#!/usr/bin/env bash
# -*- coding: utf-8 -*-

declare -rg _mainmoddir="$(dirname "${BASH_SOURCE[0]}")/.." 2> /dev/null

declare -rg _supported_qcow_handlers=("xmount" "xloop")
# NOTE: expects 'qcow_handler' to be set in the environment, else
# will only build support for xmount
build_initialize_components() {
    _deps_base_dir="${_mainmoddir}/binaries"
    # We might want to move the "binaries" repos from the dnbd3-rootfs module to main repo one day...
    # TODO check for its existence using modinfo -k <kernel_version>
    if [[ ! -f "${_deps_base_dir}/dnbd3/build/src/kernel/dnbd3/dnbd3.ko" ]] || \
        [[ ! -f "${_deps_base_dir}/dnbd3/build/src/client/dnbd3-client" ]]; then
            echo "Could not find dnbd3, building it..."
            if ! CMAKE_FLAGS="-DKERNEL_BUILD_DIR=${kernel_headers}" \
                build_compile_dnbd3 "${_deps_base_dir}/dnbd3/"; then
                    echo "Failed to build dnbd3."
                    return 1
            fi
    fi

    # process qcow handler
    echo "Supported handlers: ${_supported_qcow_handlers[*]}"
    IFS='|' _pattern="^(${_supported_qcow_handlers[*]})$" export _pattern
    if [ -z "$qcow_handler" ]; then
        echo "No qcow handler specified, will use xmount."
    elif [[ ! "$qcow_handler" =~ $_pattern ]] ; then
        echo "Unknown qcow handler '$qcow_handler' - will use xmount"
    fi
    if [ -z "$qcow_handler" ] || [ "$qcow_handler" = "xmount" ]; then
        if [[ ! -f "${_deps_base_dir}/xmount/trunk/build/src/xmount" ]]; then
            echo "Could not find xmount binary, building it..."
            if ! build_compile_xmount "${_deps_base_dir}/xmount/"; then
                echo "Failed to build xmount binary."
                return 1
            fi
        fi
        if [[ ! -f "${_deps_base_dir}/qemu-xmount/libxmount_input_qemu.so" ]]; then
            echo "Could not find xmount qemu library, building it..."
            if ! build_compile_qemu_xmount "${_deps_base_dir}/qemu-xmount/"; then
                echo "Failed to build xmount qemu library."
                return 1
            fi
        fi
    fi
    if [ "$qcow_handler" = "xloop" ]; then
        if [ ! -f "${_deps_base_dir}/xloop/build/src/kernel/xloop/xloop.ko" ]; then
            echo "Could not find loop kernel modules, building them..."
            if ! build_compile_xloop "${_deps_base_dir}/xloop"; then
                echo "Failed to build qcow loop kernel modules."
                return 1
            fi
        fi
    fi

    # always compile this helper since it does not cost much to do so
    if [[ ! -f "${_deps_base_dir}/systemd-preserve-process-marker/systemd-preserve-process-marker" ]]; then
        echo "Could not find systemd-preserve-process-marker binary, building it ..."
        if ! build_compile_systemd_preserve_process_marker \
            "${_deps_base_dir}/systemd-preserve-process-marker/"; then
                    echo "Failed to build systemd-preserve-process-marker"
                    return 1
        fi
    fi
    echo "Compilation of dnbd3-rootfs dependencies succeeded."
    return 0
}

clean_components() {
    local __doc__='
    Removes all compiled kernel specific files.
    NOTE: This method is triggered manually and not supported by dracut itself.

    Example:

    `clean`
    '
    local _submoddir="${_mainmoddir}/binaries"
    build_clean_xmount "${_submoddir}/xmount/"
    build_clean_qemu_xmount "${_submoddir}/qemu-xmount/"
    build_clean_dnbd3 "${_submoddir}/dnbd3/"
    build_clean_xloop "${_submoddir}/xloop"
    build_clean_xlosetup "${_submoddir}/kernel-qcow2-util-linux"
    build_clean_systemd_preserve_process_marker \
        "${_submoddir}/systemd-preserve-process-marker/"
    return 0
}
# endregion

build_compile_qemu_xmount() {
    local __doc__='
    Compiles qemu libxmount.
    NOTE: expects xmount installation under
    $1/../xmount/trunk/build/release_build/

