#!/usr/bin/env bash

# shellcheck source=lib/util.bash
source "$(dirname "${BASH_SOURCE[0]}")/util.bash"

# shellcheck source=lib/logging.bash
source "$(dirname "${BASH_SOURCE[0]}")/logging.bash"

main() {
	[[ -z $1 ]] && usage && exit 2

	local action="$1"
	shift

	debug "Handling action '$action'"

	local action_path="$BASEDIR/lib/actions/$action.bash"

	debug "Checking $action_path"

	if [[ ! -f $action_path ]]
	then
		debug "No script found to handle action, showing usage"
		usage
		exit 2
	fi

	# Declare some global variables
	declare -a RSTAR_TOOLS
	declare -A RSTAR_PLATFORM

	[[ -z $RSTAR_BACKEND ]] && RSTAR_BACKEND="moar"
	[[ -z $RSTAR_PREFIX ]] && RSTAR_PREFIX="$BASEDIR"

	# Figure out system details
	debug "Discovering system information"
	discover_system

	# Export RSTAR_ variables
	export RSTAR_TOOLS
	export RSTAR_BACKEND
	export RSTAR_PREFIX
	export RSTAR_PLATFORM

	# Source the file defining the action.
	debug "Sourcing $action_path"
	source "$action_path"

	# Ensure all required tools are available
	depcheck_bin || exit 3
	depcheck_perl || exit 3

	# Maintain our own tempdir
	export TMPDIR="$BASEDIR/tmp"
	mkdir -p -- "$TMPDIR"
	debug "\$TMPDIR set to $TMPDIR"

	# Actually perform the action
	debug "Running action"
	action "$@"
	local action_exit=$?

	# Clean up if necessary
	if [[ -z $RSTAR_MESSY ]]
	then
		debug "Cleaning up tempfiles at $TMPDIR"
		rm -rf -- "$TMPDIR"
	fi

	# Use the action's exit code
	exit $action_exit
}

usage() {
	cat <<EOF
Usage:
	rstar -h
	rstar build-docker [-T tag] [-b backend] [-d description] [-l] [-n name] [-t version] <base>
	rstar clean [-s]
	rstar dist [version]
	rstar fetch
	rstar install [-b backend] [-p prefix] [core] [modules]
	rstar sysinfo
	rstar test [-p prefix] [spectest] [modules]

rstar is the entry point for all utilities to deal with Rakudo Star.

Actions:
	build-docker  Build a Docker image for Rakudo Star. You can specify the
	              tag of the resulting image using -T, which will cause -d,
	              -t, and -l to be ignored. -n specifies the name of the
	              image. If -l is passed, a "latest" tag will also be made.
	              You can specify a specific backend with -b.
	clean         Clean up the repository. If -s is given, the src
	              directory will also be removed.
	dist          Create a distributable tarball of this repository. If no
	              version identifier is specified, it will use the current
	              year and month in "yyyy.mm" notation.
	fetch         Fetch all required sources.
	install       Install Raku on this system. By default, MoarVM will be
	              used as the only backend, and the Rakudo Star directory
	              will be used as prefix. If neither core nor modules are
	              given as explicit targets, all targets will be installed.
	sysinfo       Show information about your system. Useful for debugging.
	test          Run tests on Raku and the bundled ecosystem modules. If
	              neither spectest nor modules are given as explicit
	              targets, all targets will be tested.
EOF
}

# This function checks for the availability of (binary) utilities in the user's
# $PATH environment variable.
depcheck_bin() {
	local missing=()
	local bindep_db

	for tool in "${RSTAR_DEPS_BIN[@]}"
	do
		debug "Checking for availability of $tool"
		command -v "$tool" > /dev/null && continue

		missing+=("$tool")
	done

	if [[ ${missing[*]} ]]
	then
		alert "Some required tools are missing:"

		for tool in "${missing[@]}"
		do
			alert "  $tool"
		done

		# Resolve the basename for the bindep file
		bindep_db="bindeps.d/${RSTAR_PLATFORM[key]}.txt"

		debug "bindep_db resolved to $bindep_db"

