#!/usr/bin/env bash

set -euo pipefail

# Ensure we're in a flakes-enabled environment with required tools
if ! command -v nix &> /dev/null; then
    echo "❌ Nix is not installed. Please install Nix first:"
    echo "curl --proto '=https' --tlsv1.2 -sSf -L https://install.determinate.systems/nix | sh -s -- install"
    exit 1
fi

# Check if we need to enter a new shell
if [ -z "${INSIDE_NIX_SHELL+x}" ]; then
    export NIX_CONFIG="experimental-features = nix-command flakes"
    export INSIDE_NIX_SHELL=1
    exec nix shell nixpkgs#git nixpkgs#mkpasswd --command bash "$0"
fi

# Function to setup from template
setup_from_template() {
    local TEMPLATE=starter
    local DIR_NAME="self-host-playbook"

    if [ -d "$DIR_NAME" ]; then
        echo "📂 Directory '$DIR_NAME' already exists"
        read -p "Do you want to proceed in the existing directory? (y/N) " -n 1 -r
        echo
        if [[ $REPLY =~ ^[Yy]$ ]]; then
            cd "$DIR_NAME"
        else
            echo "❌ Please choose a different directory or remove the existing one"
            exit 1
        fi
    else
        echo "🔄 Creating new self-host-playbook configuration from template..."
        nix flake new --template "git+https://code.m3tam3re.com/m3tam3re/self-host-playbook#${TEMPLATE}" "$DIR_NAME"
        cd "$DIR_NAME"
    fi
}

# Function to generate SSH key
generate_ssh_key() {
    local KEY_NAME="self-host-playbook"
    local KEY_PATH="$HOME/.ssh/${KEY_NAME}"

    if [ ! -f "$KEY_PATH" ]; then
        mkdir -p "$HOME/.ssh"
        echo "🔑 Generating new SSH key pair..." >&2
        ssh-keygen -t ed25519 -f "$KEY_PATH" -N "" >&2
        echo "✅ New SSH key pair generated" >&2
    else
        echo "🔑 Using existing SSH key pair" >&2
    fi

    if [ ! -f "${KEY_PATH}.pub" ]; then
        echo "❌ Error: Public key file not found" >&2
        exit 1
    fi

    printf "%s" "$KEY_PATH"
}

# Function to hash password using mkpasswd
hash_password() {
    local password=$1
    mkpasswd -m sha-512 "$password"
}

# Function to display device detection guide
show_device_guide() {
    echo
    echo "📝 How to find your root device name:"
    echo "------------------------------------"
    echo "1. SSH into your server with the credentials provided by your cloud provider or use the web console"
    echo "2. Run the following command:"
    echo "   lsblk -d -o NAME,SIZE"
    echo
    echo "Look for the main disk, usually the largest one. It will be shown as:"
    echo "- AWS (older): xvda"
    echo "- AWS (newer): nvme0n1"
    echo "- GCP/Azure/Linode: sda"
    echo "- DigitalOcean: vda"
    echo
    echo "The device name will be /dev/[name shown in lsblk]"
    echo
    echo "💡 Example:"
    echo "   NAME SIZE"
    echo "   sda  76.3G"
    echo "   sr0  1024M"
    echo "------------------------------------"
    echo
}

# Function to get device name based on provider
get_device_name() {
    local provider=$1
    case $provider in
        "aws-new")
            echo "/dev/nvme0n1"
            ;;
        "aws-old")
            echo "/dev/xvda"
            ;;
        "gcp")
            echo "/dev/sda"
            ;;
        "azure")
            echo "/dev/sda"
            ;;
        "digitalocean")
            echo "/dev/vda"
            ;;
        "linode")
            echo "/dev/sda"
            ;;
        "hetzner")
            echo "/dev/sda"
            ;;
        *)
            echo "unknown"
            ;;
    esac
}

echo "🚀 Welcome to the Self-Host Playbook!"
echo "================================================"
echo "This script will help you manage your NixOS server with:"
echo "- Portainer (Docker management)"
echo "- n8n (Workflow automation)"
echo "- Baserow (No-code database)"
echo "- Caddy (Automatic HTTPS reverse proxy)"
echo "================================================"
echo

read -p "Press ANY KEY to continue or CTRL + C to abort..."
echo
# Generate SSH key
SSH_KEY_PATH=$(generate_ssh_key) || exit 1
SSH_PUB_KEY=$(cat "${SSH_KEY_PATH}.pub") || {
    echo "❌ Error: Failed to read public key from ${SSH_KEY_PATH}.pub"
    exit 1
}
echo
echo "🔑 Here is your public key:"
echo
cat $SSH_KEY_PATH.pub
echo ""
echo "📁 You can also find the keyfile here:"
echo
echo $SSH_KEY_PATH.pub
echo
read -p "Press ENTER to continue or CTRL + C to abort..."

