// Tiny hash router - no dependency, matches the project's "no build step"
// bias. Routes are registered with route(pattern, handler); handler gets
// (root, params) where params come from ":name" segments in the pattern.

const routes = [];

export function route(pattern, handler) {
  const keys = [];
  const regexSource = pattern
    .split('/')
    .map((segment) => {
      if (segment.startsWith(':')) {
        keys.push(segment.slice(1));
        return '([^/]+)';
      }
      return segment.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
    })
    .join('/');
  routes.push({ regex: new RegExp('^' + regexSource + '$'), keys, handler });
}

export function navigate(path) {
  location.hash = '#' + path;
}

export function start(root) {
  function render() {
    const path = (location.hash.slice(1) || '/').split('?')[0];
    for (const r of routes) {
      const match = path.match(r.regex);
      if (match) {
        const params = {};
        r.keys.forEach((key, i) => { params[key] = decodeURIComponent(match[i + 1]); });
        root.innerHTML = '';
        r.handler(root, params);
        return;
      }
    }
    root.innerHTML = '<main class="wrap"><p>Page introuvable.</p></main>';
  }

  window.addEventListener('hashchange', render);
  render();
}