{
  description = "flake for pluralkit";

  inputs = {
    nixpkgs.url = "nixpkgs/nixpkgs-unstable";
    parts.url = "github:hercules-ci/flake-parts";
    systems.url = "github:nix-systems/default";
    # process compose
    process-compose.url = "github:Platonic-Systems/process-compose-flake";
    services.url = "github:juspay/services-flake";
    # rust
    d2n.url = "github:nix-community/dream2nix";
    d2n.inputs.nixpkgs.follows = "nixpkgs";
    nci.url = "github:yusdacra/nix-cargo-integration";
    nci.inputs.parts.follows = "parts";
    nci.inputs.nixpkgs.follows = "nixpkgs";
    nci.inputs.dream2nix.follows = "d2n";
    nci.inputs.treefmt.follows = "treefmt";
    # misc
    treefmt.url = "github:numtide/treefmt-nix";
    treefmt.inputs.nixpkgs.follows = "nixpkgs";
    flake-compat.url = "https://flakehub.com/f/edolstra/flake-compat/1.tar.gz";
  };

  outputs =
    inp:
    inp.parts.lib.mkFlake { inputs = inp; } {
      systems = import inp.systems;
      imports = [
        inp.process-compose.flakeModule
        inp.nci.flakeModule
        inp.treefmt.flakeModule
      ];
      perSystem =
        {
          config,
          self',
          pkgs,
          lib,
          system,
          ...
        }:
        let
          # this is used as devshell for bot, and in the process-compose processes as environment
          mkBotEnv =
            cmd:
            pkgs.buildFHSEnv {
              name = "env";
              targetPkgs =
                pkgs: with pkgs; [
                  coreutils
                  git
                  dotnet-sdk_8
                  gcc
                  omnisharp-roslyn
                  bashInteractive
                ];
              runScript = cmd;
            };

          rustOutputs = config.nci.outputs;
          composeCfg = config.process-compose."dev";
        in
        {
          # _module.args.pkgs = import inp.nixpkgs {
          #   inherit system;
          #   config.permittedInsecurePackages = [ "dotnet-sdk-6.0.428" ];
          # };

          treefmt = {
            projectRootFile = "flake.nix";
            programs.nixfmt.enable = true;
          };

          nci.toolchainConfig = {
            channel = "nightly";
          };
          nci.projects."pluralkit-services" = {
            path = ./.;
            export = false;
          };
          # nci.crates."gateway" = {
          #   depsDrvConfig.mkDerivation = {
          #     nativeBuildInputs = [ pkgs.protobuf ];
          #   };
          #   drvConfig.mkDerivation = {
          #     nativeBuildInputs = [ pkgs.protobuf ];
          #   };
          # };

          # TODO: expose other rust packages after it's verified they build and work properly
          packages = lib.genAttrs ["gateway"] (name: rustOutputs.${name}.packages.release);
          # TODO: package the bot itself (dotnet)

          devShells = {
            services = rustOutputs."pluralkit-services".devShell;
            bot = (mkBotEnv "bash").env;
            docs = pkgs.mkShellNoCC {
              buildInputs = with pkgs; [ nodejs yarn ];
              NODE_OPTIONS = "--openssl-legacy-provider";
            };
          };

          process-compose."dev" = let
            dataDir = ".nix-process-compose";
            sourceDotenv = ''
              # shellcheck disable=SC2046
              [[ -f ".env" ]] && echo "sourcing .env file..." && export $(xargs < .env)
            '';
          in {
            imports = [ inp.services.processComposeModules.default ];

            settings.log_location = "${dataDir}/log";

            settings.environment = {
              DOTNET_CLI_TELEMETRY_OPTOUT = "1";
              NODE_OPTIONS = "--openssl-legacy-provider";
            };

