#!/usr/bin/env node
/**
 * scan-code.mjs — produces wiki/code-map.md
 *
 * Purpose: cheap, deterministic index of the codebase so future Claude
 * sessions can locate symbols without a directory walk. Per CLAUDE.md:
 * "Create scripts to navigate source code and reduce claude processing
 * time and token burn."
 *
 * Outputs a single markdown file with:
 *  - Tree of src/, contracts/, test/, scripts/, wiki/
 *  - Per-file: exported symbols (TS), pragma + contract names (CashScript),
 *    line count, first doc-comment line.
 *
 * Intentionally zero external deps — runs on plain Node.
 */
import { readdirSync, readFileSync, statSync, writeFileSync, existsSync } from 'node:fs';
import { join, relative, extname } from 'node:path';

const ROOT = join(import.meta.dirname, '..');
const TARGETS = ['src', 'contracts', 'test', 'scripts', 'wiki'];
const OUT = join(ROOT, 'wiki', 'code-map.md');

const IGNORE = new Set(['node_modules', 'dist', '.git', 'coverage', '.regtest-data']);

function walk(dir, out = []) {
  for (const entry of readdirSync(dir)) {
    if (IGNORE.has(entry)) continue;
    const full = join(dir, entry);
    const st = statSync(full);
    if (st.isDirectory()) walk(full, out);
    else out.push(full);
  }
  return out;
}

function describe(file) {
  const ext = extname(file);
  const src = readFileSync(file, 'utf8');
  const lines = src.split('\n');
  const lineCount = lines.length;
  const summary = { lineCount, symbols: [], doc: '' };

  // First non-empty non-shebang line containing a comment marker
  for (const line of lines.slice(0, 20)) {
    const t = line.trim();
    if (!t || t.startsWith('#!')) continue;
    if (t.startsWith('//') || t.startsWith('/*') || t.startsWith('*') || t.startsWith('pragma')) {
      summary.doc = t.replace(/^[/*\s]+/, '').slice(0, 120);
      break;
    }
  }

  if (ext === '.ts' || ext === '.mjs' || ext === '.js') {
    const reExport = /^\s*export\s+(?:async\s+)?(?:function|class|const|let|interface|type|enum)\s+([A-Za-z0-9_]+)/gm;
    let m;
    while ((m = reExport.exec(src)) !== null) summary.symbols.push(m[1]);
  }
  if (ext === '.cash') {
    const reContract = /^\s*contract\s+([A-Za-z0-9_]+)\s*\(/gm;
    const reFn = /^\s*function\s+([A-Za-z0-9_]+)\s*\(/gm;
    let m;
    while ((m = reContract.exec(src)) !== null) summary.symbols.push(`contract:${m[1]}`);
    while ((m = reFn.exec(src)) !== null) summary.symbols.push(`fn:${m[1]}`);
  }
  return summary;
}

const sections = [];
for (const target of TARGETS) {
  const targetPath = join(ROOT, target);
  if (!existsSync(targetPath)) continue;
  const files = walk(targetPath)
    .filter((f) => /\.(ts|mjs|js|cash|md)$/.test(f))
    .sort();
  if (files.length === 0) continue;

  const rows = [];
  for (const f of files) {
    const rel = relative(ROOT, f).replaceAll('\\', '/');
    const { lineCount, symbols, doc } = describe(f);
    const sym = symbols.length ? symbols.join(', ') : '—';
    rows.push(`| \`${rel}\` | ${lineCount} | ${sym} | ${doc || '—'} |`);
  }

  sections.push(
    `### ${target}/\n\n| File | Lines | Exports | First doc line |\n|---|---|---|---|\n${rows.join('\n')}\n`
  );
}

const stamp = new Date().toISOString();
const out = `# Code Map

_Auto-generated by \`scripts/scan-code.mjs\` at ${stamp}_

_Do not edit by hand. Regenerate with \`npm run scan\`._

${sections.join('\n')}
`;

writeFileSync(OUT, out);
console.log(`Wrote ${relative(ROOT, OUT)}`);