# Collect user input
echo ""
echo "📝 Please provide the following information:"
echo "-------------------------------------------"
read -p "1. Enter target server IP address: " SERVER_IP
read -p "2. Enter desired username for server access: " USERNAME
read -s -p "3. Enter desired password: " PASSWORD
echo
echo "4. Enter domain names for services (must point to $SERVER_IP):"
read -p "   - Domain for Portainer: " PORTAINER_DOMAIN
read -p "   - Domain for n8n: " N8N_DOMAIN
read -p "   - Domain for Baserow: " BASEROW_DOMAIN
echo
echo "5. How do you authentiate to the target machine?"
echo "-------------------------------------------"
echo "   1) Password"
echo "   2) SSH Key"
echo
read -p "Enter your choice (1-2): " KEY_CHOICE

case $KEY_CHOICE in
    1)
        INSTALL_COMMAND="nix run github:nix-community/nixos-anywhere -- --flake .#server root@$SERVER_IP"
        ;;
    2)
        INSTALL_COMMAND="nix run github:nix-community/nixos-anywhere -- --flake .#server -i $SSH_KEY_PATH root@$SERVER_IP"
        ;;
    *)
        echo "❌ Invalid choice"
        exit 1
        ;;
esac

setup_from_template

echo
echo "6. Select your cloud provider:"
echo "   1) AWS (Newer instances with NVMe)"
echo "   2) AWS (Older instances)"
echo "   3) Google Cloud Platform"
echo "   4) Microsoft Azure"
echo "   5) DigitalOcean"
echo "   6) Linode"
echo "   7) Hetzner"
echo "   8) I'm not sure (Show detection guide)"
echo

read -p "Enter your choice (1-8): " PROVIDER_CHOICE

# Set device name based on provider choice
case $PROVIDER_CHOICE in
    1)
        PROVIDER="aws-new"
        ;;
    2)
        PROVIDER="aws-old"
        ;;
    3)
        PROVIDER="gcp"
        ;;
    4)
        PROVIDER="azure"
        ;;
    5)
        PROVIDER="digitalocean"
        ;;
    6)
        PROVIDER="linode"
        ;;
    7)
        PROVIDER="hetzner"
        ;;
    8)
        show_device_guide
        read -p "Enter your root device name (e.g., /dev/sda): " DEVICE_NAME
        PROVIDER="custom"
        ;;
    *)
        echo "❌ Invalid choice"
        exit 1
        ;;
esac

if [ "$PROVIDER" != "custom" ]; then
    DEVICE_NAME=$(get_device_name "$PROVIDER")
fi

echo
echo "Using root device: $DEVICE_NAME"
read -p "Is this correct? (y/N) " CONFIRM
if [[ ! $CONFIRM =~ ^[Yy]$ ]]; then
    echo "Installation aborted. Please run the script again with the correct device."
    exit 1
fi

echo
echo "🛠️  Preparing server configuration..."

# Hash the password
HASHED_PASSWORD=$(hash_password "$PASSWORD")

echo "📝 Customizing configuration files..."
# Write configuration to JSON file
cat > config.json << EOF
{
  "username": "$USERNAME",
  "hashedPassword": "$HASHED_PASSWORD",
  "sshKey": "$SSH_PUB_KEY",
  "domains": {
    "portainer": "$PORTAINER_DOMAIN",
    "n8n": "$N8N_DOMAIN",
    "baserow": "$BASEROW_DOMAIN"
  },
  "rootDevice": "$DEVICE_NAME"
}
EOF

echo "📦 Setting up environment files..."
# Update environment files with domains
if [[ "$OSTYPE" == "darwin"* ]]; then
    sed -i '' "s/N8N_DOMAIN/$N8N_DOMAIN/g" ./env/n8n.env
    sed -i '' "s/BASEROW_DOMAIN/$BASEROW_DOMAIN/g" ./env/baserow.env
else
    sed -i "s/N8N_DOMAIN/$N8N_DOMAIN/g" ./env/n8n.env
    sed -i "s/BASEROW_DOMAIN/$BASEROW_DOMAIN/g" ./env/baserow.env
fi

echo
echo "⚠️  Important: By proceeding the existing virtual machine will be overwritten!"
echo
read -p "Do you want to proceed? (y/N) " CONFIRM
if [[ ! $CONFIRM =~ ^[Yy]$ ]]; then
    echo "Installation aborted."
    exit 1
fi
echo
echo "🚀 Starting NixOS installation..."
echo "This process might take several minutes..."

# Run nixos-anywhere installation
$INSTALL_COMMAND && {
    echo
    echo "🎉 Installation completed successfully!"
    echo "=====================================>"
    echo "You can now access your services at:"
    echo "- Portainer: https://$PORTAINER_DOMAIN"
    echo "- n8n: https://$N8N_DOMAIN"
    echo "- Baserow: https://$BASEROW_DOMAIN"
    echo
    echo "To connect to your server, use:"
    echo "ssh -i $SSH_KEY_PATH -p 2222 $USERNAME@$SERVER_IP"
    echo
    echo "⚠️  Important: Please save your SSH key path: $SSH_KEY_PATH"
    echo "=====================================>"
} || echo "Command failed with exit status $?"