#!/bin/sh

CMAKE=cmake

main() {
    cd "$(dirname $0)"

    check_command_line_args "$@"

    target=$1

    mktmp

    check_os

    ${os}_installdeps

    quit 0
}

check_command_line_args() {
    while [ $# -gt 0 ]; do
        case "$1" in
            -h|--help|--usage)
                usage
                quit 0
                ;;
            *)
                break
                ;;
        esac
    done

    if [ $# -gt 1 ]; then
        usage
        quit 1
    fi
}

check_os() {
    case "$(uname -s)" in
        Linux)
            os=linux
            ;;
        Darwin)
            os=mac
            ;;
        FreeBSD)
            os=freebsd
            ;;
        MINGW*|MSYS*)
            os=windows
            ;;
        *)
            error "Don't know how to install deps on your OS"
            ;;
    esac
}

mktmp() {
    tmp="/tmp/installdeps_$$"
    mkdir "$tmp" || quit 1
    chmod 700 "$tmp" 2>/dev/null
    trap "quit 1" PIPE HUP INT QUIT ILL TRAP KILL BUS TERM
}

quit() {
    [ -n "$tmp" ] && rm -rf "$tmp" 2>/dev/null
    exit ${1:-0}
}

usage() {
    cat <<'EOF'
Usage: ./installdeps [TARGET]
Try to install the dependencies needed for this project appropriately on the
host OS.

This program may require sudo.

A cross-compile target may be specified as the only parameter, of either
m32 which targets the host in 32 bit mode (e.g. x86 on an amd64
host) or win32, MinGW-w64-i686 or
MinGW-w64-x86_64.  win32 is an alias for
MinGW-w64-i686 to target Windows via MinGW.  Cross compiling for
Windows is only supported on Debian/Ubuntu, Fedora, Arch Linux and MSYS2.

On MSYS2 dependencies are installed for 32 or 64 bit native Windows targets
based on which shell you started (the value of $MSYSTEM) unless you specify one
or the other. You can specify a cross target of m32 or
m64 as aliases for the 32 bit or 64 bit targets respectively.
MSYS2 POSIX layer builds are not supported.

  -h, --help, --usage                Show this help screen and exit.

Examples:
  ./installdeps                        # install dependencies for a host build
  ./installdeps m32                    # make a 32 bit binary for the host OS
  ./installdeps win32                  # cross-compile for 32 bit windows (Debian/Ubuntu, Arch Linux or MSYS2)
  ./installdeps MinGW-w64-i686         # likewise
  ./installdeps MinGW-w64-x86_64       # cross-compile for 64 bit windows (Debian/Ubuntu, Arch Linux or MSYS2)
EOF
}

error() {
    printf '\nERROR: %s.\n\n' "$1" >&2
    [ -z "$2" ] && quit 1
}

warning() {
    [ -z "$1" ] && return 0
    printf '\nWARNING: %s.\n\n' "$1" >&2
}


info_msg() {
    [ -z "$1" ] && return 0
    printf '\nINFO: %s.\n\n' "$1" >&2
}

installing() {
    echo 'Installing deps...'
    echo
}

check() {
    "$@"
    if [ $? -ne 0 ]; then
        error 'command failed' NOQUIT
        echo 'The failing command was:'
        echo "$@"
        quit 1
    fi
}

countdown() {
    secs=$1
    echo
    while [ "$secs" -ne 0 ]; do
        printf '%s\r' "Starting in $secs seconds..."
        sleep 1
        secs=$((secs-1))
    done
    printf '\n\n'
}

linux_installdeps() {
    # detect host architecture
    case "$(uname -a)" in
        *x86_64*)
            amd64=1
            ;;
        *i686*)
            i686=1
            ;;
    esac

    if [ -f /etc/debian_version ]; then
        debian_installdeps
    elif [ -f /etc/fedora-release ]; then
        fedora_installdeps
    elif [ -f /etc/redhat-release ] || [ -f /etc/centos-release ]; then
        rhel_installdeps
    elif [ -f /etc/arch-release ]; then
        archlinux_installdeps
    elif [ -f /etc/solus-release ]; then
        solus_installdeps
    elif [ -f /etc/gentoo-release ]; then
        gentoo_installdeps
    elif [ -f /etc/os-release ]; then
        case "$(. /etc/os-release; echo "$ID_LIKE")" in
            *suse*)
                suse_installdeps
                ;;
        esac
    else
        error "Don't know how to install deps on your version of Linux"
    fi
}

freebsd_installdeps() {
    installing

    check sudo pkg update

    # currently the wx30 and wx31 packages produce GTK errors on CURRENT (as of 04/2019)
    check sudo pkg install -y llvm-devel cmake ccache nasm ffmpeg gettext-tools gettext png pkgconf sdl2 sfml wx31-gtk3 iconv zip ninja

    build_instructions
}

# the -j flag for make parameter, empty if 1
jobs_flag() {
    if [ $(num_cpus) -gt 1 ]; then
        echo "-j$(num_cpus)"
    fi
}

