# SPDX-FileCopyrightText: 2024 Tom Hubrecht <tom.hubrecht@dgnum.eu>
#
# SPDX-License-Identifier: EUPL-1.2

{
  config,
  lib,
  pkgs,
  utils,
  sources,
  ...
}:

let
  inherit (lib) toLower;

  python =
    let
      python3 = pkgs.python312;
      nix-pkgs = import sources.nix-pkgs { inherit pkgs python3; };
    in
    python3.override {
      packageOverrides = _: _: {
        inherit (nix-pkgs)
          django-allauth
          django-allauth-cas
          django-browser-reload
          django-bulma-forms
          django-sass-processor
          django-sass-processor-dart-sass
          django-unfold
          pykanidm
          python-cas
          loadcredential
          xlwt
          ;
      };
    };

  pythonEnv = python.withPackages (
    ps:
    [
      ps.django
      ps.gunicorn
      ps.psycopg
      ps.django-compressor
      ps.django-import-export

      # Local packages
      ps.django-allauth
      ps.django-allauth-cas
      ps.django-browser-reload
      ps.django-bulma-forms
      ps.django-sass-processor
      ps.django-sass-processor-dart-sass
      ps.django-unfold
      ps.loadcredential
      ps.pykanidm
      ps.python-cas
    ]
    ++ ps.django-allauth.optional-dependencies.saml
  );

  staticDrv = pkgs.stdenv.mkDerivation {
    name = "dgsi-static";

    src = sources.dgsi;
    sourceRoot = "source/src";

    nativeBuildInputs = [
      pkgs.dart-sass
      pythonEnv
    ];

    configurePhase = ''
      export DGSI_STATIC_ROOT=$out/static
      export CREDENTIALS_DIRECTORY=$(pwd)/../.credentials
      export DGSI_KANIDM_CLIENT="dgsi_test"
      export DGSI_KANIDM_AUTH_TOKEN="fake.token"
      export DGSI_X509_KEY=""
      export DGSI_X509_CERT=""
    '';

    doBuild = false;

    installPhase = ''
      mkdir -p $out/static
      python3 manage.py compilescss
      python3 manage.py collectstatic
    '';
  };
in

{
  users = {
    users.nginx.extraGroups = [ "django-apps" ];
    groups.django-apps = { };
  };

  systemd = {
    services = {
      dj-dgsi = {
        description = "DGSI web app";

        requires = [ "dj-dgsi.socket" ];
        wantedBy = [ "multi-user.target" ];
        after = [
          "network.target"
          "postgresql.service"
        ];

        serviceConfig = {
          DynamicUser = true;
          LoadCredential = map (name: "${name}:${config.age.secrets."dgsi-${toLower name}_file".path}") [
            "EMAIL_HOST_PASSWORD"
            "KANIDM_AUTH_TOKEN"
            "KANIDM_SECRET"
            "SECRET_KEY"
            "X509_CERT"
            "X509_KEY"
          ];
          RuntimeDirectory = "django-apps/dgsi";
          StateDirectory = "django-apps/dgsi";
          UMask = "0027";
          User = "dj-dgsi";
          Group = "django-apps";
          WorkingDirectory = sources.dgsi;
          ExecReload = "${lib.getExe' pkgs.coreutils "kill"} -s HUP $MAINPID";
          KillMode = "mixed";
          Type = "notify";
          ExecStart = utils.escapeSystemdExecArgs [
            (lib.getExe' pythonEnv "gunicorn")
            "--workers"
            4
            "--bind"
            "unix:/run/django-apps/dgsi.sock"
            "--pythonpath"
            "src"
            "app.wsgi"
          ];
        };

        environment = {
          DGSI_ALLOWED_HOSTS = builtins.toJSON [
            "profil.dgnum.eu"
            "dgsi.dgnum.eu"
          ];

          DGSI_EMAIL_HOST = "kurisu.lahfa.xyz";
          DGSI_EMAIL_HOST_USER = "web-services@infra.dgnum.eu";
          DGSI_EMAIL_USE_SSL = builtins.toJSON true;
          DGSI_FROM_EMAIL = "La Délégation Générale Numérique <noreply@infra.dgnum.eu>";
          DGSI_SERVER_EMAIL = "dgsi@infra.dgnum.eu";

          DGSI_KANIDM_CLIENT = "dgsi";
          DGSI_KANIDM_URI = "https://sso.dgnum.eu";

          DGSI_MEDIA_ROOT = "/var/lib/django-apps/dgsi/media";
          DGSI_STATIC_ROOT = "${staticDrv}/static";

          DGSI_DATABASES = builtins.toJSON {
            default = {
              ENGINE = "django.db.backends.postgresql";
              NAME = "dj-dgsi";
            };
          };
          DJANGO_SETTINGS_MODULE = "app.settings";
        };

        path = [ pythonEnv ];

        preStart = ''
          python3 src/manage.py migrate --no-input
        '';
      };
    };

    sockets."dj-dgsi" = {
      description = "Socket for the DGSI Django Application";
      wantedBy = [ "sockets.target" ];

      socketConfig = {
        ListenStream = "/run/django-apps/dgsi.sock";
        SocketMode = "600";
        SocketUser = config.services.nginx.user;
      };
    };

    mounts = [
      {
        where = "/run/django-apps/dgsi/media";
        what = "/var/lib/django-apps/dgsi/media";
        options = "bind";

        after = [ "dj-dgsi.service" ];
        partOf = [ "dj-dgsi.service" ];
        upheldBy = [ "dj-dgsi.service" ];
      }
    ];
  };

  dgn-redirections.permanent."dgsi.dgnum.eu" = "profil.dgnum.eu";

  services = {
    postgresql = {
      ensureDatabases = [ "dj-dgsi" ];
      ensureUsers = [
        {
          name = "dj-dgsi";
          ensureDBOwnership = true;
        }
      ];
    };

    nginx.virtualHosts."profil.dgnum.eu" = {
      enableACME = true;
      forceSSL = true;

      locations = {
        "/".proxyPass = "http://unix:/run/django-apps/dgsi.sock";
        "/static/".root = staticDrv;
        "/media/".root = "/run/django-apps/dgsi";
      };
    };
  };
}