CREATE TABLE staff_professions (
  id VARCHAR(26) PRIMARY KEY CHECK (id ~ '^[0-9A-HJKMNP-TV-Z]{26}$'),
  tenant_id VARCHAR(26) NOT NULL CHECK (tenant_id ~ '^[0-9A-HJKMNP-TV-Z]{26}$'),
  code VARCHAR(80) NOT NULL,
  name VARCHAR(160) NOT NULL,
  status VARCHAR(20) NOT NULL DEFAULT 'active' CHECK (status IN ('active', 'archived')),
  created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
  updated_at TIMESTAMPTZ NOT NULL DEFAULT now(),
  UNIQUE (tenant_id, id),
  UNIQUE (tenant_id, code),
  UNIQUE (tenant_id, name)
);

ALTER TABLE staff_professions ENABLE ROW LEVEL SECURITY;
ALTER TABLE staff_professions FORCE ROW LEVEL SECURITY;
CREATE POLICY staff_professions_tenant_isolation ON staff_professions
  USING (tenant_id = current_setting('app.tenant_id', true))
  WITH CHECK (tenant_id = current_setting('app.tenant_id', true));

ALTER TABLE staff_employees ADD COLUMN profession_id VARCHAR(26);
ALTER TABLE staff_employees ADD CONSTRAINT staff_employees_profession_fk
  FOREIGN KEY (tenant_id, profession_id) REFERENCES staff_professions (tenant_id, id);
CREATE INDEX staff_employees_profession_idx ON staff_employees (tenant_id, profession_id);

CREATE UNIQUE INDEX staff_employees_external_ref_idx
  ON staff_employees (tenant_id, external_ref) WHERE external_ref IS NOT NULL;

CREATE UNIQUE INDEX staff_pay_assignments_effective_version_idx
  ON staff_pay_assignments
    (tenant_id, employee_id, COALESCE(org_unit_id, ''), effective_from);

GRANT SELECT, INSERT, UPDATE, DELETE ON staff_professions TO krona_staff_app;