#!/bin/bash

set -Eu

current_pgid=$(ps -o pgid= $$ | tr -d ' ')
current_sid=$(ps -o sid= $$ | tr -d ' ')

function cleanup {
    echo "│ Cleanup function"
    # ps xao user,pid,pgid,sid,user,cmd | grep -P '(sshlog|tail)'
    sudo pkill -9 -g $current_pgid -s $current_sid
}

trap cleanup SIGINT INT TERM QUIT ERR

TAILOPTS=''
TAILLINES=''
CAT=0
GREP_PATTERN=''
GREP_OPT=''
NOCOLOR=0
LOG_MAP='{
    "default": {
        "default": "cmd:journalctl --output cat"
    },
    "host": {
        "journal": "cmd:journalctl --output cat",
        "vrack": "/var/log/neutron/neutron-ovh-vrack-agent.log",
        "bgp": "/var/log/neutron/neutron-ovh-bgp-agent.log",
        "l3": "/var/log/neutron/neutron-ovh-l3-agent.log",
        "metadata": "/var/log/neutron/neutron-ovh-metadata-agent.log",
        "nova": "/var/log/nova/*.log",
        "libvirt": "/var/log/libvirt/libvirtd.log",
        "ovs": "/var/log/openvswitch/*.log",
        "neutron": "/var/log/neutron/*.log",
        "default": "/var/log/nova/*.log /var/log/neutron/*.log"
    },
    "snat": {
        "journal": "cmd:journalctl --output cat",
        "vrack": "/var/log/neutron/neutron-ovh-vrack-agent.log",
        "bgp": "/var/log/neutron/neutron-ovh-bgp-agent.log",
        "l3": "/var/log/neutron/neutron-ovh-l3-agent.log",
        "dhcp": "/var/log/neutron/neutron-dhcp-agent.log",
        "metadata": "/var/log/neutron/neutron-ovh-metadata-agent.log",
        "neutron": "/var/log/neutron/*.log",
        "ovs": "/var/log/openvswitch/*.log",
        "default": "/var/log/neutron/*.log"
    },
    "neutron": {
        "journal": "cmd:journalctl --output cat",
        "apache": "/var/log/apache2/neutron-api*log",
        "api": "/var/log/neutron/neutron-api.log",
        "rpc": "/var/log/neutron/neutron-rpc.log",
        "default": "/var/log/neutron/*.log"
    },
    "nova": {
        "journal": "cmd:journalctl --output cat",
        "apache": "/var/log/apache2/nova-api*log",
        "api": "/var/log/nova/nova-api.log",
        "conductor": "/var/log/nova/nova-conductor.log",
        "scheduler": "/var/log/nova/nova-scheduler.log",
        "placement": "/var/log/placement/placement-api.log",
        "default": "/var/log/nova/*.log"
    },
    "cinder": {
        "journal": "cmd:journalctl --output cat",
        "apache": "/var/log/apache2/cinder-api*log",
        "api": "/var/log/cinder/cinder-api.log",
        "scheduler": "/var/log/cinder/cinder-scheduler.log",
        "volume": "/var/log/cinder/cinder-volume.log",
        "backup": "/var/log/cinder/cinder-backup.log",
        "default": "/var/log/cinder/*.log"
    },
    "glance": {
        "journal": "cmd:journalctl --output cat",
        "default": "/var/log/glance/*.log"
    },
    "ironic": {
        "journal": "cmd:journalctl --output cat",
        "api": "/var/log/ironic/ironic-api.log",
        "conductor": "/var/log/ironic/ironic-ovh-conductor.log",
        "metadata": "/var/log/ironic/ironic-ovh-metadata-server.log",
        "neutron": "/var/log/neutron/*.log",
        "nova": "/var/log/nova/*log",
        "default": "/var/log/ironic/*.log"
    },
    "rabbit": {
        "journal": "cmd:journalctl --output cat",
        "default": "/var/log/rabbitmq/*.log"
    },
    "rabbit-nova": {
        "journal": "cmd:journalctl --output cat",
        "default": "/var/log/rabbitmq/*.log"
    },
    "rabbit-neutron": {
        "journal": "cmd:journalctl --output cat",
        "default": "/var/log/rabbitmq/*.log"
    }
}'

function sshlog {
    HOST_GROUP="$1"
    LOG_KEYS=(${2:-default})

    # Get matching host from /etc/hosts - retrieve maximum MAX_HOSTS
    found_hosts=$(cat /etc/hosts | \
        grep -Pv '(^#|^$)' | \
        awk '{print $2}' | \
        grep -Pi "^($HOST_GROUP|$HOST_GROUP[0-9]*\.${OS_REGION_NAME:-.*}\..*)$" | head -n ${MAX_HOSTS:-10} | xargs
    )

    # Get group from host arg
    len=$(echo $found_hosts | wc -w)
    if [[ $len -eq 0 ]]; then
        echo no host found
        exit 1
    elif [[ $len -eq 1 ]]; then
        group_name=$(echo $found_hosts | cut -d. -f1 | tr -d '[0-9]')
    else
        group_name=$HOST_GROUP
    fi

    # Find matching group from LOG_MAP
    found_group=$(echo $LOG_MAP | jq -r 'keys[]' | grep -P "^$group_name$" || true)
    if [[ -z $found_group ]]; then
        # fallback on default group
        group_name="default"
    fi

