# ------------------------------------------------------------------------------
# Error management functions
# This file is part of the init.sh project
# Copyright (c) 2019-2021 Geoffray Levasseur <fatalerrors@geoffray-levasseur.org>
# ------------------------------------------------------------------------------
# This file is distributed under 3-clause BSD license.
# The complete license agreement can be obtained at:
# https://opensource.org/licenses/BSD-3-Clause
# ------------------------------------------------------------------------------
 

# ------------------------------------------------------------------------------
# Exit with error
function die()
{
    local errorcode=$1

    # Don't trigger the ERR signal as we already managed the error
    trap - ERR

    if [[ "$KEEPGOING" != "true" ]] || [[ "$2" == "--force" ]]; then
        prnt E "Premature exit with error (code #$errorcode)."
        # We remove KEEPGOING in case of --force so error() behave correctly
        export KEEPGOING=false
        exit $errorcode
    else
        prnt W "Continuing despite error #$errorcode."
    fi
    unset errorcode

    # Put the trigger back (only executed with --keepgoing)
    trap "error ${LINENO}" ERR
}
export -f die


# ------------------------------------------------------------------------------
# Function trigered on Ctrl+C pressed or external kill affecting us
function terminate()
{
    prnt E "$1 recieved, exiting at once."
    die 128 --force
}
trap "terminate 'Ctrl + C'" SIGINT
trap "terminate 'SIGTERM'"  SIGTERM


# ------------------------------------------------------------------------------
# Function triggered on error
function error()
{
    local parent_lineno="$1"
    local message="$2"
    local code="${3:-1}"

    # Print error header
    prnt E "${BIWhite}*** ${BIRed}A fatal error occured, the script will stop now!$DEFAULTCOL"

    if [[ -n "$message" ]]; then
        prnt E "Error line $parent_lineno, code $code with message:"
        echo -e "\t\t$message"
    else
        prnt E "Error ligne $(caller), with error code $code."
    fi
    unset parent_lineno message code
}
# Trigger error function on error
trap "error ${LINENO}; backtrace; err_exit" ERR


# ------------------------------------------------------------------------------
# Exit program in case of error unless keepgoing is set to true
function err_exit
{
    if [[ $KEEPGOING != true ]]; then
        if [[ -f $tmpfile ]]; then
            rm -f $tmpfile
        fi
        exit 255
    fi
}


# ------------------------------------------------------------------------------
# Print a backtrace
function backtrace
{
    echo "========= Call stack ========="
    typeset -i i=0

    local func=
    for func in "${FUNCNAME[@]}"; do
        if [[ $i -ne 0 ]]; then
            printf '%15s() %s:%d\n' \
                "$func" "${BASH_SOURCE[$i]}" "${BASH_LINENO[ (( $i - 1)) ]}"
        fi
        let i++ || true
    done
    unset func i
    echo "=============================="
}


# ------------------------------------------------------------------------------
# Execute command outside of error control, echoes ouput error code
noerror()
{
    if [[ $1 == "--noout" ]]; then
        local noout=true
        shift
    fi

    set +o errexit
    trap - ERR

    if [[ -n $noout ]]; then
        $@ > /dev/null 2>&1
    else
        $@
    fi
    echo $?

    trap "error ${LINENO}" ERR
    set -o errexit
}
export -f noerror


# ------------------------------------------------------------------------------
# Test and exit if not root (or any UID 0 user)
check_root()
{
    if [[ $NO_ROOT_CHECK == true ]]; then
        return 0
    fi
    if [[ $EUID -ne 0 ]]; then
        prnt E "check_root: That script must be run with root privileges."
        die 4 --force
    fi
}
export -f check_root

# EOF