# Copyright 1999-2019 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2

# @ECLASS: ruby-fakegem.eclass
# @MAINTAINER:
# Ruby herd <ruby@gentoo.org>
# @AUTHOR:
# Author: Diego E. Pettenò <flameeyes@gentoo.org>
# Author: Alex Legler <a3li@gentoo.org>
# Author: Hans de Graaff <graaff@gentoo.org>
# @SUPPORTED_EAPIS: 4 5 6 7
# @BLURB: An eclass for installing Ruby packages to behave like RubyGems.
# @DESCRIPTION:
# This eclass allows to install arbitrary Ruby libraries (including Gems),
# providing integration into the RubyGems system even for "regular" packages.

inherit ruby-ng

# @ECLASS-VARIABLE: RUBY_FAKEGEM_NAME
# @DESCRIPTION:
# Sets the Gem name for the generated fake gemspec.
# This variable MUST be set before inheriting the eclass.
RUBY_FAKEGEM_NAME="${RUBY_FAKEGEM_NAME:-${PN}}"

# @ECLASS-VARIABLE: RUBY_FAKEGEM_VERSION
# @DESCRIPTION:
# Sets the Gem version for the generated fake gemspec.
# This variable MUST be set before inheriting the eclass.
RUBY_FAKEGEM_VERSION="${RUBY_FAKEGEM_VERSION:-${PV/_pre/.pre}}"

# @ECLASS-VARIABLE: RUBY_FAKEGEM_TASK_DOC
# @DESCRIPTION:
# Specify the rake(1) task to run to generate documentation.
RUBY_FAKEGEM_TASK_DOC="${RUBY_FAKEGEM_TASK_DOC-rdoc}"

# @ECLASS-VARIABLE: RUBY_FAKEGEM_RECIPE_TEST
# @DESCRIPTION:
# Specify one of the default testing function for ruby-fakegem:
#  - rake (default; see also RUBY_FAKEGEM_TASK_TEST)
#  - rspec (calls ruby-ng_rspec, adds dev-ruby/rspec:2 to the dependencies)
#  - rspec3 (calls ruby-ng_rspec, adds dev-ruby/rspec:3 to the dependencies)
#  - cucumber (calls ruby-ng_cucumber, adds dev-util/cucumber to the
#    dependencies)
#  - none
RUBY_FAKEGEM_RECIPE_TEST="${RUBY_FAKEGEM_RECIPE_TEST-rake}"

# @ECLASS-VARIABLE: RUBY_FAKEGEM_TASK_TEST
# @DESCRIPTION:
# Specify the rake(1) task used for executing tests. Only valid
# if RUBY_FAKEGEM_RECIPE_TEST is set to "rake" (the default).
RUBY_FAKEGEM_TASK_TEST="${RUBY_FAKEGEM_TASK_TEST-test}"

# @ECLASS-VARIABLE: RUBY_FAKEGEM_RECIPE_DOC
# @DESCRIPTION:
# Specify one of the default API doc building function for ruby-fakegem:
#  - rake (default; see also RUBY_FAKEGEM_TASK_DOC)
#  - rdoc (calls `rdoc-2`, adds dev-ruby/rdoc to the dependencies);
#  - yard (calls `yard`, adds dev-ruby/yard to the dependencies);
#  - none
case ${EAPI} in
	4|5|6)
		RUBY_FAKEGEM_RECIPE_DOC="${RUBY_FAKEGEM_RECIPE_DOC-rake}"
		;;
	*)
		RUBY_FAKEGEM_RECIPE_DOC="${RUBY_FAKEGEM_RECIPE_DOC-rdoc}"
		;;
esac

# @ECLASS-VARIABLE: RUBY_FAKEGEM_DOCDIR
# @DEFAULT_UNSET
# @DESCRIPTION:
# Specify the directory under which the documentation is built;
# if empty no documentation will be installed automatically.
# Note: if RUBY_FAKEGEM_RECIPE_DOC is set to `rdoc`, this variable is
# hardwired to `doc`.

# @ECLASS-VARIABLE: RUBY_FAKEGEM_EXTRADOC
# @DEFAULT_UNSET
# @DESCRIPTION:
# Extra documentation to install (readme, changelogs, …).

