# Copyright Tom Hubrecht, (2023)
#
# Tom Hubrecht <tom@hubrecht.ovh>
#
# This software is a computer program whose purpose is to configure
# machines and servers with NixOS.
#
# This software is governed by the CeCILL  license under French law and
# abiding by the rules of distribution of free software.  You can  use,
# modify and/ or redistribute the software under the terms of the CeCILL
# license as circulated by CEA, CNRS and INRIA at the following URL
# "http://www.cecill.info".
#
# As a counterpart to the access to the source code and  rights to copy,
# modify and redistribute granted by the license, users are provided only
# with a limited warranty  and the software's author,  the holder of the
# economic rights,  and the successive licensors  have only  limited
# liability.
#
# In this respect, the user's attention is drawn to the risks associated
# with loading,  using,  modifying and/or developing or reproducing the
# software by the user in light of its specific status of free software,
# that may mean  that it is complicated to manipulate,  and  that  also
# therefore means  that it is reserved for developers  and  experienced
# professionals having in-depth computer knowledge. Users are therefore
# encouraged to load and test the software's suitability as regards their
# requirements in conditions enabling the security of their systems and/or
# data to be ensured and,  more generally, to use and operate it in the
# same conditions as regards security.
#
# The fact that you are presently reading this means that you have had
# knowledge of the CeCILL license and that you accept its terms.

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

let
  inherit (lib)
    mdDoc mkDefault mkEnableOption mkIf mkOption

    optional optionalString

    types;

  cfg = config.services.demarches-simplifiees;

  settingsFormat = pkgs.formats.keyValue { };

  env = settingsFormat.generate "ds-fr-env" cfg.settings;

  ds-fr = pkgs.writeShellScriptBin "ds-fr" ''
    set -a
    cd ${cfg.package}

    ${optionalString (cfg.secretFile != null) "source ${cfg.secretFile}"}
    source ${env}

    BIN="$1"
    shift

    SUDO="exec"
    if [[ $USER != ${cfg.user} ]]; then
      SUDO='exec /run/wrappers/bin/sudo -u ${cfg.user} --preserve-env'
    fi

    $SUDO ${cfg.package}/bin/$BIN "$@"
  '';

in {
  options.services.demarches-simplifiees = {
    enable = mkEnableOption "demarches-simplifiees.";

    package = mkOption {
      type = types.package;
      default = pkgs.callPackage ./package {
        inherit (cfg) initialDeploymentDate dataDir logDir;
      };
    };

    user = mkOption {
      type = types.str;
      default = "ds-fr";
      description = mdDoc "User account under which DS runs.";
    };

    group = mkOption {
      type = types.str;
      default = "ds-fr";
      description = mdDoc "Group account under which DS runs.";
    };

    dataDir = mkOption {
      type = types.str;
      default = "/var/lib/ds-fr";
    };

    logDir = mkOption {
      type = types.str;
      default = "/var/log/ds-fr";
    };

    secretFile = mkOption {
      type = types.nullOr types.path;
      default = null;
    };

    settings = mkOption { inherit (settingsFormat) type; };

    initialDeploymentDate = mkOption {
      type = types.nullOr types.str;
      default = null;
    };
  };

  config = mkIf cfg.enable {
    services.demarches-simplifiees.settings =
      (builtins.mapAttrs (_: mkDefault) {
        RAILS_ENV = "production";
        RAILS_ROOT = builtins.toString cfg.package;

        # Application host name
        #
        # Examples:
        # * For local development: localhost:3000
        # * For preproduction: staging.ds.example.org
        # * For production: ds.example.org
        APP_HOST = "localhost:3000";

        # Rails key for signing sensitive data
        # See https://guides.rubyonrails.org/security.html
        #
        # For production you MUST generate a new key, and keep it secret.
        # Secrets must be long and random. Use bin/rails secret to get new unique secrets.

        # Secret key for One-Time-Password codes, used for 2-factors authentication
        # OTP_SECRET_KEY = "";

        # Protect access to the instance with a static login/password (useful for staging environments)
        BASIC_AUTH_ENABLED = "disabled";
        BASIC_AUTH_USERNAME = "";
        BASIC_AUTH_PASSWORD = "";

        # ActiveStorage service to use for attached files.
        # Possible values:
        # - "local": store files on the local filesystem
        # - "amazon": store files remotely on an S3 storage service
        # - "openstack": store files remotely on an OpenStack storage service
        #
        # (See config/storage.yml for the configuration of each service.)
        ACTIVE_STORAGE_SERVICE = "local";

