#!/bin/bash

##################################################
# Mount dir                                      #
# - /opt/kafka/data                              #
# - /opt/kafka/logs                              #
# ENV                                            #
# - CONF                                         #
# - CLUSTER_ID                                   #
# - LEAD_CONTROLLER                              #
# - KAFKA_HEAP_OPTS                              #
# - EXTRA_ARGS                                   #
# - _CONF_*                                      #
##################################################

set -euo pipefail
export LANG=en_US.UTF-8
trap Quit EXIT

PIDS=
GOT_SIGTERM=
CONF=${CONF:?}
CONF_FILE=config/$CONF.properties
CLUSTER_ID=${CLUSTER_ID:?}
LEAD_CONTROLLER=${LEAD_CONTROLLER:-}

function Print {
    local file=/dev/null
    [ '-f' = "$1" ] && file=$2 && shift && shift
    date +"[%F %T] $*" | tee -a $file
}

function Quit {
    while :; do
        pkill -f java && Print killing java ... || break
        sleep 1
    done
    Print Container stopped.
    test -n "$GOT_SIGTERM"
}

function Usage {
    Print 'This container should run with
    **root user**
    **/opt/kafka/{data,logs} mounted from host**
    '
}

function ModifyConf {
    local kv=
    ! cp -f $CONF_FILE.origin $CONF_FILE \
        && Print Skipped modifying $CONF_FILE ... \
        && return 0
    Print Modifying $CONF_FILE ...
    echo -e "\n#### Docker" >> $CONF_FILE
    while read kv; do
        [ -z "$kv" ] && break
        Print Modifying property: ${kv%%=*} ...
        sed -i "/^${kv%%=*} *=/d" $CONF_FILE
        echo "$kv" >> $CONF_FILE
    done <<< "$(env | grep '^_CONF_' | sed 's/_CONF_//')"
}

function StartProc {
    [[ ! "$CONF" =~ ^broker|controller|server$ ]] \
        && Print Unknown conf: $CONF! \
        && exit 1
    Print Formatting storage ...
    if [ -z "$LEAD_CONTROLLER" -a 'broker' != "$CONF" ]; then
        kafka-storage.sh format -g -t $CLUSTER_ID -c $CONF_FILE -s
    else
        kafka-storage.sh format -g -t $CLUSTER_ID -c $CONF_FILE -N
    fi
    Print Starting kafka ...
    kafka-server-start.sh $CONF_FILE &>> logs/kafka.out &
    PIDS="$PIDS $!"
    Print Kafka started.
    [ -e data/$CONF.lock ] && return 0
    [ -z "$LEAD_CONTROLLER" -o 'broker' == "$CONF" ] \
        && touch data/$CONF.lock \
        && return 0
    Print Join in kraft cluster with $LEAD_CONTROLLER after 10s ...
    sleep 10
    [ ! -e /proc/$! ] && Print Unexpected error! && exit
    timeout 10 kafka-metadata-quorum.sh --command-config $CONF_FILE \
        --bootstrap-controller $LEAD_CONTROLLER add-controller \
        && touch data/$CONF.lock \
        && return 0
    Print Failed to join cluster with $LEAD_CONTROLLER!
    exit 1
}

function Main {
    local pid=
    cd /opt/kafka
    Usage
    ModifyConf
    StartProc
    trap "GOT_SIGTERM=1; Print Got SIGTERM ..." SIGTERM
    while [ -z "$GOT_SIGTERM" ] && sleep 2; do
        for pid in $PIDS; do
            [ ! -e /proc/$pid ] && Print Unexpected error! && exit
        done
    done
}

# Start here
Main