/*
 * Utility functions used across multiple frontend modules. These are pure
 * functions with no side effects and no dependency on application state.
 */

/* ── Formatting ─────────────────────────────────────────────────────────── */

export function prettifyStatus(status) {
  return status
    .split('_')
    .map((part) => part.charAt(0).toUpperCase() + part.slice(1))
    .join(' ');
}

export function formatDateTime(value) {
  return new Date(value).toLocaleString();
}

export function formatTime(value) {
  return new Date(value).toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' });
}

export function formatRelativeTime(value) {
  const diffMs = Date.now() - new Date(value).getTime();
  const diffMinutes = Math.round(diffMs / 60000);

  if (diffMinutes < 1) {
    return 'just now';
  }

  if (diffMinutes < 60) {
    return `${diffMinutes} minute(s) ago`;
  }

  const diffHours = Math.round(diffMinutes / 60);

  if (diffHours < 24) {
    return `${diffHours} hour(s) ago`;
  }

  return `${Math.round(diffHours / 24)} day(s) ago`;
}

export function formatFileSize(bytes) {
  if (bytes < 1024) {
    return `${bytes} B`;
  }

  if (bytes < 1024 * 1024) {
    return `${(bytes / 1024).toFixed(1)} KB`;
  }

  return `${(bytes / (1024 * 1024)).toFixed(1)} MB`;
}

/* ── Naming & Sanitization ──────────────────────────────────────────────── */

export function sanitizeForFilename(value) {
  return String(value || 'report')
    .trim()
    .replace(/\s+/g, '-')
    .replace(/[^a-zA-Z0-9-_]/g, '')
    .slice(0, 40);
}

export function generateReportNumber() {
  const now = new Date();
  const stamp = `${now.getFullYear()}${String(now.getMonth() + 1).padStart(2, '0')}${String(
    now.getDate()
  ).padStart(2, '0')}-${String(now.getHours()).padStart(2, '0')}${String(
    now.getMinutes()
  ).padStart(2, '0')}${String(now.getSeconds()).padStart(2, '0')}`;

  return `POC-${stamp}`;
}

export function buildGeneratedFilename(report, field, sequence, extension) {
  const reportNumber = sanitizeForFilename(report.answers.reportNumber || report.reportNumber);
  const sectionCode = sanitizeForFilename(field.id).slice(0, 10).toUpperCase();
  return `${reportNumber}_${sectionCode}_${String(sequence).padStart(3, '0')}.${extension}`;
}

/* ── Badge helpers ──────────────────────────────────────────────────────── */

export function badgeClassForTone(tone) {
  if (tone === 'success') {
    return 'badge-online';
  }

  if (tone === 'error') {
    return 'badge-error';
  }

  if (tone === 'warning') {
    return 'badge-offline';
  }

  return 'badge-neutral';
}

/* ── Template helpers ───────────────────────────────────────────────────── */

export function makeTemplateKey(code, version) {
  return `${code}::${version}`;
}

/*
 * Multiple versions of the same template can exist in local cache because old
 * drafts remain bound to the version they started with. The catalog therefore
 * picks the newest version per template code for the creation UI while keeping
 * older records available in the version lookup map.
 */
export function deriveTemplateCatalog(templateRows) {
  const byCode = new Map();

  for (const row of templateRows) {
    const existing = byCode.get(row.code);
    const shouldReplace = !existing || Number(row.version) > Number(existing.version);

    if (shouldReplace) {
      byCode.set(row.code, row);
    }
  }

  return Array.from(byCode.values())
    .sort((left, right) => left.name.localeCompare(right.name))
    .map((item) => ({
      code: item.code,
      name: item.name,
      description: item.description,
      activeVersion: item.version,
      publishedAt: item.publishedAt
    }));
}

/* ── General ────────────────────────────────────────────────────────────── */

/*
 * Debounce helper. Returns a wrapper that delays invocation until `ms`
 * milliseconds of inactivity have passed, preventing expensive operations
 * (such as a full form re-render) from running on every keystroke.
 */
export function debounce(fn, ms) {
  let timer = null;

  return function debounced(...args) {
    clearTimeout(timer);
    timer = setTimeout(() => fn.apply(this, args), ms);
  };
}