const { buildBusinessValidationError } = require("../utils/businessValidationError");
const { lockLender, auditLoan } = require("./companyLoans");

// Call under the lender lock for all pre-payment actions. Bank facts never use
// this gate. A closed cause cannot mask another active cause.
async function assertNotFrozen(tx, lenderId) {
  if (await tx.loanFreezeReason.count({ where: { lender_id: lenderId, status: "active" } })) {
    throw buildBusinessValidationError("loan.lender_frozen", {}, 409);
  }
}
async function openReason(tx, batch, request, kind, sourceKey) {
  const repayment = await require("./companyLoanPayments").readLoanRepayment(tx, batch);
  await lockLender(tx, repayment.lender_id);
  const existing = await tx.loanFreezeReason.findUnique({ where: { kind_source_key: { kind, source_key: sourceKey } } });
  if (existing) {
    if (existing.payment_batch_id !== batch.id) throw buildBusinessValidationError("loan.invalid_input", {}, 409);
    return existing;
  }
  const reason = await tx.loanFreezeReason.create({ data: { lender_id: repayment.lender_id, payment_batch_id: batch.id,
    kind, source_key: sourceKey, created_by: request.employee.id } });
  await auditLoan(tx, request, "LOAN_FREEZE_OPENED", repayment.id, { paymentBatchId: batch.id, freezeId: reason.id, kind });
  return reason;
}

// Internal only: S6/S7 call after resolving their source fact in this same
// transaction. Never expose a generic close/unfreeze route to users.
async function closeReason(tx, batch, request, kind, sourceKey, basis) {
  const repayment = await require("./companyLoanPayments").readLoanRepayment(tx, batch);
  await lockLender(tx, repayment.lender_id);
  const reason = await tx.loanFreezeReason.findUnique({ where: { kind_source_key: { kind, source_key: sourceKey } } });
  if (!reason || reason.payment_batch_id !== batch.id || !basis?.action || !basis?.recordId) {
    throw buildBusinessValidationError("loan.invalid_input", {}, 409);
  }
  if (reason.status === "closed") return reason;
  const closed = await tx.loanFreezeReason.update({ where: { id: reason.id }, data: { status: "closed",
    closed_by: request.employee.id, closed_at: new Date(), closure_basis: basis } });
  await auditLoan(tx, request, "LOAN_FREEZE_CLOSED", repayment.id, { paymentBatchId: batch.id, freezeId: reason.id, kind, basis });
  return closed;
}
async function state(tx, lenderId) {
  const reasons = await tx.loanFreezeReason.findMany({ where: { lender_id: lenderId }, orderBy: [{ created_at: "asc" }, { id: "asc" }] });
  return { frozen: reasons.some((r) => r.status === "active"), reasons: reasons.map((r) => ({ id: r.id, kind: r.kind,
    sourceKey: r.source_key, paymentBatchId: r.payment_batch_id, status: r.status, closureBasis: r.closure_basis })) };
}
module.exports = { assertNotFrozen, openReason, closeReason, state };