#!/usr/bin/env bash

# Change the working directory. In usage, this is the same as using cd,
# however,  it will make additional checks to ensure everything is going fine.
chgdir() {
	debug "bashtard/chgdir" "Changing workdir to $1"
	cd -- "$1" || die "Failed to change directory to $1"
}

# Read a particular value from a key/value configuration file. Using this
# function introduces a dependency on awk.
config() {
	config_for "${BASHTARD_PLATFORM[fqdn]}" "$@"
}

config_for() {
	local host=$1 ; shift
	local key=$1 ; shift
	local default=$1 ; shift

	local default
	local file
	local files

	files=(
		"$BASHTARD_ETCDIR/hosts.d/$host"
		"$BASHTARD_ETCDIR/os.d/${BASHTARD_PLATFORM[key]}"
		"$BASHTARD_ETCDIR/defaults"
	)

	if [[ ! -z "$BASHTARD_PLAYBOOK" ]]
	then
		debug "bashtard/config_for" "BASHTARD_PLAYBOOK=$BASHTARD_PLAYBOOK, adding etc entries"
		files+=(
			"$BASHTARD_ETCDIR/playbooks.d/$BASHTARD_PLAYBOOK/etc/os.d"
			"$BASHTARD_ETCDIR/playbooks.d/$BASHTARD_PLAYBOOK/etc/defaults"
		)
	fi

	files+=(
		"$BASHTARD_BASEDIR/etc/os.d/${BASHTARD_PLATFORM[key]}"
		"$BASHTARD_BASEDIR/etc/defaults"
	)

	# Check configuration files
	for file in "${files[@]}"
	do
		debug "bashtard/config_for" "Checking for '$key' in '$file'"

		[[ ! -f $file ]] && continue

		value="$(awk -F= '$1 == "'"$key"'" { print $NF }' "$file")"

		if [[ -n $value ]]
		then
			debug "bashtard/config_for" "Found $key=$value in $file"

			printf "%s" "$value"
			return
		fi
	done

	# Return default value
	if [[ -n $default ]]
	then
		printf "%s" "$default"
		return
	fi

	# Error
	alert "bashtard/config_for" "No configuration value for $key"
}

# Create a datetime stamp. This is a wrapper around the date utility, ensuring
# that the date being formatted is always in UTC and respect SOURCE_DATE_EPOCH,
# if it is set.
datetime() {
	local date_opts

	# Apply SOURCE_DATE_EPOCH as the date to base off of.
	if [[ $SOURCE_DATE_EPOCH ]]
	then
		date_opts+=("-d@$SOURCE_DATE_EPOCH")
		date_opts+=("-u")
	fi

	date "${date_opts[@]}" +"${1:-%FT%T}"
}

# Log a message as error, and exit the program. This is intended for serious
# issues that prevent the script from running correctly. The exit code can be
# specified with -i, or will default to 1.
die() {
	local OPTIND
	local code

	while getopts ":i:" opt
	do
		case "$opt" in
			i) code=$OPTARG ;;
			*) alert "bashtard/die" "Unused argument specified: $opt" ;;
		esac
	done

	shift $(( OPTIND -1 ))

	alert "$@"
	exit "${code:-1}"
}

# Fetch a file from an URL. Using this function introduces a dependency on curl.
fetch_http() {
	local OPTIND
	local buffer

	while getopts ":o:" opt
	do
		case "$opt" in
			o) buffer=$OPTARG ;;
			*) alert "bashtard/fetch_http" "Unused argument specified: $opt" ;;
		esac
	done

	shift $(( OPTIND -1 ))

	[[ -z $buffer ]] && buffer="$(tmpfile)"

	notice "bashtard/fetch_http" "Downloading $1 to $buffer"

	for util in curl wget
	do
		command -v "$util" > /dev/null || continue
		"fetch_http_$util" "$1" "$buffer" || continue
		local exit_code=$?