    # get log files from map[group][key]
    log_files=()
    for key in ${LOG_KEYS[@]}; do
        found_log=$(echo $LOG_MAP | jq .\"$group_name\" | jq -r 'keys[]' | grep -P "^$key$" || true)
        if  [[ -z $found_log ]]; then
            echo "[$key] does not match any of $(echo $LOG_MAP | jq .\"$group_name\" | jq 'keys[]')"
            exit 1
        fi
        log_files+=($(echo $LOG_MAP | jq -r .\"$group_name\".\"$found_log\"))
    done

    # build logging command
    if [[ ${log_files[@]} =~ cmd: ]]; then
        if [[ ${#LOG_KEYS[@]} > 1 ]]; then
           echo "${log_files[@]} have cmd:xx -- only 1 log arg supported"
           exit 1
        fi
        CMD=$(echo ${log_files[@]} | sed -e 's/^cmd://')
        LOGCMD="echo '==> $CMD <==' ; timeout 3600 $CMD $TAILOPTS"
    else
        LOGCMD="timeout 3600 tail -v $TAILOPTS ${log_files[@]}"
    fi

    if [[ -n $GREP_PATTERN ]]; then
        [[ -z $GREP_OPT ]] && GREP_OPT='-Pi'
        GREPCMD="grep --line-buffered ${GREP_OPT} '$GREP_PATTERN'"
    else
        GREPCMD=tee
    fi

    echo "│"
    echo "│    Host:   $found_hosts"
    echo "│    Files:  ${log_files[@]}"
    echo "│    Cmd:    $LOGCMD | $GREPCMD"
    echo "│"

    if [[ $NOCOLOR -eq 1 ]]; then
        color_cmd="tee"
    else
        color_cmd="os-log-color"
    fi

    for h in $(echo $found_hosts); do
        short=$(echo $h | sed -e 's/\.cloud.ovh.*//')
        # Execute tail cmd through ssh
        # stdbuf -o0 : do not buffer stdout
        # awk: prefix each line whith  "host filename ..."  #  filename is retrieved using tail -v
        # grep -F '' --line-buffered: try to not mix output
        sudo ssh -o "UserKnownHostsFile=/dev/null" -o "StrictHostKeyChecking=no" -l admin $h \
            "$LOGCMD | $GREPCMD" 2> /dev/null | \
            stdbuf -o0 awk -v host=$short '/^==>/{size=split($2,splitted,"/");filename=splitted[size] ;next} !/^==>/{print host,filename,$0}' | \
            grep -F '' --line-buffered  &
    done | $color_cmd

    wait
    cleanup
}

function sshlog_completion
{
    local cur first

    cur=${COMP_WORDS[COMP_CWORD]}
    first=${COMP_WORDS[1]}

    case ${COMP_CWORD} in
        1) COMPREPLY=($(compgen -W "$(sshlog -s | jq -r 'keys[]'| xargs) $(cat /etc/hosts | grep -Pv '(^#|^$)' | awk '{print $2}' | grep -Pi "[0-9]\.${OS_REGION_NAME:-.*}\." | xargs)" -- ${first})) ;;
        *) group=$(echo $first | cut -d. -f1 | tr -d "[0-9]");
           sshlog_group=$(sshlog -s | jq -r .\"${group}\")
           [[ ! $sshlog_group = null ]] && sshlog_group=$group || sshlog_group=default
           COMPREPLY=($(compgen -W "$(sshlog -s | jq -r .\"${sshlog_group}\" | jq 'keys[]'| xargs 2> /dev/null)" -- ${cur})) ;;
    esac
}


function print_help {
    echo "
$(basename $0) [group|hostname] [log type]

Options:

$(declare -f main | \
    grep -P '(help=|--|-[a-zA-Z]\))' | \
    xargs | \
    sed -e 's/; /\n/g' -e 's/help=/#/g' | \
    column -t -s '#')
"
    exit
}


function main {
    [[ $# == 0 ]] && print_help

    while [[ $# -ne 0 ]]; do
        arg="$1"; shift
        case "$arg" in
            -n)
                help="NB: nb lines. tail option"
                export TAILLINES=$1 && shift;;
            --nocolor|-N)
                help="no color"
                export NOCOLOR=1 ;;
            --cat|-c)
                help="cat instead tail -f"
                export CAT=1 ;;
            --grep|-g)
                help="grep -Pi pattern"
                export GREP_PATTERN=$1 && shift;;
            --grepopt|-G)
                help="grep options, default -Pi"
                export GREP_OPT=$1
                [[ ! $GREP_OPT =~ ^\- ]] && echo "grep opt should begin with ^-.." && exit 1
                shift;;
            --show|-s)
                help="display log map"
                echo $LOG_MAP ; exit ;;
            --max|-m)
                help="maximum nb hosts o get log from"
                export MAX_HOSTS=$1 && shift ;;
            --completion)
                help='completion function (eval "$(sshlog --completion)")'
                declare -f sshlog_completion
                echo complete -F sshlog_completion sshlog
                exit ;;
            --help|-h)
                help="this help"
                print_help ;;
            *) [[ ! $arg =~ ^\-+.* ]] && POSITIONNAL_ARGS+=($arg) || EXTRA_ARGS+=($arg)
        esac
    done

    if [[ $CAT -eq 1 ]]; then
        export TAILLINES="+1"
    else
        export TAILOPTS="$TAILOPTS -f"
    fi

    if [[ -n $TAILLINES ]]; then
        export TAILOPTS="$TAILOPTS -n $TAILLINES"
    fi

    HOST_GROUP=${POSITIONNAL_ARGS[0]}
    LOG_KEYS=${POSITIONNAL_ARGS[@]:1}

    sshlog "$HOST_GROUP" "${LOG_KEYS[@]}"
}

main "$@"