#!/bin/bash
#
# .---.                  .              .
# |                      |              |
# |--- .--. .-.  .-.  .-.|  .-. .--.--. |.-.  .-. .--.  .-.
# |    |   (.-' (.-' (   | (   )|  |  | |   )(   )|  | (.-'
# '    '     --'  --'  -' -  -' '  '   -' -'   -' '   -  --'
#
#                    Freedom in the Cloud
#
# Go functions
#
# License
# =======
#
# Copyright (C) 2014-2016 Bob Mottram <bob@freedombone.net>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

# For reasons unknown we initially have to upgrade to an intermediate version
# before getting to the version we want
GO_INTERMEDIATE_VERSION=1.4.2

GO_VERSION=1.9.4

GO_REPO="https://go.googlesource.com/go"
GO_PACKAGE_MANAGER_REPO="https://github.com/gpmgo/gopm"
GVM_HOME=/home/git/gvm
GVM_REPO="https://github.com/moovweb/gvm"
GVM_COMMIT='25ea8ae158e2861c92e2b22c458e60840157832f'

function select_go_version {
    if [ ! -d $GVM_HOME/bin ]; then
        echo $'GVM was not installed'
        exit 629532
    fi
    export GVM_ROOT=$GVM_HOME
    if ! grep -q "GVM_ROOT=" ~/.bashrc; then
        echo "export GVM_ROOT=$GVM_ROOT" >> ~/.bashrc
    else
        sed -i "s|export GVM_ROOT=.*|export GVM_ROOT=$GVM_ROOT|g" ~/.bashrc
    fi
    cd $GVM_ROOT/bin
    [[ -s "$GVM_ROOT/scripts/gvm" ]] && source "$GVM_ROOT/scripts/gvm"
    gvm use go${GO_VERSION} --default

    if [ ${#GOPATH} -lt 2 ]; then
        echo $'GOPATH was not set'
        exit 629825
    fi

    systemctl set-environment GOPATH=$GOPATH
}

function mesh_upgrade_golang_from_source {
    chroot "$rootdir" adduser --disabled-login --gecos 'go' ipfs

    git clone $GO_REPO $rootdir/home/go/go${GO_VERSION}
    cd $rootdir/home/go/go${GO_VERSION}
    git checkout go${GO_VERSION} -b go${GO_VERSION}

    git clone $GO_REPO $rootdir/home/go/go${GO_INTERMEDIATE_VERSION}
    cd $rootdir/home/go/go${GO_INTERMEDIATE_VERSION}
    git checkout go${GO_INTERMEDIATE_VERSION} -b go${GO_INTERMEDIATE_VERSION}

    cat <<EOF > ${rootdir}/root/upgrade_golang.sh
#!/bin/bash

apt-get -yq install build-essential libc6-dev
apt-get -yq install gcc-multilib g++-multilib make
apt-get -yq install curl git mercurial binutils bison

if [ -d /home/go/Maildir ]; then
    rm -rf /home/go/Maildir
fi

export GOROOT=/home/go
export GOPATH=/home/go/go${GO_INTERMEDIATE_VERSION}

cd /home/go/go${GO_INTERMEDIATE_VERSION}/src
./all.bash
if [ ! -f /home/go/go${GO_INTERMEDIATE_VERSION}/bin/go ]; then
    exit 63722
fi

export GOROOT_BOOTSTRAP=/home/go/go${GO_INTERMEDIATE_VERSION}

cd /home/go/go${GO_VERSION}/src
./all.bash
if [ ! -f /home/go/go${GO_VERSION}/bin/go ]; then
    exit 528352
fi

chown -R go:go /home/go

export GOPATH=/home/go/go${GO_VERSION}
export GOROOT=/home/go
echo "export GOPATH=/home/go/go${GO_VERSION}" >> /home/go/.bashrc
echo "export GOPATH=/home/go/go${GO_VERSION}" >> ~/.bashrc
echo "export GOROOT=/home/go" >> /home/go/.bashrc
echo "export GOROOT=/home/go" >> ~/.bashrc
echo "systemctl set-environment GOPATH=\$GOPATH" >> ~/.bashrc
echo "systemctl set-environment GOROOT=\$GOROOT" >> ~/.bashrc
echo "systemctl set-environment GOPATH=\$GOPATH" >> /home/go/.bashrc
echo "systemctl set-environment GOROOT=\$GOROOT" >> /home/go/.bashrc
systemctl set-environment GOPATH=\$GOPATH
systemctl set-environment GOROOT=\$GOROOT

exit 0
EOF
    chroot ${rootdir} chmod +x /root/upgrade_golang.sh
    chroot ${rootdir} /root/upgrade_golang.sh
    if [ ! -f ${rootdir}/home/go/go${GO_VERSION}/bin/go ]; then
        echo $'Failed to upgrade golang'
        cat ${rootdir}/root/upgrade_golang.sh
        rm -f ${rootdir}/root/upgrade_golang.sh
        exit 836535
    fi
    rm -f ${rootdir}/root/upgrade_golang.sh
}

function mesh_upgrade_golang {
    prefix=
    if [ $rootdir ]; then
        prefix="chroot $rootdir"
    fi
    $prefix adduser --disabled-login --gecos 'go' go

