{ inputs, config, lib, ... }:

with lib;
let
  cfg = config.modules.services.nixos-mailserver;
in
{
  imports = [ inputs.nixos-mailserver.nixosModules.mailserver ];

  options.modules.services.nixos-mailserver = {
    enable = mkEnableOption "nixos-mailserver";
    webmail = {
      enable = mkOption {
        type = types.bool;
        default = false;
        description = lib.mdDoc "Whether to enable roundcube webmail";
      };
      domain = mkOption { type = types.str; };
      realHost = mkOption { type = types.str; };
    };
  };

  config = mkIf cfg.enable {
    sops.secrets.sefidel-imap-pass = {
      mode = "0440";
      owner = "dovecot2";
      group = "dovecot2";
    };
    sops.secrets.system-imap-pass = {
      mode = "0440";
      owner = "dovecot2";
      group = "dovecot2";
    };
    sops.secrets.internal-imap-pass = {
      mode = "0440";
      owner = "dovecot2";
      group = "dovecot2";
    };

    # TODO: https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/merge_requests/316
    # WTF: nobody knows why this is needed, but removing it breaks dovecot2.
    services.dovecot2.sieve.extensions = [ "fileinto" ];

    systemd.services.dovecot2 = {
      serviceConfig.SupplementaryGroups = [ "acme" ];
    };

    services.postfix = {
      dnsBlacklists = [
        # TODO: add sources
        "b.barracudacentral.org"
        "bl.spamcop.net"
      ];
      dnsBlacklistOverrides = ''
        exotic.sh OK
        sefidel.net OK
        sefidel.com OK
        192.168.0.0/16 OK
      '';
    };

    # HACK: nixos-mailserver sets up reload hook on 'fqdn', which is 'mail.exotic.sh'.
    # Since our cert is a wildcard cert with domain 'exotic.sh', it is excluded from the hook.
    security.acme.certs."exotic.sh".reloadServices = [
      "postfix.service"
      "dovecot2.service"
    ];

    mailserver = {
      enable = true;
      fqdn = "mail.exotic.sh";
      domains = [ "exotic.sh" "nand.moe" "sefidel.com" "sefidel.net" ];
      mailboxes = {
        Trash = {
          auto = "no";
          specialUse = "Trash";
        };
        Junk = {
          auto = "subscribe";
          specialUse = "Junk";
        };
        Drafts = {
          auto = "subscribe";
          specialUse = "Drafts";
        };
        Sent = {
          auto = "subscribe";
          specialUse = "Sent";
        };
      };

      loginAccounts = {
        "contact@sefidel.com" = {
          catchAll = [ "sefidel.com" ];
          hashedPasswordFile = config.sops.secrets.sefidel-imap-pass.path;
        };
        "contact@sefidel.net" = {
          aliases = [
            "sefidel"
            "dev@sefidel.net"
            "social@sefidel.net"
            "media@sefidel.net"
            "bot@sefidel.net"
            "public@sefidel.net"
            "admin"
            "admin@sefidel.net"
            "postmaster"
            "postmaster@sefidel.net"
          ];
          hashedPasswordFile = config.sops.secrets.sefidel-imap-pass.path;
        };
        "sef@exotic.sh" = {
          aliases = [
            "sef"
            "sefidel"
            "sefidel@exotic.sh"
            "admin"
            "admin@exotic.sh"
            "postmaster"
            "postmaster@exotic.sh"
            "admin@nand.moe"
            "postmaster@nand.moe"
          ];
          hashedPasswordFile = config.sops.secrets.sefidel-imap-pass.path;
        };
        "system@exotic.sh" = {
          aliases = [ "system" "system@nand.moe" ];
          hashedPasswordFile = config.sops.secrets.system-imap-pass.path;
        };
        "internal@exotic.sh" = {
          aliases = [ "internal" ];
          hashedPasswordFile = config.sops.secrets.internal-imap-pass.path;
        };
      };
      localDnsResolver = false;
      certificateScheme = "manual";
      certificateFile = "${config.security.acme.certs."exotic.sh".directory}/cert.pem";
      keyFile = "${config.security.acme.certs."exotic.sh".directory}/key.pem";
      enableImap = true;
      enableImapSsl = true;
      enableSubmission = true;
      enableSubmissionSsl = true;
      virusScanning = false;
    };

    services.roundcube = mkIf cfg.webmail.enable {
      enable = true;
      hostName = cfg.webmail.realHost;
      database.host = "localhost"; # use localDB, pgsql db/user creation is done automatically.

      plugins = [
        "archive"
        "enigma"
        "help"
        "markasjunk"
        "vcard_attachments"
        "zipdownload"
      ];

      extraConfig = ''
        # STARTTLS required for authn, therefore the domain must match the SSL cert.
        $config['smtp_server'] = 'tls://${config.mailserver.fqdn}';
      '';
    };

    services.nginx.virtualHosts.${cfg.webmail.realHost} = {
      enableACME = mkForce false; # conflicts with useACMEHost
      forceSSL = true;
      useACMEHost = cfg.webmail.domain;
    };

    modules.persistence.directories = [
      "/var/lib/dovecot"
      "/var/lib/rspamd"
      "/var/lib/redis-rspamd"
      "/var/vmail"
      "/var/dkim"
      "/var/sieve"
      "/var/spool/mail"
    ];

    networking.firewall.allowedTCPPorts = [ 143 993 465 587 ];
  };
}