#!/bin/bash

# Ask the user which database system to use
read -p "Which database system are you using? (mysql/postgresql/sqlite): " DB_SYSTEM

# Check if selected database system is installed
if [ "$DB_SYSTEM" == "mysql" ]; then
    if ! command -v mysql &> /dev/null; then
        echo "mysql is not installed or not found in PATH. Please install mysql and try again."
        exit 1
    fi
elif [ "$DB_SYSTEM" == "postgresql" ]; then
    if ! command -v psql &> /dev/null; then
        echo "postgresql is not installed or not found in PATH. Please install postgresql and try again."
        exit 1
    fi
elif [ "$DB_SYSTEM" == "sqlite" ]; then
    if ! command -v sqlite3 &> /dev/null; then
        echo "sqlite3 is not installed or not found in PATH. Please install sqlite3 and try again."
        exit 1
    fi
else
    echo "Invalid database system selected. Please choose either 'mysql', 'postgresql', or 'sqlite'."
    exit 1
fi

EXIT_CODE=0

echo
echo "You will be prompted to provide details for creating the Drust database."
echo "Press ENTER to accept the default values."
echo

if [ "$DB_SYSTEM" == "sqlite" ]; then
    DEFAULT_DB_NAME="drust.db"

    # Only prompt for database name, as user and password are not used by SQLite
    read -p "Enter database name [$DEFAULT_DB_NAME]: " DB_NAME
    DB_NAME=${DB_NAME:-$DEFAULT_DB_NAME}

    # For SQLite, just check if the database file exists and create it if it doesn't
    if [ ! -f "$DB_NAME" ]; then
        echo "Creating SQLite database file: $DB_NAME"
        sqlite3 "$DB_NAME" ".quit"
        EXIT_CODE=$?
    else
        echo "SQLite database file $DB_NAME already exists."
        exit 1
    fi
else
    DEFAULT_DB_NAME="drust"
    DEFAULT_DB_USER="drust"
    DEFAULT_DB_PASS="demo"
    DEFAULT_DB_HOST="localhost"

    # Prompt for database details, allow defaults
    read -p "Enter database name [$DEFAULT_DB_NAME]: " DB_NAME
    DB_NAME=${DB_NAME:-$DEFAULT_DB_NAME}

    read -p "Enter database user [$DEFAULT_DB_USER]: " DB_USER
    DB_USER=${DB_USER:-$DEFAULT_DB_USER}

    read -p "Enter database password [$DEFAULT_DB_PASS]: " DB_PASS
    DB_PASS=${DB_PASS:-$DEFAULT_DB_PASS}

    read -p "Enter database host [$DEFAULT_DB_HOST]: " DB_HOST
    DB_HOST=${DB_HOST:-$DEFAULT_DB_HOST}

    # Prompt for database system root or another privileged user's credentials
    echo
    read -p "Enter $DB_SYSTEM root or admin user: " DB_ROOT_USER
    read -sp "Enter $DB_SYSTEM root or admin password: " DB_ROOT_PASS
    echo

    # Confirm before proceeding
    echo
    echo "You are about to create the database \"$DB_NAME\" and assign privileges to user \"$DB_USER\"."
    read -p "Are you sure you want to proceed? (y/N): " confirm
    if [[ ! "$confirm" =~ ^[Yy]$ ]]; then
        echo "Operation cancelled."
        exit 1
    fi

    # Execute commands for MySQL or PostgreSQL
    if [ "$DB_SYSTEM" == "mysql" ]; then
        mysql -u "$DB_ROOT_USER" -p"$DB_ROOT_PASS" -h "$DB_HOST" <<EOF
CREATE DATABASE IF NOT EXISTS $DB_NAME;
CREATE USER IF NOT EXISTS '$DB_USER'@'$DB_HOST' IDENTIFIED BY '$DB_PASS';
GRANT ALL PRIVILEGES ON $DB_NAME.* TO '$DB_USER'@'$DB_HOST';
FLUSH PRIVILEGES;
EOF
    elif [ "$DB_SYSTEM" == "postgresql" ]; then
        PGPASSWORD="$DB_ROOT_PASS" psql -U "$DB_ROOT_USER" -h "$DB_HOST" <<EOF
CREATE DATABASE $DB_NAME;
CREATE USER $DB_USER WITH ENCRYPTED PASSWORD '$DB_PASS';
GRANT ALL PRIVILEGES ON DATABASE $DB_NAME TO $DB_USER;
EOF
    fi
    EXIT_CODE=$?
fi

if [ $EXIT_CODE -eq 0 ]; then
    echo "Operation completed successfully."
else
    echo "An error occurred. Exit code: $EXIT_CODE"
fi

# Exit the script with the mysql command's exit code
exit $EXIT_CODE