flake.nix

{
  description = "Huggingface space flake";
  inputs.nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
  outputs = { self, nixpkgs }:
    let
      supportedSystems = [ "x86_64-linux" "x86_64-darwin" "aarch64-linux" "aarch64-darwin" ];
      forAllSystems = nixpkgs.lib.genAttrs supportedSystems;
      genPkgs = forAllSystems (system: nixpkgs.legacyPackages.${system});
      
      # Extract values from README.md front matter
      readmeContent = builtins.readFile ./README.md;
      lines = builtins.split "\n" readmeContent;
      
      # Helper function to extract YAML front matter values
      extractYamlValue = key: 
        let
          matchingLines = builtins.filter (line: 
            builtins.isString line && builtins.match "${key}: .*" line != null
          ) lines;
        in
        if matchingLines != [] then
          let match = builtins.match "${key}: (.*)" (builtins.head matchingLines);
          in if match != null then builtins.head match else null
        else null;
      
      sdk = extractYamlValue "sdk";
      appPort = extractYamlValue "app_port";
    in
    {      
      packages = forAllSystems (system: let
        pkgs = genPkgs.${system};

        pythonEnv = pkgs.python3.withPackages (ps: with ps; [
          gradio
        ]);
      in {
        default = pkgs.stdenv.mkDerivation {
          pname = "gradio-app";
          version = "0.1.0";
          src = ./.;
          buildInputs = with pkgs; [
            pythonEnv
          ];
          dontBuild = true;
          installPhase = ''
            mkdir -p $out/bin
            cp ${./app.py} $out/bin/app.py
            
            # Create bash script to run gradio with python
            cat > $out/bin/run-gradio << 'EOF'
            #!/usr/bin/env bash
            set -euo pipefail
            
            # Set default port if not provided
            PORT=''${PORT:-${appPort}}
            
            echo "Starting Gradio app on port $PORT..."
            cd "$(dirname "$0")"
            ${pythonEnv}/bin/python app.py --server-port "$PORT" --server-name 0.0.0.0
            EOF
            
            chmod +x $out/bin/run-gradio
          '';
          meta.mainProgram = "run-gradio";
        };
        gradio-docker = pkgs.dockerTools.buildImage {
          name = "gradio-app-image";
          tag = "latest";
          contents = [ self.packages.${system}.default ];
          config = {
            Cmd = [ "${self.packages.${system}.default}/bin/run-gradio" ];
            ExposedPorts = {
              "${appPort}/tcp" = {};
            };
            Env = [
              "PORT=${appPort}"
              "GRADIO_SERVER_NAME=0.0.0.0"
            ];
          };
        };
      });

      # devShells = forAllSystems (system: let
      # in {
      #   default = pkgs.${system}.mkShell {
      #     buildInputs = with pkgs.${system}; [
      #       (python3.withPackages (ps: with ps; [
      #         gradio
      #       ]))
      #     ];
      #   };
      # });
    };
}