/**
 * useSiteVersion Composable
 *
 * Gets the current site version for footer badges and version displays.
 * Fetches the latest release version from the DCS Portal API.
 *
 * @example
 * ```vue
 * <script setup lang="ts">
 * import { useSiteVersion } from '@duffcloudservices/cms'
 *
 * const { version, releaseNotesUrl } = useSiteVersion()
 * </script>
 *
 * <template>
 *   <footer>
 *     <a v-if="version" :href="releaseNotesUrl" class="version-badge">
 *       v{{ version }}
 *     </a>
 *   </footer>
 * </template>
 * ```
 */

import { platformFetch } from '@duffcloudservices/cms-core'
import { ref, computed, onMounted } from 'vue'
import type { SiteVersionReturn } from '../types/release-notes'

/**
 * Get environment variable value.
 */
function getEnvVar(key: string, defaultValue = ''): string {
  try {
    if (typeof import.meta !== 'undefined' && import.meta.env) {
      const value = (import.meta.env as Record<string, string | undefined>)[key]
      if (value !== undefined) return value
    }
  } catch {
    // import.meta not available
  }
  return defaultValue
}

// Cache for site version
let versionCache: { version: string; expiresAt: number } | null = null
const CACHE_TTL = 10 * 60 * 1000 // 10 minutes

/**
 * useSiteVersion composable for displaying the current site version.
 *
 * @param options - Optional configuration
 * @returns Site version data and computed URL
 */
export function useSiteVersion(options: { fetchOnMount?: boolean } = {}): SiteVersionReturn {
  const { fetchOnMount = true } = options

  const apiBaseUrl = getEnvVar('VITE_API_BASE_URL', 'https://portal.duffcloudservices.com')
  // @deprecated VITE_SITE_SLUG: the site is now resolved server-side from the
  // request Host or the dedicated Container App's DCS_SITE_SLUG. It is no longer
  // used for routing; retained only for source compatibility.
  void getEnvVar('VITE_SITE_SLUG', '')

  const version = ref<string | null>(null)
  const isLoading = ref(false)

  const releaseNotesUrl = computed(() => {
    if (!version.value) return '/releaseNotes/latest'
    return `/releaseNotes/${version.value}`
  })

  async function fetchVersion(): Promise<void> {
    // Check cache
    if (versionCache && versionCache.expiresAt > Date.now()) {
      version.value = versionCache.version
      return
    }

    isLoading.value = true

    try {
      // Fetch the latest release notes to get the version
      const url = `${apiBaseUrl}/api/v1/release-notes/latest`
      // C-298 layer 2 — see useReleaseNotes: an HTML body is a misroute, not "no release
      // notes yet", and this composable's catch would otherwise swallow it silently.
      const response = await platformFetch(url, {
        headers: {
          Accept: 'application/json',
        },
      })

      if (!response.ok) {
        // No release notes yet - that's fine
        return
      }

      const data = await response.json()
      const latestVersion = data.version

      // Cache the result
      versionCache = {
        version: latestVersion,
        expiresAt: Date.now() + CACHE_TTL,
      }

      version.value = latestVersion
    } catch (e) {
      console.error('[@duffcloudservices/cms] Failed to fetch site version:', e)
    } finally {
      isLoading.value = false
    }
  }

  // Fetch on mount if enabled
  if (fetchOnMount && typeof window !== 'undefined') {
    onMounted(() => {
      fetchVersion()
    })
  }

  return {
    version,
    isLoading,
    releaseNotesUrl,
  }
}