#!/usr/bin/env bash

#########################################################################
# This script attempts to install the appopriate build dependencies 	#
# for the host system.                                              	#
#                                                                   	#
# This is primarily developed on the latest Ubuntu LTS release and  	#
# MacOS; other platforms are not supported.                         	#
#								    	#
# The primary packages required:				    	#
#									#
#	- clang								#
#	- clang-tidy							#
#	- cmake								#
#	- cppcheck							#
#	- doxygen							#
#	- git								#
#	- graphviz							#
#	- make								#
#	- scdoc								#
#									#
# Furthermore, certain CI systems require additional packages, and some	#
# base system packages are also useful.					#
#									#
#	- bash								#
#	- ca-certificates						#
#	- gzip								#
#	- ssh								#
#	- tar								#
#########################################################################

set -eu

AUTOMATED_MODE=${AUTOMATED_MODE:-}

install_debianesque () {
	APTARGS=""
	SUDO="sudo"
	if [ "$(whoami)" == "root" ]
	then
	  SUDO=
	fi

	if [ ! -z "${AUTOMATED_MODE}" ]
	then
		APTARGS="-y"
	fi

	echo "[+] distribution is ${DISTRIB_ID}, choosing Debianesque install."

	if [ -z "$(command -v cmake)" ]
	then
		install-cmake-debian.sh
	fi

	echo "[+] installing tools"
	sudo $SUDO apt-get $APTARGS install git clang scdoc 		\
		python3-pip doxygen graphviz valgrind
}

install_alpine () {
	APK_ADD="apk add --update-cache"
	echo "[+] distribution is ${DISTRIB_ID}, choosing Alpine install."

	$APK_ADD alpine-sdk

	echo "[+] setting up base system"
	$APK_ADD bash ca-certificates gzip openssh tar

	echo "[+] installing development tooling"
	$APK_ADD clang clang-extra-tools cmake cppcheck doxygen g++ git	\
		 graphviz make scdoc valgrind
}

install_redhat () {
	DNF_INSTALL="dnf install -y"
	SUDO="sudo"
	if [ "$(whoami)" == "root" ]
	then
	  SUDO=
	fi

	echo "[+] setting up base system"
	# dnf is probably the slowest package manager I've used, so
	# install everything in one shot.
	$DNF_INSTALL ca-certificates gzip openssh tar			\
		     clang clang-tools-extra cmake cppcheck doxygen	\
		     gcc-c++ git graphviz libstdc++-devel make scdoc	\
		     valgrind rpmdevtools
}

install_unsupported () {
	echo "[+] distribution is ${DISTRIB_ID}, choosing Redhat install."
	echo "[!] This distribution is unsupported." > /dev/stderr
	exit 1;
}

install_macos () {
	# TODO: consider supporting macports?
	echo "[+] host system is MacOS"

	echo "[+] installing tools"
	brew install git cmake scdoc

	echo "[+] installing libraries and development headers"
	# TODO: look up proper package names in homebrew
}


install_linux () {
  DISTRIB_ID="${DISTRIB_ID:-}"
	echo "[+] host system is Linux"
	if [[ -f "/etc/lsb-release" ]]
	then
		source /etc/lsb-release
	elif [[ -d "/etc/apt" ]]
	then
		DISTRIB_ID="apt-based"
	elif [[ -f "/etc/rpi-issue" ]] 
	then
		DISTRIB_ID=apt-based
	elif [[ -d "/etc/apk" ]]
	then
		DISTRIB_ID=alpine
	elif [[ -d "/etc/dnf" ]]
	then
		DISTRIB_ID="redhat"
	else
		DISTRIB_ID="unsupported/unknown"
	fi

	case ${DISTRIB_ID} in
		Ubuntu)		install_debianesque	;;
		Debian)		install_debianesque	;;
		apt-based)	install_debianesque	;;
		alpine)		install_alpine		;;
		redhat)		install_redhat		;;
		*)
			echo "[!] distribution ${DISTRIB_ID} isn't supported in this script." > /dev/null
			exit 1
			;;
	esac
}


case "$(uname -s)" in
	Linux)		install_linux ;;
	Darwin)		install_macos ;;
	*)
		echo "[!] platform $(uname -s) isn't supported in this script." > /dev/null
		;;
esac