#!/bin/bash

# Configuration
CK_USER="default"  # Change to your own ClickHouse username
CK_PIN="galaxy2019"
CK_HOST="127.0.0.1"
CK_PORT="9001"
METRICS_FILE="/opt/tsg/olap/node-exporter/prom/clickhouse_metrics.prom"
TIMEOUT=100

# Query ClickHouse data
query_clickhouse() {
    clickhouse-client -h "$CK_HOST" --port "$CK_PORT" -m -u "$CK_USER" --password "$CK_PIN" --max_execution_time="$TIMEOUT" --query="$1"
}

# Check if ClickHouse service is running
if pgrep -f "clickhouse-server/config.xml" > /dev/null; then
    echo "# HELP clickhouse_up ClickHouse service status (1=up, 0=down)" > $METRICS_FILE
    echo "# TYPE clickhouse_up gauge" >> $METRICS_FILE 
    echo "clickhouse_up 1" >> $METRICS_FILE
else
    echo "# HELP clickhouse_up ClickHouse service status (1=up, 0=down)" > $METRICS_FILE
    echo "# TYPE clickhouse_up gauge" >> $METRICS_FILE
    echo "clickhouse_up 0" >> $METRICS_FILE
    exit 1  # Exit the script if ClickHouse is not running
fi

# Record start time
start_time=$(date +%s)

# Query metrics
process_count=$(query_clickhouse "SELECT count(*) FROM system.processes")
merge_count=$(query_clickhouse "SELECT count(*) FROM system.merges")
expired_parts_count=$(query_clickhouse "SELECT count() FROM system.parts WHERE delete_ttl_info_max < (now() - INTERVAL 3 DAY) AND delete_ttl_info_max > toDateTime('2000-01-01 00:00:00')")

# Record end time and calculate execution time
end_time=$(date +%s)
execution_time=$((end_time - start_time))

# Write Prometheus format metrics to the file
{
    echo "# HELP ck_processes_count Number of running processes in ClickHouse"
    echo "# TYPE ck_processes_count gauge"
    echo "ck_processes_count $process_count"
    echo "# HELP ck_merges_count Number of running merges in ClickHouse"
    echo "# TYPE ck_merges_count gauge"
    echo "ck_merges_count $merge_count"
    echo "# HELP ck_connect_time Time taken to connect and run queries in seconds"
    echo "# TYPE ck_connect_time gauge"
    echo "ck_connect_time $execution_time"
    echo "# HELP ck_expired_parts_count Number of expired parts in ClickHouse"
    echo "# TYPE ck_expired_parts_count gauge"
    echo "ck_expired_parts_count $expired_parts_count"
} >> "$METRICS_FILE"