import { RNX_CHANGELOG_API_URL, RNX_CHANGELOG_URL } from '../src/runtime-delivery'
import type { ChangelogEntry } from '../../../scripts/changelog/types'

function isChangelogEntry(value: unknown): value is ChangelogEntry {
  if (!value || typeof value !== 'object') return false
  const sections = Reflect.get(value, 'sections')
  return (
    typeof Reflect.get(value, 'title') === 'string' &&
    Array.isArray(sections) &&
    sections.every(
      (section) =>
        section &&
        typeof section === 'object' &&
        typeof Reflect.get(section, 'title') === 'string' &&
        Array.isArray(Reflect.get(section, 'items')) &&
        Reflect.get(section, 'items').every(
          (item: unknown) =>
            item &&
            typeof item === 'object' &&
            typeof Reflect.get(item, 'summary') === 'string' &&
            typeof Reflect.get(item, 'hash') === 'string',
        ),
    )
  )
}

export async function fetchRuntimeReleaseNotes(
  version: string,
  fetchImpl: typeof fetch = fetch,
): Promise<ChangelogEntry | null> {
  try {
    const url = new URL(RNX_CHANGELOG_API_URL)
    url.searchParams.set('version', version)
    const response = await fetchImpl(url, {
      headers: { accept: 'application/json' },
      signal: AbortSignal.timeout(5000),
    })
    if (!response.ok) return null
    const payload: unknown = await response.json()
    if (!payload || typeof payload !== 'object') return null
    const entries = Reflect.get(payload, 'entries')
    if (!Array.isArray(entries) || !isChangelogEntry(entries[0])) return null
    return entries[0]
  } catch {
    return null
  }
}

export function formatRuntimeReleaseNotes(
  version: string,
  entry: ChangelogEntry | null,
): string {
  const lines = [`what's new in rnx engine v${version}:`]
  if (!entry || entry.sections.length === 0) {
    lines.push(`  release notes are not available yet`)
  } else {
    for (const section of entry.sections) {
      lines.push(`  ${section.title}:`)
      for (const item of section.items) {
        lines.push(`    • ${item.summary}`)
      }
    }
  }
  lines.push(`  full changelog: ${RNX_CHANGELOG_URL}`)
  return lines.join('\n')
}