#! /usr/bin/env bash
#
# Zeekctl test setup script.  This script should be sourced in each test
# script.  This script requires that some env. vars. are correctly defined
# in btest.cfg.
#
# This script installs Zeek to a directory that is unique to each test,
# and provides a few functions and environment variables that can be used
# directly by test scripts.
#
# This script provides these functions that can be used directly in
# test scripts:
#   installfile       Install a file into the test-specific Zeek install dir.
#   replaceprefix     Replace text "@PREFIX@" in a specified file with the
#                     test-specific directory path of the Zeek install.
#
# This script automatically exports some environment variables that are needed
# by test scripts:
#   ZEEKCTL_INSTALL_PREFIX - Test-specific directory path of the Zeek install.
#   ZEEKCTL_INSTALL_PYTHON_DIR - Absolute path of the Python module directory
#       for the above install.
#   PATH - Enable test scripts to run the correct copy of "zeekctl" without
#          specifying a path.
#
# A user can modify the behavior of this script by setting any of the
# following env. variables:
#   ZEEKCTL_TEST_DEBUG - If this is set (value doesn't matter), then the
#                       test-specific Zeek install directory will not be removed
#                       when a test terminates (this is useful for debugging).



# installfile <rel.path> [<destdir>] [--new]
#
# Install a file to the test-specific Zeek installation directory.
#
# The <rel.path> is the pathname (relative to the "Cfg" directory, which is
# located in the btest base directory) of the file to be installed,
# and it must follow a naming convention: <dir>/<dest.name>__<text>
# where <dir> is the directory, <dest.name> is the destination filename, and
# <text> is some descriptive text for the file (to allow choosing
# among different variations of the same file).
# The file will be copied to $ZEEKCTL_INSTALL_PREFIX/<dir>/<dest.name>
#
# If <destdir> is specified, then the file will be copied to
# $ZEEKCTL_INSTALL_PREFIX/<destdir>/<dest.name>
#
# The destination directory and file must already exist.
# If "--new" is given, then skip check for existence of destination file.
installfile() {
    set +x

    if [ -z "$1" ]; then
        return
    fi

    newfile="no"
    destdir=""
    origrelpath=$1
    if [ -n "$2" ]; then
        if [ "$2" = "--new" ]; then
            newfile="yes"
        else
            destdir=$2
        fi
        if [ "$3" = "--new" ]; then
            newfile="yes"
        fi
    fi

    # Make sure original file exists
    origpath=$ZEEKCTLCFG/$origrelpath
    if [ ! -f "$origpath" ]; then
        echo "Error: source file not found: $origpath" 1>&2
        exit 1
    fi

    # Remove the optional double-underscore delimiter (and following text) to
    # derive the destination filename
    relpath=$(echo $origrelpath | awk -F'__' '{print $1}')
    destfile=$(basename "$relpath")

    # Destination directory is either specified by user or is the original
    # directory path
    if [ -z "$destdir" ]; then
        destdir=$(dirname "$relpath")
    fi

    # If destination directory is not yet absolute, make it so:
    if [[ "$destdir" != /* ]]; then
        destdir="$ZEEKCTL_INSTALL_PREFIX/$destdir"
    fi

    # Make sure destination directory exists
    if [ ! -d "$destdir" ]; then
        echo "Error: destination directory not found: $destdir" 1>&2
        exit 1
    fi

    # Finally, build the destination pathname
    destpath=$destdir/$destfile

    if [ "$newfile" = "no" ]; then
        # Make sure destination file exists (usually, we're overwriting an
        # existing file, so this is a good safety check to catch typos)
        if [ ! -f "$destpath" ]; then
            echo "Error: destination file not found: $destpath (if this is a new file, use the --new option)" 1>&2
            exit 1
        fi
    fi

    cp $origpath $destpath
    set -x
}


# replaceprefix <rel.path>
#
# Replace the text "@PREFIX@" with the zeek install prefix in the specified
# file (given as a relative pathname).
replaceprefix() {
    set +x

    if [ -z "$1" ]; then
        return
    fi

    destfile=$ZEEKCTL_INSTALL_PREFIX/$1
    if [ ! -f $destfile ]; then
        echo "Error: file not found: $destfile" 1>&2
        exit 1
    fi

    # Using "cp" and "rm" here in order to preserve permissions of file
    sed "s#@PREFIX@#${ZEEKCTL_INSTALL_PREFIX}#g" $destfile > $destfile.new && cp $destfile.new $destfile && rm $destfile.new
    test $? -ne 0 && exit 1

    set -x
}

#####
# The following functions are needed by this script, but are not likely to be
# needed by any zeekctl test scripts.


