#!/bin/bash
# =============================================================================
# SAP HANA Backup Status Monitoring Script
# Checks last successful backup age
# =============================================================================

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

# 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 backup status check..."

# SQL Query for last successful backup
BACKUP_SQL="SELECT TOP 1 SYS_START_TIME FROM M_BACKUP_CATALOG WHERE ENTRY_TYPE_NAME = 'complete data backup' AND STATE_NAME = 'successful' ORDER BY SYS_START_TIME DESC"

# Execute SQL query
backup_result=$(execute_hana_sql "$BACKUP_SQL")
sql_status=$?

if [ $sql_status -ne 0 ]; then
    log_message "$SCRIPT_NAME" "ERROR: Failed to execute backup query. Exit code: ${sql_status}"
    send_alert "$SCRIPT_NAME" "HANA Backup Error" "Failed to execute backup query. Exit code: ${sql_status}"
    exit 1
fi

last_backup_date=$(echo "$backup_result" | tr -d '"' | sed 's/\..*//')

if [[ -z "$last_backup_date" || "$last_backup_date" == *"error"* || "$last_backup_date" == *"Error"* ]]; then
    message="No successful complete data backup found for ${COMPANY_NAME} HANA."
    log_message "$SCRIPT_NAME" "CRITICAL: ${message}"
    send_alert "$SCRIPT_NAME" "HANA Backup" "$message"
    exit 1
fi

# Calculate backup age
last_backup_epoch=$(date -d "$last_backup_date" +%s 2>/dev/null)
if [ $? -ne 0 ]; then
    log_message "$SCRIPT_NAME" "ERROR: Failed to parse backup date: ${last_backup_date}"
    send_alert "$SCRIPT_NAME" "HANA Backup" "Failed to parse backup date: ${last_backup_date}"
    exit 1
fi

current_epoch=$(date +%s)
threshold_seconds=$((BACKUP_THRESHOLD_HOURS * 3600))
age_seconds=$((current_epoch - last_backup_epoch))
age_hours=$((age_seconds / 3600))

if [ $age_seconds -lt 0 ]; then
    log_message "$SCRIPT_NAME" "WARNING: Backup timestamp is in the future. Possible clock skew."
    age_hours=0
fi

if [ $age_seconds -gt $threshold_seconds ]; then
    message="Last successful HANA backup for ${COMPANY_NAME} is ${age_hours} hours old, which exceeds the threshold of ${BACKUP_THRESHOLD_HOURS} hours. Last backup was on: ${last_backup_date}."
    log_message "$SCRIPT_NAME" "CRITICAL: ${message}"
    send_alert "$SCRIPT_NAME" "HANA Backup" "$message"
    exit 1
else
    message="Last successful backup is ${age_hours} hours old (Threshold: ${BACKUP_THRESHOLD_HOURS} hours)."
    log_message "$SCRIPT_NAME" "SUCCESS: ${message}"
fi

log_message "$SCRIPT_NAME" "Backup check complete."