# @ECLASS-VARIABLE: RUBY_FAKEGEM_DOC_SOURCES
# @DESCRIPTION:
# Allow settings defined sources to scan for documentation.
# This only applies if RUBY_FAKEGEM_DOC_TASK is set to `rdoc`.
RUBY_FAKEGEM_DOC_SOURCES="${RUBY_FAKEGEM_DOC_SOURCES-lib}"

# @ECLASS-VARIABLE: RUBY_FAKEGEM_BINWRAP
# @DESCRIPTION:
# Binaries to wrap around (relative to the RUBY_FAKEGEM_BINDIR directory)
RUBY_FAKEGEM_BINWRAP="${RUBY_FAKEGEM_BINWRAP-*}"

# @ECLASS-VARIABLE: RUBY_FAKEGEM_BINDIR
# @DESCRIPTION:
# Path that contains binaries to be binwrapped. Equivalent to the
# gemspec bindir option.
RUBY_FAKEGEM_BINDIR="${RUBY_FAKEGEM_BINDIR-bin}"

# @ECLASS-VARIABLE: RUBY_FAKEGEM_REQUIRE_PATHS
# @DEFAULT_UNSET
# @DESCRIPTION:
# Extra require paths (beside lib) to add to the specification

# @ECLASS-VARIABLE: RUBY_FAKEGEM_GEMSPEC
# @DEFAULT_UNSET
# @DESCRIPTION:
# Filename of .gemspec file to install instead of generating a generic one.

# @ECLASS-VARIABLE: RUBY_FAKEGEM_EXTRAINSTALL
# @DEFAULT_UNSET
# @DESCRIPTION:
# List of files and directories relative to the top directory that also
# get installed. Some gems provide extra files such as version information,
# Rails generators, or data that needs to be installed as well.

case "${EAPI:-0}" in
	0|1|2|3)
		die "Unsupported EAPI=${EAPI} (too old) for ruby-fakegem.eclass" ;;
	4|5|6|7)
		;;
	*)
		die "Unsupported EAPI=${EAPI} (unknown) for ${ECLASS}"
		;;
esac


RUBY_FAKEGEM_SUFFIX="${RUBY_FAKEGEM_SUFFIX:-}"


[[ ${RUBY_FAKEGEM_TASK_DOC} == "" ]] && RUBY_FAKEGEM_RECIPE_DOC="none"

case ${RUBY_FAKEGEM_RECIPE_DOC} in
	rake)
		IUSE+=" doc"
		ruby_add_bdepend "doc? ( dev-ruby/rake )"
		RUBY_FAKEGEM_DOCDIR="doc"
		;;
	rdoc)
		IUSE+=" doc"
		ruby_add_bdepend "doc? ( dev-ruby/rdoc )"
		RUBY_FAKEGEM_DOCDIR="doc"
		;;
	yard)
		IUSE+="doc"
		ruby_add_bdepend "doc? ( dev-ruby/yard )"
		RUBY_FAKEGEM_DOCDIR="doc"
		;;
	none)
		[[ -n ${RUBY_FAKEGEM_DOCDIR} ]] && IUSE+=" doc"
		;;
esac

[[ ${RUBY_FAKEGEM_TASK_TEST} == "" ]] && RUBY_FAKEGEM_RECIPE_TEST="none"

case ${RUBY_FAKEGEM_RECIPE_TEST} in
	rake)
		IUSE+=" test"
		RESTRICT+=" !test? ( test )"
		ruby_add_bdepend "test? ( dev-ruby/rake )"
		;;
	rspec)
		IUSE+=" test"
		RESTRICT+=" !test? ( test )"
		# Also require a new enough rspec-core version that installs the
		# rspec-2 wrapper.
		ruby_add_bdepend "test? ( dev-ruby/rspec:2 >=dev-ruby/rspec-core-2.14.8-r2 )"
		;;
	rspec3)
		IUSE+=" test"
		RESTRICT+=" !test? ( test )"
		ruby_add_bdepend "test? ( dev-ruby/rspec:3 )"
		;;
	cucumber)
		IUSE+=" test"
		RESTRICT+=" !test? ( test )"
		ruby_add_bdepend "test? ( dev-util/cucumber )"
		;;
	*)
		RUBY_FAKEGEM_RECIPE_TEST="none"
		;;
esac

SRC_URI="https://rubygems.org/gems/${RUBY_FAKEGEM_NAME}-${RUBY_FAKEGEM_VERSION}${RUBY_FAKEGEM_SUFFIX:+-${RUBY_FAKEGEM_SUFFIX}}.gem"

ruby_add_bdepend virtual/rubygems
ruby_add_rdepend virtual/rubygems
case ${EAPI} in
	4|5|6)
		;;
	*)
		ruby_add_depend virtual/rubygems
		;;
esac

