#!/usr/bin/env bash

# SPDX-FileCopyrightText: 2022 Patrick Spek <p.spek@tyil.nl>
#
# SPDX-License-Identifier: AGPL-3.0-or-later

# 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() {
	debug "$BASHTARD_NAME/main" "Running from $BASHTARD_LIBDIR"
	debug "$BASHTARD_NAME/main" "Configuration dir is at $BASHTARD_ETCDIR"
	debug "$BASHTARD_NAME/main" "> $0 $*"

	[[ -z $1 ]] && usage && exit 2

	export BASHTARD_COMMAND="$1" ; shift

	debug "$BASHTARD_NAME/main" "Handling subcommand '$BASHTARD_COMMAND'"

	subcommand_src="$BASHTARD_LIBDIR/subcommands/$BASHTARD_COMMAND.bash"

	debug "$BASHTARD_NAME/main" "Checking $subcommand_src"

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

	# Declare some global variables
	declare -A BASHTARD_PLATFORM

	# Figure out system details
	debug "$BASHTARD_NAME/main" "Discovering system information"
	discover_system

	# Export BASHTARD_ variables
	export BASHTARD_PLATFORM

	# Source the file defining the subcommand.
	debug "$BASHTARD_NAME/main" "Sourcing $subcommand_src"
	source "$subcommand_src"

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

	# Actually perform the subcommand
	debug "$BASHTARD_NAME/main" "Running subcommand '$BASHTARD_COMMAND'"
	subcommand "$@"
	local subcommand_exit=$?

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

	## Use the subcommand's exit code
	exit $subcommand_exit
}

usage() {
	local playbooks
	local playbook_length
	local playbook_longest=0

	cat <<EOF
Usage:
	$BASHTARD_NAME -h
	$BASHTARD_NAME add <playbook>
	$BASHTARD_NAME del <playbook>
	$BASHTARD_NAME init [repository]
	$BASHTARD_NAME pkg <install|uninstall> <name>
	$BASHTARD_NAME ssh <command>
	$BASHTARD_NAME sync [playbook]
	$BASHTARD_NAME sysinfo
	$BASHTARD_NAME var [-p <playbook>] <key>
	$BASHTARD_NAME var [-s] <key> <value>

Perform maintenance on your infra.

Commands:
	add      Add a configuration playbook to this machine.
	init     Initialize the $BASHTARD_NAME configuration system.
	pkg      Interface into the pkg abstraction used by $BASHTARD_NAME.
	del      Remove a configuration playbook from this machine.
	ssh      Run a given command on all known hosts.
	sync     Pull latest changes through git, and synchronize all added
	         playbooks.
	sysinfo  Show gathered information about this system.
	var      Show or set the value of a given configuration key.

Playbooks:
EOF

	# Find all playbooks
	mapfile -t playbooks < <(find \
		"$BASHTARD_ETCDIR/playbooks.d"/* \
		-maxdepth 0 \
		-type d \
	)

	# Find longest playbook name
	for playbook in "${playbooks[@]}"
	do
		playbook_length="$(printf "%s" "$(basename "$playbook")" | wc -c)"

		if (( playbook_longest < playbook_length ))
		then
			playbook_longest=$playbook_length
		fi
	done

	# Render playbook descriptions
	for playbook in "${playbooks[@]}"
	do
		printf "\t%-${playbook_longest}s  %s\n" \
			"$(basename "$playbook")" \
			"$(cat "$playbook/description.txt")"
	done
}

# 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() {
	BASHTARD_PLATFORM["os"]="$(discover_system_os)"
	BASHTARD_PLATFORM["arch"]="$(discover_system_arch)"
	BASHTARD_PLATFORM["version"]="$(discover_system_version)"
	BASHTARD_PLATFORM["term"]="$TERM"
	BASHTARD_PLATFORM["fqdn"]="$(hostname -f)"

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

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

discover_system_arch() {
	uname -m
}

discover_system_distro() {
	if [[ -f /etc/os-release ]]
	then
		(
			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 "$BASHTARD_NAME/main" "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() {
	local key

	key+="${BASHTARD_PLATFORM[os]}"

	if [[ ${BASHTARD_PLATFORM[distro]} ]]
	then
		key+="-${BASHTARD_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 "$@"