setup

#!/usr/bin/env bash

set -o errexit
set -o errtrace
set -o nounset 
set -o pipefail

# Read the URL from the 'latest' file
LATEST=`cat latest`
# Extract the filename from the URL (e.g., postcodesio-2023.tar.gz)
LATEST_FILENAME=$(basename "$LATEST")

echo "Postcodes.io Database Setup Script"
echo "----------------------------------"
echo ""
echo "In order to create, setup and download your database we need Postgresql user credentials with superuser privileges to carry out some operations.\n"
echo "Your Postgresql user credentials will be used to:"
echo "- Create a new database"
echo "- Create a new Postgresql user and password for the new database. If user already exists this step is skipped"
echo "- Stream the latest pg_dump (at $LATEST) to your newly created database"
echo "- Apply read-only privileges for the new user to the new database"
echo ""

# --- Configuration Section (Updated for Non-Interactive Mode) ---

# 1. Postgres Superuser
if [ -z "${POSTGRES_SUPERUSER:-}" ]; then
    read -p "Postgresql Superuser (for database creation) [default: postgres]:" POSTGRES_SUPERUSER
fi
POSTGRES_SUPERUSER=${POSTGRES_SUPERUSER:-postgres}

# 2. App User
if [ -z "${POSTGRES_USER:-}" ]; then
    read -p "New Database Username (for readonly access) [default: postcodesio]:" POSTGRES_USER
fi
POSTGRES_USER=${POSTGRES_USER:-postcodesio}

# 3. App Password
if [ -z "${POSTGRES_PASSWORD:-}" ]; then
    read -p "Password for new user [default: secret]:" POSTGRES_PASSWORD
fi
POSTGRES_PASSWORD=${POSTGRES_PASSWORD:-secret}

# 4. Host
if [ -z "${POSTGRES_HOST:-}" ]; then
    read -p "Postgresql Host [default: localhost]:" POSTGRES_HOST
fi
POSTGRES_HOST=${POSTGRES_HOST:-localhost}

# 5. Database Name
# Handle mismatch: user might set POSTGRES_DATABASE, script expects POSTGRES_DB
if [ -z "${POSTGRES_DB:-}" ]; then
    # Fallback to POSTGRES_DATABASE if set, otherwise prompt
    if [ -n "${POSTGRES_DATABASE:-}" ]; then
        POSTGRES_DB="$POSTGRES_DATABASE"
    else
        read -p "Database Name [default: postcodesiodb]:" POSTGRES_DB
    fi
fi
POSTGRES_DB=${POSTGRES_DB:-postcodesiodb}

# 6. Port
if [ -z "${POSTGRES_PORT:-}" ]; then
    read -p "Postgresql Port: [default: 5432]:" POSTGRES_PORT
fi
POSTGRES_PORT=${POSTGRES_PORT:-5432}

PSQL="psql --username=$POSTGRES_SUPERUSER --host=$POSTGRES_HOST --port=$POSTGRES_PORT"

# --- Database Logic ---

# Create postgres user
# With thanks to Erwin Brandstetter (http://stackoverflow.com/questions/8092086/create-postgresql-role-user-if-it-doesnt-exist)
echo "\nCreating new user $POSTGRES_USER if it does not already exist..."

$PSQL --quiet --command="DO
\$body\$
BEGIN
   IF NOT EXISTS (
      SELECT *
      FROM   pg_catalog.pg_user
      WHERE  usename = '$POSTGRES_USER') THEN

      CREATE ROLE $POSTGRES_USER LOGIN PASSWORD '$POSTGRES_PASSWORD';
   END IF;
END
\$body\$"

echo "Done\n"

sleep 1

# Create Database
echo "Creating new database called $POSTGRES_DB..."
if createdb -p $POSTGRES_PORT -h $POSTGRES_HOST -U $POSTGRES_SUPERUSER $POSTGRES_DB
then
	echo "Done\n"
else
	echo "Failed to create database. Please check the error message and take action"
	exit 1
fi

sleep 1

# --- Import Logic (Updated for Local File Check) ---

echo "Preparing to import dataset..."

if [ -f "$LATEST_FILENAME" ]; then
    # Case A: Local file exists
    echo "Found local file: $LATEST_FILENAME"
    echo "Importing from local file...\n"
    echo "Please wait a few minutes for this operation to finish...\n"

    # Check if the file is gzipped based on extension or just try gunzip
    cat "$LATEST_FILENAME" | gunzip -c | $PSQL --dbname=$POSTGRES_DB -v ON_ERROR_STOP=1 --quiet
else
    # Case B: Local file not found, use original streaming download
    echo "Local file '$LATEST_FILENAME' not found."
    echo "Downloading latest dataset from $LATEST and importing to Postgresql (Streaming)...\n"
    echo "Please wait a few minutes for this operation to finish...\n"

    wget -O - $LATEST | gunzip -c | $PSQL --dbname=$POSTGRES_DB -v ON_ERROR_STOP=1 --quiet
fi

echo "Done\n"

# Grant Permissions on App User
echo "Granting read (SELECT) permissions on new user..."

COMMAND="GRANT CONNECT ON DATABASE $POSTGRES_DB TO $POSTGRES_USER; \
GRANT SELECT ON ALL TABLES IN SCHEMA public TO $POSTGRES_USER; \
"

if echo $COMMAND | $PSQL --dbname=$POSTGRES_DB
then
	echo "Done\n"
else
	echo "Failed to grant privileges. Please check the error message and take action"
	exit 1
fi

echo "Database setup is complete"
echo ""
echo "Run the API server with the right database credentials to proceed:"
echo "POSTGRES_USER=$POSTGRES_USER POSTGRES_DATABASE=$POSTGRES_DB POSTGRES_PASSWORD=$POSTGRES_PASSWORD POSTGRES_HOST=$POSTGRES_HOST npm start"
echo "Alternatively update those credentials in your .env file"