#!/usr/bin/env bash

# Zion Peer Configuration Generator
# This script generates the exact peer configuration needed for Zion

set -euo pipefail  # Exit on error, undefined vars, pipe failures

# Colors for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m'

# Configuration file for peer information
CONFIG_FILE="$(dirname "$0")/CURRENT_WORKING/zion.conf"

print_status() {
    echo -e "${GREEN}[INFO]${NC} $1"
}

print_warning() {
    echo -e "${YELLOW}[WARNING]${NC} $1"
}

print_error() {
    echo -e "${RED}[ERROR]${NC} $1"
}

print_header() {
    echo -e "${BLUE}================================${NC}"
    echo -e "${BLUE}Zion Peer Configuration Generator${NC}"
    echo -e "${BLUE}================================${NC}"
}

# Validate IP address format and range
validate_ip() {
    local ip="$1"
    
    # Check basic format
    if [[ ! $ip =~ ^10\.8\.0\.([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])$ ]]; then
        return 1
    fi
    
    # Extract last octet
    local last_octet="${ip##*.}"
    
    # Check if IP is in reserved ranges
    if [[ $last_octet -eq 0 ]] || [[ $last_octet -eq 1 ]] || [[ $last_octet -eq 255 ]]; then
        return 1
    fi
    
    return 0
}

# Validate WireGuard public key format
validate_public_key() {
    local key="$1"
    
    # WireGuard keys are base64 encoded and exactly 44 characters long
    if [[ ! $key =~ ^[A-Za-z0-9+/]{43}=$ ]]; then
        return 1
    fi
    
    return 0
}

# Load Zion configuration if available
load_zion_config() {
    if [[ -f "$CONFIG_FILE" ]]; then
        print_status "Found Zion configuration file: $CONFIG_FILE"
        return 0
    else
        print_warning "Zion configuration file not found: $CONFIG_FILE"
        print_warning "Using hardcoded peer information"
        return 1
    fi
}

show_usage() {
    echo "Usage: $0 <node_name> <public_key> <ip_address>"
    echo ""
    echo "Arguments:"
    echo "  node_name   - Name of the node (e.g., mynode)"
    echo "  public_key  - WireGuard public key (base64 encoded)"
    echo "  ip_address  - IP address in 10.8.0.x format"
    echo ""
    echo "Example:"
    echo "  $0 mynode ABC123... 10.8.0.30"
    echo ""
    echo "This will generate the peer configuration to add to Zion's /etc/wireguard/wg0.conf"
    echo ""
    echo "Options:"
    echo "  -c, --config FILE  Use custom Zion config file"
    echo "  -h, --help         Show this help message"
}

main() {
    local config_file="$CONFIG_FILE"
    
    # Parse command line options
    while [[ $# -gt 0 ]]; do
        case $1 in
            -c|--config)
                config_file="$2"
                shift 2
                ;;
            -h|--help)
                show_usage
                exit 0
                ;;
            -*)
                print_error "Unknown option: $1"
                show_usage
                exit 1
                ;;
            *)
                break
                ;;
        esac
    done
    
    print_header
    echo ""

    if [[ $# -ne 3 ]]; then
        print_error "Incorrect number of arguments"
        show_usage
        exit 1
    fi

    local NODE_NAME="$1"
    local PUBLIC_KEY="$2"
    local IP_ADDRESS="$3"

    # Validate node name
    if [[ ! $NODE_NAME =~ ^[a-zA-Z0-9][a-zA-Z0-9_-]*[a-zA-Z0-9]$ ]] && [[ $NODE_NAME != [a-zA-Z0-9] ]]; then
        print_error "Invalid node name format. Use alphanumeric characters, hyphens, and underscores only"
        exit 1
    fi

    # Validate IP address
    if ! validate_ip "$IP_ADDRESS"; then
        print_error "IP address must be in 10.8.0.x format (x cannot be 0, 1, or 255)"
        exit 1
    fi

    # Validate public key
    if ! validate_public_key "$PUBLIC_KEY"; then
        print_error "Invalid WireGuard public key format"
        print_error "Expected: 44 character base64 string ending with ="
        exit 1
    fi

    print_status "Generating Zion peer configuration for: $NODE_NAME"
    echo ""

    echo "Add the following to Zion's /etc/wireguard/wg0.conf:"
    echo "----------------------------------------"
    echo "# $NODE_NAME"
    echo "[Peer]"
    echo "PublicKey = $PUBLIC_KEY"
    echo "AllowedIPs = $IP_ADDRESS/32"
    echo "----------------------------------------"
    echo ""

    print_warning "After adding this to Zion's config:"
    echo "1. Save the file"
    echo "2. Restart Zion's WireGuard: sudo systemctl restart wg-quick@wg0"
    echo "3. Start the new node's WireGuard: sudo wg-quick up $NODE_NAME"
    echo ""

    # Try to load Zion config, fall back to hardcoded if not available
    if ! load_zion_config; then
        # Show hardcoded peer structure
        echo "Zion's current peer structure (add your peer at the end):"
        echo "----------------------------------------"
        echo "#Cth"
        echo "[Peer]"
        echo "PublicKey = NBktXKy1s0n2lIlIMODvOqKNwAtYdoZH5feKt5P43i0="
        echo "AllowedIPs = 10.8.0.10/32"
        echo ""
        echo "#Aza"
        echo "[Peer]"
        echo "PublicKey = qmTKA257DLOrfhk5Zw8RyRmBSonmm6epbloT0P0ZWDc="
        echo "AllowedIPs = 10.8.0.2/32"
        echo ""
        echo "#Nyar"
        echo "[Peer]"
        echo "PublicKey = 2BA7L1oJP1tK6dIUNHMgcZmOmYmlyPRe2RaBqfUsEWo="
        echo "AllowedIPs = 10.8.0.20/32"
        echo ""
        echo "#Galaxy"
        echo "[Peer]"
        echo "PublicKey = QBNt00VSedxPlq3ZvsdYaqIcbudCAyxv9TG65aPVZzM="
        echo "AllowedIPs = 10.8.0.99/32"
        echo ""
        echo "# Add your peer here:"
        echo "# $NODE_NAME"
        echo "# [Peer]"
        echo "# PublicKey = $PUBLIC_KEY"
        echo "# AllowedIPs = $IP_ADDRESS/32"
        echo "----------------------------------------"
    else
        # Parse and display current peers from config file
        print_status "Current peers in Zion configuration:"
        echo "----------------------------------------"
        if grep -E "^#.*" "$config_file" | grep -E "^#[A-Za-z]" | head -10; then
            echo ""
            echo "# Add your peer here:"
            echo "# $NODE_NAME"
            echo "# [Peer]"
            echo "# PublicKey = $PUBLIC_KEY"
            echo "# AllowedIPs = $IP_ADDRESS/32"
        else
            print_warning "No peer sections found in Zion config"
        fi
        echo "----------------------------------------"
    fi
}

# Run main function
main "$@"