import { ExecutionPlanError, hexDigest, type ExecutionPlan, type PlannedQuery } from "./plan.js";
/** Contracts promised by a direct result. Interface dependencies are explicit; accidental
 * overlap among today's implementations does not silently widen an exported interface contract. */
export function resultInterfaces(plan: ExecutionPlan, operationKey: string): string[] {
  const operation = plan.definition.operations.find((operation) => operation.key === operationKey);
  if (!operation) throw new ExecutionPlanError("UNKNOWN_OPERATION", operationKey, "No installed public operation");
  if (operation.output.kind !== "object-ref") return [];
  const expected = operation.output.expectation;
  if (expected.kind === "atom")
    return plan.definition.workspace.conformances
      .filter((c) => c.atomId === expected.atomId)
      .map((c) => c.interfaceRevisionId)
      .sort();
  const interfaces = new Map(plan.definition.workspace.interfaceImports.map((i) => [String(i.revisionId), i]));
  const result = new Set<string>();
  const visit = (id: string) => {
    if (result.has(id)) return;
    result.add(id);
    for (const dependency of interfaces.get(id)?.requiredInterfaces ?? []) visit(dependency);
  };
  visit(expected.interfaceRevisionId);
  return [...result].sort();
}
/** Compile-time observeResult compatibility. Observation does not grant read or mutation authority. */
export function checkResultProjection(plan: ExecutionPlan, operationKey: string, queryId: string): PlannedQuery {
  if (hexDigest(plan.definition) !== plan.digest)
    throw new ExecutionPlanError("INVALID_PLAN", "projection", "Plan digest mismatch");
  const query = plan.definition.queries.find((q) => q.id === queryId);
  if (!query) throw new ExecutionPlanError("UNKNOWN_PROJECTION", queryId, "No installed query");
  const declaration = query.query.checked.declaration;
  if (declaration.placement?.kind !== "replica" || declaration.root.kind !== "object")
    throw new ExecutionPlanError(
      "INVALID_RESULT_PROJECTION",
      queryId,
      "Result observation requires a direct-object replica declaration",
    );
  if (!resultInterfaces(plan, operationKey).includes(declaration.root.interface))
    throw new ExecutionPlanError(
      "RESULT_PROJECTION_MISMATCH",
      operationKey,
      `Result does not promise ${declaration.root.interface}`,
    );
  return query;
}