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

  outputs = {
    self,
    nixpkgs,
  }: {
    templates = {
      default = {
        description = ".NET dev environment (FHS) with SDK, EF Core, and optional Rider support";
        welcomeText = ''
          .NET skeletal project created.
          - Build:   dotnet build
          - Run:     dotnet run
          - Rider:   rider . (inside nix develop)
        '';
        path = ./.;
      };
    };

    devShells = let
      supportedSystems = [
        "x86_64-linux"
        "aarch64-linux"
        "x86_64-darwin"
        "aarch64-darwin"
      ];
    in
      nixpkgs.lib.genAttrs supportedSystems (
        system: let
          pkgs = import nixpkgs {
            inherit system;
            config.allowUnfree = true;
          };
          fhs = pkgs.buildFHSEnv {
            name = "dotnet-fhs-shell";
            targetPkgs = pkgs: [
              pkgs.dotnet-sdk
              pkgs.dotnet-ef
              pkgs.dotnet-aspnetcore
              pkgs.csharpier
              pkgs.icu
              pkgs.openssl
              pkgs.krb5
              pkgs.zlib
              pkgs.git
              pkgs.gnumake
            ];
            runScript = "bash";
            profile = ''
              export DOTNET_ROOT=${pkgs.dotnet-sdk}
              export DOTNET_CLI_HOME=$HOME/.dotnet
              export DOTNET_SKIP_FIRST_TIME_EXPERIENCE=1
              export DOTNET_CLI_TELEMETRY_OPTOUT=1
              export PATH=${pkgs.dotnet-sdk}/bin:$PATH
            '';
          };
        in {
          default = fhs.env.overrideAttrs (_: {
            shellHook = ''
              # Initialize git repository if not already present
              if [ ! -d .git ]; then
                git init
                echo "✓ Initialized git repository"
              fi

              export DOTNET_ROOT=${pkgs.dotnet-sdk}
              export DOTNET_CLI_HOME=$HOME/.dotnet
              export DOTNET_SKIP_FIRST_TIME_EXPERIENCE=1
              export DOTNET_CLI_TELEMETRY_OPTOUT=1
              export PATH=${pkgs.dotnet-sdk}/bin:$PATH
              echo "FHS shell for .NET development"
              echo "DOTNET_ROOT=$DOTNET_ROOT"
            '';
          });
        }
      );

    packages = let
      supportedSystems = [
        "x86_64-linux"
        "aarch64-linux"
        "x86_64-darwin"
        "aarch64-darwin"
      ];
    in
      nixpkgs.lib.genAttrs supportedSystems (
        system: let
          pkgs = import nixpkgs {
            inherit system;
            config.allowUnfree = true;
          };
        in {
          default = pkgs.buildDotnetModule {
            pname = "sample-dotnet-app";
            version = "0.1.0";
            src = ./.;
            projectFile = "SampleApp.csproj";
            nugetDeps = ./deps.nix;
            selfContainedBuild = false;
            meta.mainProgram = "SampleApp";
          };

          devHelper = pkgs.writeShellScriptBin "dev-helper" ''
            echo ".NET dev environment"
            command -v dotnet >/dev/null 2>&1 && dotnet --version || true
            echo "This binary is built by Nix (packages.devHelper)."
          '';
        }
      );

    apps = let
      supportedSystems = [
        "x86_64-linux"
        "aarch64-linux"
        "x86_64-darwin"
        "aarch64-darwin"
      ];
    in
      nixpkgs.lib.genAttrs supportedSystems (
        system: let
          pkgs = nixpkgs.legacyPackages.${system};
        in {
          default = {
            type = "app";
            program = pkgs.lib.getExe self.packages.${system}.default;
          };
          dev-helper = {
            type = "app";
            program = pkgs.lib.getExe self.packages.${system}.devHelper;
          };
        }
      );
  };
}