        # Configuration for the OpenStack storage service (if enabled)
        FOG_OPENSTACK_API_KEY = "";
        FOG_OPENSTACK_USERNAME = "";
        FOG_OPENSTACK_URL = "";
        FOG_OPENSTACK_REGION = "";
        DS_PROXY_URL = "";

        # SAML
        SAML_IDP_ENABLED = "disabled";

        # External service: authentication through France Connect
        FC_PARTICULIER_ID = "";
        FC_PARTICULIER_SECRET = "";
        FC_PARTICULIER_BASE_URL = "";

        # External service: authentication through Agent Connect
        AGENT_CONNECT_ID = "";
        AGENT_CONNECT_SECRET = "";
        AGENT_CONNECT_BASE_URL = "";
        AGENT_CONNECT_JWKS = "";
        AGENT_CONNECT_REDIRECT = "";

        # External service: integration with HelpScout (optional)
        HELPSCOUT_MAILBOX_ID = "";
        HELPSCOUT_CLIENT_ID = "";
        HELPSCOUT_CLIENT_SECRET = "";
        HELPSCOUT_WEBHOOK_SECRET = "";

        # External service: external supervision
        SENTRY_ENABLED = "disabled";
        SENTRY_CURRENT_ENV = "development";
        SENTRY_DSN_RAILS = "";
        SENTRY_DSN_JS = "";

        # External service: Matomo web analytics
        MATOMO_ENABLED = "disabled";
        MATOMO_COOKIE_DOMAIN = "*.www.demarches-simplifiees.fr";
        MATOMO_DOMAIN = "*.www.demarches-simplifiees.fr";
        MATOMO_ID = "";
        MATOMO_HOST = "matomo.example.org";

        # Default SMTP Provider: Mailjet
        MAILJET_API_KEY = "";
        MAILJET_SECRET_KEY = "";

        # Alternate SMTP Provider: SendInBlue/DoList
        SENDINBLUE_CLIENT_KEY = "";
        SENDINBLUE_SMTP_KEY = "";
        SENDINBLUE_USER_NAME = "";
        # SENDINBLUE_LOGIN_URL="https://app.sendinblue.com/account/saml/login/truc"

        # Alternate SMTP Provider: Mailtrap (mail catcher for staging environments)
        # When enabled, all emails will be sent using this provider
        MAILTRAP_ENABLED = "disabled";
        MAILTRAP_USERNAME = "";
        MAILTRAP_PASSWORD = "";

        # Alternative SMTP Provider: Mailcatcher (Catches mail and serves it through a dream.)
        # When enabled, all emails will be sent using this provider
        MAILCATCHER_ENABLED = "disabled";
        MAILCATCHER_HOST = "";
        MAILCATCHER_PORT = "";

        # External service: live chat for admins (specific to démarches-simplifiées.fr)
        CRISP_ENABLED = "disabled";
        CRISP_CLIENT_KEY = "";

        # API Entreprise credentials
        # https://api.gouv.fr/api/api-entreprise.html
        API_ENTREPRISE_KEY = "";

        # External service: CRM for following admin accounts pipeline (specific to démarches-simplifiées.fr)
        PIPEDRIVE_KEY = "";

        # Networks bypassing the email login token that verifies new devices, and rack-attack throttling
        TRUSTED_NETWORKS = "";

        # External service: mesuring performance of the Rails app (specific to démarches-simplifiées.fr)
        SKYLIGHT_AUTHENTICATION_KEY = "";
        #   "sXaot-fKhBlkI8qaSirQyuZbrpv5sVFoOturQ0pFEh0";

        # Enable or disable Lograge logs
        LOGRAGE_ENABLED = "disabled";

        # Logs source for Lograge
        #
        # Examples:
        # * For local development: tps_local
        # * For preproduction: tps_staging
        # * For production: tps_prod
        LOGRAGE_SOURCE = "tps_prod";

        # External service: timestamping a daily archive of dossiers status changes
        UNIVERSIGN_API_URL = "https://ws.universign.eu/tsa/post/";
        UNIVERSIGN_USERPWD = "";

        # External service: API Geo / Adresse
        API_ADRESSE_URL = "https://api-adresse.data.gouv.fr";
        API_GEO_URL = "https://geo.api.gouv.fr";

        # External service: API Education
        API_EDUCATION_URL = "https://data.education.gouv.fr/api/records/1.0";

        # Encryption key for sensitive columns in the database
        ENCRYPTION_SERVICE_SALT = "";

        # ActiveRecord encryption keys. Generate them with bin/rails db:encryption:init (you can omit deterministic_key)
        AR_ENCRYPTION_PRIMARY_KEY = "";
        AR_ENCRYPTION_KEY_DERIVATION_SALT = "";

        # Salt for invisible_captcha session data.
        # Must be the same value for all app instances behind a load-balancer.
        INVISIBLE_CAPTCHA_SECRET = "kikooloool";

