# Copyright 2021-2022 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2

# @ECLASS: kotlin-compiler.eclass
# @MAINTAINER:
# Yuan Liao <liaoyuan@gmail.com>
# @AUTHOR:
# Yuan Liao <liaoyuan@gmail.com>
# @SUPPORTED_EAPIS: 6 7 8
# @BLURB: An eclass for Kotlin compiler packages
# @DESCRIPTION:
# This eclass should be inherited by every Kotlin compiler package that is
# intended to be recognized by app-eselect/eselect-kotlin, the Kotlin eselect
# module.

case "${EAPI:-0}" in
	6|7|8) ;;
	*) die "${ECLASS}: EAPI ${EAPI:-0} not supported" ;;
esac

# Allow use of EAPI 7 version manipulators in older EAPIs for both this eclass
# and consumer ebuilds
[[ "${EAPI:-0}" -eq 6 ]] && inherit eapi7-ver

# @ECLASS-VARIABLE: KOTLIN_COMPILER_HOME
# @DEFAULT_UNSET
# @REQUIRED
# @DESCRIPTION:
# The installation target path for the Kotlin compiler after EPREFIX
# (${EPREFIX} will be automatically prepended when the path is used in this
# eclass). Default is unset, must be overridden from ebuild BEFORE the
# pkg_preinst phase.

# @ECLASS-VARIABLE: KOTLIN_COMPILER_VER
# @PRE_INHERIT
# @DESCRIPTION:
# The Kotlin feature release version (e.g. 1.4, 1.5) this Kotlin compiler is
# for. Defaults to $(ver_cut 1-2), can be overridden from ebuild BEFORE
# inheriting this eclass.
: ${KOTLIN_COMPILER_VER:="$(ver_cut 1-2)"}

RDEPEND="
	app-eselect/eselect-kotlin
"

EXPORT_FUNCTIONS pkg_preinst pkg_postinst pkg_postrm

# @FUNCTION: kotlin-compiler_pkg_preinst
# @DESCRIPTION:
# Installs the Kotlin compiler package description file for this package to the
# path for all description files defined by the Kotlin eselect module.
kotlin-compiler_pkg_preinst() {
	# If KOTLIN_COMPILER_HOME is not set, symbolic links to ${EPREFIX}/ will
	# be created by the Kotlin eselect module. This not only breaks normal
	# functionalities but also introduces risks of removing the entire system
	# in the same way as the infamous 'rm -rf /*'. Therefore, fail fast here to
	# prevent more serious issues.
	if [[ -z "${KOTLIN_COMPILER_HOME}" ]]; then
		eerror "The ebuild for this package inherits kotlin-compiler.eclass"
		eerror "without setting the required KOTLIN_COMPILER_HOME variable."
		eerror "Please inform the package's maintainers of this error. Thanks!"
		eerror
		die "KOTLIN_COMPILER_HOME is not set in the ebuild"
	fi

	# The package description file's name should be the last component of the
	# path defined by KOTLIN_COMPILER_HOME
	local pkg_desc="${KOTLIN_COMPILER_HOME##*/}"
	insinto "/usr/share/eselect-kotlin/pkgs/${KOTLIN_COMPILER_VER}"
	newins - "${pkg_desc}" <<- _EOF_
		GENTOO_KOTLIN_HOME="${EPREFIX%/}/${KOTLIN_COMPILER_HOME#/}"
		_EOF_
}

# @ECLASS-VARIABLE: _KOTLIN_COMPILER_TOOLS
# @INTERNAL
# @DESCRIPTION:
# The array of executables provided by a standard Kotlin compiler package.
_KOTLIN_COMPILER_TOOLS=(
	kapt
	kotlin
	kotlinc
	kotlinc-js
	kotlinc-jvm
	kotlin-dce-js
)

# @FUNCTION: _kotlin-compiler_update_versioned_exe
# @INTERNAL
# @DESCRIPTION:
# Creates versioned Kotlin tool executables for KOTLIN_COMPILER_VER.
_kotlin-compiler_update_versioned_exe() {
	local tool
	for tool in "${_KOTLIN_COMPILER_TOOLS[@]}"; do
		ln -snf "${EPREFIX}/usr/libexec/eselect-kotlin/run-kotlin-tool.sh" \
			"${EROOT}/usr/bin/${tool}${KOTLIN_COMPILER_VER}"
	done
}

# @FUNCTION: _kotlin-compiler_cleanup_versioned_exe
# @INTERNAL
# @DESCRIPTION:
# Removes versioned Kotlin tool executables for KOTLIN_COMPILER_VER if there is
# no more package for the feature release installed on the system.
_kotlin-compiler_cleanup_versioned_exe() {
	local ver_symlink="${EROOT}/etc/eselect/kotlin/homes/${KOTLIN_COMPILER_VER}"
	if ! [[ -L "${ver_symlink}" && -d "${ver_symlink}" ]]; then
		local tool
		for tool in "${_KOTLIN_COMPILER_TOOLS[@]}"; do
			rm "${EROOT}/usr/bin/${tool}${KOTLIN_COMPILER_VER}"
		done
	fi
}

# @FUNCTION: kotlin-compiler_pkg_postinst
# @DESCRIPTION:
# Performs tasks that need to be done after a new Kotlin compiler is installed.
kotlin-compiler_pkg_postinst() {
	eselect kotlin update
	_kotlin-compiler_update_versioned_exe
}

# @FUNCTION: kotlin-compiler_pkg_postrm
# @DESCRIPTION:
# Performs tasks that need to be done after a Kotlin compiler is removed.
kotlin-compiler_pkg_postrm() {
	eselect kotlin cleanup
	eselect kotlin update
	_kotlin-compiler_cleanup_versioned_exe
}