{
  description = "JupyterHub Notebook Viewer Development Environment";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
    flake-utils.url = "github:numtide/flake-utils";
  };

  outputs = { self, nixpkgs, flake-utils }:
    flake-utils.lib.eachDefaultSystem (system:
      let
        pkgs = nixpkgs.legacyPackages.${system};
        
        # Python with required packages
        python = pkgs.python311.withPackages (ps: with ps; [
          flask
          python-dotenv
          nbformat
          nbconvert
          werkzeug
          jinja2
          markupsafe
          itsdangerous
          click
          blinker
          jupyter-core
          traitlets
          jupyter-client
          ipython
          bleach
          defusedxml
          mistune
          pandocfilters
          beautifulsoup4
          webencodings
          fastjsonschema
          jsonschema
          pyrsistent
          pyzmq
          tornado
          nest-asyncio
          psutil
          packaging
          platformdirs
          debugpy
          matplotlib-inline
          pygments
          cffi
          argon2-cffi
          jupyterlab-pygments
          nbclient
          tinycss2
        ]);

        # Development tools
        devTools = with pkgs; [
          # Core development
          python
          nodejs_20
          
          # System tools
          curl
          jq
          tree
          htop
          
          # Container tools
          docker
          docker-compose
          
          # Documentation tools
          pandoc
          
          # LaTeX for nbconvert
          texlive.combined.scheme-medium
          
          # Version control
          git
          
          # Text editors
          vim
          nano
          
          # Network tools
          netcat
          
          # Process management
          #supervisor
        ];

        # Shell script for easy setup
        setupScript = pkgs.writeShellScriptBin "setup-dev" ''
          echo "Setting up JupyterHub Notebook Viewer development environment..."
          
          # Create directories
          mkdir -p shared notebooks templates
          
          # Copy example .env if it doesn't exist
          if [ ! -f .env ]; then
            cp .env.example .env 2>/dev/null || echo "No .env.example found, using defaults"
          fi
          
          # Set up git hooks if in git repo
          if [ -d .git ]; then
            echo "Setting up git hooks..."
            cp .githooks/* .git/hooks/ 2>/dev/null || true
          fi
          
          # Create sample notebook if shared directory is empty
          if [ ! "$(ls -A shared)" ]; then
            echo "Creating sample notebook..."
            cat > shared/sample.ipynb << 'EOF'
          {
           "cells": [
            {
             "cell_type": "markdown",
             "metadata": {},
             "source": [
              "# Sample Notebook\n",
              "\n",
              "This is a sample Jupyter notebook for testing the viewer."
             ]
            },
            {
             "cell_type": "code",
             "execution_count": null,
             "metadata": {},
             "outputs": [],
             "source": [
              "print('Hello from JupyterHub Notebook Viewer!')\n",
              "import numpy as np\n",
              "import matplotlib.pyplot as plt\n",
              "\n",
              "x = np.linspace(0, 10, 100)\n",
              "y = np.sin(x)\n",
              "\n",
              "plt.figure(figsize=(10, 6))\n",
              "plt.plot(x, y)\n",
              "plt.title('Sample Plot')\n",
              "plt.xlabel('X')\n",
              "plt.ylabel('sin(x)')\n",
              "plt.grid(True)\n",
              "plt.show()"
             ]
            }
           ],
           "metadata": {
            "kernelspec": {
             "display_name": "Python 3",
             "language": "python",
             "name": "python3"
            },
            "language_info": {
             "name": "python",
             "version": "3.11.0"
            }
           },
           "nbformat": 4,
           "nbformat_minor": 4
          }
          EOF
          fi
          
          echo "Development environment setup complete!"
          echo "Run 'python app.py' to start the development server"
        '';

        # Script for running tests
        testScript = pkgs.writeShellScriptBin "run-tests" ''
          echo "Running tests for JupyterHub Notebook Viewer..."
          