		# If there's a bindep file, use it to resolve the missing utils
		# into a list of package names.
		if [[ -f "etc/$bindep_db" ]]
		then
			local packages
			local pacman_cmd
			local package

			debug "bindep_db found"

			# Create a list of packages that needs to be installed
			for tool in "${missing[@]}"
			do
				package="$(config_etc_kv "$bindep_db" "$tool")"

				# Don't add duplicates
				in_args "$package" "${packages[@]}" && continue

				packages+=("$package")

				unset package
			done

			# Figure out which package manager command install on
			# the current platform.
			pacman_cmd="$(config_etc_kv pacmans.txt "${RSTAR_PLATFORM[key]}") "

			# Tell the user of the command to install missing
			# dependencies
			info "The missing tools can be installed using your system package manager:"
			info "$pacman_cmd$(join_args -c " " "${packages[@]}")"
		fi

		return 1
	fi
}

# This function checks for the availability of all Perl modules required.
depcheck_perl() {
	local missing=()

	for module in "${RSTAR_DEPS_PERL[@]}"
	do
		debug "Checking for availability of $module"
		perl -M"$module" -e 0 2> /dev/null && continue

		missing+=("$module")
	done

	if [[ ${missing[*]} ]]
	then
		alert "Some required Perl modules are missing:"

		for module in "${missing[@]}"
		do
			alert "  $module"
		done

		if grep -q "^${RSTAR_PLATFORM[key]}=" "$BASEDIR/etc/perlmans.txt"
		then
			info "The missing Perl modules can be installed using this command:"
			info "$(config_etc_kv perlmans.txt "${RSTAR_PLATFORM[key]}") $(join_args -c " " "${missing[@]}")"
		fi

		return 1
	fi
}

# Discover information about the system. If any bugs are reported and you want
# more information about the system the user is running on, additional checks
# can be added here, and the user will simply have to include the output of the
# sysinfo command in their message to you.
discover_system() {
	RSTAR_PLATFORM["os"]="$(discover_system_os)"
	RSTAR_PLATFORM["arch"]="$(discover_system_arch)"
	RSTAR_PLATFORM["version"]="$(discover_system_version)"
	RSTAR_PLATFORM["term"]="$TERM"

	# When on a Linux-using OS, check for the specific distribution in use.
	if [[ ${RSTAR_PLATFORM[os]} == *"linux"* ]]
	then
		RSTAR_PLATFORM["distro"]="$(discover_system_distro)"
	fi

	RSTAR_PLATFORM[key]="$(discover_system_key)"
}

discover_system_arch() {
	uname -m
}

discover_system_distro() {
	if [[ -f /etc/os-release ]]
	then
		printf "%s" "$(source /etc/os-release && printf "%s" "$NAME" | awk '{print tolower($0)}' | sed 's@[/+ ]@_@g')"
		return
	fi

	crit "No /etc/os-release found. Are you sure you're on a sane GNU+Linux distribution?"

	if command -v pacman > /dev/null
	then
		warn "Found pacman, assuming Archlinux as distro."
		printf "%s" "archlinux"
		return
	fi
}

discover_system_version() {
	printf "%s" "$(uname -r | awk '{print tolower($0)}')"
}

discover_system_key() {
	key+="${RSTAR_PLATFORM[os]}"

	if [[ ${RSTAR_PLATFORM[distro]} ]]
	then
		key+="-${RSTAR_PLATFORM[distro]}"
	fi

	printf "%s" "$key"
}

discover_system_os() {
	if command -v uname > /dev/null
	then
		printf "%s" "$(uname -s | awk '{print tolower($0)}' | sed 's@[/+ ]@_@g')"
		return
	fi
}

main "$@"