import { existsSync } from 'node:fs';
import { join } from 'node:path';
import type { TaxonomyHydrationInput, TaxonomyHydrationResult } from '@/lib/server/taxonomy/types';
import { withRetry } from '@/lib/server/utils/retry';

function candidateBinaryPaths() {
  return [
    process.env.FISCAL_XBRL_BIN?.trim(),
    join(process.cwd(), 'bin', 'fiscal-xbrl'),
    join(process.cwd(), 'rust', 'target', 'release', 'fiscal-xbrl'),
    join(process.cwd(), 'rust', 'target', 'debug', 'fiscal-xbrl')
  ].filter((value): value is string => typeof value === 'string' && value.length > 0);
}

export function resolveFiscalXbrlBinary() {
  const resolved = candidateBinaryPaths().find((path) => existsSync(path));
  if (!resolved) {
    throw new Error('Rust XBRL sidecar binary is required but was not found. Set FISCAL_XBRL_BIN or build `fiscal-xbrl` under rust/target.');
  }

  return resolved;
}

export async function hydrateFilingTaxonomySnapshotFromSidecar(
  input: TaxonomyHydrationInput
): Promise<TaxonomyHydrationResult> {
  return withRetry(() => hydrateFromSidecarImpl(input));
}

async function hydrateFromSidecarImpl(input: TaxonomyHydrationInput): Promise<TaxonomyHydrationResult> {
  const binary = resolveFiscalXbrlBinary();
  const timeoutMs = Math.max(Number(process.env.XBRL_ENGINE_TIMEOUT_MS ?? 45_000), 1_000);
  const command = [binary, 'hydrate-filing'];
  const requestBody = JSON.stringify({
    filingId: input.filingId,
    ticker: input.ticker,
    cik: input.cik,
    accessionNumber: input.accessionNumber,
    filingDate: input.filingDate,
    filingType: input.filingType,
    filingUrl: input.filingUrl,
    primaryDocument: input.primaryDocument,
    cacheDir: process.env.FISCAL_XBRL_CACHE_DIR ?? join(process.cwd(), '.cache', 'xbrl')
  });

  const child = Bun.spawn(command, {
    stdin: 'pipe',
    stdout: 'pipe',
    stderr: 'pipe',
    env: {
      ...process.env
    }
  });

  child.stdin.write(new TextEncoder().encode(requestBody));
  child.stdin.end();

  const timeout = setTimeout(() => {
    child.kill();
  }, timeoutMs);

  try {
    const [stdout, stderr, exitCode] = await Promise.all([
      new Response(child.stdout).text(),
      new Response(child.stderr).text(),
      child.exited
    ]);

    if (stderr.trim().length > 0) {
      console.warn(`[fiscal-xbrl] ${stderr.trim()}`);
    }

    if (exitCode !== 0) {
      throw new Error(`Rust XBRL sidecar failed with exit code ${exitCode}: ${stderr.trim() || stdout.trim() || 'no error output'}`);
    }

    return JSON.parse(stdout) as TaxonomyHydrationResult;
  } finally {
    clearTimeout(timeout);
  }
}