# number of CPUs to use for jobs, 1 less than total to not overload resources
num_cpus() {
    if [ -n "$_num_cpus" ]; then
        if [ $((_num_cpus - 1)) -lt 1 ]; then
            echo 1
        else
            echo $((_num_cpus - 1))
        fi
        return 0
    fi

    # determine number of CPUs and cache it
    if command -v nproc >/dev/null; then
        _num_cpus=$(nproc)
    elif [ $os = linux -o $os = windows ]; then
        _num_cpus=$(grep '^processor		*:' /proc/cpuinfo | wc -l)
    elif [ $os = mac ] || [ $os = freebsd ]; then
        _num_cpus=$(sysctl -n hw.ncpu)
    fi

    [ -z "$_num_cpus" ] && _num_cpus=1

    num_cpus
}

check_cross() {
    target=$(echo "$target" | tr 'A-Z' 'a-z')

    if [ -z "$target" ]; then
        if [ -n "$msys2" ]; then
            case "$MSYSTEM" in
                MINGW32)
                    target='mingw-w64-i686'
                    ;;
                MINGW64)
                    target='mingw-w64-x86_64'
                    ;;
                MSYS)
                    error 'host builds in MSYS mode are not supported, supply a target or start a MINGW shell'
                    ;;
                *)
                    error 'unknown value for $MSYSTEM: '"$MSYSTEM"' '
                    ;;
            esac
        else
            return
        fi
    fi

    case "$target" in
        win32|mingw*)
            if [ -z "$arch_linux" -a -z "$msys2" -a -z "$debian" -a -z "$fedora" ]; then
                error 'win32 cross compiling targets are only supported on Debian/Ubuntu, Fedora, Arch and MSYS2 at the moment'
            fi

            case "$target" in
                win32)
                    target='mingw-w64-i686'
                    ;;
                mingw-w64-i686)
                    ;;
                mingw-w64-x86_64)
                    ;;
                *)
                    error "target must be one of 'm32', 'win32', 'MinGW-w64-i686' or 'MinGW-w64-x86_64'"
                    ;;
            esac

            # get the necessary win32 headers
            check git submodule update --remote --recursive
            ;;
        m32|-m32)
            target=m32
            if [ -z "$msys2" -a -z "$fedora" -a -z "$arch_linux" -a -z "$solus" -a -z "$suse" ]; then
                error '32 bit builds are only supported on Fedora, OpenSUSE, Arch, Solus and MSYS2 at the moment'
            fi

            if [ -n "$msys2" ]; then
                target='mingw-w64-i686'
            else
                cmake_flags="$cmake_flags -DCMAKE_TOOLCHAIN_FILE=../cmake/Toolchain-cross-m32.cmake"
            fi
            ;;
        m64)
            if [ -z "$msys2" ]; then
                error '64 bit cross target only supported on MSYS2 at the moment'
            fi
            target='mingw-w64-x86_64'
            ;;
        *)
            error "unknown cross target: '$target' "
            ;;
    esac
}

debian_installdeps() {
    debian=1
    check_cross
    installing

    if [ -z "$target" ]; then
        sudo apt-get -qq -y update

        sfml_libs=$(apt-cache search libsfml | grep -E 'graphics|window|network' | sed 's/ - .*//')

        glew_lib=$(apt-cache search libglew | grep '^libglew[0-9]' | sed 's/ - .*//')

        check sudo apt-get -qy install build-essential g++ nasm cmake ccache gettext zlib1g-dev libgl1-mesa-dev libavcodec-dev libavformat-dev libswscale-dev libavutil-dev libgettextpo-dev libpng-dev libsdl2-dev libsdl2-2.0 libglu1-mesa-dev libglu1-mesa libgles2-mesa-dev libsfml-dev $sfml_libs $glew_lib libopenal-dev libwxgtk3.0-dev libwxgtk3.0 libgtk2.0-dev libgtk-3-dev ccache zip
    else
        case "$target" in
            mingw-w64-i686)
                target='i686-w64-mingw32.static'
                CMAKE="/usr/lib/mxe/usr/bin/i686-w64-mingw32.static-cmake"
                ;;
            mingw-w64-x86_64)
                target='x86-64-w64-mingw32.static'
                CMAKE="/usr/lib/mxe/usr/bin/x86_64-w64-mingw32.static-cmake"
                ;;
            *)
                error "unknown cross target (you shouldn't see this)"
                ;;
        esac

