#!/bin/bash

# Configuration
DB_NAME="DB_NAME"
DB_USER="DB_USER"
BACKUP_DIR="/path/to/backup/dir"
LOG_FILE="/var/log/maintenance.log"
EMAIL="your-email@example.com"
DATE=$(date +'%Y-%m-%d_%H-%M-%S')
USER_LIST="/path/to/user_list.txt"  # File containing list of users to be managed

# Function to backup the database
backup_database() {
    BACKUP_FILE="$BACKUP_DIR/$DB_NAME-backup-$DATE.sql"
    pg_dump -U $DB_USER $DB_NAME > $BACKUP_FILE
    if [ $? -eq 0 ]; then
        echo "$DATE: Database backup successful" >> $LOG_FILE
    else
        echo "$DATE: Database backup failed" >> $LOG_FILE
    fi
}

# Function to vacuum the database
vacuum_database() {
    psql -U $DB_USER -d $DB_NAME -c "VACUUM;"
    if [ $? -eq 0 ]; then
        echo "$DATE: Database vacuum successful" >> $LOG_FILE
    else
        echo "$DATE: Database vacuum failed" >> $LOG_FILE
    fi
}

# Function to reindex the database
reindex_database() {
    psql -U $DB_USER -d $DB_NAME -c "REINDEX DATABASE $DB_NAME;"
    if [ $? -eq 0 ]; then
        echo "$DATE: Database reindex successful" >> $LOG_FILE
    else
        echo "$DATE: Database reindex failed" >> $LOG_FILE
    fi
}

# Function to add a user
add_user() {
    while IFS= read -r username; do
        sudo useradd -m -s /bin/bash $username
        if [ $? -eq 0 ]; then
            echo "$DATE: User $username added" >> $LOG_FILE
        else
            echo "$DATE: Failed to add user $username" >> $LOG_FILE
        fi
    done < "$USER_LIST"
}

# Function to remove a user (commented out for safety)
# remove_user() {
#     while IFS= read -r username; do
#         sudo userdel -r $username
#         if [ $? -eq 0 ]; then
#             echo "$DATE: User $username removed" >> $LOG_FILE
#         else
#             echo "$DATE: Failed to remove user $username" >> $LOG_FILE
#         fi
#     done < "$USER_LIST"
# }

# Placeholder function for modifying user details
modify_user() {
    # Modify user details as needed
    echo "Modify user function placeholder"
}

# Main script logic

echo "Starting maintenance and user management tasks at $DATE"

# Perform database maintenance tasks
backup_database
vacuum_database
reindex_database

# Perform user management tasks
add_user
# Uncomment below line if you want to perform user removal
# remove_user
# Uncomment below line if you want to perform user modification
# modify_user

echo "Tasks completed at $(date +'%Y-%m-%d_%H-%M-%S')"