# Normalize the specified pathname by resolving any ".." and symlinks in
# the path.
canonicalpath() {
    newpath=`python3 -c "from __future__ import print_function; import os,sys; print(os.path.realpath(sys.argv[1]))" "$1"`
    test $? -ne 0 && exit 1
    echo $newpath
}

# Set the correct install prefix directory in all files where it's needed
# (this is done immediately after untarring the Zeek install).
replaceprefixes() {
    # Put in place the test's actual prefix in files where we
    # previously put in place the @PREFIX@ pattern:
    for i in etc/zeekctl.cfg bin/zeekctl bin/zeek-config ; do
        sed "s#@PREFIX@#${ZEEKCTL_INSTALL_PREFIX}#" $i > $i.new && cp $i.new $i && rm $i.new
        if [ $? -ne 0 ]; then
            return 1
        fi
    done

    # We can now use zeek-config to figure out additional paths. This
    # avoids assumptions about where Zeek places directories.
    local pydir=$(./bin/zeek-config --python_dir)

    # Finally, substitute those in additional files whose location we
    # didn't previously know.
    for i in $pydir/zeekctl/ZeekControl/version.py ; do
        sed "s#@PREFIX@#${ZEEKCTL_INSTALL_PREFIX}#" $i > $i.new && cp $i.new $i && rm $i.new
        if [ $? -ne 0 ]; then
            return 1
        fi
    done
}

# Cleanup when a zeekctl test script terminates for any reason (this is called
# automatically).
cleanup() {
    set +x
    set +e

    # Make sure all Zeek instances started by this test are stopped.
    # Hide the output to avoid user confusion if a test fails (for example,
    # this command will fail if "zeekctl install" was not run).
    zeekctl stop > /dev/null 2>&1

    # Cleanup the test-specific Zeek install directory only if ZEEKCTL_TEST_DEBUG
    # is not set.
    if [ -z "${ZEEKCTL_TEST_DEBUG}" ]; then
        test -n "$ZEEKCTL_INSTALL_PREFIX" && rm -rf "$ZEEKCTL_INSTALL_PREFIX"
    fi
}


# Create a test-specific directory, install Zeek to this directory, and export
# the env. vars. ZEEKCTL_INSTALL_PREFIX and PATH which are both needed by
# zeekctl test scripts.
main() {
    # Exit if any command fails (this is useful to debug a failing zeekctl test
    # script).
    set -e

    if [ -z "${INSTALL}" ]; then
        echo "Error: the INSTALL env. variable is not defined (should be in btest.cfg)" 1>&2
        exit 1
    fi

    basedir="${INSTALL}"
    tarfile=$basedir/zeek-test-install.tar

    if [ ! -f "$tarfile" ]; then
        echo "Error: $tarfile doesn't exist (run the 'Scripts/build-zeek' script)" 1>&2
        exit 1
    fi

    trap "cleanup" EXIT

    # Export "ZEEKCTL_INSTALL_PREFIX" which is used in test scripts that need
    # the directory path of the Zeek install.
    export ZEEKCTL_INSTALL_PREFIX=`canonicalpath "$basedir/test.$$"`

    # Create test-specific zeek installation directory
    mkdir "$ZEEKCTL_INSTALL_PREFIX"

    # Install zeek
    (cd "$ZEEKCTL_INSTALL_PREFIX" && tar xf "$tarfile" && replaceprefixes)

    # Update PATH to ensure that test scripts are running the correct copy of
    # zeekctl.
    export PATH=$ZEEKCTL_INSTALL_PREFIX/bin:$PATH

    # Provide the Python module installation directory to the tests.
    # This avoids hardwiring assumptions about the location of that
    # directory into the tests.
    export ZEEKCTL_INSTALL_PYTHON_DIR=$(zeek-config --python_dir)

    # If the user set the env. var. ZEEKCTL_TEST_DEBUG, then leave a file in
    # the test directory to help setup the environment for running zeekctl
    # manually.
    if [ -n "${ZEEKCTL_TEST_DEBUG}" ]; then
        how2run=${ZEEKCTL_INSTALL_PREFIX}/how_to_run_zeekctl
        echo "# In order to run zeekctl in this directory, type '. ./how_to_run_zeekctl'" >> $how2run
        echo "export PATH=$ZEEKCTL_INSTALL_PREFIX/bin:\$PATH" >> $how2run
    fi

    # Output all commands in a zeekctl test script (if a test fails, this might
    # be useful for debugging).
    set -x
}

main