        # if on the travis ubuntu trusty, add xenial sources for newer gnutls
        # otherwise the mxe pkg server does not work
        if [ -n "$TRAVIS" ]; then
            if grep -q trusty /etc/apt/sources.list 2>/dev/null; then
                sudo sh -c "sed 's/trusty/xenial/g' /etc/apt/sources.list > /etc/apt/sources.list.d/xenial.list"
            fi
        fi

        sudo apt-get -qq -y update

        curl_gnutls_lib=$(apt-cache search libcurl | grep -E '^libcurl[0-9]+-gnutls - ' | sed 's/ - .*//' | sort | tail -1)

        sudo apt-get -qy install apt apt-transport-https ca-certificates $curl_gnutls_lib curl

        # this is necessary to upgrade libcurl from trusty to xenial on travis
        sudo apt-get -qy -f install

        debian_rel=trusty

        apt_ssl_exceptions=/etc/apt/apt.conf.d/80ssl-exceptions

        if ! grep -Eq '(pkg|mirror)\.mxe\.cc' $apt_ssl_exceptions 2>/dev/null; then
            sudo sh -c "cat >> $apt_ssl_exceptions" <<EOF
Acquire::https::pkg.mxe.cc::Verify-Peer "false";
Acquire::https::pkg.mxe.cc::Verify-Host "false";
Acquire::https::mirror.mxe.cc::Verify-Peer "false";
Acquire::https::mirror.mxe.cc::Verify-Host "false";
EOF
        fi

        mxe_apt_sources=/etc/apt/sources.list.d/mxeapt.list

        sudo apt-get -qq -y update

        if [ -z "$(apt-cache search '^mxe-source$')" ]; then
            if [ ! -f "$mxe_apt_sources" ]; then
                echo "deb https://pkg.mxe.cc/repos/apt $debian_rel main" | sudo -- sh -c "cat > $mxe_apt_sources"
                sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys C6BF758A33A3A276 || :
            else
                error "$mxe_apt_sources exists but mxe packages are not found in apt, either delete it or fix it"
            fi
        fi

        set --
        for dep in gcc zlib ffmpeg gettext sdl2 sfml openal wxwidgets; do
            set -- "$@" "mxe-${target}-$dep"
        done
        check sudo apt-get --allow-unauthenticated -qq -y update
        # native wx-common needed for wxrc executable
        check sudo apt-get --allow-unauthenticated -qy install build-essential cmake ccache wx-common "$@"
    fi

    build_instructions
}

fedora_installdeps() {
    fedora=1
    ffmpeg=ffmpeg-devel
    no_ffmpeg=
    rpms_installed=

    check_cross
    installing

    warning=

    # using --nogpgcheck with dnf because keys can be a problem on rawhide

    fedora_release=$(rpm -E %fedora)
    tries=3
    curdir=$(pwd)

    # make sure rpmfusion is installed for ffmpeg
    while [ $tries -gt 0 ]; do
        mkdir -p "${tmp}/fusion"
        cd "${tmp}/fusion"
        if ! curl -fLO https://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-${fedora_release}.noarch.rpm; then
            fedora_release=$((fedora_release - 1))
            tries=$((tries - 1))
            continue
        fi
        if ! curl -fLO https://download1.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-release-${fedora_release}.noarch.rpm; then
            tries=0
            break
        fi
        # check if already installed
        if rpm -q rpmfusion-free-release-${fedora_release} >/dev/null 2>&1 && rpm -q rpmfusion-nonfree-release-${fedora_release} >/dev/null 2>&1; then
            info_msg 'rpmfusion already installed, good'
            break
        fi
        # otherwise try to install
        if ! sudo rpm --nodeps -Uvh ./rpmfusion-*.rpm; then
            tries=0
            break
        fi
        break
    done
    cd "$curdir"
    if [ $tries -eq 0 ]; then
        warning 'installing rpmfusion repos failed, continuing without ffmpeg'
        no_ffmpeg=1
        cmake_flags="$cmake_flags -DENABLE_FFMPEG=NO"
    fi

    # non-multiarch packages first
    check sudo dnf -y --nogpgcheck --best --allowerasing install gcc gcc-c++ make cmake ccache git nasm redhat-rpm-config pkgconfig ccache ninja-build

