# Java Service Template - Quick Start Guide

This guide explains how to initialize the database, establish Flyway baseline, and start the application.

## Prerequisites

Before running the application, ensure you have:

1. **Java 21** installed
2. **Maven** installed  
3. **PostgreSQL** server running locally (or configure external access)
4. **Redis** server running locally (or configure external access)

## Quick Start Script

The project includes a script to automate the entire setup process:

### Using the Start Script

```bash
# Make the script executable (if not already done)
chmod +x start_app.sh

# Run the complete setup and start the application
./start_app.sh
```

This script will:
1. Check PostgreSQL connectivity
2. Build the application using Maven
3. Create the database named `java_template`
4. Establish Flyway baseline and run migrations
5. Start the application

### Manual Steps (Alternative)

If you prefer to run the steps manually:

#### 1. Build the Application
```bash
mvn clean package -DskipTests
```

#### 2. Set Up Database

Make sure PostgreSQL is running, then:

```bash
# Connect to PostgreSQL as superuser
psql -h localhost -p 5432 -U postgres

# Create the database
CREATE DATABASE java_template;
\q
```

#### 3. Run the Application with Flyway

```bash
# The application will automatically run Flyway migrations on startup
java -jar tmpl-api/target/tmpl-api-0.1.0-SNAPSHOT.jar \
  -Dspring.profiles.active=dev \
  -DDB_HOST=localhost \
  -DDB_PORT=5432 \
  -DDB_NAME=java_template \
  -DDB_USER=postgres \
  -DDB_PASS=postgres
```

## Configuration

The application uses the following default configuration:

- **Database**: PostgreSQL at `localhost:5432`, database name `java_template`
- **Database User**: `postgres` with password `postgres`
- **Redis**: At `localhost:6379`
- **Application Port**: `8080`
- **Management Port**: `8080` (in dev profile, merged with app port)

These can be overridden using environment variables:
- `DB_HOST`, `DB_PORT`, `DB_NAME`, `DB_USER`, `DB_PASS`
- `REDIS_HOST`, `REDIS_PORT`

## Database Migrations

The application includes Flyway migrations:
- `V1__init.sql`: Basic schema initialization
- `V2__create_order.sql`: Creates the order table with audit columns

Flyway will automatically apply these migrations on application startup.

## Accessing the Application

Once started, the application will be available at:
- **Main endpoint**: http://localhost:8080
- **API Documentation**: http://localhost:8080/swagger-ui.html
- **Health check**: http://localhost:8080/actuator/health
- **Metrics**: http://localhost:8080/actuator/prometheus

## Troubleshooting

### Common Issues:

1. **PostgreSQL not accessible**: Make sure PostgreSQL server is running and accessible
2. **Database permissions**: Ensure the database user has CREATE privileges
3. **Port conflicts**: Check if ports 8080 and 6379 are available
4. **Connection timeouts**: Verify network connectivity to database and Redis

### Environment Variables:

You can customize the configuration using environment variables:

```bash
export DB_HOST=localhost
export DB_PORT=5432
export DB_NAME=java_template
export DB_USER=postgres
export DB_PASS=postgres
export REDIS_HOST=localhost
export REDIS_PORT=6379
```

Then run the application normally.