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

let
  svc_domain = "ldap.${config.mine.shared.settings.domain}";

  resetPasswordStartPatch = pkgs.writeText "lldap-reset-password-start.patch" ''
diff --git a/server/src/main.rs b/server/src/main.rs
index 6f42473..b3746a1 100644
--- a/server/src/main.rs
+++ b/server/src/main.rs
@@ -171,7 +171,7 @@ async fn set_up_server(config: Configuration) -> Result<ServerBuilder> {
         ))?;
     }
     if config.force_update_private_key || config.force_ldap_user_pass_reset.is_yes() {
-        bail!("Restart the server without --force-update-private-key or --force-ldap-user-pass-reset to continue.");
+        // bail!("Restart the server without --force-update-private-key or --force-ldap-user-pass-reset to continue.");
     }
     let server_builder = infra::ldap_server::build_ldap_server(
         &config,
'';

  whoamiPatch = pkgs.writeText "lldap-whoami.patch" ''
diff --git a/server/src/infra/ldap_handler.rs b/server/src/infra/ldap_handler.rs
index 7257c31..feda03c 100644
--- a/server/src/infra/ldap_handler.rs
+++ b/server/src/infra/ldap_handler.rs
@@ -26,7 +26,7 @@ use ldap3_proto::proto::{
     LdapDerefAliases, LdapExtendedRequest, LdapExtendedResponse, LdapFilter, LdapModify,
     LdapModifyRequest, LdapModifyType, LdapOp, LdapPartialAttribute, LdapPasswordModifyRequest,
     LdapResult as LdapResultOp, LdapResultCode, LdapSearchRequest, LdapSearchResultEntry,
-    LdapSearchScope,
+    LdapSearchScope, OID_PASSWORD_MODIFY, OID_WHOAMI,
 };
 use std::collections::HashMap;
 use tracing::{debug, instrument, warn};
@@ -181,7 +181,7 @@ fn root_dse_response(base_dn: &str) -> LdapOp {
             LdapPartialAttribute {
                 atype: "supportedExtension".to_string(),
                 // Password modification extension.
-                vals: vec![b"1.3.6.1.4.1.4203.1.11.1".to_vec()],
+                vals: vec![OID_PASSWORD_MODIFY.as_bytes().to_vec()],
             },
             LdapPartialAttribute {
                 atype: "supportedControl".to_string(),
@@ -204,6 +204,11 @@ fn root_dse_response(base_dn: &str) -> LdapOp {
                 atype: "isGlobalCatalogReady".to_string(),
                 vals: vec![b"false".to_vec()],
             },
+            LdapPartialAttribute {
+                atype: "supportedExtension".to_string(),
+                // whoami extension.
+                vals: vec![OID_WHOAMI.as_bytes().to_vec()],
+            },
         ],
     })
 }
@@ -413,16 +418,33 @@ impl<Backend: BackendHandler + LoginHandler + OpaqueHandler> LdapHandler<Backend
 
     #[instrument(skip_all, level = "debug")]
     async fn do_extended_request(&mut self, request: &LdapExtendedRequest) -> Vec<LdapOp> {
-        match LdapPasswordModifyRequest::try_from(request) {
-            Ok(password_request) => self
+        if let Ok(password_request) = LdapPasswordModifyRequest::try_from(request) {
+            return self
                 .do_password_modification(&password_request)
                 .await
-                .unwrap_or_else(|e: LdapError| vec![make_extended_response(e.code, e.message)]),
-            Err(_) => vec![make_extended_response(
-                LdapResultCode::UnwillingToPerform,
-                format!("Unsupported extended operation: {}", &request.name),
-            )],
+                .unwrap_or_else(|e: LdapError| vec![make_extended_response(e.code, e.message)]);
         }
+
+        if request.name == OID_WHOAMI {
+            let dn = self
+                .user_info
+                .as_ref()
+                .map(|user_info| {
+                    format!(
+                        "dn:uid={},ou=people,{}",
+                        user_info.user.clone().into_string(),
+                        self.ldap_info.base_dn_str
+                    )
+                })
+                .unwrap_or_default();
+
+            return vec![make_extended_response(LdapResultCode::Success, dn)];
+        }
+
+        return vec![make_extended_response(
+            LdapResultCode::UnwillingToPerform,
+            format!("Unsupported extended operation: {}", &request.name),
+        )];
     }
 