    # try to install multiarch libgcc, glibc-devel and pkgconfig if available
    if [ -n "$amd64" ]; then
        for pkg in pkgconfig libgcc glibc-devel; do
            if [ "$target" = m32 ]; then
                sudo dnf -y --nogpgcheck --best --allowerasing install "$pkg".i686
            else
                sudo dnf -y --nogpgcheck --best --allowerasing install "$pkg".x86_64
            fi
        done
    fi

    set --
    if [ -z "$target" -o "$target" = m32 ]; then
        # try to install both 64 bit and 32 bit versions on 64 bit hosts (see below)
        if [ -n "$amd64" ]; then
            # this is sometimes necessary for rawhide
            set -- --exclude='glibc32*'
        fi
        for pkg in zlib-devel mesa-libGL-devel ffmpeg-devel gettext-devel libpng-devel SDL2-devel SFML-devel openal-soft-devel wxGTK3-devel gtk3-devel; do
            case $pkg in
                *ffmpeg*)
                    [ -n "$no_ffmpeg" ] && continue
                    ;;
            esac

            if [ -n "$amd64" ]; then
                if [ "$target" = m32 ]; then
                    set -- "$@" "${pkg}.i686"
                else
                    set -- "$@" "${pkg}.x86_64"
                fi
            else
                set -- "$@" "$pkg"
            fi
        done

        # fedora has a bug where all necessary -devel packages are not pulled in for 32 bit direct -devel deps
        # this hack adds them to the list
        if [ -n "$amd64" -a "$target" = m32 ]; then
            info_msg 'Calculating dependencies, this will take a while..'
            curdeps=
            newdeps=$@
            while [ "$curdeps" != "$newdeps" ]; do
                curdeps=$newdeps
                set -- $(echo "$@" $(sudo dnf -y --nogpgcheck repoquery --deplist "$@" 2>/dev/null | sed -n 's/\.x86_64$/.i686/; s/^ *provider: *\([^ ]*-devel-.*\)$/\1/p' | sort -u) | sed 's/  */\n/g' | sort -u)
                newdeps=$@
                printf '%s' .
            done

            echo
            info_msg 'Done'

            ## install the RPMs with rpm --force get around file conflicts

            host_rpms=$(echo "$@" | sed 's/\.i686//g')

            # first update the host arch versions to reduce chances of conflicts
            check sudo dnf -y --nogpgcheck --allowerasing --best install $host_rpms

            oldcwd=$PWD
            mkdir "$tmp/rpms"
            cd "$tmp/rpms"

            check sudo dnf -y --nogpgcheck --allowerasing --best download "$@"

            # first try installing with dnf to pull in deps
            check sudo dnf -y --nogpgcheck --allowerasing --best --skip-broken install *.rpm

            # follow up with rpm --force to ignore conflicts
            check sudo rpm -Uvh --force *.rpm

            rm -f *.rpm

            # reinstall the host rpms to make sure any overwritten files are the host version
            check sudo dnf -y --nogpgcheck --allowerasing --best download $host_rpms

            check sudo dnf -y --nogpgcheck --allowerasing --best --skip-broken install *.rpm

            check sudo rpm -Uvh --force *.rpm

            cd "$oldcwd"
            rm -rf "$tmp/rpms"

            ffmpeg=ffmpeg-devel.i686

            rpms_installed=1
        fi
    else # mingw build
        set -- "$@" pkgconfig
        case "$target" in
            mingw-w64-i686)
                target=mingw32
                cmake_flags="$cmake_flags -DCMAKE_TOOLCHAIN_FILE=../cmake/Toolchain-cross-MinGW-w64-i686.cmake -DENABLE_LINK=NO"
                ;;
            mingw-w64-x86_64)
                target=mingw64
                cmake_flags="$cmake_flags -DCMAKE_TOOLCHAIN_FILE=../cmake/Toolchain-cross-MinGW-w64-x86_64.cmake -DENABLE_LINK=NO"
                ;;
            *)
                error 'unknown cross target (this should not happen)'
                ;;
        esac
        # install static deps
        for pkg in zlib gettext libpng SDL2 wxWidgets; do
            set -- "$@" "${target}-${pkg}-static"
        done
        # install deps that are not available as static
        for pkg in openal-soft; do
            set -- "$@" "${target}-${pkg}"
        done

        warning='SFML is required for LINK support, Fedora does not currently have a MinGW SFML package, if you want LINK support you will need to install it manually'
    fi

    [ -z "$rpms_installed" ] && check sudo dnf -y --nogpgcheck --best --allowerasing install "$@"

    if ! rpm -q $ffmpeg >/dev/null 2>&1; then
        warning 'ffmpeg failed to install (probably due to conflicts)'
        cmake_flags="$cmake_flags -DENABLE_FFMPEG=NO"
    fi

