#!/usr/bin/env bash
set -e

# Define a wrapper for gum to handle Nix run fallback and TTY redirection
gum() {
    local cmd="$1"
    shift
    local GUM_CMD
    if command -v gum >/dev/null 2>&1; then
        GUM_CMD="gum"
    else
        # Use --quiet to avoid progress bars in captured output
        GUM_CMD="nix run --quiet --extra-experimental-features nix-command --extra-experimental-features flakes nixpkgs#gum --"
    fi

    case "$cmd" in
        input|confirm|choose|filter|write)
            $GUM_CMD "$cmd" "$@" < /dev/tty
            ;;
        *)
            $GUM_CMD "$cmd" "$@"
            ;;
    esac
}

clear
gum style \
    --foreground 212 --border-foreground 212 --border double \
    --align center --width 50 --margin "1 2" --padding "2 4" \
    "NOMARCHY" "The Omarchy-flavored NixOS"

echo "This script will generate your private downstream environment."
echo ""

# 1. Gather User Information
USERNAME=$(gum input --placeholder "Enter your Linux username")
HOSTNAME=$(gum input --placeholder "Enter a hostname for this machine (e.g., nomarchy-sys)")

# 2. Setup the Local Directory
LOCAL_DIR="$HOME/.nomarchy"
echo "Creating local downstream repository at $LOCAL_DIR..."
mkdir -p "$LOCAL_DIR"/{system,home,secrets}

# 3. Harvest the Hardware Configuration
# A barebones install leaves this in /etc/nixos. We need it.
echo "Copying hardware configuration..."
sudo cp /etc/nixos/hardware-configuration.nix "$LOCAL_DIR/system/"
sudo chown "$USER:users" "$LOCAL_DIR/system/hardware-configuration.nix"

# 4. Generate the Downstream Flake
echo "Drafting your private flake.nix..."
cat <<EOF > "$LOCAL_DIR/flake.nix"
{
  description = "Private Downstream Machine Config (Nomarchy)";

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixos-25.11";
    home-manager = {
      url = "github:nix-community/home-manager/release-25.11";
      inputs.nixpkgs.follows = "nixpkgs";
    };
    
    # The Public Upstream Core
    nomarchy.url = "git+https://git.bemagri.xyz/bernardo/Nomarchy.git";
  };

  outputs = { self, nixpkgs, home-manager, nomarchy, ... }@inputs: 
  let
    system = "x86_64-linux";
    targetUser = "$USERNAME";
  in {
    # THE SYSTEM DOMAIN
    nixosConfigurations."$HOSTNAME" = nixpkgs.lib.nixosSystem {
      inherit system;
      specialArgs = { inputs = nomarchy.inputs // inputs; }; 
      modules = [ 
        ./system/hardware-configuration.nix
        ./system/configuration.nix
        nomarchy.nixosModules.system
      ];
    };

    # THE USER DOMAIN
    homeConfigurations."$USERNAME" = home-manager.lib.homeManagerConfiguration {
      pkgs = nixpkgs.legacyPackages."\${system}";
      extraSpecialArgs = { inputs = nomarchy.inputs // inputs; inherit targetUser; }; 
      modules = [ 
        nomarchy.nixosModules.home
        ./home/home.nix
      ];
    };
  };
}
EOF

# 5. Generate the Scaffolding Files
cat <<EOF > "$LOCAL_DIR/system/configuration.nix"
{ pkgs, ... }: {
  networking.hostName = "$HOSTNAME";
  
  # Add your private cryptography and C++ toolchains here later!
  environment.systemPackages = with pkgs; [ gcc cmake gdb ];
}
EOF

cat <<EOF > "$LOCAL_DIR/home/home.nix"
{ ... }: {
  home.username = "$USERNAME";
  home.homeDirectory = "/home/$USERNAME";
  home.stateVersion = "25.11";
  
  home.shellAliases = {
    update-sys = "sudo nixos-rebuild switch --flake ~/.nomarchy#$HOSTNAME";
    update-home  = "nix run home-manager/release-25.11 -- switch --flake ~/.nomarchy#$USERNAME";
  };
}
EOF

# 6. Initialize Version Control
echo "Initializing Git repository..."
nix run nixpkgs#git -- -C "$LOCAL_DIR" init
nix run nixpkgs#git -- -C "$LOCAL_DIR" add .

# 7. Execution
clear
gum style \
    --foreground 212 --border-foreground 212 --border normal \
    --align center --width 50 --margin "1 2" --padding "1 2" \
    "Ready for Genesis"
echo "Your private downstream configuration has been generated."

if gum confirm "Build Nomarchy OS now? (This will take a few minutes)"; then
    echo "Building System Engine..."
    sudo nixos-rebuild switch --flake "$LOCAL_DIR#$HOSTNAME" --extra-experimental-features "nix-command flakes"
    
    echo "Building User Interface..."
    nix run home-manager/release-25.11 -- switch --flake "$LOCAL_DIR#$USERNAME"
    
    clear
    gum style \
        --foreground 212 --border-foreground 212 --border double \
        --align center --width 50 --margin "1 2" --padding "2 4" \
        "Installation Complete"
    echo "Welcome to Nomarchy OS. Reboot to enter your new environment."
else
    echo "Aborted. You can review your files in $LOCAL_DIR and run the build manually later."
fi