     async fn handle_modify_change(
'';

  pkgLLDAPCli = pkgs.callPackage ./../../../../shared/pkgs/lldap-cli.nix {};
in {
  imports = [
    ./provision.nix
  ];
  
  environment.systemPackages = [
    pkgLLDAPCli
  ];
  
  services.lldap = {
    enable = true;

    package = pkgs.lldap.overrideAttrs (old: {
      patches = old.patches ++ [ resetPasswordStartPatch whoamiPatch ];
    });

    settings = {
      verbose = true;
      ldap_user_email = "fricloudlldap.grief462@simplelogin.com";
      ldap_base_dn = config.mine.shared.settings.ldap.dc;
    };

    environment = {
      # always set admin password on startup
      LLDAP_LDAP_USER_PASS_FILE = config.age.secrets.lldap-admin-user-pass.path;
      LLDAP_FORCE_LDAP_USER_PASS_RESET = "true";
    };
  };

  services.nginx.virtualHosts."${svc_domain}" = {
    forceSSL = true;
    enableACME = true;
    locations."/".proxyPass = "http://localhost:${builtins.toString config.services.lldap.settings.http_port}";
  };

  # persistent files
  environment.persistence.root.directories = [
    { directory = "/var/lib/private/lldap"; mode = "0700"; }
  ];

  # lldap user + setup secrets owner (need to add user for secrets to work)
  users.users.lldap = { group = "lldap"; isSystemUser = true; };
  users.groups.lldap = {};
  age.secrets = {
    lldap-admin-user-pass.owner = "lldap";
  };

  # set settings other services can use
  #  CN = Common Name
  #  OU = Organizational Unit
  #  DC = Domain Component
  #
  # The users are all located in ou=people, + the base DN, so by default user bob is at cn=bob,ou=people,dc=example,dc=com.
  # Similarly, the groups are located in ou=groups, so the group family will be at cn=family,ou=groups,dc=example,dc=com.
  # Testing group membership through memberOf is supported, so you can have a filter like: (memberOf=cn=admins,ou=groups,dc=example,dc=com).
  mine.shared.settings.ldap = rec {
    host = "localhost";
    port = 3890;
    url = "ldap://${host}:${builtins.toString port}";

    dc = "dc=${config.mine.shared.settings.domain_sld},dc=${config.mine.shared.settings.domain_tld}";
    bind_dn = "uid=${users.bind},ou=${ou.users},${dc}";
    search_base = "ou=${ou.users},${dc}";
    user_filter = ph: let
      attrs = [ attr.uid attr.email ];
    in config.mine.shared.lib.ldap.mkFilter (lconfig: llib:
      llib.mkAnd [
        (llib.mkGroup lconfig.groups.member)
        (llib.mkOr (lib.forEach attrs (v: llib.mkSearch v ph)))
      ]
    );

    oc = {
      person = "person";
      mailAccount = "mailAccount";
      groupOfUniqueNames = "groupOfUniqueNames";
    };

    provision = config.services.lldap.provision;

    users = {
      admin = "admin";
      # bind = "bind_user";
    } // (lib.mapAttrs (n: v: v.user_id) config.services.lldap.provision.users);

    groups = {
      admin = "lldap_admin";
      member = "base_member";
      password_manager = "lldap_password_manager";
      strict_readonly = "lldap_strict_readonly";
      # system = "system_service";
      # system_email = "system_email";
    } // (lib.mapAttrs (n: v: v.display_name) config.services.lldap.provision.groups);

    ou = {
      groups = "groups";
      users = "people";
    };

    attr = let
      toCamelCase = w: let
        parts = lib.splitString "_" w;
        cap = lib.imap0 (i: v: if i == 0 then v else (lib.toUpper (lib.substring 0 1 v)) + (lib.substring 1 (lib.stringLength v) v));
      in lib.concatStrings (cap parts);
    in {
      uid = "uid";
      firstname = "givenName";
      lastname = "sn";
      email = "mail";
      avatar = "jpegPhoto";
      groupname = "cn";