    [ -n "$warning" ] && warning "$warning"

    build_instructions
}

rhel_installdeps() {
    rhel=1
    ffmpeg=ffmpeg-devel
    no_ffmpeg=
    rpms_installed=

    check_cross
    installing

    warning=

    rhel_release=$(rpm -E %rhel)
    tries=3
    curdir=$(pwd)

    # this source is necessary for mingw packages on rhel, and may be for other things in the future
    check sudo yum -y install epel-release

    # make sure rpmfusion is installed for ffmpeg
    while [ $tries -gt 0 ]; do
        mkdir -p "${tmp}/fusion"
        cd "${tmp}/fusion"
        if ! curl -fLO https://download1.rpmfusion.org/free/el/rpmfusion-free-release-${rhel_release}.noarch.rpm; then
            rhel_release=$((rhel_release - 1))
            tries=$((tries - 1))
            continue
        fi
        if ! curl -fLO https://download1.rpmfusion.org/nonfree/el/rpmfusion-nonfree-release-${rhel_release}.noarch.rpm; then
            tries=0
            break
        fi
        # check if already installed
        if rpm -q rpmfusion-free-release-${rhel_release} >/dev/null 2>&1 && rpm -q rpmfusion-nonfree-release-${rhel_release} >/dev/null 2>&1; then
            info_msg 'rpmfusion already installed, good'
            break
        fi
        # otherwise try to install
        if ! sudo rpm --nodeps -Uvh ./rpmfusion-*.rpm; then
            tries=0
            break
        fi
        break
    done
    cd "$curdir"
    if [ $tries -eq 0 ]; then
        warning 'installing rpmfusion repos failed, continuing without ffmpeg'
        no_ffmpeg=1
        cmake_flags="$cmake_flags -DENABLE_FFMPEG=NO"
    fi

    # non-multiarch packages first
    CMAKE=cmake3
    check sudo yum -y install gcc gcc-c++ make cmake3 ccache git nasm redhat-rpm-config pkgconfig ccache ninja-build

    # try to install multiarch libgcc, glibc-devel and pkgconfig if available
    if [ -n "$amd64" ]; then
        for pkg in pkgconfig libgcc glibc-devel; do
            if [ "$target" = m32 ]; then
                sudo yum -y install "$pkg".i686
            else
                sudo yum -y install "$pkg".x86_64
            fi
        done
    fi

    set --
    if [ -z "$target" -o "$target" = m32 ]; then
        # try to install both 64 bit and 32 bit versions on 64 bit hosts (see below)
        if [ -n "$amd64" ]; then
            # this is sometimes necessary for rawhide
            set -- --exclude='glibc32*'
        fi

        warning='RHEL does not currently have SFML packages, LINK support will be disabled'
        cmake_flags="$cmake_flags -DENABLE_LINK=NO"

        for pkg in zlib-devel mesa-libGL-devel ffmpeg-devel gettext-devel libpng-devel SDL2-devel openal-soft-devel wxGTK3-devel gtk3-devel; do
            case $pkg in
                *ffmpeg*)
                    [ -n "$no_ffmpeg" ] && continue
                    ;;
            esac

            if [ -n "$amd64" ]; then
                if [ "$target" = m32 ]; then
                    set -- "$@" "${pkg}.i686"
                else
                    set -- "$@" "${pkg}.x86_64"
                fi
            else
                set -- "$@" "$pkg"
            fi
        done

        # redhat has a bug where all necessary -devel packages are not pulled in for 32 bit direct -devel deps
        # this hack adds them to the list
        if [ -n "$amd64" -a "$target" = m32 ]; then
            info_msg 'Calculating dependencies, this will take a while..'
            curdeps=
            newdeps=$@
            while [ "$curdeps" != "$newdeps" ]; do
                curdeps=$newdeps
                set -- $(echo "$@" $(repoquery --deplist "$@" 2>/dev/null | sed -n 's/\.x86_64$/.i686/; s/^ *provider: *\([^ ]*-devel-.*\)$/\1/p' | sort -u) | sed 's/  */\n/g' | sort -u)
                newdeps=$@
                printf '%s' .
            done

            echo
            info_msg 'Done'

            ## install the RPMs with rpm --force get around file conflicts

            host_rpms=$(echo "$@" | sed 's/\.i686//g')

            # first update the host arch versions to reduce chances of conflicts
            check sudo yum -y install $host_rpms

            oldcwd=$PWD
            mkdir "$tmp/rpms"
            cd "$tmp/rpms"

            check sudo yum -y download "$@"

