const FILENAME_VARIANT_RULES: Array<{ pattern: RegExp; variant: string }> = [
  { pattern: /arm64[-_]?v8a/i, variant: 'arm64-v8a' },
  { pattern: /armeabi[-_]?v7a/i, variant: 'armeabi-v7a' },
  { pattern: /x86[-_]?64/i, variant: 'x86_64' },
  { pattern: /(?<![a-z0-9])x86(?![a-z0-9])/i, variant: 'x86' },
  { pattern: /universal/i, variant: 'universal' }
];

const VARIANT_LABELS: Record<string, string> = {
  universal: 'Universal',
  'arm64-v8a': 'ARM64 (arm64-v8a)',
  'armeabi-v7a': 'ARMv7 (armeabi-v7a)',
  x86_64: 'x86_64',
  x86: 'x86'
};

export function detectVariantFromFileName(fileName: string) {
  const baseName = fileName.trim().replace(/\.apk$/i, '');
  for (const rule of FILENAME_VARIANT_RULES) {
    if (rule.pattern.test(baseName)) {
      return rule.variant;
    }
  }
  const normalized = baseName
    .toLowerCase()
    .replace(/[^a-z0-9]+/g, '-')
    .replace(/^-+|-+$/g, '')
    .slice(0, 64);
  return normalized || 'universal';
}

export function formatReleaseVariantLabel(variant: string) {
  return VARIANT_LABELS[variant] ?? variant;
}

export function groupReleasesByVersion<T extends { version: string; versionCode: number }>(releases: T[]) {
  const groups = new Map<string, T[]>();
  for (const release of releases) {
    const key = `${release.versionCode}:${release.version}`;
    const list = groups.get(key) ?? [];
    list.push(release);
    groups.set(key, list);
  }
  return [...groups.entries()]
    .sort((left, right) => Number(right[0].split(':')[0]) - Number(left[0].split(':')[0]))
    .map(([key, items]) => ({
      key,
      version: items[0]?.version ?? '',
      versionCode: items[0]?.versionCode ?? 0,
      variants: [...items].sort((a, b) => {
        const left = 'variant' in a ? String((a as { variant?: string }).variant ?? '') : '';
        const right = 'variant' in b ? String((b as { variant?: string }).variant ?? '') : '';
        return left.localeCompare(right, 'ru');
      })
    }));
}