# @FUNCTION: ruby_fakegem_gemsdir
# @RETURN: Returns the gem data directory
# @DESCRIPTION:
# This function returns the gems data directory for the ruby
# implementation in question.
ruby_fakegem_gemsdir() {
	local _gemsitedir=$(ruby_rbconfig_value 'sitelibdir')
	_gemsitedir=${_gemsitedir//site_ruby/gems}
	_gemsitedir=${_gemsitedir#${EPREFIX}}

	[[ -z ${_gemsitedir} ]] && {
		eerror "Unable to find the gems dir"
		die "Unable to find the gems dir"
	}

	echo "${_gemsitedir}"
}

# @FUNCTION: ruby_fakegem_doins
# @USAGE: <file> [file...]
# @DESCRIPTION:
# Installs the specified file(s) into the gems directory.
ruby_fakegem_doins() {
	(
		insinto $(ruby_fakegem_gemsdir)/gems/${RUBY_FAKEGEM_NAME}-${RUBY_FAKEGEM_VERSION}
		doins "$@"
	) || die "failed $0 $@"
}

# @FUNCTION: ruby_fakegem_newins
# @USAGE: <file> <newname>
# @DESCRIPTION:
# Installs the specified file into the gems directory using the provided filename.
ruby_fakegem_newins() {
	(
		# Since newins does not accept full paths but just basenames
		# for the target file, we want to extend it here.
		local newdirname=/$(dirname "$2")
		[[ ${newdirname} == "/." ]] && newdirname=

		local newbasename=$(basename "$2")

		insinto $(ruby_fakegem_gemsdir)/gems/${RUBY_FAKEGEM_NAME}-${RUBY_FAKEGEM_VERSION}${newdirname}
		newins "$1" ${newbasename}
	) || die "failed $0 $@"
}

# @FUNCTION: ruby_fakegem_install_gemspec
# @DESCRIPTION:
# Install a .gemspec file for this package. Either use the file indicated
# by the RUBY_FAKEGEM_GEMSPEC variable, or generate one using
# ruby_fakegem_genspec.
ruby_fakegem_install_gemspec() {
	local gemspec="${T}"/${RUBY_FAKEGEM_NAME}-${_ruby_implementation}

	(
		if [[ ${RUBY_FAKEGEM_GEMSPEC} != "" ]]; then
			ruby_fakegem_gemspec_gemspec ${RUBY_FAKEGEM_GEMSPEC} ${gemspec}
		else
			local metadata="${WORKDIR}"/${_ruby_implementation}/metadata

			if [[ -e ${metadata} ]]; then
				ruby_fakegem_metadata_gemspec ${metadata} ${gemspec}
			else
				ruby_fakegem_genspec ${gemspec}
			fi
		fi
	) || die "Unable to generate gemspec file."

	insinto $(ruby_fakegem_gemsdir)/specifications
	newins ${gemspec} ${RUBY_FAKEGEM_NAME}-${RUBY_FAKEGEM_VERSION}.gemspec || die "Unable to install gemspec file."
}

# @FUNCTION: ruby_fakegem_gemspec_gemspec
# @USAGE: <gemspec-input> <gemspec-output>
# @DESCRIPTION:
# Generates an installable version of the specification indicated by
# RUBY_FAKEGEM_GEMSPEC. This file is eval'ed to produce a final specification
# in a way similar to packaging the gemspec file.
ruby_fakegem_gemspec_gemspec() {
	${RUBY} -e "puts eval(File::open('$1').read).to_ruby" > $2
}

# @FUNCTION: ruby_fakegem_metadata_gemspec
# @USAGE: <gemspec-metadata> <gemspec-output>
# @DESCRIPTION:
# Generates an installable version of the specification indicated by
# the metadata distributed by the gem itself. This is similar to how
# rubygems creates an installation from a .gem file.
ruby_fakegem_metadata_gemspec() {
	${RUBY} -r yaml -e "puts Gem::Specification.from_yaml(File::open('$1', :encoding => 'UTF-8').read).to_ruby" > $2
}

# @FUNCTION: ruby_fakegem_genspec
# @USAGE: <output-gemspec>
# @DESCRIPTION:
# Generates a gemspec for the package and places it into the "specifications"
# directory of RubyGems.
# If the metadata normally distributed with a gem is present then that is
# used to generate the gemspec file.
#
# As a fallback we can generate our own version.
# In the gemspec, the following values are set: name, version, summary,
# homepage, and require_paths=["lib"].
# See RUBY_FAKEGEM_NAME and RUBY_FAKEGEM_VERSION for setting name and version.
# See RUBY_FAKEGEM_REQUIRE_PATHS for setting extra require paths.
ruby_fakegem_genspec() {
	case ${EAPI} in
		4|5|6) ;;
		*)
			eqawarn "Generating generic fallback gemspec *without* dependencies"
			eqawarn "This will only work when there are no runtime dependencies"
			eqawarn "Set RUBY_FAKEGEM_GEMSPEC to generate a proper specifications file"
			;;
	esac

	local required_paths="'lib'"
	for path in ${RUBY_FAKEGEM_REQUIRE_PATHS}; do
		required_paths="${required_paths}, '${path}'"
	done