            # first try installing with yum to pull in deps
            check sudo yum -y --skip-broken install *.rpm

            # follow up with rpm --force to ignore conflicts
            check sudo rpm -Uvh --force *.rpm

            rm -f *.rpm

            # reinstall the host rpms to make sure any overwritten files are the host version
            check sudo yum -y download $host_rpms

            check sudo yum -y --skip-broken install *.rpm

            check sudo rpm -Uvh --force *.rpm

            cd "$oldcwd"
            rm -rf "$tmp/rpms"

            ffmpeg=ffmpeg-devel.i686

            rpms_installed=1
        fi
    else # mingw build
        set -- "$@" pkgconfig
        case "$target" in
            mingw-w64-i686)
                target=mingw32
                cmake_flags="$cmake_flags -DCMAKE_TOOLCHAIN_FILE=../cmake/Toolchain-cross-MinGW-w64-i686.cmake -DENABLE_LINK=NO"
                ;;
            mingw-w64-x86_64)
                target=mingw64
                cmake_flags="$cmake_flags -DCMAKE_TOOLCHAIN_FILE=../cmake/Toolchain-cross-MinGW-w64-x86_64.cmake -DENABLE_LINK=NO"
                ;;
            *)
                error 'unknown cross target (this should not happen)'
                ;;
        esac
        # install static deps
        for pkg in zlib gettext libpng SDL2 wxWidgets; do
            set -- "$@" "${target}-${pkg}-static"
        done
        # install deps that are not available as static
        for pkg in openal-soft; do
            set -- "$@" "${target}-${pkg}"
        done

        warning='SFML is required for LINK support, RHEL/EPEL does not currently have a MinGW SFML package, if you want LINK support you will need to install it manually'
    fi

    [ -z "$rpms_installed" ] && check sudo yum -y install "$@"

    if ! rpm -q $ffmpeg >/dev/null 2>&1; then
        warning 'ffmpeg failed to install (probably due to conflicts)'
        cmake_flags="$cmake_flags -DENABLE_FFMPEG=NO"
    fi

    [ -n "$warning" ] && warning "$warning"

    build_instructions
}

suse_installdeps() {
    suse=1
    check_cross
    installing

    tools="\
make cmake ccache nasm gettext-tools pkg-config ccache zip sfml2-devel\
" # ffmpeg-devel

    libs="\
gcc gcc-c++ libpng16-devel libSDL2-devel openal-soft-devel wxWidgets-3_0-devel\
" # ffmpeg-devel
    # ffmpeg requires packman repos

    if [ "$target" = m32 ]; then
        libs=$(echo "$libs" | sed -E 's/([^ ]) ([^ ])/\1-32bit \2/g; s/$/-32bit/;')
        cmake_flags="$cmake_flags -DENABLE_LINK=NO"
    fi

    check sudo zypper in -y $tools $libs

    build_instructions
}

archlinux_require_yaourt() {
    if ! command -v yaourt >/dev/null; then
        (
            cd "$tmp"
            git clone https://aur.archlinux.org/package-query.git
            cd package-query
            makepkg --noconfirm -si
            cd ..
            git clone https://aur.archlinux.org/yaourt.git
            cd yaourt
            makepkg --noconfirm -si
        )
        [ $? -ne 0 ] && error 'could not install yaourt'
    fi
    pacman='yaourt --aur --m-arg=--skipinteg'
}

archlinux_installdeps() {
    arch_linux=1

    pacman='sudo pacman'
    command -v pacaur >/dev/null && pacman='pacaur --noedit'
    command -v yaourt >/dev/null && pacman='yaourt --aur --m-arg=--skipinteg'

    check_cross
    installing

    # check for gcc-multilib
    gcc_pkg=gcc
    if $pacman -Q gcc-multilib >/dev/null 2>&1; then
        gcc_pkg=gcc-multilib
    fi

    # update catalogs
    check $pacman -Sy

    # common needed dev packages
    # not using the base-devel group because it can break gcc-multilib
    check $pacman --noconfirm --needed -S binutils file grep gawk gzip libtool make patch sed util-linux nasm cmake ccache pkg-config git ccache zip

    gtk=gtk3

    $pacman -Q gtk3-classic >/dev/null 2>&1 && gtk=gtk3-classic

    libs="zlib mesa gettext libpng sdl2 openal wxgtk3 $gtk sfml ffmpeg"

    if [ -z "$target" -o "$target" = m32 ]; then
        if [ -z "$target" -o -z "$amd64" ]; then
            # native build
            check $pacman --noconfirm --needed -S "$gcc_pkg" $libs
        else
            # try to build 32 bit binaries