		printf "%s" "$buffer"
		return $exit_code
	done

	die "bashtard/fetch_http" "Unable to download file over HTTP!"
}

fetch_http_curl() {
	curl -Ls "$1" > "$2"
}

fetch_http_wget() {
	wget --quiet --output-document "$2" "$1"
}

# Check if the first argument given appears in the list of all following
# arguments.
in_args() {
	local needle="$1"
	shift

	for arg in "$@"
	do
		[[ $needle == "$arg" ]] && return 0
	done

	return 1
}

# Join a list of arguments into a single string. By default, this will join
# using a ",", but you can set a different character using -c. Note that this
# only joins with a single character, not a string of characters.
join_args() {
	local OPTIND
	local IFS=","

	while getopts ":c:" opt
	do
		case "$opt" in
			c) IFS="$OPTARG" ;;
			*) warn "bashtard/join_args" "Unused opt specified: $opt" ;;
		esac
	done

	shift $(( OPTIND - 1))

	printf "%s" "$*"
}

# OS independent package management
pkg() {
	local system="bashtard/pkg"

	local action=$1 ; shift
	local pkg="$(config "pkg.$1")" ; shift

	if [[ -z $pkg ]]
	then
		crit "$system" "No package name for $pkg"
		return 1
	fi

	if [[ "$(type -t pkg_$action)" != "function" ]]
	then
		crit "$system" "Invalid package manager action $action"
		return 1
	fi

	"pkg_$action" "$pkg"
}

pkg_install() {
	local system="bashtard/pkg/install"

	local app=$1 ; shift

	case "${BASHTARD_PLATFORM[key]}" in
		freebsd)       set -- /usr/sbin/pkg install -y "$app" ;;
		linux-debian*) set -- apt install -y "$app" ;;
		linux-gentoo)  set -- emerge --ask=n --update "$app" ;;
		*)
			crit "$system" "No package manager configured for ${BASHTARD_PLATFORM[key]}"
			return 1
			;;
	esac

	notice "$system" "$*"
	$@
}

pkg_uninstall() {
	local system="bashtard/pkg/uninstall"

	local app=$1 ; shift

	case "${BASHTARD_PLATFORM[key]}" in
		freebsd)       set -- /usr/sbin/pkg uninstall -y "$app" ;;
		linux-debian*) set -- apt remove -y "$app" ;;
		linux-gentoo)  set -- emerge --ask=n --unmerge "$app" ;;
		*)
			crit "$system" "No package manager configured for ${BASHTARD_PLATFORM[key]}"
			return 1
			;;
	esac

	notice "$system" "$*"
	$@
}

# OS independent service management.
svc() {
	local system="bashtard/svc"

	local service
	local action

	action=$1 ; shift
	service="$(config svc.$1)" ; shift

	if [[ -z $service ]]
	then
		crit "$system" "No service name for $service"
		return 1
	fi

	if [[ "$(type -t svc_$action)" != "function" ]]
	then
		crit "$system" "Invalid service manager action $action"
		return 1
	fi

	"svc_$action" "$service"
}

svc_disable() {
	local system="bashtard/svc/disable"

	local service=$1

	case "${BASHTARD_PLATFORM[key]}" in
		linux-gentoo) set -- /sbin/rc-update del "$service" ;;
		linux-*)      set -- systemctl disable "$service" ;;
		*)
			crit "$system" "No service manager configured for ${BASHTARD_PLATFORM[key]}"
			return 1
	esac

	notice "$system" "$*"
	$@
}

svc_enable() {
	local system="bashtard/svc/enable"

	local service=$1

	case "${BASHTARD_PLATFORM[key]}" in
		linux-gentoo) set -- /sbin/rc-update add "$service" ;;
		linux-*)      set -- systemctl enable "$service" ;;
		*)
			crit "$system" "No service manager configured for ${BASHTARD_PLATFORM[key]}"
			return 1
	esac

	notice "$system" "$*"
	$@
}

svc_reload() {
	local system="bashtard/svc/reload"

