let _adr_id_format = std.contract.custom (
  fun label =>
    fun value =>
      if std.string.is_match "^adr-[0-9]{3}$" value then
        'Ok value
      else
        'Error {
          message = "ADR id must match 'adr-NNN' format (e.g. 'adr-001'), got: '%{value}'"
        }
) in

let _non_empty_constraints = std.contract.custom (
  fun label =>
    fun value =>
      if std.array.length value == 0 then
        'Error {
          message = "constraints must not be empty — an ADR with no constraints is passive documentation, not an active constraint"
        }
      else
        'Ok value
) in

let _non_empty_negative = std.contract.custom (
  fun label =>
    fun value =>
      if std.array.length value.negative == 0 then
        'Error {
          message = "consequences.negative must not be empty on id='%{value.id}' — an ADR with no negative consequences is incomplete"
        }
      else
        'Ok value
) in

let _requires_justification = std.contract.custom (
  fun label =>
    fun value =>
      if value.ontology_check.verdict == 'RequiresJustification
         && !(std.record.has_field "invariant_justification" value) then
        'Error {
          message = "ADR '%{value.id}': ontology_check.verdict = 'RequiresJustification but invariant_justification field is missing"
        }
      else
        'Ok value
) in

{
  AdrIdFormat                    = _adr_id_format,
  NonEmptyConstraints            = _non_empty_constraints,
  NonEmptyNegativeConsequences   = _non_empty_negative,
  RequiresJustificationWhenRisky = _requires_justification,
}