          # Basic import test
          python -c "
          import app
          print('✓ App imports successfully')
          
          # Test configuration loading
          from dotenv import load_dotenv
          load_dotenv()
          print('✓ Environment variables loaded')
          
          # Test nbconvert
          import nbformat
          import nbconvert
          print('✓ Jupyter dependencies working')
          "
          
          # Test Flask app creation
          python -c "
          import app
          test_app = app.app.test_client()
          response = test_app.get('/')
          if response.status_code in [200, 404]:  # 404 is OK if no shared dir
            print('✓ Flask app responds correctly')
          else:
            print('✗ Flask app error:', response.status_code)
            exit(1)
          "
          
          echo "All tests passed!"
        '';

        # Development server with auto-reload
        devServerScript = pkgs.writeShellScriptBin "dev-server" ''
          echo "Starting development server with auto-reload..."
          export FLASK_DEBUG=True
          export FLASK_ENV=development
          
          # Load .env file
          if [ -f .env ]; then
            export $(cat .env | grep -v '^#' | xargs)
          fi
          
          # Start the server
          python app.py
        '';

      in
      {
        # Development shell
        devShells.default = pkgs.mkShell {
          buildInputs = devTools ++ [
            setupScript
            testScript
            devServerScript
          ];

          shellHook = ''
            echo "🚀 JupyterHub Notebook Viewer Development Environment"
            echo "=================================================="
            echo ""
            echo "Available commands:"
            echo "  setup-dev     - Set up development environment"
            echo "  dev-server    - Start development server with auto-reload"
            echo "  run-tests     - Run basic tests"
            echo "  python app.py - Start the application"
            echo ""
            echo "Docker commands:"
            echo "  docker-compose up              - Start with Docker"
            echo "  docker-compose up --build      - Rebuild and start"
            echo "  docker-compose up -d           - Start in background"
            echo "  docker-compose --profile with-proxy up - Start with nginx proxy"
            echo ""
            echo "Configuration:"
            echo "  Edit .env file to configure the application"
            echo "  JUPYTERHUB_SHARED_DIR: $(echo ''${JUPYTERHUB_SHARED_DIR:-/shared})"
            echo ""
            
            # Auto-setup on first run
            if [ ! -f .env ] && [ ! -d shared ]; then
              echo "First run detected, running setup..."
              setup-dev
            fi
          '';

          # Environment variables for development
          FLASK_DEBUG = "True";
          FLASK_ENV = "development";
          PYTHONPATH = ".";
        };

        # Package for the application
        packages.default = pkgs.stdenv.mkDerivation {
          pname = "jupyterhub-notebook-viewer";
          version = "1.0.0";

          src = ./.;

          buildInputs = [ python ];

          installPhase = ''
            mkdir -p $out/bin $out/share/jupyterhub-notebook-viewer
            
            # Copy application files
            cp app.py $out/share/jupyterhub-notebook-viewer/
            cp -r templates $out/share/jupyterhub-notebook-viewer/
            
            # Create wrapper script
            cat > $out/bin/jupyterhub-notebook-viewer << EOF
            #!${pkgs.bash}/bin/bash
            cd $out/share/jupyterhub-notebook-viewer
            exec ${python}/bin/python app.py "\$@"
            EOF
            chmod +x $out/bin/jupyterhub-notebook-viewer
          '';

          meta = with pkgs.lib; {
            description = "Web viewer for JupyterHub shared notebooks";
            license = licenses.mit;
            platforms = platforms.unix;
          };
        };

        # Docker image build
        packages.docker = pkgs.dockerTools.buildImage {
          name = "jupyterhub-notebook-viewer";
          tag = "latest";
          
          contents = [ python pkgs.pandoc ];
          
          config = {
            Cmd = [ "${python}/bin/python" "/app/app.py" ];
            WorkingDir = "/app";
            ExposedPorts = {
              "5000/tcp" = {};
            };
          };
        };

        # Formatter for nix files
        formatter = pkgs.nixpkgs-fmt;
      });
}