            services.redis."redis" = {
              enable = true;
              dataDir = "${dataDir}/redis";
            };
            services.postgres."postgres" = {
              enable = true;
              dataDir = "${dataDir}/postgres";
              initialScript.before = ''
                CREATE DATABASE pluralkit;
                CREATE USER postgres WITH password 'postgres';
                GRANT ALL PRIVILEGES ON DATABASE pluralkit TO postgres;
                ALTER DATABASE pluralkit OWNER TO postgres;
              '';
            };

            settings.processes =
              let
                procCfg = composeCfg.settings.processes;
                mkServiceInitProcess =
                  {
                    name,
                    inputs ? [ ],
                    ...
                  }:
                  let
                    shell = rustOutputs.${name}.devShell;
                  in
                  {
                    command = pkgs.writeShellApplication {
                      name = "pluralkit-${name}-init";
                      runtimeInputs =
                        (with pkgs; [
                          coreutils
                          shell.stdenv.cc
                        ])
                        ++ shell.nativeBuildInputs
                        ++ inputs;
                      text = ''
                        ${sourceDotenv}
                        set -x
                        exec cargo build --bin ${name}
                      '';
                    };
                  };
              in
              {
                ### bot ###
                pluralkit-bot-init = {
                  command = pkgs.writeShellApplication {
                    name = "pluralkit-bot-init";
                    runtimeInputs = [
                      pkgs.coreutils
                      pkgs.git
                    ];
                    text = ''
                      ${sourceDotenv}
                      set -x
                      exec ${mkBotEnv "dotnet build -c Release -o obj/"}/bin/env
                    '';
                  };
                };
                pluralkit-bot = {
                  command = pkgs.writeShellApplication {
                    name = "pluralkit-bot";
                    runtimeInputs = [ pkgs.coreutils ];
                    text = ''
                      ${sourceDotenv}
                      set -x
                      exec ${mkBotEnv "dotnet obj/PluralKit.Bot.dll"}/bin/env
                    '';
                  };
                  depends_on.pluralkit-bot-init.condition = "process_completed_successfully";
                  depends_on.postgres.condition = "process_healthy";
                  depends_on.redis.condition = "process_healthy";
                  depends_on.pluralkit-gateway.condition = "process_healthy";
                  # TODO: add liveness check
                  ready_log_line = "Received Ready";
                };
                ### migrations ###
                pluralkit-migrate-init = mkServiceInitProcess {
                  name = "migrate";
                };
                pluralkit-migrate = {
                  command = pkgs.writeShellApplication {
                    name = "pluralkit-migrate";
                    text = ''
                      ${sourceDotenv}
                      set -x
                      exec target/debug/migrate
                    '';
                  };
                  depends_on.postgres.condition = "process_healthy";
                  depends_on.pluralkit-migrate-init.condition = "process_completed_successfully";
                };
                ### gateway ###
                pluralkit-gateway-init = mkServiceInitProcess {
                  name = "gateway";
                };
                pluralkit-gateway = {
                  command = pkgs.writeShellApplication {
                    name = "pluralkit-gateway";
                    runtimeInputs = with pkgs; [
                      coreutils
                      curl
                      gnugrep
                    ];
                    text = ''
                      ${sourceDotenv}
                      set -x
                      exec target/debug/gateway
                    '';
                  };
                  depends_on.postgres.condition = "process_healthy";
                  depends_on.redis.condition = "process_healthy";
                  depends_on.pluralkit-gateway-init.condition = "process_completed_successfully";
                  # configure health checks
                  # TODO: don't assume port?
                  liveness_probe.exec.command = ''curl -s -o /dev/null -w "%{http_code}" http://localhost:5000/stats | grep "302"'';
                  liveness_probe.period_seconds = 5;
                  readiness_probe.exec.command = procCfg.pluralkit-gateway.liveness_probe.exec.command;
                  readiness_probe.period_seconds = 5;
                  readiness_probe.initial_delay_seconds = 3;
                };
                # TODO: add the rest of the services
              };
          };
        };
    };
}