const { getErrorReason } = require("../constants/errorReasons");
const { buildBusinessValidationError } = require("../utils/businessValidationError");

function resolvePaymentBatchCreationReadiness({ entityType, entityIds, paymentChannel = "bank", snapshots, departmentReadiness, accountReadiness, reservedEntityIds, reviewerIds }) {
  const blockers = [];
  const addPaymentReadinessBlocker = (reasonCode, snapshot) => {
    getErrorReason(reasonCode);
    blockers.push({ reasonCode, ...(snapshot ? { entityId: snapshot.entityId, entityCode: snapshot.entityCode } : {}) });
  };
  if (entityType !== "reimbursement") addPaymentReadinessBlocker("payment_batch.travel_payment_frozen");
  const selected = snapshots.filter((snapshot) => entityIds.includes(snapshot.entityId));
  if (!entityIds.length || selected.length !== entityIds.length) addPaymentReadinessBlocker("payment_batch.source_not_found");
  const companies = new Set();
  for (const snapshot of selected) {
    if (snapshot.status !== "approved" || snapshot.snapshotJson?.paidAt) addPaymentReadinessBlocker("payment_batch.source_status_invalid", snapshot);
    if (!departmentReadiness.get(snapshot.departmentId ?? null)?.enabled) addPaymentReadinessBlocker("payment_batch.department_unavailable", snapshot);
    if (reservedEntityIds.has(snapshot.entityId)) addPaymentReadinessBlocker("payment_batch.active_batch_exists", snapshot);
    const payee = snapshot.snapshotJson?.payee;
    if (payee?.bankAccountUnavailable) addPaymentReadinessBlocker("payment_batch.payee_account_unavailable", snapshot);
    if (paymentChannel !== "bank") continue;
    if (!snapshot.legalEntityId) addPaymentReadinessBlocker("payment_batch.legal_entity_required", snapshot);
    else companies.add(snapshot.legalEntityId);
    if (!payee?.bankInstitutionCode) addPaymentReadinessBlocker("payment_batch.payee_bank_required", snapshot);
    else if (payee.bankInstitutionCode !== "CCB") addPaymentReadinessBlocker("payment_batch.payee_bank_unsupported", snapshot);
    if (!payee?.bankAccountEncrypted) addPaymentReadinessBlocker("payment_batch.payee_account_required", snapshot);
  }
  if (paymentChannel === "bank") {
    if (companies.size > 1) addPaymentReadinessBlocker("payment_batch.multiple_legal_entities");
    for (const companyId of companies) {
      const account = accountReadiness.get(companyId);
      if (!account?.paymentAccount) addPaymentReadinessBlocker("payment_batch.payment_account_required");
      else if (!account.paymentAccountSnapshot) addPaymentReadinessBlocker("payment_batch.payment_account_unavailable");
    }
  }
  if (!reviewerIds.length) addPaymentReadinessBlocker("payment_batch.reviewer_required");
  return { ready: blockers.length === 0, blockers };
}

function paymentReadinessError(readiness, departmentReadiness) {
  const blocker = readiness.blockers[0];
  const detailsByReason = {
    "payment_batch.travel_payment_frozen": { entityType: "travel_payment_frozen" },
    "payment_batch.source_not_found": { entityIds: "contains_not_found" },
    "payment_batch.source_status_invalid": { entity: `${blocker.entityCode}:invalid_pay_status` },
    "payment_batch.department_unavailable": { featureFlag: "payment_batch_v1_disabled", reason: [...departmentReadiness.values()].find((value) => !value.enabled)?.gate?.reason ?? "department_not_allowed" },
    "payment_batch.active_batch_exists": { entityIds: "contains_active_payment_batch" },
    "payment_batch.payee_account_unavailable": { payeeBankAccount: "decrypt_failed" },
    "payment_batch.legal_entity_required": { legalEntity: "single_legal_entity_required" },
    "payment_batch.multiple_legal_entities": { legalEntity: "single_legal_entity_required" },
    "payment_batch.payee_bank_required": { payeeBankAccount: `${blocker.entityCode}:ccb_account_required` },
    "payment_batch.payee_account_required": { payeeBankAccount: `${blocker.entityCode}:ccb_account_required` },
    "payment_batch.payee_bank_unsupported": { payeeBankAccount: `${blocker.entityCode}:ccb_account_required` },
    "payment_batch.payment_account_required": { paymentAccount: "active_ccb_account_required" },
    "payment_batch.payment_account_unavailable": { paymentAccount: "decrypt_failed" },
    "payment_batch.reviewer_required": { review: "no_eligible_reviewer" },
  };
  return buildBusinessValidationError(getErrorReason(blocker.reasonCode).code, detailsByReason[blocker.reasonCode], blocker.reasonCode === "payment_batch.source_not_found" ? 404 : 409);
}

module.exports = { resolvePaymentBatchCreationReadiness, paymentReadinessError };