import { CONSTANT } from '~/constants'

/**
 * Fetches the latest release notes from GitHub and parses the SHA-256 checksums.
 * Returns a mapping from filename to checksum.
 */
export async function getChecksums() {
  if (import.meta.env.DEV) {
    return CONSTANT.CHECKSUMS
  }
  const res = await fetch('https://api.github.com/repos/zen-browser/desktop/releases/latest', {
    headers: {
      Accept: 'application/vnd.github+json',
      'X-GitHub-Api-Version': '2022-11-28',
      'User-Agent': 'zen-browser-checksum-fetcher',
    },
  })
  if (!res.ok) throw new Error(`Failed to fetch GitHub release: ${res.statusText}`)
  const data = await res.json()
  const body = data.body as string

  // Extract the checksum block
  const match = body.match(/File Checksums \(SHA-256\)[\s\S]*?```([\s\S]*?)```/)
  const checksums: Record<string, string> = {}
  if (match?.[1]) {
    for (const line of match[1].split('\n')) {
      const [hash, filename] = line.trim().split(/\s+/, 2)
      if (hash && filename) checksums[filename] = hash
    }
  }
  return checksums
}