    GOARCH=
    if [[ $ARCHITECTURE == *"386" || $ARCHITECTURE == *"686" ]]; then
        GOARCH=386
    fi
    if [[ $ARCHITECTURE == *"amd64" || $ARCHITECTURE == "x86_64" ]]; then
        GOARCH=amd64
    fi
    if [[ $ARCHITECTURE == *"arm"* ]]; then
        GOARCH=armv6l
    fi
    if [[ $ARCHITECTURE == *"aarch"* || $ARCHITECTURE == *"arm64"* ]]; then
        GOARCH=arm64
    fi
    if [ ! $GOARCH ]; then
        echo $'No architecture specified'
        ARCHITECTURE=$(uname -m)
        if [[ $ARCHITECTURE == "arm"* ]]; then
            GOARCH=armv6l
            echo $"Using $GOARCH"
        fi
        if [[ $ARCHITECTURE == *"aarch"* || $ARCHITECTURE == *"arm64"* ]]; then
            GOARCH=arm64
            echo $"Using $GOARCH"
        fi
        if [[ $ARCHITECTURE == "amd"* || $ARCHITECTURE == "x86_64" ]]; then
            GOARCH=amd64
            echo $"Using $GOARCH"
        fi
        if [[ $ARCHITECTURE == *"386" || $ARCHITECTURE == *"686" ]]; then
            GOARCH=386
            echo $"Using $GOARCH"
        fi
    fi
    if [ ! $GOARCH ]; then
        echo $'System architecture was not detected when installing Go'
        echo "uname reports: $(uname -m)"
        exit 63945284
    fi
    GO_SOURCE=https://storage.googleapis.com/golang/go${GO_VERSION}.linux-${GOARCH}.tar.gz

    if [ ! -d ${rootdir}${INSTALL_DIR} ]; then
        chroot "$rootdir" mkdir -p ${INSTALL_DIR}
    fi
    cd ${rootdir}${INSTALL_DIR}
    if [ ! -f ${rootdir}${INSTALL_DIR}/go${GO_VERSION}.linux-${GOARCH}.tar.gz ]; then
        wget ${GO_SOURCE}
    fi
    if [ ! -f ${rootdir}${INSTALL_DIR}/go${GO_VERSION}.linux-${GOARCH}.tar.gz ]; then
        exit 26524
    fi
    $prefix tar -C /home/go -xzf ${INSTALL_DIR}/go${GO_VERSION}.linux-${GOARCH}.tar.gz
    if [ ! -d ${rootdir}/home/go/go/bin ]; then
        echo 'Go binary not installed'
        exit 763562
    fi
    mv ${rootdir}/home/go/go ${rootdir}/home/go/go${GO_VERSION}
    echo "export GOROOT=/home/go" >> ${rootdir}/root/.bashrc
    echo "export GOROOT=/home/go" >> ${rootdir}/etc/skel/.bashrc
    echo "export GOROOT=/home/go" >> ${rootdir}/home/$MY_USERNAME/.bashrc
    echo "export GOROOT=/home/go" >> ${rootdir}/home/go/.bashrc

    echo "export GOPATH=\$GOROOT/go${GO_VERSION}/bin" >> ${rootdir}/root/.bashrc
    echo "export GOPATH=\$GOROOT/go${GO_VERSION}/bin" >> ${rootdir}/etc/skel/.bashrc
    echo "export GOPATH=\$GOROOT/go${GO_VERSION}/bin" >> ${rootdir}/home/$MY_USERNAME/.bashrc
    echo "export GOPATH=\$GOROOT/go${GO_VERSION}/bin" >> ${rootdir}/home/go/.bashrc

    echo 'export PATH=$PATH:$GOPATH' >> ${rootdir}/root/.bashrc
    echo 'export PATH=$PATH:$GOPATH' >> ${rootdir}/etc/skel/.bashrc
    echo 'export PATH=$PATH:$GOPATH' >> ${rootdir}/home/$MY_USERNAME/.bashrc
    echo 'export PATH=$PATH:$GOPATH' >> ${rootdir}/home/go/.bashrc
    $prefix chown -R $MY_USERNAME:$MY_USERNAME /home/$MY_USERNAME
    $prefix chown -R go:go /home/go
    cp ${rootdir}/home/go/go${GO_VERSION}/bin/* ${rootdir}/usr/bin
}

function upgrade_golang {
    if grep -Fxq "upgrade_golang:$GO_VERSION" $COMPLETION_FILE; then
        return
    fi

    rootdir=
    mesh_upgrade_golang

    # alter the go version used by the gogs daemon
    if [ -f /etc/systemd/system/gogs.service ]; then
        sed -i "s|Environment=.*|Environment=\"USER=gogs\" \"HOME=/home/gogs\" \"GOPATH=/home/go/go${GO_VERSION}\"|g" /etc/systemd/system/gogs.service
        systemctl daemon-reload
        systemctl restart gogs
    fi

    set_completion_param "$FUNCNAME" "$GO_VERSION"
}

# NOTE: deliberately there is no "exit 0"
