}

function detect_package_manager() {
	local sudo
	if [ "x$user" != "xroot" ]; then sudo="sudo "; fi

	if [ "x$OS" = "xarch" ]; then
		install_package_cmd="${sudo}pacman -S --noconfirm"
		check_package_cmd="pacman -Q"
	elif [ "x$OS" = "xdebian" ]; then
		install_package_cmd="${sudo}apt-get install -y"
	elif [ "x$OS" = "darwin" ]; then
		if [ "x$user" != "xroot" ]; then
			echo "Running as root on macOS is unsupported"
			exit 1
		fi

		install_package_cmd="brew install"
		check_package_cmd="brew list --formula"
	else
		echo "Unknown and unsupported package manager"
		exit 1
	fi
}

function check_package_installed() {
	$check_package_cmd "$1" &>/dev/null || return 1
}

function install_git() {
	if check_package_installed lazygit; then
		echo "Git is already installed...skipping"
		return
	fi

	echo "Installing git..."
	$install_package_cmd lazygit
}

function install_oh_my_zsh() {
	local oh_my_zsh_dir="$HOME/.oh-my-zsh"
	if [ -d "$oh_my_zsh_dir" ]; then
		echo "Oh My Zsh is already installed"
		return
	fi

	echo "Installing Oh My Zsh..."
	git -C "$HOME" clone https://code.cotugno.family/kevin/ohmyzsh.git "$(basename "$oh_my_zsh_dir")"
}

function install_asdf() {
	local asdf_dir="$HOME/.asdf"
	if [ -d "$asdf_dir" ]; then
		echo "asdf is already installed"
		return
	fi

	echo "Installing asdf..."
	if [ "$OS" = "darwin" ]; then
		$install_package_cmd asdf
		. "/usr/local/opt/asdf/libexec/asdf.sh"
	else
		git -C "$HOME" clone https://code.cotugno.family/kevin/asdf.git "$(basename "$asdf_dir")"
		git -C "$asdf_dir" checkout "$(git -C "$asdf_dir" describe --tags --abbrev=0)"
		. "$asdf_dir/asdf.sh"
	fi
}

function setup_asdf() {
	local asdf_plugins=(ruby nodejs)

	for plugin in ${asdf_plugins[@]}; do
		if [[ ! -d "$HOME/.asdf/plugins/$plugin" ]]; then
			echo "Installing asdf $plugin plugin"
			asdf plugin add "$plugin"
			asdf install "$plugin" latest
		else
			echo "asdf plugin $plugin already installed"
		fi
	done
}

function install_files() {
	for file in $(cat install.txt); do
		echo "Installing $file"

		if [ "$(dirname "$file")" != "." ]; then
			mkdir -p "$HOME/$(dirname "$file")"
		fi
		cp "$file" "$HOME/$file"
	done
}

is_sudo
detect_os
detect_package_manager
install_git
install_oh_my_zsh
install_asdf
setup_asdf
install_files