      # custom
      # member_email = "member_email";
      # mail_disk_quota = "mail_disk_quota";
    } // (lib.mapAttrs (n: v: toCamelCase v.name) config.services.lldap.provision.user_attributes);

    age_secret = config.age.secrets.lldap-bind-user-pass.path;
  };

  mine.shared.lib.ldap = rec {
    mkGroup = group_name: "memberof=cn=${group_name},ou=${config.mine.shared.settings.ldap.ou.groups},${config.mine.shared.settings.ldap.dc}";
    mkOC = object_class_name: "objectclass=${object_class_name}";
    mkSearch = attribute: ph: "${attribute}=${ph}";

    mkFilterAdvanced = expr: let
      isExpr = value: if value ? type then true else false;

      __mkExpr = value: if isExpr value then mkFilterAdvanced value else "(${value})";
      _mkExpr = op: value: "(${op}" + (builtins.concatStringsSep "" (lib.forEach value (v: __mkExpr v))) + ")";
      mkExpr = expr: assert isExpr expr; if expr.type == "and" then _mkExpr "&" expr.values else _mkExpr "|" expr.values;
    in mkExpr expr;

    mkAndOr = andExprs: orExprs: mkFilterAdvanced {
      type = "and";
      values = andExprs ++ [
        { type = "or"; values = orExprs; }
      ];
    };

    mkFilter = t: mkFilterAdvanced (t config.mine.shared.settings.ldap config.mine.shared.lib.ldap);
    mkScope = t: t config.mine.shared.settings.ldap config.mine.shared.lib.ldap;

    mkAnd = v: { type = "and"; values = v; };
    mkOr = v: { type = "or"; values = v; };

    # mkProvision helpers for creating users
    mkProvisionEmail = name: "${name}@${config.mine.shared.settings.domain}";
    mkProvisionUserNormal = name: config.mine.shared.lib.ldap.mkScope (lconfig: llib: {
      user_id = name;
      display_name = name; # required for nextcloud
      membermail = mkProvisionEmail name;
      mail = "env:EMAIL_${lib.toUpper name}";
      groups = [ lconfig.groups.member ];
      membermaildiskquota = 100*1024*1024; # mb
      nextcloudquota = 5*1024*1024; # mb
    });

    mkProvisionUserSystem = name: password_file: config.mine.shared.lib.ldap.mkScope (lconfig: llib: {
      user_id = name;
      membermail = mkProvisionEmail name;
      mail = mkProvisionEmail name;
      password = "file:${password_file}";
      groups = [ lconfig.groups.system_mail lconfig.groups.system_service ];
      membermaildiskquota = 10*1024*1024; # mb
    });

    mkProvisionUserSystemExt = name: password_file: custom_attrs: lib.recursiveUpdate (config.mine.shared.lib.ldap.mkScope (lconfig: llib: {
      user_id = name;
      membermail = mkProvisionEmail name;
      password = "file:${password_file}";
      groups = [ lconfig.groups.system_mail lconfig.groups.system_service ];
      membermaildiskquota = 10*1024*1024; # mb
    })) custom_attrs;

    mkProvisionUserAdmin = name: config.mine.shared.lib.ldap.mkScope (lconfig: llib: {
      user_id = name;
      display_name = name; # required for nextcloud
      membermail = mkProvisionEmail name;
      mail = mkProvisionEmail name;
      groups = with lconfig.groups; [ admin nextcloud_admin grafana_admin drasl_admin member ];
      membermaildiskquota = 100*1024*1024; # mb
      nextcloudquota = 100*1024*1024; # mb
    });
  };

  mine.shared.meta.lldap = {
    name = "LDAP";
    description = "We host our own LDAP server, you can use it to change your displayname, name, password, etc.";
    url = "https://${svc_domain}";

    package = let
      pkg = config.services.lldap.package;
    in {
      name = pkg.pname;
      version = pkg.version;
      meta = pkg.meta;
    };
  };
}