#!/bin/bash
set -euo pipefail

echo "============================================"
echo "PostgreSQL Installation Script"
echo "============================================"
echo ""
echo "This script will run the following commands with sudo:"
echo "  - mkdir -p /etc/apt/keyrings"
echo "  - curl ... | gpg --dearmor -o /etc/apt/keyrings/postgresql.gpg"
echo "  - tee /etc/apt/sources.list.d/pgdg.list"
echo "  - apt-get update"
echo "  - apt-get install -y postgresql"
echo ""
read -p "Continue with installation? (y/N) " -n 1 -r
echo
if [[ ! $REPLY =~ ^[Yy]$ ]]; then
    echo "Installation cancelled."
    exit 0
fi

echo ""
echo "Starting installation (commands will be shown as they run)..."
echo ""

# Enable command tracing
set -x

# Create directory for keyrings if it doesn't exist
sudo mkdir -p /etc/apt/keyrings

# Download and install the PostgreSQL GPG key
if [ ! -f /etc/apt/keyrings/postgresql.gpg ]; then
    curl -fsSL https://www.postgresql.org/media/keys/ACCC4CF8.asc | \
        sudo gpg --dearmor -o /etc/apt/keyrings/postgresql.gpg
fi

# Add PostgreSQL repository
echo "deb [signed-by=/etc/apt/keyrings/postgresql.gpg] http://apt.postgresql.org/pub/repos/apt $(lsb_release -cs)-pgdg main" | \
    sudo tee /etc/apt/sources.list.d/pgdg.list > /dev/null

# Update package lists
sudo apt-get update

# Install latest PostgreSQL
sudo apt-get install -y postgresql

# Disable command tracing for cleaner output
set +x

echo ""
echo "============================================"
# Verify installation
if command -v psql &> /dev/null; then
    echo "PostgreSQL installed successfully!"
    psql --version
else
    echo "Error: PostgreSQL installation failed" >&2
    exit 1
fi
echo "============================================"