#!/bin/bash

set -e

unmount_virtual()
{
    umount "$1/proc" || true
    umount "$1/sys" || true
    umount "$1/tree/proc" || true
    umount "$1/tree/sys" || true
}

pass_snapshot()
{
    echo -n "$snapshotdir/$1-snapshot.tar.gz"
}

has_pass()
{
    if [ -e $(pass_snapshot "$1") ]
    then
        return 0
    else
        return 1
    fi
}

update_morph()
{
    local dir="$1"
    cp baserock-bootstrap "$dir/." # update bootstrap script
    rm -rf "$dir/tree/baserock/gits/morph"
    mkdir -p "$dir/tree/baserock/gits/morph"

    # Copy everything except the target directory into the target directory.
    # The point is to be able to keep the working area for a bootstrap inside
    # the morph source directory. This is useful for Jenkins jobs.
    local base=$(basename $(basename "$dir"))
    find . -mindepth 1 -maxdepth 1 ! -name "$base" ! -name '*.tar.gz' \
        -exec cp -a '{}' "$dir/tree/baserock/gits/morph" ';'
}

run_pass()
{
    local dir="$1"
    local passname="$2"
    local tarball=$(pass_snapshot "$passname")

    if "$snapshot" && has_pass "$passname"
    then
        tar -C "$dir" -xhf "$tarball"
        update_morph "$dir"
    else
        update_morph "$dir"
        "./do-squeeze-chroot" bash -x baserock-bootstrap "$passname" || exit 1
        if "$snapshot"
        then
            tar -C "$dir" -caf "$tarball" .
        fi
    fi
}

export LC_ALL=C

if [ "x$1" = x ]
then
    echo "Usage: $0 chroot-dir" 1>&2
    exit 1
fi

mkdir -p "$1"
dir="$1/squeeze-chroot"
: ${snapshot:=true}
snapshotdir="$1"

cat >"./do-squeeze-chroot" <<EOF
#!/bin/sh

# clear the temporary directory used outside the chroot
export TMPDIR=

if mount -t proc proc "$dir/proc"; then
  trap "umount \"$dir/proc\"" INT TERM EXIT
  if mount -t sysfs sysfs "$dir/sys"; then
    trap "umount \"$dir/proc\" \"$dir/sys\"" INT TERM EXIT
    if [ "x$CCACHE_HOST_DIR" != "x" ]; then
      if mount --bind "$CCACHE_HOST_DIR" "$dir/var/tmp/ccache"; then
        trap "umount \"$dir/proc\" \"$dir/sys\" \"$dir/var/tmp/ccache\"" \
          INT TERM EXIT
        chroot "$dir" "\$@"
      fi
    else
      chroot "$dir" "\$@"
    fi
  fi
fi
EOF
chmod +x "./do-squeeze-chroot"

if ([ "x$DEBIAN_MIRROR" = x ] && echo DEBIAN_MIRROR is unspecified >&2) ||
    ([ "x$GIT_TARBALLS" = x ] && echo GIT_TARBALLS is unspecified >&2)
then
    echo You have to set DEBIAN_MIRROR and other environment variables 1>&2
    exit 1
fi

if ! which dpkg 2> /dev/null; then
    echo "Warning: dpkg not found -- should debootstrap fail to autodetect "
    echo "your architecture, set ARCH in the environment (probably to amd64)"
fi

# prepare the ccache directory in the chroot, if necessary
if [ "x$CCACHE_HOST_DIR" = "x" ]; then
    # print a warning if the CCACHE_HOST_DIR is not set
    echo "CCACHE_HOST_DIR is unspecified, but that's ok" >&2
fi

unmount_virtual "$dir"
rm -rf "$dir"
mkdir "$dir"

chrootsnapshot="$snapshotdir/squeeze.tar.gz"
if ! "$snapshot" || ! has_pass pass1a; then
    if "$snapshot" && [ -e "$chrootsnapshot" ]
    then
        tar -C "$dir" -xhf "$chrootsnapshot"
    else
        EXTRAPACKAGES="build-essential,gawk,bison,flex,python,autoconf"
        EXTRAPACKAGES="$EXTRAPACKAGES,autopoint,automake,gettext,libtool"
        EXTRAPACKAGES="$EXTRAPACKAGES,help2man,texinfo,sudo,ccache,gperf"
        EXTRAPACKAGES="$EXTRAPACKAGES,python-pip,python-simplejson,python-yaml"

        EXTRAARGS=
        if [ -n $ARCH]; then
            EXTRAARGS=$ARCH
        fi

        debootstrap $EXTRAARGS --include="$EXTRAPACKAGES" squeeze \
                    "$dir" "$DEBIAN_MIRROR"

        mkdir -p "$dir/etc"
        hostname > "$dir/etc/hostname"
        cat <<EOF > "$dir/etc/hosts"
127.0.0.1   localhost
127.0.1.1   `hostname`
EOF
   
        # create the directory for cached ccache object files
        mkdir -p "$dir/var/tmp/ccache"
    
        # manually build and install cliapp
        "./do-squeeze-chroot" mkdir -p /src
        "./do-squeeze-chroot" \
            git clone git://roadtrain.codethink.co.uk/delta/cliapp /src/cliapp
        "./do-squeeze-chroot" \
            sh -c 'cd /src/cliapp && "$@"' -- python setup.py build
        "./do-squeeze-chroot" \
            sh -c 'cd /src/cliapp && "$@"' -- python setup.py install
        
        "./do-squeeze-chroot" pip install ordereddict
    
        if "$snapshot"
        then
            tar -caf "$chrootsnapshot" -C "$dir" .
        fi
    fi
fi

# Unpack existing snapshot, or run pass1 of bootstrap and then make snapshot.

if ! "$snapshot" || ! has_pass pass1b
then
    run_pass "$dir" pass1a
fi

if ! "$snapshot" || ! has_pass pass2a
then
    run_pass "$dir" pass1b
fi

if ! "$snapshot" || ! has_pass pass2b
then
    run_pass "$dir" pass2a
fi

if ! "$snapshot" || ! has_pass pass3a
then
    run_pass "$dir" pass2b
fi

if ! "$snapshot" || ! has_pass pass3b
then
    run_pass "$dir" pass3a
fi

snapshot=false run_pass "$dir" pass3b

echo "Passes 1, 2, and 3 of bootstrap done (possibly cached)."