# public-inbox configuration for depot@tvl.su
#
# The account itself is a Yandex 360 account in the tvl.su organisation, which
# is accessed via IMAP. Yandex takes care of spam filtering for us, so there is
# no particular SpamAssassin or other configuration.
{ config, depot, lib, pkgs, ... }:

let
  cfg = config.services.depot.inbox;

  imapConfig = pkgs.writeText "offlineimaprc" ''
    [general]
    accounts = depot

    [Account depot]
    localrepository = Local
    remoterepository = Remote

    [Repository Local]
    type = Maildir
    localfolders = /var/lib/public-inbox/depot-imap

    [Repository Remote]
    type = IMAP
    ssl = yes
    sslcacertfile = /etc/ssl/certs/ca-bundle.crt
    remotehost = imap.yandex.ru
    remoteuser = depot@tvl.su
    remotepassfile = /var/run/agenix/depot-inbox-imap
  '';
in
{
  options.services.depot.inbox = with lib; {
    enable = mkEnableOption "Enable public-inbox for depot@tvl.su";

    depotPath = mkOption {
      description = "path to local depot replica";
      type = types.str;
      default = "/var/lib/depot";
    };
  };

  config = lib.mkIf cfg.enable {
    # Having nginx *and* other services use ACME certificates for the
    # same hostname is unsupported in NixOS without resorting to doing
    # all ACME configuration manually.
    #
    # To work around this, we duplicate the TLS certificate used by
    # nginx to a location that is readable by public-inbox daemons.
    systemd.services.inbox-cert-sync = {
      startAt = "daily";

      script = ''
        ${pkgs.coreutils}/bin/install -D -g ${config.users.groups."public-inbox".name} -m 0440 \
          /var/lib/acme/inbox.tvl.su/fullchain.pem /var/lib/public-inbox/tls/fullchain.pem

        ${pkgs.coreutils}/bin/install -D -g ${config.users.groups."public-inbox".name} -m 0440 \
          /var/lib/acme/inbox.tvl.su/key.pem /var/lib/public-inbox/tls/key.pem
      '';
    };

    services.public-inbox = {
      enable = true;

      http.enable = true;
      http.port = 8053;

      imap = {
        enable = true;
        port = 993;
        cert = "/var/lib/public-inbox/tls/fullchain.pem";
        key = "/var/lib/public-inbox/tls/key.pem";
      };

      nntp = {
        enable = true;
        port = 563;
        cert = "/var/lib/public-inbox/tls/fullchain.pem";
        key = "/var/lib/public-inbox/tls/key.pem";
      };

      inboxes.depot = rec {
        address = [
          "depot@tvl.su" # primary address
          "depot@tazj.in" # legacy address
        ];

        description = "TVL depot development (mail to depot@tvl.su)";
        coderepo = [ "depot" ];
        url = "https://inbox.tvl.su/depot";

        watch = [
          "maildir:/var/lib/public-inbox/depot-imap/INBOX/"
        ];

        newsgroup = "su.tvl.depot";
      };

      settings.coderepo.depot = {
        dir = cfg.depotPath;
        cgitUrl = "https://code.tvl.fyi";
      };

      settings.publicinbox.wwwlisting = "all";
      settings.publicinbox.nntpserver = [ "inbox.tvl.su" ];
    };

    networking.firewall.allowedTCPPorts = [
      993 # imap
      563 # nntp
    ];

    age.secrets.depot-inbox-imap = {
      file = depot.ops.secrets."depot-inbox-imap.age";
      mode = "0440";
      group = config.users.groups."public-inbox".name;
    };

    systemd.services.offlineimap-depot = {
      description = "download mail for depot@tvl.su";
      wantedBy = [ "multi-user.target" ];
      startAt = "minutely";

      script = ''
        mkdir -p /var/lib/public-inbox/depot-imap
        ${pkgs.offlineimap}/bin/offlineimap -c ${imapConfig}
      '';

      serviceConfig = {
        Type = "oneshot";

        # Run in the same user context as public-inbox itself to avoid
        # permissions trouble.
        User = config.users.users."public-inbox".name;
        Group = config.users.groups."public-inbox".name;
      };
    };
  };
}