            # lib32-sfml and lib32-ffmpeg are in AUR
            archlinux_require_yaourt

            # enable multilib repos if not enabled
            cp /etc/pacman.conf ${tmp}/pacman.conf
            cat <<'EOF' >> ${tmp}/pacman.conf
[multilib-testing]
Include = /etc/pacman.d/mirrorlist
[multilib]
Include = /etc/pacman.d/mirrorlist
EOF
            pacman="$pacman --config ${tmp}/pacman.conf"

            # pull in multilib repo info
            $pacman -Sy

            yes | check $pacman --needed -S gcc-multilib

            libs32=
            for lib in $libs; do
                libs32="$libs32 lib32-$lib"
            done

            check $pacman --noconfirm --needed -S $libs32
        fi
    else
        # windows cross build
        case "$target" in
            *i686*)
                cmake_flags="$cmake_flags -DCMAKE_TOOLCHAIN_FILE=../cmake/Toolchain-cross-MinGW-w64-i686.cmake -DENABLE_LINK=NO"
                ;;
            *x86_64*)
                cmake_flags="$cmake_flags -DCMAKE_TOOLCHAIN_FILE=../cmake/Toolchain-cross-MinGW-w64-x86_64.cmake -DENABLE_LINK=NO"
                ;;
            *)
                # this will never be reached, it's checked in check_cross()
                error 'unknown cross target (you should not see this)'
                ;;
        esac

        check $pacman --noconfirm --needed -S "$gcc_pkg"

        archlinux_require_yaourt

        pkg_prefix='mingw-w64-'

        # cross toolchain (without headers and crt, we'll use -git versions)
        set --
        for p in binutils gcc winpthreads; do
            set -- "$@" "${pkg_prefix}${p}"
        done
        check $pacman --noconfirm --needed -S "$@"

        # build library deps from AUR

        info_msg 'We will now build dependencies from AUR, this will take quite a while and has a high probability of failure. In fact, it is definitely broken at the time of this writing. Press CTRL-C now to abort'

        countdown 16

        # pass appropriate make -jX flag through makepkg
        export MAKEPKG_CONF=${MAKEPKG_CONF:-/etc/makepkg.conf}

        grep -Ev '^[ 	]*MAKEFLAGS=' "$MAKEPKG_CONF" > "$tmp/makepkg.conf"

        export MAKEFLAGS=$(jobs_flag)
        echo "MAKEFLAGS=\"$MAKEFLAGS\"" >> "$tmp/makepkg.conf"

        export MAKEPKG_CONF="$tmp/makepkg.conf"

        # now do the AUR builds

        # first we need -headers-git and -crt-git (unless the non-git packages are installed)
        for p in "${pkg_prefix}headers" "${pkg_prefix}crt"; do
          if ! $pacman -Q "$p" >/dev/null 2>&1; then
              check $pacman --noconfirm --needed -S "${p}-git"
          else
              warning "${pkg_prefix}headers-git and ${pkg_prefix}crt-git are recommended over the regular versions, if you have build failures try to install them"
          fi
        done

        # and the actual deps
        for p in zlib gettext libpng pkg-config sdl2 openal wxmsw; do
            pkg="${pkg_prefix}${p}"
            # check if already installed
            if ! $pacman -Q "$pkg" >/dev/null 2>&1; then
                set -- "$@" "${pkg_prefix}${p}"
            fi
        done
        [ $# -gt 0 ] && check $pacman --noconfirm --needed -S "$@"

        warning 'SFML is required for LINK support, the SFML package in AUR is currently broken, if you want LINK support you will need to install it manually'
    fi

    build_instructions
}

solus_installdeps() {
    solus=1

    check_cross
    installing

    check sudo eopkg -y update-repo
    check sudo eopkg -y install -c system.devel
    check sudo eopkg -y install git ccache

    set -- sdl2-devel openal-soft-devel wxwidgets-devel libgtk-2-devel libgtk-3-devel
    if [ -n "$amd64" -a "$target" = m32 ]; then
        info_msg 'Calculating dependencies, this will take a while..'

