refact(wh): Use auth token id for user dimension

Previously the function used to upsert into the user dimension required
both an auth token id, and a user id. However, the user id can be
determined from the auth token, in fact it already was via the
whx_user_dimension_source view. This refactor removes the user id as an
argument, since it is not needed and will not be directly available when
this function is used when populating the new auth token accumulating
fact.

internal/db/schema/migrations/oss/postgres/15/01_wh_rename_key_columns.up.sql

@@ -97,6 +97,7 @@ begin;
   ;
 
   -- replaces function from 14/01_wh_user_dimension_oidc.up.sql
+  -- replaced in 82/02_wh_upsert_user_refact.up.sql
   drop function wh_upsert_user;
   create function wh_upsert_user(p_user_id wt_user_id, p_auth_token_id wt_public_id) returns wh_dim_key
   as $$

internal/db/schema/migrations/oss/postgres/60/03_wh_sessions.up.sql

@@ -216,7 +216,8 @@ begin;
   create trigger wh_update_session_connection_accumulating_fact after insert on session_host_set_host
     for each row execute procedure wh_upsert_host();
 
-  -- replaced function in 16/04_wh_credential_dimension.up.sql
+  -- Replaces function from 16/04_wh_credential_dimension.up.sql
+  -- Replaced in 82/02_wh_upsert_user_refact.up.sql
   create or replace function wh_insert_session() returns trigger
   as $$
   declare

internal/db/schema/migrations/oss/postgres/82/02_wh_upsert_user_refact.up.sql

@@ -0,0 +1,111 @@
+-- Copyright (c) HashiCorp, Inc.
+-- SPDX-License-Identifier: BUSL-1.1
+
+begin;
+
+  drop trigger wh_insert_session on session;
+  drop function wh_insert_session;
+  drop function wh_upsert_user;
+
+  -- Replaces function from 15/01_wh_rename_key_columns.up.sql
+  create function wh_upsert_user(p_auth_token_id wt_public_id) returns wh_dim_key
+  as $$
+  declare
+    src     whx_user_dimension_target%rowtype;
+    target  whx_user_dimension_target%rowtype;
+    new_row wh_user_dimension%rowtype;
+    acct_id wt_public_id;
+  begin
+    select auth_account_id into strict acct_id
+      from auth_token
+     where public_id = p_auth_token_id;
+
+    select * into target
+      from whx_user_dimension_target as t
+     where t.auth_account_id = acct_id;
+
+    select target.key, t.* into src
+      from whx_user_dimension_source as t
+     where t.auth_account_id = acct_id;
+
+    if src is distinct from target then
+
+      -- expire the current row
+      update wh_user_dimension
+         set current_row_indicator = 'Expired',
+             row_expiration_time   = current_timestamp
+       where auth_account_id       = acct_id
+         and current_row_indicator = 'Current';
+
+      -- insert a new row
+      insert into wh_user_dimension (
+             user_id,                  user_name,              user_description,
+             auth_account_id,          auth_account_type,      auth_account_name,             auth_account_description,
+             auth_account_external_id, auth_account_full_name, auth_account_email,
+             auth_method_id,           auth_method_type,       auth_method_name,              auth_method_description,
+             auth_method_external_id,
+             user_organization_id,     user_organization_name, user_organization_description,
+             current_row_indicator,    row_effective_time,     row_expiration_time
+      )
+      select user_id,                  user_name,              user_description,
+             auth_account_id,          auth_account_type,      auth_account_name,             auth_account_description,
+             auth_account_external_id, auth_account_full_name, auth_account_email,
+             auth_method_id,           auth_method_type,       auth_method_name,              auth_method_description,
+             auth_method_external_id,
+             user_organization_id,     user_organization_name, user_organization_description,
+             'Current',                current_timestamp,      'infinity'::timestamptz
+        from whx_user_dimension_source
+       where auth_account_id = acct_id
+      returning * into new_row;
+
+      return new_row.key;
+    end if;
+    return target.key;
+
+  end;
+  $$ language plpgsql;
+  comment on function wh_upsert_user is
+    'wh_upsert_user a function insert or updates the wh_user_dimension table'
+    'for the user that corresponds to the provided auth_token_id.';
+
+  -- Replaces function from 60/03_wh_sessions.up.sql
+  create function wh_insert_session() returns trigger
+  as $$
+  declare
+    new_row wh_session_accumulating_fact%rowtype;
+  begin
+    with
+    pending_timestamp (date_dim_key, time_dim_key, ts) as (
+      select wh_date_key(start_time), wh_time_key(start_time), start_time
+        from session_state
+       where session_id = new.public_id
+         and state      = 'pending'
+    )
+    insert into wh_session_accumulating_fact (
+           session_id,
+           auth_token_id,
+           host_key,
+           user_key,
+           credential_group_key,
+           session_pending_date_key,
+           session_pending_time_key,
+           session_pending_time
+    )
+    select new.public_id,
+           new.auth_token_id,
+           'no host source', -- will be updated by wh_upsert_host
+           wh_upsert_user(new.auth_token_id),
+           'no credentials', -- will be updated by wh_upsert_credential_group
+           pending_timestamp.date_dim_key,
+           pending_timestamp.time_dim_key,
+           pending_timestamp.ts
+      from pending_timestamp
+      returning * into strict new_row;
+    return null;
+  end;
+  $$ language plpgsql;
+
+  create trigger wh_insert_session after insert on session
+    for each row execute procedure wh_insert_session();
+
+commit;