    Provides the following file:
    "$1/libxmount_input_qemu.so"

    Example:

    `build_compile_qemu_xmount /qemu_source /xmount/installation`
    '
    pushd "$1"
    local xmount_installation="../xmount/trunk/build/release_build/usr"
    [ ! -z "$2" ] && xmount_installation="$2"
    ./configure --enable-xmount-input --python="$(which python2)" \
        --extra-cflags="-std=gnu99" \
        --disable-werror \
        --extra-cflags="-fPIC" \
        --extra-cflags="-I${xmount_installation}/include" \
        --extra-cflags="-I${xmount_installation}/include/xmount" \
        --disable-fdt --target-list=""
    make -j libxmount_input_qemu.so
    local ret=$?
    popd
    return $ret
}
build_clean_qemu_xmount() {
    local __doc__='Clean the build of `build_compile_qemu_xmount`.'
    pushd "$1"
    make clean
    local ret=$?
    popd
    return $ret
}
build_compile_xmount() {
    local __doc__='
    Compiles xmount.

    Provides the xmount installation under:
    "$1/trunk/build/release_build/"

    Example:

    `build_compile_xmount /xmount_source /xmount_source/build /usr`
    '
    pushd "$1"

    local destination_directory="./release_build"
    [ ! -z "$2" ] && destination_directory="$2"
    local install_prefix="/usr"
    [ ! -z "$3" ] && install_prefix="$3"

    mkdir --parents trunk/build
    cd trunk/build || return 1
    cmake -DCMAKE_BUILD_TYPE=Release \
        -DCMAKE_INSTALL_PREFIX="$install_prefix" ..
    make -j
    make install DESTDIR="$destination_directory"
    local ret=$?
    popd
    return $ret
}
build_clean_xmount() {
    local __doc__='Clean the build of `build_compile_xmount`.'
    rm --recursive --force "$1/trunk/build"
}
build_compile_dnbd3() {
    local __doc__='
    Compiles dnbd3 kernel module and client.

    Examples:

    `build_compile_dnbd3 path/to/dnbd3/source/`

    Passing the kernel version to cmake:
    `CMAKE_FLAGS="-DKERNEL_BUILD_DIR=<path_to_kernel_build_dir>" \
        build_compile_dnbd3 path/to/dnbd3/source/`
    '
    [ -z "$1" ] && return 1
    pushd "$1"
    (
        mkdir --parents build
        cd build
        # Inject CMAKE_FLAGS as a way to control how cmake is called,
        # e.g. to pass the kernel version
        cmake ${CMAKE_FLAGS} \
            -DDNBD3_KERNEL_MODULE=ON \
            -DDNBD3_CLIENT_FUSE=OFF \
            -DDNBD3_SERVER=OFF \
            -DDNBD3_SERVER_FUSE=OFF \
            ..
        make -j
    )
    local ret=$?
    popd
    return $ret
}
build_clean_dnbd3() {
    [ -z "$1" ] && return 1
    rm -rf "$1/build"
}
build_compile_xloop() {
    [ -z "$1" ] && return 1
    pushd "$1"
    if [ -z "$kernel_headers" ]; then
        echo "Kernel header directory not set, ignoring."
        return 1
    fi
    (
        set -o errexit
        mkdir -p build
        cd build
        cmake \
            -DCMAKE_BUILD_TYPE=Release \
            -DKERNEL_BUILD_DIR="$kernel_headers" \
            ..
        make -j
    )
    local ret=$?
    popd
    return $ret
}
build_clean_xloop() {
    [ -z "$1" ] && return 1
    rm -rf "$1/build"
}
build_compile_systemd_preserve_process_marker() {
    local __doc__='
    Compiles simple c program.

    Examples:

    `build_compile_systemd_preserve_process_marker path/to/program/folder`
    '
    pushd "$1"
    make
    local ret=$?
    popd
    return $ret
}
build_clean_systemd_preserve_process_marker() {
    local __doc__='
    Clean the build of
    `build_compile_systemd_preserve_process_marker`.
    '
    pushd "$1"
    make clean
    local ret=$?
    popd
    return $ret
}
# region vim modline
# vim: set tabstop=4 shiftwidth=4 expandtab:
# vim: foldmethod=marker foldmarker=region,endregion:
# endregion