/**
 * Copyright since 2025 Mifos Initiative
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */

/** Shape the KYC document-type picker works with. */
export interface KycDocumentType {
  name: string;
  code: string;
  mandatory: boolean;
  category?: string;
}

export const ENTITY_KYC_CATEGORY = 'Entity KYC documents';

/**
 * The KYC documents every legal entity must produce, whatever its constitution — RBI Master
 * Direction on KYC, Annexure I. Codes match PROOF_META in kyc-proof-types.ts, which is what
 * groups them under "Entity KYC documents" and supplies each chip's banner text.
 *
 * This is the single source for the entity list so a non-individual client sees the same
 * documents wherever the picker is rendered — the create stepper, the edit stepper, before a
 * constitution has been chosen and after, and once the backend KYC template has loaded.
 */
export const ENTITY_KYC_DOCUMENT_TYPES: { name: string; code: string }[] = [
  { name: 'Certificate of Incorporation / Registration Certificate', code: 'CERT_INCORPORATION' },
  { name: 'PAN Card of Entity', code: 'ENTITY_PAN' },
  { name: 'Memorandum & Articles of Association / Partnership Deed / Trust Deed', code: 'CONSTITUTIVE_DOC' },
  { name: 'Board Resolution / Authorization Letter', code: 'BOARD_RESOLUTION' },
  { name: 'KYC of Authorized Signatory / Power of Attorney Holder', code: 'AUTH_SIGNATORY_KYC' },
  { name: 'GST Registration Certificate', code: 'GST_CERTIFICATE' }
];

/**
 * Codes the backend KYC template uses for documents the entity list already covers
 * (ClientKycApiResource.getRequiredDocuments). Folding them onto the entity codes keeps one
 * chip per document instead of "PAN Card of Company" sitting next to "PAN Card of Entity".
 */
const ENTITY_DOC_CODE_ALIASES: Record<string, string> = {
  CERT_INCORPORATION: 'CERT_INCORPORATION',
  COI: 'CERT_INCORPORATION',
  REG_CERT: 'CERT_INCORPORATION',
  ENTITY_PAN: 'ENTITY_PAN',
  PAN: 'ENTITY_PAN',
  CONSTITUTIVE_DOC: 'CONSTITUTIVE_DOC',
  MOA: 'CONSTITUTIVE_DOC',
  AOA: 'CONSTITUTIVE_DOC',
  PARTNERSHIP_DEED: 'CONSTITUTIVE_DOC',
  TRUST_DEED: 'CONSTITUTIVE_DOC',
  BOARD_RESOLUTION: 'BOARD_RESOLUTION',
  AUTH_SIGNATORY_KYC: 'AUTH_SIGNATORY_KYC',
  SIGNATORY_KYC: 'AUTH_SIGNATORY_KYC',
  GST_CERTIFICATE: 'GST_CERTIFICATE',
  GST_CERT: 'GST_CERTIFICATE'
};

/**
 * The per-constitution lists carry no codes of their own (code === name), so those entries are
 * matched on the label instead. Patterns are anchored deliberately: a document that merely
 * mentions another one ("Proof of Business Existence (GST Certificate / Shop License)") is a
 * distinct requirement and has to survive as its own chip rather than vanish into GST.
 */
const ENTITY_DOC_NAME_PATTERNS: { pattern: RegExp; code: string }[] = [
  { pattern: /^certificate of incorporation\b/, code: 'CERT_INCORPORATION' },
  { pattern: /^registration certificate\b/, code: 'CERT_INCORPORATION' },
  {
    pattern: /^(memorandum|articles of association|partnership deed|trust deed|llp agreement|by-?laws)\b/,
    code: 'CONSTITUTIVE_DOC'
  },
  { pattern: /^pan\b/, code: 'ENTITY_PAN' },
  { pattern: /^(board resolution|designated partners resolution|resolution authorizing)\b/, code: 'BOARD_RESOLUTION' },
  { pattern: /^(kyc of|authorized signatory kyc|proprietor'?s kyc)\b/, code: 'AUTH_SIGNATORY_KYC' },
  { pattern: /^gst (registration )?certificate\b/, code: 'GST_CERTIFICATE' }
];

/** The entity document this one duplicates, or null when it is a requirement of its own. */
function resolveEntityDocCode(doc: { name?: string; code?: string }): string | null {
  const code = (doc.code || '').toUpperCase().trim();
  // A constitution list stores the label in `code`, so only treat it as a code when it is one.
  if (code && !code.includes(' ') && ENTITY_DOC_CODE_ALIASES[code]) {
    return ENTITY_DOC_CODE_ALIASES[code];
  }
  const name = (doc.name || '').toLowerCase().trim();
  return ENTITY_DOC_NAME_PATTERNS.find((p) => p.pattern.test(name))?.code || null;
}

/**
 * Puts the RBI entity documents in front of whatever list a caller has (per-constitution docs,
 * or the backend KYC template) instead of letting that list replace them.
 *
 * Without this the officer sees a different set of documents on every screen for the same
 * client: the entity list until a constitution is picked, the constitution's own list after,
 * and the backend template's list once the client exists and is reopened for edit. Anything in
 * `extra` that isn't already one of the six stays, grouped under `extraCategory` — those are
 * genuine constitution-specific requirements (Karta declaration, Udyam certificate, government
 * notification) and dropping them would lose real requirements.
 *
 * A mandatory flag on a duplicate carries over to the entity chip it folds into, so the
 * "at least one mandatory document" validator still sees it.
 */
export function withEntityKycDocuments(
  extra: { name: string; code?: string; mandatory?: boolean }[] = [],
  extraCategory?: string | null
): KycDocumentType[] {
  const mandatoryCodes = new Set<string>();
  const leftovers: KycDocumentType[] = [];

  extra.forEach((doc) => {
    const entityCode = resolveEntityDocCode(doc);
    if (entityCode) {
      if (doc.mandatory) {
        mandatoryCodes.add(entityCode);
      }
      return;
    }
    leftovers.push({
      name: doc.name,
      code: doc.code || doc.name,
      mandatory: !!doc.mandatory,
      category: extraCategory ? `${extraCategory} documents` : 'Additional documents'
    });
  });

  const base: KycDocumentType[] = ENTITY_KYC_DOCUMENT_TYPES.map((d) => ({
    name: d.name,
    code: d.code,
    mandatory: mandatoryCodes.has(d.code),
    category: ENTITY_KYC_CATEGORY
  }));

  return [
    ...base,
    ...leftovers
  ];
}