	local service=$1

	case "${BASHTARD_PLATFORM[key]}" in
		freebsd)      set -- service "$service" reload ;;
		linux-gentoo) set -- /sbin/rc-service "$service" reload ;;
		linux-*)      set -- systemctl reload "$service" ;;
		*)
			crit "$system" "No service manager configured for ${BASHTARD_PLATFORM[key]}"
			return 1
	esac

	notice "$system" "$*"
	$@
}

svc_restart() {
	local system="bashtard/svc/restart"

	local service=$1

	case "${BASHTARD_PLATFORM[key]}" in
		freebsd)      set -- service "$service" restart ;;
		linux-gentoo) set -- /sbin/rc-service "$service" restart ;;
		linux-*)      set -- systemctl restart "$service" ;;
		*)
			crit "$system" "No service manager configured for ${BASHTARD_PLATFORM[key]}"
			return 1
	esac

	notice "$system" "$*"
	$@
}

svc_start() {
	local system="bashtard/svc/start"

	local service=$1

	case "${BASHTARD_PLATFORM[key]}" in
		freebsd)      set -- service "$service" start ;;
		linux-gentoo) set -- /sbin/rc-service "$service" start ;;
		linux-*)      set -- systemctl start "$service" ;;
		*)
			crit "$system" "No service manager configured for ${BASHTARD_PLATFORM[key]}"
			return 1
	esac

	notice "$system" "$*"
	$@
}

svc_stop() {
	local system="bashtard/svc/stop"

	local service=$1

	case "${BASHTARD_PLATFORM[key]}" in
		freebsd)      set -- service "$service" stop ;;
		linux-gentoo) set -- /sbin/rc-service "$service" stop ;;
		linux-*)      set -- systemctl stop "$service" ;;
		*)
			crit "$system" "No service manager configured for ${BASHTARD_PLATFORM[key]}"
			return 1
	esac

	notice "$system" "$*"
	$@
}

file_template()
{
	local file="$BASHTARD_ETCDIR/playbooks.d/$BASHTARD_PLAYBOOK/share/$1" ; shift
	local sedfile="$(tmpfile)"

	if [[ ! -f $file ]]
	then
		crit "bashtard/template" "Tried to render template from $file, but it doesn't exist"
		return
	fi

	for kv in "$@"
	do
		debug "bashtard/template" "Adding $kv to sedfile at $sedfile"

		key="$(awk -F= '{ print $1 }' <<< $kv)"

		if [[ -z "$key" ]]
		then
			crit "bashtard/template" "Empty key in '$kv' while rendering $file?"
		fi

		value="$(awk -F= '{ print $NF }' <<< $kv)"

		if [[ -z "$value" ]]
		then
			crit "bashtard/template" "Empty key in '$kv' while rendering $file?"
		fi

		printf 's@${%s}@%s@g\n' "$key" "$value" >> "$sedfile"
	done

	sed -f "$sedfile" "$file"
}

# Create a temporary directory. Similar to tempfile, but you'll get a directory
# instead.
tmpdir() {
	local dir

	dir="$(mktemp -d)"

	# Ensure the file was created succesfully
	if [[ ! -d "$dir" ]]
	then
		die "bashtard/tmpdir" "Failed to create a temporary directory at $dir"
	fi

	debug "bashtard/tmpdir" "Temporary file created at $dir"

	printf "%s" "$dir"
}

# Create a temporary file. In usage, this is no different from mktemp itself,
# however, it will apply additional checks to ensure everything is going
# correctly, and the files will be cleaned up automatically at the end.
tmpfile() {
	local file

	file="$(mktemp)"

	# Ensure the file was created succesfully
	if [[ ! -f "$file" ]]
	then
		die "bashtard/tmpfile" "Failed to create a temporary file at $file"
	fi

	debug "bashtard/tmpfile" "Temporary file created at $file"

	printf "%s" "$file"
}