#!/usr/bin/env bash
# Nomarchy Installer
# Interactive TUI installer for existing NixOS systems

set -euo pipefail

# Colors
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
CYAN='\033[0;36m'
NC='\033[0m' # No Color
BOLD='\033[1m'

# Detect if we're running from flake or locally
NOMARCHY_FLAKE="${NOMARCHY_FLAKE:-github:blu/nomarchy}"

print_banner() {
    echo -e "${CYAN}"
    cat << 'EOF'
    _   __                          __
   / | / /___  ____ ___  ____ _____/ /___  __
  /  |/ / __ \/ __ `__ \/ __ `/ __/ / __/ / /
 / /|  / /_/ / / / / / / /_/ / / / / /__ / /
/_/ |_/\____/_/ /_/ /_/\__,_/_/ /_/\___//_/

EOF
    echo -e "${NC}"
    echo -e "${BOLD}An opinionated NixOS configuration with Hyprland${NC}"
    echo ""
}

check_requirements() {
    echo -e "${BLUE}Checking requirements...${NC}"

    if [ ! -f /etc/NIXOS ]; then
        echo -e "${RED}Error: This installer requires NixOS.${NC}"
        echo "For other Linux distributions, please use the ISO installer."
        exit 1
    fi

    if [ "$(id -u)" = "0" ]; then
        echo -e "${RED}Error: Do not run this installer as root.${NC}"
        echo "The installer will use sudo when needed."
        exit 1
    fi

    echo -e "${GREEN}Requirements met!${NC}"
    echo ""
}

prompt_username() {
    local current_user
    current_user=$(whoami)

    echo -e "${BOLD}Username${NC}"
    echo -e "Current user: ${CYAN}${current_user}${NC}"
    read -rp "Enter username (press Enter for '${current_user}'): " username
    username="${username:-$current_user}"
    echo ""
}

prompt_hostname() {
    local current_hostname
    current_hostname=$(hostname)

    echo -e "${BOLD}Hostname${NC}"
    echo -e "Current hostname: ${CYAN}${current_hostname}${NC}"
    read -rp "Enter hostname (press Enter for '${current_hostname}'): " hostname_input
    hostname_input="${hostname_input:-$current_hostname}"
    echo ""
}

prompt_timezone() {
    local current_tz
    current_tz=$(timedatectl show --property=Timezone --value 2>/dev/null || echo "UTC")

    echo -e "${BOLD}Timezone${NC}"
    echo -e "Current timezone: ${CYAN}${current_tz}${NC}"
    echo "Common timezones: America/New_York, America/Los_Angeles, Europe/London, Asia/Tokyo"
    read -rp "Enter timezone (press Enter for '${current_tz}'): " timezone
    timezone="${timezone:-$current_tz}"
    echo ""
}

prompt_locale() {
    echo -e "${BOLD}Locale${NC}"
    echo "Default: en_US.UTF-8"
    read -rp "Enter locale (press Enter for 'en_US.UTF-8'): " locale
    locale="${locale:-en_US.UTF-8}"
    echo ""
}

prompt_keyboard() {
    echo -e "${BOLD}Keyboard Layout${NC}"
    echo "Default: us"
    echo "Examples: us, uk, de, fr, es, us,gr (multiple separated by comma)"
    read -rp "Enter keyboard layout(s): " keyboard
    keyboard="${keyboard:-us}"

    echo "Keyboard variants (leave empty for default):"
    echo "Example: ,polytonic (for Greek polytonic as second layout)"
    read -rp "Enter keyboard variant(s): " keyboard_variant
    keyboard_variant="${keyboard_variant:-}"
    echo ""
}

prompt_location() {
    echo -e "${BOLD}Location (for Gammastep night light)${NC}"
    echo "Enter coordinates for automatic night light adjustment."
    echo "Leave empty to disable or set manually later."
    read -rp "Latitude (e.g., 40.7): " lat
    read -rp "Longitude (e.g., -74.0): " lon
    lat="${lat:-0}"
    lon="${lon:-0}"
    echo ""
}

prompt_features() {
    echo -e "${BOLD}Optional Features${NC}"

    read -rp "Enable Syncthing file sync? [Y/n]: " syncthing
    syncthing="${syncthing:-y}"
    [[ "$syncthing" =~ ^[Yy] ]] && enable_syncthing="true" || enable_syncthing="false"

    read -rp "Enable Mullvad VPN? [y/N]: " mullvad
    mullvad="${mullvad:-n}"
    [[ "$mullvad" =~ ^[Yy] ]] && enable_mullvad="true" || enable_mullvad="false"

    read -rp "Enable printing support? [Y/n]: " printing
    printing="${printing:-y}"
    [[ "$printing" =~ ^[Yy] ]] && enable_printing="true" || enable_printing="false"

    echo ""
    echo -e "${YELLOW}WARNING: The following option disables CPU security mitigations.${NC}"
    echo "This improves performance but reduces security. Only enable if you understand the risks."
    read -rp "Enable mitigations=off (insecure)? [y/N]: " mitigations
    mitigations="${mitigations:-n}"
    [[ "$mitigations" =~ ^[Yy] ]] && enable_mitigations_off="true" || enable_mitigations_off="false"

    echo ""
}

generate_config() {
    local config_dir="$HOME/.config/nomarchy"
    mkdir -p "$config_dir/wallpapers"

    echo -e "${BLUE}Generating configuration...${NC}"