	# We use the _ruby_implementation variable to avoid having stray
	# copies with different implementations; while for now we're using
	# the same exact content, we might have differences in the future,
	# so better taking this into consideration.
	local quoted_description=${DESCRIPTION//\"/\\\"}
	cat - > $1 <<EOF
# generated by ruby-fakegem.eclass
Gem::Specification.new do |s|
  s.name = "${RUBY_FAKEGEM_NAME}"
  s.version = "${RUBY_FAKEGEM_VERSION}"
  s.summary = "${quoted_description}"
  s.homepage = "${HOMEPAGE}"
  s.require_paths = [${required_paths}]
end
EOF
}

# @FUNCTION: ruby_fakegem_binwrapper
# @USAGE: <command> [path] [content]
# @DESCRIPTION:
# Creates a new binary wrapper for a command installed by the RubyGem.
# path defaults to /usr/bin/$command content is optional and can be used
# to inject additional ruby code into the wrapper. This may be useful to
# e.g. force a specific version using the gem command.
ruby_fakegem_binwrapper() {
	(
		local gembinary=$1
		local newbinary=${2:-/usr/bin/$gembinary}
		local content=$3
		local relativegembinary=${RUBY_FAKEGEM_NAME}-${RUBY_FAKEGEM_VERSION}/${RUBY_FAKEGEM_BINDIR}/${gembinary}
		local binpath=$(dirname $newbinary)
		[[ ${binpath} = . ]] && binpath=/usr/bin

		# Try to find out whether the package is going to install for
		# one or multiple implementations; if we're installing for a
		# *single* implementation, no need to use “/usr/bin/env ruby”
		# in the shebang, and we can actually avoid errors when
		# calling the script by default.
		local rubycmd=
		for implementation in $(_ruby_get_all_impls); do
			# ignore non-enabled implementations
			use ruby_targets_${implementation} || continue
			if [ -z $rubycmd ]; then
				# if no other implementation was set before, set it.
				rubycmd="$(ruby_implementation_command ${implementation})"
			else
				# if another implementation already arrived, then make
				# it generic and break out of the loop. This ensures
				# that we do at most two iterations.
				rubycmd="/usr/bin/env ruby"
				break
			fi
		done

		cat - > "${T}"/gembin-wrapper-${gembinary} <<EOF
#!${rubycmd}
# This is a simplified version of the RubyGems wrapper
#
# Generated by ruby-fakegem.eclass

require 'rubygems'

${content}
load Gem::default_path[-1] + "/gems/${relativegembinary}"

EOF

		exeinto ${binpath:-/usr/bin}
		newexe "${T}"/gembin-wrapper-${gembinary} $(basename $newbinary)
	) || die "Unable to create fakegem wrapper"
}

# @FUNCTION: all_fakegem_compile
# @DESCRIPTION:
# Build documentation for the package if indicated by the doc USE flag
# and if there is a documetation task defined.
all_fakegem_compile() {
	if [[ -n ${RUBY_FAKEGEM_DOCDIR} ]] && use doc; then
		case ${RUBY_FAKEGEM_RECIPE_DOC} in
			rake)
				rake ${RUBY_FAKEGEM_TASK_DOC} || die "failed to (re)build documentation"
				;;
			rdoc)
				rdoc ${RUBY_FAKEGEM_DOC_SOURCES} || die "failed to (re)build documentation"
				rm -f doc/js/*.gz || die "failed to remove duplicated compressed javascript files"
				;;
			yard)
				yard doc ${RUBY_FAKEGEM_DOC_SOURCES} || die "failed to (re)build documentation"
				;;
		esac
	fi
}

# @FUNCTION: all_ruby_unpack
# @DESCRIPTION:
# Unpack the source archive, including support for unpacking gems.
all_ruby_unpack() {
	# Special support for extracting .gem files; the file need to be
	# extracted twice and the mtime from the archive _has_ to be
	# ignored (it's always set to epoch 0).
	for archive in ${A}; do
		case "${archive}" in
			*.gem)
				# Make sure that we're not running unpack for more than
				# one .gem file, since we won't support that at all.
				[[ -d "${S}" ]] && die "Unable to unpack ${archive}, ${S} exists"

				ebegin "Unpacking .gem file..."
				tar -mxf "${DISTDIR}"/${archive} || die
				eend $?

