sp-mastodon-module/module.nix

{
  config,
  lib,
  pkgs,
  ...
}:
let
  sp = config.selfprivacy;
  cfg = sp.modules.mastodon;
  oauthClientID = "mastodon";
  auth-passthru = config.selfprivacy.passthru.auth;
  oauthDiscoveryURL = config.services.kanidm.serverSettings.origin;
  issuer = lib.strings.removeSuffix "/.well-known/openid-configuration" oauthDiscoveryURL;

  usersGroup = "sp.mastodon.users";
  adminsGroup = "sp.mastodon.admins";

  oauthClientSecretFP = auth-passthru.mkOAuth2ClientSecretFP oauthClientID;
  oauthRedirectURL = "https://${cfg.subdomain}.${sp.domain}/auth/auth/openid_connect/callback";

  # emailPassword = pkgs.runCommand "genpassword" {} "echo `head -c 32 /dev/urandom | base64 | sed 's/[+=\\/A-Z]//g'` > $out";
  # emailPasswordHash = pkgs.runCommand "genpassword" {} "echo `head -c 32 /dev/urandom | base64 | sed 's/[+=\\/A-Z]//g'` > $out";
in
{
  options.selfprivacy.modules.mastodon = {
    enable =
      (lib.mkOption {
        default = false;
        type = lib.types.bool;
        description = "Enable Mastodon";
      })
      // {
        meta = {
          type = "enable";
        };
      };
    location =
      (lib.mkOption {
        type = lib.types.str;
        description = "Mastodon location";
      })
      // {
        meta = {
          type = "location";
        };
      };
    subdomain =
      (lib.mkOption {
        default = "mastodon";
        type = lib.types.strMatching "[A-Za-z0-9][A-Za-z0-9\-]{0,61}[A-Za-z0-9]";
        description = "Subdomain";
      })
      // {
        meta = {
          widget = "subdomain";
          type = "string";
          regex = "[A-Za-z0-9][A-Za-z0-9\-]{0,61}[A-Za-z0-9]";
          weight = 0;
        };
      };
  };

  config = lib.mkIf cfg.enable {
    assertions = [
      {
        assertion = sp.sso.enable;
        message = "Mastodon cannot be enabled when SSO is disabled.";
      }
    ];

    fileSystems = lib.mkIf sp.useBinds {
      "/var/lib/mastodon" = {
        device = "/volumes/${cfg.location}/mastodon";
        options = [ "bind" ];
      };
    };

    # services.postgresql = {
    #   ensureDatabases = [ "mastodon" ];
    #   ensureUsers = [
    #     {
    #       name = "mastodon";
    #       ensureDBOwnership = true;
    #     }
    #   ];
    # };

    services.mastodon = {
      enable = true;
      localDomain = "${cfg.subdomain}.${sp.domain}";
      enableUnixSocket = false;
      configureNginx = true;
      database.createLocally = true;
      streamingProcesses = 3;

      smtp = {
        createLocally = false;
        user = "noreply.mastodon@${sp.domain}";
        fromAddress = "noreply.mastodon@${sp.domain}";
        passwordFile = "/run/keys/mastodon/email_password";
        authenticate = true;
      };
    };

    mailserver.loginAccounts."noreply.mastodon@${sp.domain}" = {
      hashedPassword = "/run/keys/mastodon/email_password";
      sendOnly = true;
    };

    services.postfix.config.virtual_mailbox_maps = [ "hash:/run/postfix/mastodon.cf" ];

    systemd = {
      services.mastodon-email-password-setup = {
        enable = true;
        wantedBy = [ "multi-user.target" "mastodon-web.service" "postfix.service" ];
        serviceConfig = {
          Type = "oneshot";
          ExecStart = pkgs.writeShellScript "gen-mastodon-email-password" ''
            export password=$(head -c 32 /dev/urandom | base64 | sed 's/[+=\\/A-Z]//g')

            rm -f /run/keys/mastodon/email_password || true
            mkdir /run/keys/mastodon/ || true # Create /run/keys/mastodon if it doesn't exist
            echo $password > /run/keys/mastodon/email_password
            chmod 400 /run/keys/mastodon/email_password
            chown ${config.services.mastodon.user}:${config.services.mastodon.group} /run/keys/mastodon/email_password

            rm -f /run/postfix/mastodon.cf || true
            mkdir /run/postfix/ || true # Create /run/postfix if it doesn't exist
            export hashedPassword=$(mkpasswd -sm bcrypt "$password")
            echo "noreply.mastodon@${sp.domain}: $hashedPassword" > /run/postfix/mastodon.cf
            chmod 440 /run/postfix/mastodon.cf
            chown ${config.services.postfix.user}:${config.services.postfix.group} /run/postfix/mastodon.cf
          '';
        };
      };

      services.mastodon-web = {
        unitConfig.RequiresMountsFor = lib.mkIf sp.useBinds "/volumes/${cfg.location}/mastodon";
        serviceConfig = {
          loadCredentials = ["client-secret:${oauthClientSecretFP}"];
          ExecStart = lib.mkForce pkgs.writeShellScript "run-mastodon-with-client-secret" ''
            export CLIENT_SECRET=$(cat $CREDENTIALS_DIRECTORY/client-secret)
            ${config.services.mastodon.package}/bin/puma -C config/puma.rb`
          '';
        };
        environment = {
          OIDC_ENABLED = "true";
          OIDC_DISPLAY_NAME= "Kanidm";
          OIDC_ISSUER = issuer;
          OIDC_DISCOVERY = "true";
          OIDC_SCOPE = "openid,profile";
          OIDC_UID_FIELD = "sub";
          OIDC_CLIENT_ID = oauthClientID;
          OIDC_REDIRECT_URI = oauthRedirectURL;
        };        
      };
      slices.mastodon = {
        description = "Mastodon service slice";
      };
    };

    selfprivacy.auth.clients.${oauthClientID} = {
      inherit usersGroup;
      inherit adminsGroup;
      subdomain = cfg.subdomain;
      originLanding = "https://${cfg.subdomain}.${sp.domain}/";
      originUrl = oauthRedirectURL;
      clientSystemdUnits = [ "mastodon.service" ];
      enablePkce = true;
      linuxUserOfClient = "mastodon";
      linuxGroupOfClient = "mastodon";
    };
  };
}