#!/bin/bash

get_slave_receiver_location() {
    ps ww o cmd= --ppid "$slave_postmaster_pid" | awk '$0~/^postgres: wal receiver process.*[0-9A-F]+\/[0-9A-F]+[[:space:]]*$/ {split($NF, f, "/"); printf "%08s%08s\n", f[1], f[2]}'
}

get_master_sender_location() {
    ps ww o cmd= --ppid "$( head -n 1 data-master/postmaster.pid )" | awk '$0~/^postgres: wal sender process.*[0-9A-F]+\/[0-9A-F]+[[:space:]]*$/ {split($NF, f, "/"); printf "%08s%08s\n", f[1], f[2]}' | LC_ALL=C sort | tail -n 1
}

make_sr_slave () {
    export codename="$1"
    backup_source="$2"
    export use_port="$3"
    directory="data-$codename"

    mkdir "$directory"
    chmod 700 "$directory"

    tar xzf omnipitr/backup/"$backup_source"-data.tar.gz -C "$directory/"

    mv "$directory/data-$backup_source"/* "$directory/"
    rmdir "$directory/data-$backup_source"

    perl -pi -e '
    s/\A \s* (?: [#] \s* )? port \s* = \s*.*/port = \047$ENV{use_port}\047/x;
    s{\A \s* (?: [#] \s* )? archive_command \s* = \s*.*}{archive_command = \047/bin/true\047}x;
    s{\A \s* (?: [#] \s* )? hot_standby \s* = \s*.*}{hot_standby = on}x;
    ' "$directory/postgresql.conf"

    echo "restore_command = '/opt/omnipitr/bin/omnipitr-restore -sr -t /home/depesz/omnipitr/tmp/sr-restore/ -l /home/depesz/omnipitr/log.${codename} -p /home/depesz/omnipitr/pause.${codename} -s gzip=/home/depesz/omnipitr/archive -v -f /home/depesz/${directory}.finish %f %p'" >> "$directory"/recovery.conf
    echo "standby_mode = 'on'" >> "$directory"/recovery.conf
    echo "primary_conninfo = 'port=54001 user=depesz'" >> "$directory"/recovery.conf
    echo "trigger_file = '/home/depesz/${directory}.finish'" >> "$directory"/recovery.conf

    touch omnipitr/log.${codename}

    pg_ctl -D "$directory/" -w -s start

    if [[ ! -e "${directory}/postmaster.pid" ]]
    then
        echo "$codename Pg didn't start?" >&2
        exit 1
    fi
    slave_postmaster_pid="$( head -n 1 "${directory}/postmaster.pid" )"

    i=0
    while true
    do
        location="$( get_slave_receiver_location )"
        if [[ "" != "$location" ]]
        then
            break
        fi
        i=$(( $i + 1 ))
        if (( $i > 360 ))
        then
            echo "There is no wal receiver process in $directory after 60 seconds?!" >&2
            exit 1
        fi
        sleep 1
    done

    generate_load 5

    sleep 5

    i=0
    while true
    do
        new_location="$( get_slave_receiver_location )"
        if [[ "$new_location" != "$location" ]]
        then
            break
        fi
        i=$(( $i + 1 ))
        if (( $i > 360 ))
        then
            echo "Wal receiver location didn't change in 60 seconds of load generation!" >&2
            exit 1
        fi
        sleep 1
    done

    sleep 5

    stop_load_generators

    i=0
    while true
    do
        master_location="$( get_master_sender_location )"
        slave_location="$( get_slave_receiver_location )"
        if [[ "$master_location" == "$slave_location" ]]
        then
            break
        fi
        i=$(( $i + 1 ))
        if (( $i > 720 ))
        then
            echo "Slave didn't catchup to master in 720 seconds!" >&2
            exit 1
        fi
        sleep 1
    done
}