import { readFile, stat } from 'node:fs/promises';
import { resolve } from 'node:path';
import type { RegulatoryControlDocument } from '../../src/compliance/regulatory-rag';
import { validateRegulatoryControlDocument } from './regulatory-chunker';
import { createRegulatoryRagRuntime } from './regulatory-rag-runtime';

const MAXIMUM_CORPUS_BYTES = 64 * 1024 * 1024;

async function main(): Promise<void> {
  const inputPath = process.argv[2];
  if (!inputPath) throw new Error('Usage: npm run rag:ingest -- <regulatory-corpus.json>');
  const resolvedPath = resolve(inputPath);
  const inputStat = await stat(resolvedPath);
  if (!inputStat.isFile() || inputStat.size > MAXIMUM_CORPUS_BYTES) throw new Error('Regulatory corpus must be a file no larger than 64 MiB.');
  const bytes = await readFile(resolvedPath);
  let value: unknown;
  try { value = JSON.parse(bytes.toString('utf8')); } catch { throw new Error('Regulatory corpus is not valid JSON.'); }
  const documents = corpusDocuments(value);
  const result = await createRegulatoryRagRuntime().ingestion.ingest(documents);
  console.log(`Indexed ${result.documentCount} regulatory documents as ${result.chunkCount} chunks with ${result.embeddingModel}.`);
}

function corpusDocuments(value: unknown): RegulatoryControlDocument[] {
  if (!isObject(value) || ![1, 2].includes(Number(value.schemaVersion)) || !Array.isArray(value.documents) || !value.documents.length) {
    throw new Error('Regulatory corpus must use schemaVersion 1 or 2 and contain a non-empty documents array.');
  }
  if (value.documents.length > 100_000) throw new Error('Regulatory corpus exceeds the 100000 document limit.');
  return value.documents.map(validateRegulatoryControlDocument);
}

function isObject(value: unknown): value is Record<string, unknown> {
  return Boolean(value) && typeof value === 'object' && !Array.isArray(value);
}

void main().catch(error => {
  console.error(error instanceof Error ? error.message : 'Regulatory ingestion failed.');
  process.exitCode = 1;
});