#! /usr/bin/env bash

# Init variables
APTPKG_VERSION="0.1.0"

# Show help
show_help(){
	cat > /dev/stdout <<EOF

aptpkg v$APTPKG_VERSION

Easily create debian packages.

Documentation: https://man.sr.ht/~earnestma/aptpkg

Usage:
	aptpkg [directory]
	aptpkg -h, --help          Show help

EOF
}

# Incorrect aptpkg usage: explain, show help, and exit
error_usage_die(){
	echo "ERROR: " "$1"
	show_help
	exit 1
}

# Verify sha512sums
verify(){
	echo "$sha512sums" | sha512sum -c
}

# Copy/ install wrapper for files
cin-bin(){
	install -Dm755 "$@"
}
cin-file(){
	install -Dm644 "$@"
}

# Check that "build" file exists in directory
check(){
	if ! [ -f "$1/build" ]; then
		echo "No package of that name exists."
		exit 1
	fi
}

# Generate the debian control file
gen_control_file(){
	mkdir -p "$builddir"/DEBIAN
	echo "Package: $name
Version: $version-$rev
Architecture: amd64
Maintainer: $(grep -am 1 -hr "Maintainer: " build | sed 's/# Maintainer: //')
Section:
Priority:
Homepage: $url
Description: $description
$customcontrol
" > "$builddir"/DEBIAN/control
}

# Download a debian package
build_deb(){
	echo "Getting $source"
	wget "$source" -qP dist/

	( cd dist ; verify )
}

# Download and build using files
build_file(){
	builddir=${name}_${version}-${rev}_amd64

	cd "$1"
	mkdir -p "$builddir"

	for url in $source; do
		echo "Getting $source"
		wget -q "$url"
	done

	verify

	# Run
	steps "$@"

	gen_control_file "$@"

	for maintfile in preinst postinst prerm postrm; do
		[ -f $maintfile ] && cin-bin $maintfile "$builddir"/DEBIAN/$maintfile
	done

	cd -

	dpkg-deb --build --root-owner-group "$1"/"$builddir" dist/
}

# Determine which function to run
load_build(){
	mkdir -p dist

	# shellcheck disable=SC1090
	source "$1/build"

	case "$type" in
		deb)
			build_deb ;;
		file)
			build_file "$@" ;;
	esac
}

# Run!
case $1 in
	-h|--help)
		show_help ;;
	*)
		if [ $# -ne 1 ]; then
			error_usage_die "You must provide one directory"
		fi

		check "$1"
		load_build "$1" ;;
esac