#!/bin/sh
# Version: 2.1.0
#
# Purpose: Performs an automated refresh of a SAP HANA schema. It exports a
#          production schema and re-imports it under a new name ("Aurora")
#          to create an up-to-date, non-production environment for testing.
#          Designed to be run via cron, typically in the early morning.
#
# -----------------------------------------------------------------------------

# --- Basic Setup ---
# Exit immediately if any command fails or if an unset variable is used.
set -eu

# --- Configuration ---
# Load the configuration file located in the same directory as the script.
SCRIPT_DIR=$(dirname "$0")
CONFIG_FILE="${SCRIPT_DIR}/aurora.conf"

if [ ! -f "$CONFIG_FILE" ]; then
    echo "❌ FATAL: Configuration file not found at '${CONFIG_FILE}'" >&2
    exit 1
fi
# shellcheck source=aurora.conf
. "$CONFIG_FILE"

# --- Validate Configuration ---
if [ ! -x "$HDBSQL" ]; then
    echo "❌ FATAL: hdbsql is not found or not executable at '${HDBSQL}'" >&2
    exit 1
fi

# --- Derived Variables (Do Not Edit) ---
TIMESTAMP=$(date "+%Y-%m-%d %H:%M:%S")
AURORA_SCHEMA="${SOURCE_SCHEMA}_AURORA"
EXPORT_DIR="${BACKUP_BASE_DIR}/${AURORA_SCHEMA}_TEMP_EXPORT"
COMPANY_NAME_BASE=$(echo "${SOURCE_SCHEMA}" | sed 's/^SBO_//' | sed 's/_PROD$//')

# --- Main Execution ---
echo
echo "🚀 [$(date "+%T")] Starting Aurora Refresh for '${SOURCE_SCHEMA}'"
echo "--------------------------------------------------------"
echo "  Source Schema:      ${SOURCE_SCHEMA}"
echo "  Target Aurora Schema: ${AURORA_SCHEMA}"
echo "  Temp Export Path:   ${EXPORT_DIR}"
echo "--------------------------------------------------------"

# 1. Drop the old Aurora schema if it exists.
echo "🗑️  Dropping old schema '${AURORA_SCHEMA}' (if it exists)..."
"$HDBSQL" -U "$DB_ADMIN_KEY" "DROP SCHEMA \"${AURORA_SCHEMA}\" CASCADE" >/dev/null 2>&1 || echo "   -> Schema did not exist. Continuing."

# 2. Prepare the temporary export directory.
echo "📁 Preparing temporary export directory..."
rm -rf "$EXPORT_DIR"
mkdir -p "$EXPORT_DIR"

# 3. Export the source schema.
echo "⬇️  Exporting source schema '${SOURCE_SCHEMA}' to binary files..."
"$HDBSQL" -U "$DB_ADMIN_KEY" "EXPORT \"${SOURCE_SCHEMA}\".\"*\" AS BINARY INTO '${EXPORT_DIR}' WITH REPLACE;" >/dev/null
echo "   -> Export complete."

# 4. Import the data into the new Aurora schema.
echo "⬆️  Importing data and renaming schema to '${AURORA_SCHEMA}'..."
"$HDBSQL" -U "$DB_ADMIN_KEY" "IMPORT \"${SOURCE_SCHEMA}\".\"*\" FROM '${EXPORT_DIR}' WITH IGNORE EXISTING RENAME SCHEMA \"${SOURCE_SCHEMA}\" TO \"${AURORA_SCHEMA}\";" >/dev/null
echo "   -> Import complete."

# 5. Update company name in CINF and OADM tables.
echo "✍️  Updating company name fields in the new schema..."

# First, get the original company name from the source schema.
# The query returns a header and the name in quotes. sed gets the second line, tr removes the quotes, xargs trims whitespace.
echo "   -> Fetching original company name from '${SOURCE_SCHEMA}'..."
ORIGINAL_COMPNY_NAME=$("$HDBSQL" -U "$DB_ADMIN_KEY" "SELECT \"CompnyName\" FROM \"${SOURCE_SCHEMA}\".\"CINF\"" | sed -n '2p' | tr -d '"' | xargs)

# Construct the new name in the desired format.
DATE_STAMP=$(date "+%Y-%m-%d")
NEW_COMPNY_NAME="AURORA - ${ORIGINAL_COMPNY_NAME} - ${DATE_STAMP}"
echo "   -> New company name set to: '${NEW_COMPNY_NAME}'"

echo "   -> Updating CINF table..."
"$HDBSQL" -U "$DB_ADMIN_KEY" "UPDATE \"${AURORA_SCHEMA}\".CINF SET \"CompnyName\" = '${NEW_COMPNY_NAME}';" >/dev/null

echo "   -> Updating OADM table..."
"$HDBSQL" -U "$DB_ADMIN_KEY" "UPDATE \"${AURORA_SCHEMA}\".OADM SET \"CompnyName\" = '${NEW_COMPNY_NAME}', \"PrintHeadr\" = '${NEW_COMPNY_NAME}';" >/dev/null
echo "   -> Company info updated."

# 6. Grant privileges to the read/write user.
echo "🔑 Granting ALL privileges on '${AURORA_SCHEMA}' to '${AURORA_USER}'..."
"$HDBSQL" -U "$DB_ADMIN_KEY" "GRANT ALL PRIVILEGES ON SCHEMA \"${AURORA_SCHEMA}\" TO \"${AURORA_USER}\";" >/dev/null
echo "   -> Privileges granted."

# 7. Run post-import SQL scripts, if any are defined.
if [ -n "$POST_IMPORT_SQL" ]; then
    echo "⚙️  Running post-import SQL scripts..."
    # Use word splitting intentionally here
    # shellcheck disable=SC2086
    for sql_file in $POST_IMPORT_SQL; do
        full_path="${SQL_SCRIPTS_ROOT}/${sql_file}"
        if [ -f "$full_path" ]; then
            echo "   -> Executing: ${sql_file}"
            "$HDBSQL" -U "$DB_ADMIN_KEY" -I "$full_path"
        else
            echo "   -> ⚠️ WARNING: Script not found: ${full_path}" >&2
        fi
    done
else
    echo "ℹ️  No post-import SQL scripts to run."
fi

# 8. Clean up the temporary export files.
echo "🧹 Cleaning up temporary directory '${EXPORT_DIR}'..."
rm -rf "$EXPORT_DIR"
echo "   -> Cleanup complete."

echo "--------------------------------------------------------"
echo "✅ [$(date "+%T")] Aurora Refresh finished successfully!"
echo

exit 0