#!/bin/bash

#
# This script creates a tarball with everything needed to build
# an application image on another system. It is useful to allow
# the parts that require Linux to be built separately from the
# parts that can be built on any system.
# It is intended to be called from Buildroot's Makefiles so that
# the environment is set up properly.
#
# Inputs:
#   $1 = the archive name (if not passed, we'll make up a name)
#   BASE_DIR = the build directory (aka, the future $NERVES_SYSTEM directory)
#   PWD = the buildroot directory
#
# Outputs:
#   Archive tarball
#

set -e

# The first parameter is the name of the archive to create. If it's not set
# we'll set it below.
ARCHIVE_NAME=$1
BR2_EXTERNAL_NERVES_PATH=$PWD/..

if [ -z $ARCHIVE_NAME ]; then
    echo "ERROR: Please specify an archive name"
    exit 1
fi

# Check the working directory
if [ ! -f $PWD/package/pkg-generic.mk ]; then
    echo "ERROR: mksystem.sh must be run from the buildroot directory"
    exit 1
fi

# Check BASE_DIR
if [ -z $BASE_DIR ]; then
    echo "ERROR: BASE_DIR undefined? Script should be called from Buildroot."
    exit 1
fi

NERVES_DEFCONFIG=$(grep BR2_DEFCONFIG= $BASE_DIR/.config | sed -e 's/BR2_DEFCONFIG=".*\/\(.*\)"/\1/')

WORK_DIR=$BASE_DIR/tmp-system
rm -fr $WORK_DIR
mkdir -p $WORK_DIR/$ARCHIVE_NAME

# Save the version to the archive in case we need it for debug
VERSION=$(cat ../VERSION)
echo $VERSION >$WORK_DIR/$ARCHIVE_NAME/nerves-system.tag

# Add some help text for the curious
cat << EOT > $WORK_DIR/$ARCHIVE_NAME/README.md
# Nerves system image

This is an automatically generated archive created by \`nerves_system_br\`. It is
useful for building embedded Elixir projects without worrying too much
about the cross-compiler and Linux parts. See http://nerves-project.org
for more information.

## Build information

Configuration: $NERVES_DEFCONFIG
nerves_system_br: $VERSION
EOT

# Copy common nerves shell scripts over
cp $BR2_EXTERNAL_NERVES_PATH/nerves-env.sh $WORK_DIR/$ARCHIVE_NAME
cp $BR2_EXTERNAL_NERVES_PATH/nerves.mk $WORK_DIR/$ARCHIVE_NAME
cp -R $BR2_EXTERNAL_NERVES_PATH/scripts $WORK_DIR/$ARCHIVE_NAME

# Copy the built configuration over
cp $BASE_DIR/.config $WORK_DIR/$ARCHIVE_NAME

# Copy the staging and images directories over
mkdir -p $WORK_DIR/$ARCHIVE_NAME/images $WORK_DIR/$ARCHIVE_NAME/staging
cp -R $BASE_DIR/images/* $WORK_DIR/$ARCHIVE_NAME/images
cp -R $BASE_DIR/staging/* $WORK_DIR/$ARCHIVE_NAME/staging

# Clean up extra files that were copied over and aren't needed
rm -f $WORK_DIR/$ARCHIVE_NAME/images/*.fw
rm -f $WORK_DIR/$ARCHIVE_NAME/images/$ARCHIVE_NAME.img

tar c -z -f $BASE_DIR/$ARCHIVE_NAME.tar.gz -C $WORK_DIR $ARCHIVE_NAME

rm -fr $WORK_DIR