#!/bin/bash
#
# This script produces a Hive script that generates DDL on every table.
# The DDLs could then be run on another HDInsight cluster.
# This method of copying table metadata is supported only for non-transactional tables.
#

HDINSIGHT_UTILITIES_FNAME='HDInsightUtilities-v01.sh'
HDINSIGHT_UTILITIES="/tmp/$HDINSIGHT_UTILITIES_FNAME"
# shellcheck source=/dev/null
wget -O "$HDINSIGHT_UTILITIES" -q https://hdiconfigactions.blob.core.windows.net/linuxconfigactionmodulev01/$HDINSIGHT_UTILITIES_FNAME && source "$HDINSIGHT_UTILITIES"

HIVE_MIGRATION_UTILS_FNAME='hive-migration-utils-v01.sh'
HIVE_MIGRATION_UTILS="/tmp/$HIVE_MIGRATION_UTILS_FNAME"
# shellcheck source=hive-migration-utils-v01.sh
wget -O "$HIVE_MIGRATION_UTILS" -q "https://hdiconfigactions.blob.core.windows.net/linuxhivemigrationv01/${HIVE_MIGRATION_UTILS_FNAME}" && source "$HIVE_MIGRATION_UTILS"

HIVE_DDL_SCRIPT='/tmp/hdi_hive_ddls.hql'

PRIMARY_HEADNODE=$(get_primary_headnode)
echo "Getting Beeline command."
BEE_CMD=$(get_beeline_command_and_kinit "$PRIMARY_HEADNODE")

dbs=$(eval "$BEE_CMD -e 'show databases;'")
rm -f "${HIVE_DDL_SCRIPT}"
for d in $dbs; do
    [[ "$d" == "sys" ]] && continue
    echo "-- database: ${d}" >> "${HIVE_DDL_SCRIPT}"
    echo "CREATE DATABASE IF NOT EXISTS $d; USE $d;" >> "${HIVE_DDL_SCRIPT}"
    tables=$(eval "$BEE_CMD -e 'USE $d; SHOW TABLES;'" | tr '\n' ' ' | tr -s ' ')
    for t in $tables; do
        [[ "$t" == "hivesampletable" && "$d" == "default" ]] && continue
        ddl=$(eval "$BEE_CMD -e 'USE $d; SHOW CREATE TABLE $t;'")
        if is_transactional_table "${ddl}"; then
            echo "Skipping transactional table \`$d\`.\`$t\`."
            continue
        fi
        echo "Adding table \`$d\`.\`$t\` to Hive script."
        echo "-- table: ${d}.${t}" >> "${HIVE_DDL_SCRIPT}"
        echo "$ddl;" >> "${HIVE_DDL_SCRIPT}"
        [[ "$(to_upper "$ddl")" == *"PARTITIONED BY"* ]] && echo "MSCK REPAIR TABLE \`$d\`.\`$t\`;" >> "${HIVE_DDL_SCRIPT}"
    done
done

echo "Hive DDL script written to '${HIVE_DDL_SCRIPT}'."