        # first expand all dep lists recursively for -devel packages
        curdeps=
        newdeps=$@
        while [ "$curdeps" != "$newdeps" ]; do
            curdeps=$newdeps
            set -- $(echo "$@" $(sudo eopkg info "$@" 2>/dev/null | sed -n 's/^Dependencies  *:  *\(.*\)/\1/p' | sort -u) | sed 's/  */\n/g' | grep -- '-devel$' | sort -u)
            newdeps=$@
        done

        # transform to 32bit package names
        first=1
        for pkg in "$@"; do
            if [ "$first" = 1 ]; then
                set --
                first=0
            fi
            case "$pkg" in
                *-32bit-devel)
                    # already 32 bit
                    ;;
                *-devel)
                    set -- "$@" "${pkg%-devel}-32bit-devel"
                    ;;
                *)
                    set -- "$@" "$pkg"
                    ;;
            esac
        done

        # prune the ones that don't exist
        first=1
        for pkg in "$@"; do
            if [ "$first" = 1 ]; then
                set --
                first=0
            fi
            if ! sudo eopkg info "$pkg" | grep -q 'not found in binary repositories'; then
                set -- "$@" "$pkg"
            fi
        done
    else
        # no 32bit versions of these
        set -- "$@" SFML-devel ffmpeg-devel
    fi

    check sudo eopkg -y install "$@"

    if [ -n "$amd64" -a "$target" = m32 ]; then
        warning 'SFML is required for LINK support, there is no 32 bit SFML package in Solus currently, if you want LINK support you will need to install it manually'
        warning 'ffmpeg is required for game recording, there is no 32 bit ffmpeg package in Solus currently, you may wish to install it manually'

        cmake_flags="$cmake_flags -DENABLE_LINK=NO -DENABLE_FFMPEG=NO"
    fi

    build_instructions
}

gentoo_installdeps() {
    installing

    check sudo emerge-webrsync
    check sudo emerge -vuDUa gcc make cmake ccache binutils libsdl2 libsfml wxGTK zlib dev-util/pkgconfig nasm

    build_instructions
}

windows_installdeps() {
    msys2=1

    check_cross
    installing

    # update catalogs
    check pacman -Sy

    set --
    for p in SDL2 ffmpeg openal sfml wxWidgets zlib binutils cmake crt-git extra-cmake-modules gcc gcc-libs gcc-libgfortran gdb headers-git make pkg-config tools-git windows-default-manifest libmangle-git nasm; do
        set -- "$@" "${target}-${p}"
    done

    # install
    check pacman --noconfirm --needed -S git make zip ccache "$@"

    cmake_flags="$cmake_flags -G 'MSYS Makefiles'"

    if [ "$MSYSTEM" = MSYS ]; then
        case "$target" in
            *i686)
                pre_build=\
"MSYSTEM=MINGW32 bash -l
cd $(pwd)"
                ;;
            *x86_64)
                pre_build=\
"MSYSTEM=MINGW64 bash -l
cd $(pwd)"
                ;;
        esac
        post_build=exit
    fi

    build_instructions
}

mac_installdeps() {
    if ! xcode-select -p >/dev/null 2>&1 && \
       ! pkgutil --pkg-info=com.apple.pkg.CLTools_Executables >/dev/null 2>&1 && \
       ! pkgutil --pkg-info=com.apple.pkg.DeveloperToolsCLI >/dev/null 2>&1; then

        error 'Please install XCode and the XCode Command Line Tools, then run this script again. On newer systems this can be done with: xcode-select --install   '
    fi

    if command -v brew >/dev/null; then
        brew_installdeps
    elif command -v port >/dev/null; then
        macports_installdeps
    elif command -v fink >/dev/null; then
        fink_installdeps
    else
        error 'You have no package manager, please install homebrew, macports or fink'
    fi
}

brew_installdeps() {
    check_cross
    installing

    check brew -v update

    set --
    for f in nasm cmake ccache ffmpeg gettext libpng pkg-config sdl2 sfml wxmac ccache; do
        if brew info "$f" | grep -Eq '^Not installed$'; then
            set -- "$@" "$f"
        fi
    done
    [ $# -gt 0 ] && check brew -v install "$@"

    brew -v cleanup

    build_instructions
}

macports_installdeps() {
    check_cross
    installing

    check sudo port -v selfupdate
    check sudo port -v install cmake ccache nasm ffmpeg gettext libpng pkgconfig libsdl2 sfml wxWidgets-3.0 libiconv
    check sudo port select wxWidgets wxWidgets-3.0

    build_instructions
}

fink_installdeps() {
    check_cross
    installing

    check sudo fink -vy selfupdate
    check sudo fink -vy install cmake ccache nasm ffmpeg libgettext8-dev gettext-tools libpng16 pkgconfig sdl2 wxwidgets300-osxcocoa libiconv-dev sfml24-dev ccache

    build_instructions
}

build_instructions() {
    cat <<EOF

Done! To build do:

$pre_build
mkdir -p build && cd build
$CMAKE .. $cmake_flags
make $(jobs_flag)
$post_build

EOF
}

main "$@"