{ lib, pkgs, unstablePkgs, ... }:

let
  inherit (pkgs) dockerTools;

  akkomaLocalPort = "1111";
  akkomaDir = "/srv/akkoma";

  akkoma = unstablePkgs.akkoma.overrideAttrs {
    patches = [ ./docker-entrypoint.patch ];
    postInstall = ''
      cp docker-entrypoint.sh $out/docker-entrypoint.sh
    '';
  };

  baseImageArm = dockerTools.pullImage {
    imageName = "alpine";
    imageDigest = "sha256:1e42bbe2508154c9126d48c2b8a75420c3544343bf86fd041fb7527e017a4b4a";
    sha256 = "06c0q5kk60i89y1d83a28wk282ymp806xjcsmlca4cwwqp590j0q";
    finalImageName = "alpine";
    finalImageTag = "3.20.3";
    os = "linux";
    arch = "arm64";
  };

  akkomaImage = dockerTools.buildLayeredImage {
    name = "akkoma";
    tag = akkoma.version;
    fromImage = baseImageArm;

    contents = with unstablePkgs; [
      exiftool imagemagick ffmpeg_7-headless postgresql elixir
    ] ++ [ akkoma ];

    extraCommands = ''
      mkdir -p opt/akkoma
    '';
  };

in
{
  virtualisation.oci-containers.containers = {
    akkoma = {
      imageFile = akkomaImage;
      image = "akkoma:${akkoma.version}";
      ports = [ "127.0.0.1:${akkomaLocalPort}:4000"];

      volumes = [
        "${akkomaDir}/data:/var/lib/akkoma"
        "${akkomaDir}/config:/opt/akkoma/config"
      ];

      # TODO: remove redundant variables
      environment = {
        "RUNTIME_DIRECTORY" = "/opt/akkoma";
        "AKKOMA_CONFIG_PATH" = "/opt/akkoma/config/config.exs";
        "RELEASE_COOKIE" = "99ff9ca022574585269e737cdc4fa28b";
        "RELEASE_NAME" = "akkoma";
        "MIX_ENV" = "prod";
        "DB_NAME" = "akkoma";
        "DB_USER" = "akkoma";
        "DB_PASS" = "akkoma";
        "DB_HOST" = "db";
      };

      entrypoint = "${akkoma}/docker-entrypoint.sh";
      workdir = "${akkoma}";

      extraOptions = [
        "--network-alias=akkoma"
        "--network=akkoma"
      ];
    };

    akkoma-db = {
      # TODO: pull through `dockerTools`.
      image = "postgres:14-alpine";
      volumes = [ "${akkomaDir}/pgdata:/var/lib/postgresql/data" ];

      environment = {
        "POSTGRES_DB" = "akkoma";
        "POSTGRES_USER" = "akkoma";
        "POSTGRES_PASSWORD" = "akkoma";
      };

      extraOptions = [
        "--network-alias=db"
        "--network=akkoma"
      ];
    };
  };

  # systemd configuration to combine containers.
  # mostly condensed from compose2nix output.
  # TODO: make this automatic!!
  systemd = let
    root = "docker-akkoma-root";
    network = "docker-akkoma-network";

    containerService = {
      serviceConfig = {
        Restart = lib.mkOverride 90 "always";
        RestartMaxDelaySec = lib.mkOverride 90 "1m";
        RestartSec = lib.mkOverride 90 "100ms";
        RestartSteps = lib.mkOverride 90 9;
      };
      after = [ "${network}.service" ]; requires = [ "${network}.service" ];
      partOf = [ "${root}.target" ]; wantedBy = [ "${root}.target" ];
    };
  in {
    services = {
      "docker-akkoma-db" = containerService;
      "docker-akkoma" = containerService;

      "${network}" = {
        path = [ pkgs.docker ];
        serviceConfig = {
          Type = "oneshot";
          RemainAfterExit = true;
          ExecStop = "docker network rm -f akkoma";
        };
        script = ''
          docker network inspect akkoma || docker network create akkoma --driver=bridge
        '';
        partOf = [ "${root}.target" ]; wantedBy = [ "${root}.target" ];
      };
    };

    targets = {
      "${root}" = { wantedBy = [ "multi-user.target" ]; };
    };
  };
}