#!/bin/bash
# =============================================================================
# SAP HANA Log Segment Monitoring Script
# Checks log segment states (Truncated, Free)
# =============================================================================

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" &>/dev/null && pwd)"
SCRIPT_NAME="hana_log_segments"

# Load configuration
source "${SCRIPT_DIR}/hana.conf"
source "${SCRIPT_DIR}/hana_lib.sh"

# Acquire lock
if ! acquire_lock "$SCRIPT_NAME"; then
    exit 1
fi
trap 'release_lock "$SCRIPT_NAME"' EXIT

log_message "$SCRIPT_NAME" "Starting log segment check..."

# SQL Query for log segments
SQL_QUERY="SELECT b.host, b.service_name, a.state, count(*) FROM PUBLIC.M_LOG_SEGMENTS a JOIN PUBLIC.M_SERVICES b ON (a.host = b.host AND a.port = b.port) GROUP BY b.host, b.service_name, a.state;"

# Execute SQL query
sql_output=$(execute_hana_sql "$SQL_QUERY")
sql_status=$?

if [ $sql_status -ne 0 ]; then
    log_message "$SCRIPT_NAME" "ERROR: The hdbsql command failed."
    send_alert "$SCRIPT_NAME" "HANA Monitor Error" "The hdbsql command failed."
    exit 1
fi

# Parse SQL output
total_segments=0
truncated_segments=0
free_segments=0

while IFS= read -r line; do
    # Skip empty lines and header
    if [[ -z "$line" || "$line" == *"STATE"* || "$line" == *"host"* ]]; then
        continue
    fi
    
    cleaned_line=$(echo "$line" | tr -d '"')
    state=$(echo "$cleaned_line" | awk -F',' '{print $3}' | xargs)
    count=$(echo "$cleaned_line" | awk -F',' '{print $4}' | xargs)
    
    # Validate count is a number
    if ! [[ "$count" =~ ^[0-9]+$ ]]; then
        continue
    fi
    
    total_segments=$((total_segments + count))
    if [[ "$state" == "Truncated" ]]; then
        truncated_segments=$((truncated_segments + count))
    elif [[ "$state" == "Free" ]]; then
        free_segments=$((free_segments + count))
    fi
done <<< "$sql_output"

log_message "$SCRIPT_NAME" "Total Segments: ${total_segments}"
log_message "$SCRIPT_NAME" "Truncated Segments: ${truncated_segments}"
log_message "$SCRIPT_NAME" "Free Segments: ${free_segments}"

if [ $total_segments -eq 0 ]; then
    log_message "$SCRIPT_NAME" "WARNING: No log segments found."
    send_alert "$SCRIPT_NAME" "HANA Log Segment Warning" "No log segments found."
    exit 1
fi

# Calculate percentages
truncated_percentage=$((truncated_segments * 100 / total_segments))
free_percentage=$((free_segments * 100 / total_segments))

# Check thresholds and alert
if [ $truncated_percentage -gt $TRUNCATED_PERCENTAGE_THRESHOLD ]; then
    send_alert "$SCRIPT_NAME" "HANA Log Segment" "${truncated_percentage}% of log segments are 'Truncated' (threshold: ${TRUNCATED_PERCENTAGE_THRESHOLD}%)."
fi

if [ $free_percentage -lt $FREE_PERCENTAGE_THRESHOLD ]; then
    send_alert "$SCRIPT_NAME" "HANA Log Segment" "Only ${free_percentage}% of log segments are 'Free' (threshold: ${FREE_PERCENTAGE_THRESHOLD}%)."
fi

log_message "$SCRIPT_NAME" "Log segment check complete."