#!/usr/bin/env sh

# args.
USER=$(echo $1 | cut -d @ -f 1);
HOST=$(echo $1 | cut -d @ -f 2);
DBUSER=$2;
DBNAME=$3;

function usage {
    echo "Usage: `basename $0` SSH_USER@HOST MYSQL_USER MYSQL_DBNAME";
    exit 1;
}

# Error-checking for options.
if [[ -z $USER ]]; then
    echo "SSH user not specified.";
    usage;
fi
if [[ -z $HOST ]]; then
    echo "Host not specified.";
    usage;
fi
if [[ -z $DBUSER ]]; then
    echo "MySQL user not specified.";
    usage;
fi
if [[ -z $DBNAME ]]; then
    echo "Database name not specified.";
    usage;
fi
if [[ ! -f ~/.my.cnf ]]; then
    echo "Local mysql client credentials must be specified in the file: ~/.my.cnf. The format is something like:

[client]
host = localhost
user = root
password = PaSsWoRd
    ";
    usage;
fi

# Download mysql dump.
TMPDUMP=$(mktemp "/tmp/mysqldownload_${DBNAME}_XXXX");
ssh -C $USER@$HOST "mysqldump -v --databases --user=$DBUSER --password $DBNAME" 1> "$TMPDUMP";

# Ensure a file was downloaded.
if [[ 0 != $? || ! -s $TMPDUMP ]]; then
    echo "Database downloading failed.";
    exit 3;
fi

# Create local database.
echo "Dropping local database $DBNAME...";
mysql -e "DROP DATABASE IF EXISTS \`$DBNAME\`;";

# Download
echo "Loading database dump for $DBNAME...";
mysql < "$TMPDUMP";

echo 'Done!';

echo "(SQL dump file: $TMPDUMP)";