				ebegin "Uncompressing metadata"
				gunzip metadata.gz || die
				eend $?

				mkdir "${S}"
				pushd "${S}" &>/dev/null || die

				ebegin "Unpacking data.tar.gz"
				tar -mxf "${my_WORKDIR}"/data.tar.gz || die
				eend $?

				popd &>/dev/null || die
				;;
			*.patch.bz2)
				# We apply the patches with RUBY_PATCHES directly from DISTDIR,
				# as the WORKDIR variable changes value between the global-scope
				# and the time all_ruby_unpack/_prepare are called. Since we can
				# simply decompress them when applying, this is much easier to
				# deal with for us.
				einfo "Keeping ${archive} as-is"
				;;
			*)
				unpack ${archive}
				;;
		esac
	done
}

# @FUNCTION: all_ruby_compile
# @DESCRIPTION:
# Compile the package.
all_ruby_compile() {
	all_fakegem_compile
}

# @FUNCTION: each_fakegem_test
# @DESCRIPTION:
# Run tests for the package for each ruby target if the test task is defined.
each_fakegem_test() {
	case ${RUBY_FAKEGEM_RECIPE_TEST} in
		rake)
			${RUBY} -S rake ${RUBY_FAKEGEM_TASK_TEST} || die "tests failed"
			;;
		rspec)
			RSPEC_VERSION=2 ruby-ng_rspec
			;;
		rspec3)
			RSPEC_VERSION=3 ruby-ng_rspec
			;;
		cucumber)
			ruby-ng_cucumber
			;;
		none)
			ewarn "each_fakegem_test called, but \${RUBY_FAKEGEM_RECIPE_TEST} is 'none'"
			;;
	esac
}

if [[ ${RUBY_FAKEGEM_RECIPE_TEST} != none ]]; then
		# @FUNCTION: each_ruby_test
		# @DESCRIPTION:
		# Run the tests for this package.
		each_ruby_test() {
			each_fakegem_test
		}
fi

# @FUNCTION: each_fakegem_install
# @DESCRIPTION:
# Install the package for each ruby target.
each_fakegem_install() {
	ruby_fakegem_install_gemspec

	local _gemlibdirs="${RUBY_FAKEGEM_EXTRAINSTALL}"
	for directory in "${RUBY_FAKEGEM_BINDIR}" lib; do
		[[ -d ${directory} ]] && _gemlibdirs="${_gemlibdirs} ${directory}"
	done

	[[ -n ${_gemlibdirs} ]] && \
		ruby_fakegem_doins -r ${_gemlibdirs}
}

# @FUNCTION: each_ruby_install
# @DESCRIPTION:
# Install the package for each target.
each_ruby_install() {
	each_fakegem_install
}

# @FUNCTION: all_fakegem_install
# @DESCRIPTION:
# Install files common to all ruby targets.
all_fakegem_install() {
	if [[ -n ${RUBY_FAKEGEM_DOCDIR} ]] && use doc; then
		for dir in ${RUBY_FAKEGEM_DOCDIR}; do
			[[ -d ${dir} ]] || continue

			pushd ${dir} &>/dev/null || die
			dodoc -r * || die "failed to install documentation"
			popd &>/dev/null || die
		done
	fi

	if [[ -n ${RUBY_FAKEGEM_EXTRADOC} ]]; then
		dodoc ${RUBY_FAKEGEM_EXTRADOC} || die "failed to install further documentation"
	fi

	# binary wrappers; we assume that all the implementations get the
	# same binaries, or something is wrong anyway, so...
	if [[ -n ${RUBY_FAKEGEM_BINWRAP} ]]; then
		local bindir=$(find "${D}" -type d -path "*/gems/${RUBY_FAKEGEM_NAME}-${RUBY_FAKEGEM_VERSION}/${RUBY_FAKEGEM_BINDIR}" -print -quit)

		if [[ -d "${bindir}" ]]; then
			pushd "${bindir}" &>/dev/null || die
			for binary in ${RUBY_FAKEGEM_BINWRAP}; do
				ruby_fakegem_binwrapper "${binary}"
			done
			popd &>/dev/null || die
		fi
	fi
}

# @FUNCTION: all_ruby_install
# @DESCRIPTION:
# Install files common to all ruby targets.
all_ruby_install() {
	all_fakegem_install
}