/**
 * ─────────────────────────────────────────────
 *  SPB Git — Personal Git Platform
 * ─────────────────────────────────────────────
 *  Author  : Simon-Pierre Boucher
 *  Contact : contact@spboucher.ai
 *  File    : scripts/inject-headers.mjs
 *  Purpose : Bulk-inject the mandatory author header into project files
 *  License : MIT © Simon-Pierre Boucher
 * ─────────────────────────────────────────────
 */

import { execFileSync } from 'node:child_process';
import { readFileSync, writeFileSync, readdirSync, statSync } from 'node:fs';
import { basename, extname, join, relative } from 'node:path';
import process from 'node:process';

const ROOT = new URL('..', import.meta.url).pathname;

const EXEMPT_PATTERNS = [
  /\.json$/, /\.jsonl$/, /\.lock$/,
  /(^|\/)LICENSE$/,
  /\.(woff2?|ttf|otf|eot|png|jpe?g|gif|ico|webp|zip|gz|zst|pdf)$/i,
  /(^|\/)\.DS_Store$/,
  /(^|\/)\.env$/,
  /(^|\/)node_modules\//, /(^|\/)dev\//, /(^|\/)coverage\//,
  /(^|\/)dist\//, /(^|\/)logs\//, /(^|\/)\.git\//, /(^|\/)\.claude\//,
  /(^|\/)src\/web\/assets\/vendor\//,
];

const REQUIRED_MARKERS = ['SPB Git', 'Simon-Pierre Boucher', 'contact@spboucher.ai'];

/**
 * Build the header block for a given comment style.
 * @param {string} file repo-relative path
 * @param {'block'|'hash'|'html'|'dash'|'njk'} style
 */
function buildHeader(file, style) {
  const lines = [
    '─────────────────────────────────────────────',
    ' SPB Git — Personal Git Platform',
    '─────────────────────────────────────────────',
    ' Author  : Simon-Pierre Boucher',
    ' Contact : contact@spboucher.ai',
    ` File    : ${file}`,
    ' Purpose : (added by inject-headers)',
    ' License : MIT © Simon-Pierre Boucher',
    '─────────────────────────────────────────────',
  ];
  switch (style) {
    case 'block':
      return `/**\n${lines.map((l) => ` * ${l}`).join('\n')}\n */\n\n`;
    case 'hash':
      return `${lines.map((l) => `# ${l}`).join('\n')}\n\n`;
    case 'html':
      return `<!--\n${lines.map((l) => `  ${l}`).join('\n')}\n-->\n\n`;
    case 'dash':
      return `${lines.map((l) => `-- ${l}`).join('\n')}\n\n`;
    case 'njk':
      return `{#\n${lines.map((l) => `  ${l}`).join('\n')}\n#}\n`;
    default:
      throw new Error(`unknown style ${style}`);
  }
}

/** @returns {'block'|'hash'|'html'|'dash'|'njk'|null} */
function styleFor(file) {
  const ext = extname(file).toLowerCase();
  const base = basename(file);
  if (['.js', '.mjs', '.cjs', '.ts', '.css', '.scss'].includes(ext)) return 'block';
  if (['.py', '.sh', '.bash', '.yml', '.yaml', '.toml', '.service', '.gitignore', '.gitattributes', '.example'].includes(ext)) return 'hash';
  if (base === 'Dockerfile' || base === 'Makefile' || base === '.gitignore' || base === '.gitattributes') return 'hash';
  if (['.html', '.md', '.vue', '.svg'].includes(ext)) return 'html';
  if (ext === '.sql') return 'dash';
  if (ext === '.njk') return 'njk';
  return null;
}

function listFiles() {
  try {
    const out = execFileSync('git', ['ls-files'], { cwd: ROOT, encoding: 'utf8' });
    const files = out.split('\n').filter(Boolean);
    if (files.length > 0) return files;
  } catch {
    /* fall through */
  }
  const acc = [];
  const walk = (dir) => {
    for (const entry of readdirSync(dir)) {
      const full = join(dir, entry);
      const rel = relative(ROOT, full);
      if (EXEMPT_PATTERNS.some((re) => re.test(rel + (statSync(full).isDirectory() ? '/' : '')))) continue;
      if (statSync(full).isDirectory()) walk(full);
      else acc.push(rel);
    }
  };
  walk(ROOT);
  return acc;
}

let injected = 0;
for (const file of listFiles()) {
  if (EXEMPT_PATTERNS.some((re) => re.test(file))) continue;
  const style = styleFor(file);
  if (!style) continue;
  const full = join(ROOT, file);
  let content;
  try {
    content = readFileSync(full, 'utf8');
  } catch {
    continue;
  }
  const head = content.split('\n').slice(0, 40).join('\n');
  if (REQUIRED_MARKERS.every((m) => head.includes(m))) continue;
  const header = buildHeader(file, style);
  if (content.startsWith('#!')) {
    const nl = content.indexOf('\n') + 1;
    content = content.slice(0, nl) + header + content.slice(nl);
  } else {
    content = header + content;
  }
  writeFileSync(full, content);
  console.log(`+ header → ${file}`);
  injected += 1;
}
console.log(injected > 0 ? `Injected ${injected} header(s).` : 'Nothing to do — all headers present.');
process.exit(0);