# Manage a fail of the script
#
# [internal]
#
# usage: 
# ynh_exit_properly is used only by the helper ynh_abort_if_errors.
# You should not use it directly.
# Instead, add to your script:
# ynh_clean_setup () {
#        instructions...
# }
#
# This function provide a way to clean some residual of installation that not managed by remove script.
#
# It prints a warning to inform that the script was failed, and execute the ynh_clean_setup function if used in the app script
#
ynh_exit_properly () {
	local exit_code=$?
	if [ "$exit_code" -eq 0 ]; then
			exit 0	# Exit without error if the script ended correctly
	fi

	trap '' EXIT	# Ignore new exit signals
	set +eu	# Do not exit anymore if a command fail or if a variable is empty

	echo -e "!!\n  $app's script has encountered an error. Its execution was cancelled.\n!!" >&2

	if type -t ynh_clean_setup > /dev/null; then	# Check if the function exist in the app script.
		ynh_clean_setup	# Call the function to do specific cleaning for the app.
	fi

	ynh_die	# Exit with error status
}

# Exits if an error occurs during the execution of the script.
#
# usage: ynh_abort_if_errors
#
# This configure the rest of the script execution such that, if an error occurs
# or if an empty variable is used, the execution of the script stops
# immediately and a call to `ynh_clean_setup` is triggered if it has been
# defined by your script.
#
ynh_abort_if_errors () {
	set -eu	# Exit if a command fail, and if a variable is used unset.
	trap ynh_exit_properly EXIT	# Capturing exit signals on shell script
}

# Fetch the Debian release codename
#
# usage: ynh_get_debian_release
# | ret: The Debian release codename (i.e. jessie, stretch, ...)
ynh_get_debian_release () {
	echo $(lsb_release --codename --short)
}

# Start (or other actions) a service,  print a log in case of failure and optionnaly wait until the service is completely started
#
# usage: ynh_systemd_action [-n service_name] [-a action] [ [-l "line to match"] [-p log_path] [-t timeout] [-e length] ]
# | arg: -n, --service_name= - Name of the service to reload. Default : $app
# | arg: -a, --action=       - Action to perform with systemctl. Default: start
# | arg: -l, --line_match=   - Line to match - The line to find in the log to attest the service have finished to boot.
#                              If not defined it don't wait until the service is completely started.
# | arg: -p, --log_path=     - Log file - Path to the log file. Default : /var/log/$app/$app.log
# | arg: -t, --timeout=      - Timeout - The maximum time to wait before ending the watching. Default : 300 seconds.
# | arg: -e, --length=       - Length of the error log : Default : 20
ynh_systemd_action() {
    # Declare an array to define the options of this helper.
    declare -Ar args_array=( [n]=service_name= [a]=action= [l]=line_match= [p]=log_path= [t]=timeout= [e]=length= )
    local service_name
    local action
    local line_match
    local length
    local log_path
    local timeout

    # Manage arguments with getopts
    ynh_handle_getopts_args "$@"

    local service_name="${service_name:-$app}"
    local action=${action:-start}
    local log_path="${log_path:-/var/log/$service_name/$service_name.log}"
    local length=${length:-20}
    local timeout=${timeout:-300}

    # Start to read the log
    if [[ -n "${line_match:-}" ]]
    then
        local templog="$(mktemp)"
	# Following the starting of the app in its log
	if [ "$log_path" == "systemd" ] ; then
            # Read the systemd journal
            journalctl --unit=$service_name --follow --since=-0 --quiet > "$templog" &
	else
            # Read the specified log file
            tail -F -n0 "$log_path" > "$templog" &
	fi
        # Get the PID of the tail command
        local pid_tail=$!
    fi

    echo "${action^} the service $service_name" >&2
    systemctl $action $service_name \
        || ( journalctl --lines=$length -u $service_name >&2 \
        ; test -n "$log_path" && echo "--" && tail --lines=$length "$log_path" >&2 \
        ; false )

    # Start the timeout and try to find line_match
    if [[ -n "${line_match:-}" ]]
    then
        local i=0
        for i in $(seq 1 $timeout)
        do
            # Read the log until the sentence is found, that means the app finished to start. Or run until the timeout
            if grep --quiet "$line_match" "$templog"
            then
                echo "The service $service_name has correctly started." >&2
                break
            fi
            echo -n "." >&2
            sleep 1
        done
        if [ $i -eq $timeout ]
        then
            echo "The service $service_name didn't fully started before the timeout." >&2
            echo "Please find here an extract of the end of the log of the service $service_name:"
            journalctl --lines=$length -u $service_name >&2
            test -n "$log_path" && echo "--" && tail --lines=$length "$log_path" >&2
        fi

        echo ""
        ynh_clean_check_starting
    fi
}

# Clean temporary process and file used by ynh_check_starting
# (usually used in ynh_clean_setup scripts)
#
# usage: ynh_clean_check_starting
ynh_clean_check_starting () {
	# Stop the execution of tail.
	kill -s 15 $pid_tail 2>&1
	ynh_secure_remove "$templog" 2>&1
}