        # Clamav antivirus usage
        CLAMAV_ENABLED = "disabled";

        # Siret number used for API Entreprise, by default we use SIRET from dinum
        API_ENTREPRISE_DEFAULT_SIRET = "put_your_own_siret";
      }) // {
        # Database credentials
        DB_DATABASE = "ds-fr";
        DB_USERNAME = cfg.user;
        DB_PASSWORD = "";
        DB_HOST = "/run/postgresql";
        DB_POOL = "";

        # Log on stdout
        RAILS_LOG_TO_STDOUT = true;
      };

    environment.systemPackages = [ ds-fr ];

    systemd.tmpfiles.rules = [
      "f '${cfg.logDir}/production.log' 0640 ${cfg.user} ${cfg.group} - -"
      "f '${cfg.dataDir}/.env' 0600 ${cfg.user} ${cfg.group} - -"
      "d '${cfg.dataDir}/tmp' 0700 ${cfg.user} ${cfg.group} 10d -"
    ];

    systemd.services = {
      ds-fr-setup = {
        description = "Demarches Simplifiees setup";

        wantedBy = [ "multi-user.target" ];
        path = [ pkgs.bash ds-fr ];
        after = [ "postgresql.service" ];

        serviceConfig = {
          Type = "oneshot";
          User = cfg.user;
          Group = cfg.group;
          EnvironmentFile = [ env ]
            ++ (optional (cfg.secretFile != null) cfg.secretFile);
          StateDirectory = mkIf (cfg.dataDir == "/var/lib/ds-fr") "ds-fr";
          LogsDirectory = mkIf (cfg.logDir == "/var/log/ds-fr") "ds-fr";
        };

        script = ''
          [[ ! -f ${cfg.dataDir}/.initial-migration ]] \
            && ds-fr rails db:environment:set \
            && ds-fr rails db:schema:load \
            && ds-fr rails db:seed \
            && touch ${cfg.dataDir}/.initial-migration

          ds-fr rake db:migrate
          ds-fr rake after_party:run
        '';
      };

      ds-fr-work = {
        description = "Demarches Simplifiees work service";

        wantedBy = [ "multi-user.target" "ds-fr.service" ];
        after = [ "network.target" "ds-fr-setup.service" ];
        requires = [ "ds-fr-setup.service" ];

        serviceConfig = {
          ExecStart = "${ds-fr}/bin/ds-fr rails jobs:work";
          EnvironmentFile = [ env ]
            ++ (optional (cfg.secretFile != null) cfg.secretFile);
          User = cfg.user;
          Group = cfg.group;
          StateDirectory = mkIf (cfg.dataDir == "/var/lib/ds-fr") "ds-fr";
          LogsDirectory = mkIf (cfg.logDir == "/var/log/ds-fr") "ds-fr";
        };
      };

      ds-fr = {
        description = "Demarches Simplifiees web service";

        wantedBy = [ "multi-user.target" ];
        after = [ "network.target" "ds-fr-setup.service" ];
        requires = [ "ds-fr-setup.service" ];

        serviceConfig = {
          ExecStart = "${ds-fr}/bin/ds-fr rails server";
          Environment = [ "RAILS_QUEUE_ADAPTER=delayed_job" ];
          EnvironmentFile = [ env ]
            ++ (optional (cfg.secretFile != null) cfg.secretFile);
          User = cfg.user;
          Group = cfg.group;
          StateDirectory = mkIf (cfg.dataDir == "/var/lib/ds-fr") "ds-fr";
          LogsDirectory = mkIf (cfg.logDir == "/var/log/ds-fr") "ds-fr";
        };
      };
    };

    services.postgresql = {
      enable = true;

      ensureDatabases = [ "ds-fr" ];

      ensureUsers = optional (cfg.user == "ds-fr") {
        name = "ds-fr";
        ensurePermissions = { "DATABASE \"ds-fr\"" = "ALL PRIVILEGES"; };
      };

      extraPlugins = with config.services.postgresql.package.pkgs; [ postgis ];
    };

    users.users = mkIf (cfg.user == "ds-fr") {
      ds-fr = {
        inherit (cfg) group;

        isSystemUser = true;
        home = cfg.package;
      };
    };

    users.groups.${cfg.group} = { };

    services.nginx = {
      enable = true;

      virtualHosts.${cfg.settings.APP_HOST} = {
        enableACME = true;
        forceSSL = true;
        root = "${cfg.package}/public/";

        locations."/".tryFiles = "$uri @proxy";
        locations."@proxy" = { proxyPass = "http://127.0.0.1:3000"; };
      };
    };

  };
}