{
  description = "A flake for building development environment of Phoenix project.";

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

  outputs = {
    self,
    nixpkgs,
    flake-utils,
  }:
    flake-utils.lib.eachDefaultSystem (
      system: let
        pkgs = nixpkgs.legacyPackages.${system};
        erl = pkgs.beam.interpreters.erlang_27;
        erlangPackages = pkgs.beam.packagesWith erl;
        elixir = erlangPackages.elixir;
      in {
        packages = let
          version = "0.1.0";
          src = ./.;
          mixFodDeps = erlangPackages.fetchMixDeps {
            inherit version src;
            pname = "putzplan";
            sha256 = "sha256-H8FFuNayJcFvESWlGYr6H6L5zSzAjqBixBmob5Gnoc4=";
          };
          translatedPlatform =
            pkgs.lib.getAttr
            system
            {
              aarch64-darwin = "macos-arm64";
              aarch64-linux = "linux-arm64";
              armv7l-linux = "linux-armv7";
              x86_64-darwin = "macos-x64";
              x86_64-linux = "linux-x64";
            };
        in rec {
          default = erlangPackages.mixRelease {
            inherit version src mixFodDeps;
            pname = "putzplan";

            preInstall = ''
              ln -s ${pkgs.tailwindcss}/bin/tailwindcss _build/tailwind-${translatedPlatform}
              ln -s ${pkgs.esbuild}/bin/esbuild _build/esbuild-${translatedPlatform}

              ${elixir}/bin/mix assets.deploy
              ${elixir}/bin/mix phx.gen.release
            '';
          };
          dockerImage = pkgs.dockerTools.buildImage {
            name = "putzplan";
            config = {
              Entrypoint = "${default}/bin/putzplan";
              Cmd = "start";
            };
          };
        };
        devShells.default = pkgs.mkShell {
          buildInputs = with pkgs;
            [
              erl
              elixir
              lexical
              erlangPackages.elixir-ls
              next-ls

              gnumake
              authelia
              lazysql

              nix-output-monitor
            ]
            ++ lib.optionals stdenv.isLinux [
              # For ExUnit Notifier on Linux.
              libnotify

              # For file_system on Linux.
              inotify-tools
            ]
            ++ lib.optionals stdenv.isDarwin [
              # For ExUnit Notifier on macOS.
              terminal-notifier

              # For file_system on macOS.
              darwin.apple_sdk.frameworks.CoreFoundation
              darwin.apple_sdk.frameworks.CoreServices
            ];

          shellHook = ''
            export OIDC_CLIENT_ID="putzplan"
            export OIDC_BASE_URL="http://127.0.0.1:9091"
            export OIDC_CLIENT_SECRET_FILE="${pkgs.writeText "client_secret" "insecure_secret"}"
            export OIDC_REDIRECT_URI="http://127.0.0.1:4000/auth"

            # allows mix to work on the local directory
            mkdir -p .nix/{mix,hex}
            export MIX_HOME=$PWD/.nix/mix
            export HEX_HOME=$PWD/.nix/hex
            export ERL_LIBS=$HEX_HOME/lib/erlang/lib

            # concats PATH
            export PATH=$MIX_HOME/bin:$PATH
            export PATH=$MIX_HOME/escripts:$PATH
            export PATH=$HEX_HOME/bin:$PATH

            # enables history for IEx
            export ERL_AFLAGS="-kernel shell_history enabled -kernel shell_history_path '\"$PWD/.nix/erlang-history\"'"
          '';
        };
      }
    );
}