CREATE TABLE account_entry_reference_t (
    id serial not null primary key,
    account integer     not null   references account_t (id),
    account_entry integer not null references account_entry_t (id)
);


CREATE OR REPLACE VIEW joined_account_entry_v AS
  SELECT ae.id as id, 
         ae.description as description, 
         ae.account as account, 
         ae.created_at as created_at, 
         ae.amount as amount, 
         ae.account_entry_category as account_entry_category, 
         ae.document_no as document_no, 
         ae.fiscal_year as fiscal_year,
         false as is_reference, 
         0 as base_account
    FROM account_entry_t ae
  UNION
  SELECT ae.id as id, 
         ae.description as description, 
         aer.account as account, 
         ae.created_at as created_at, 
         ae.amount as amount, 
         ae.account_entry_category as account_entry_category, 
         ae.document_no as document_no, 
         ae.fiscal_year as fiscal_year,
         true as is_reference, 
         ae.account as base_account
    FROM account_entry_t ae,
         account_entry_reference_t aer
    WHERE ae.id = aer.account_entry;

update account_t set description = 'fallback_account' where id = 33;
delete from account_t where id = 32;

insert into account_t (id, description) values (1000, 'ledger');

update account_entry_t set amount = amount * -1.0 where account=33;
update account_entry_t set amount = amount * -1.0 where account in (34,35,36,37);


DO $$
DECLARE
  entry_id integer;
BEGIN
  RAISE NOTICE 'Start migration';

  FOR entry_id IN
    SELECT id
      FROM account_entry_t
      WHERE account IN (33,34,35,36,37)
  LOOP
    RAISE NOTICE 'About to migrate entry %', entry_id;
    INSERT INTO account_entry_reference_t (account, account_entry) VALUES (1000, entry_id);
  END LOOP;
END;
$$;

update account_entry_t 
  set description = 'Miete ' || extract(year from created_at)::text || ' ' || to_char(to_date(extract(month from created_at)::text, 'MM'), 'Month') 
  where account_entry_category = 2 and description = 'Miete';


DO $$
DECLARE
  entry RECORD;
  tenant RECORD;
BEGIN
  RAISE NOTICE 'Start migration of tenant accounts';

  FOR entry IN
    SELECT id, description, account
      FROM account_entry_t
      WHERE account_entry_category = 2
  LOOP
    RAISE NOTICE 'About to migrate entry %', entry.id;
    INSERT INTO account_entry_reference_t (account, account_entry) VALUES (1000, entry.id);
    SELECT * 
      INTO tenant
      FROM tenant_t
      WHERE account = entry.account;
    RAISE NOTICE 'Tenant: % %', tenant.firstname, tenant.lastname;
    UPDATE account_entry_t
      SET description = description || ' ' || tenant.firstname || ' ' || tenant.lastname
      WHERE id = entry.id;
  END LOOP;
END;
$$;

CREATE OR REPLACE FUNCTION maintain_ledger()
RETURNS TRIGGER
LANGUAGE plpgsql
AS $$
DECLARE
  tenant RECORD;
  adjusted_description text;
BEGIN
  IF ((NEW.description = 'Miete') AND (NEW.account_entry_category = 2)) THEN
    SELECT firstname, lastname
      INTO tenant
      FROM tenant_t
      WHERE account = NEW.account;
    adjusted_description := 'Miete ' || extract(year from NEW.created_at)::text || ' ' || to_char(to_date(extract(month from NEW.created_at)::text, 'MM'), 'Month') || tenant.firstname || ' ' || tenant.lastname;
    UPDATE account_entry_t
      SET description = adjusted_description
      WHERE id = NEW.id;
  END IF;
    
  INSERT INTO account_entry_reference_t (account, account_entry) VALUES (1000, NEW.id);
  RETURN NEW;
END;
$$;

CREATE TRIGGER maintain_ledger_trigger
  AFTER INSERT ON account_entry_t
  FOR EACH ROW
  WHEN (NEW.account != 1000 AND NEW.account_entry_category NOT IN (3, 4))
  EXECUTE FUNCTION maintain_ledger();


grant select, update on account_entry_reference_t_id_seq to hv2;
grant insert on account_entry_reference_t to hv2;
grant update on account_entry_t to hv2;