#!/bin/bash

# Util to pretty-print logfile of NetworkManager
#
# Unless setting NM_LOG_NO_COLOR it will colorize the output.
# Suppress coloring with:
# $ NM_LOG_NO_COLOR=1 NM-log ...
#
# If called without arguments, it either reads from stdin (if not
# connected to a terminal) or it shows the journal content.
#
# If called with first argument "j", it always shows the journal content.
#
# You can pass multiple filenames.

show-journal() {
    local since="$(systemctl show NetworkManager | sed -n 's/^ExecMainStartTimestamp=\(.*\) [A-Z0-9]\+$/\1/p')"

    if [[ "$since" == "" ]]; then
       echo "error detecting NM. Is it running?"
       systemctl status NetworkManager
    else
       exec journalctl -o short-precise --since "$since" -b 0 -u NetworkManager "$@"
    fi
}

colorize() {
    if [[ "$NM_LOG_NO_COLOR" == "" ]]; then
        GREP_COLOR='01;33' grep --color=always '^\|^\(.* \)\?<\(warn>\|info> \|error>\) \(.*\<is starting\>.*$\)\?' | \
        GREP_COLOR='01;37' grep --color=always '^\|\<platform: signal: .*$' | \
        GREP_COLOR='01;34' grep --color=always '^\|\<platform-linux: link: change \|\<platform: link: setting .*$\|\<platform: \(route\|address\): .*$\|\<platform-linux: sysctl: setting .*$' | \
        GREP_COLOR='01;35' grep --color=always '^\| audit: .*$' | \
        GREP_COLOR='01;32' grep --color=always '^\|\<device (.*): state change: '
    else
        cat -
    fi
}

(
    if [ "$1" == "j" ]; then
        shift
        show-journal "$@"
    elif [ "$#" -eq 0 -a -t 0 ]; then
        show-journal
    else
        a="${1--}"
        shift
        /usr/bin/cat "$a" "$@"
    fi
) | \
    colorize | \
    LESS=FRSXMK exec less -R