    # Parse keyboard layouts into Nix list format
    local kb_layouts_nix
    kb_layouts_nix=$(echo "$keyboard" | sed 's/,/" "/g' | sed 's/^/"/' | sed 's/$/"/')

    local kb_variants_nix
    if [ -n "$keyboard_variant" ]; then
        kb_variants_nix=$(echo "$keyboard_variant" | sed 's/,/" "/g' | sed 's/^/"/' | sed 's/$/"/')
    else
        kb_variants_nix='""'
    fi

    cat > "$config_dir/config.nix" << EOF
# Nomarchy User Configuration
# Generated by nomarchy-install on $(date)
{
  username = "${username}";
  hostname = "${hostname_input}";
  timezone = "${timezone}";
  locale = "${locale}";
  keyboardLayouts = [${kb_layouts_nix}];
  keyboardVariants = [${kb_variants_nix}];

  # Location for Gammastep (night light)
  location = {
    lat = ${lat};
    lon = ${lon};
  };

  # Features
  enableSyncthing = ${enable_syncthing};
  enableMullvad = ${enable_mullvad};
  enablePrinting = ${enable_printing};
  enableBluetooth = true;

  # Performance (security tradeoff)
  enableMitigationsOff = ${enable_mitigations_off};

  # Theme
  theme = "classical";
}
EOF

    echo -e "${GREEN}Configuration saved to ${config_dir}/config.nix${NC}"
    echo ""
}

setup_flake() {
    local config_dir="$HOME/.config/nomarchy"

    echo -e "${BLUE}Setting up flake...${NC}"

    cat > "$config_dir/flake.nix" << EOF
{
  description = "My Nomarchy Configuration";

  inputs = {
    nomarchy.url = "${NOMARCHY_FLAKE}";
    nixpkgs.follows = "nomarchy/nixpkgs";
  };

  outputs = { self, nomarchy, nixpkgs, ... }@inputs: let
    userConfig = import ./config.nix;
  in {
    nixosConfigurations.\${userConfig.hostname} = nomarchy.lib.mkHost {
      system = "x86_64-linux";
      config = userConfig;
      extraModules = [
        # Add your hardware-configuration.nix here
        /etc/nixos/hardware-configuration.nix

        # Add any custom modules here
        # ./my-custom-module.nix
      ];
    };
  };
}
EOF

    echo -e "${GREEN}Flake created at ${config_dir}/flake.nix${NC}"
    echo ""
}

download_wallpapers() {
    local wallpaper_dir="$HOME/.config/nomarchy/wallpapers"

    echo -e "${BLUE}Setting up wallpapers...${NC}"

    # Create a default wallpaper (simple gradient)
    # In production, this would download from the nomarchy repo
    if command -v convert &> /dev/null; then
        convert -size 1920x1080 gradient:'#1a1611-#2d2620' "$wallpaper_dir/default.jpg" 2>/dev/null || true
    fi

    echo -e "${YELLOW}Note: Copy your wallpapers to ${wallpaper_dir}${NC}"
    echo ""
}

show_summary() {
    echo -e "${BOLD}Configuration Summary${NC}"
    echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
    echo -e "Username:    ${CYAN}${username}${NC}"
    echo -e "Hostname:    ${CYAN}${hostname_input}${NC}"
    echo -e "Timezone:    ${CYAN}${timezone}${NC}"
    echo -e "Locale:      ${CYAN}${locale}${NC}"
    echo -e "Keyboard:    ${CYAN}${keyboard}${NC}"
    echo -e "Syncthing:   ${CYAN}${enable_syncthing}${NC}"
    echo -e "Mullvad:     ${CYAN}${enable_mullvad}${NC}"
    echo -e "Printing:    ${CYAN}${enable_printing}${NC}"
    echo -e "Mitigations: ${CYAN}${enable_mitigations_off}${NC}"
    echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
    echo ""
}

apply_config() {
    local config_dir="$HOME/.config/nomarchy"

    echo -e "${YELLOW}Ready to apply configuration.${NC}"
    read -rp "Apply now? This will rebuild NixOS. [y/N]: " apply

    if [[ "$apply" =~ ^[Yy] ]]; then
        echo -e "${BLUE}Applying configuration...${NC}"
        echo ""

        cd "$config_dir"

        # Update flake inputs
        nix flake update

        # Rebuild
        sudo nixos-rebuild switch --flake ".#${hostname_input}"

        echo ""
        echo -e "${GREEN}Configuration applied successfully!${NC}"
        echo -e "Please ${BOLD}log out and log back in${NC} to start Hyprland."
    else
        echo ""
        echo -e "${YELLOW}Configuration saved but not applied.${NC}"
        echo "To apply later, run:"
        echo -e "  ${CYAN}cd ~/.config/nomarchy && sudo nixos-rebuild switch --flake .#${hostname_input}${NC}"
    fi
}

main() {
    print_banner
    check_requirements

    echo -e "${BOLD}Let's configure your Nomarchy installation.${NC}"
    echo ""

    prompt_username
    prompt_hostname
    prompt_timezone
    prompt_locale
    prompt_keyboard
    prompt_location
    prompt_features

    show_summary

    read -rp "Proceed with this configuration? [Y/n]: " proceed
    proceed="${proceed:-y}"

    if [[ ! "$proceed" =~ ^[Yy] ]]; then
        echo "Installation cancelled."
        exit 0
    fi

    generate_config
    setup_flake
    download_wallpapers
    apply_config

    echo ""
    echo -e "${GREEN}${BOLD}Nomarchy installation complete!${NC}"
    echo ""
    echo "Next steps:"
    echo "  1. Log out and select 'Hyprland' from the session menu"
    echo "  2. Press Super+/ for Quick Actions menu"
    echo "  3. Press Super+R for app launcher"
    echo "  4. See ~/.config/nomarchy/README.md for more info"
    echo ""
}

main "$@"