import type { ApplicationFormDto } from '~~/.api-client'

export async function useApplicationFormNavigation(applicationFormId: string) {
  const { t } = useI18n()
  const { getApplicationFormById } = useApplicationForm()
  const { getVersions } = useApplicationFormVersion()

  const applicationFormAsync = useAsyncData<ApplicationFormDto>(
    `application-form-${applicationFormId}`,
    async () => await getApplicationFormById(applicationFormId),
    { deep: true }
  )

  const versionsAsync = useAsyncData(
    `application-form-${applicationFormId}-versions-nav`,
    async () => await getVersions(applicationFormId),
    { deep: false }
  )

  await Promise.all([applicationFormAsync, versionsAsync])

  if (applicationFormAsync.error.value) {
    throw createError({ statusText: applicationFormAsync.error.value.message })
  }

  const applicationForm = computed<ApplicationFormDto>(() => applicationFormAsync.data.value as ApplicationFormDto)

  const latestVersionNumber = computed<number | null>(() => {
    const versions = versionsAsync.data.value ?? []
    if (versions.length === 0) return null
    return Math.max(...versions.map((v) => v.versionNumber ?? 0))
  })

  const navigationLinks = computed(() => [
    [
      {
        label: t('applicationForms.tabs.form'),
        icon: 'i-lucide-file',
        to: `/application-forms/${applicationForm.value.id}/0`,
        exact: true
      },
      {
        label: t('applicationForms.tabs.versions'),
        icon: 'i-lucide-file-clock',
        to: `/application-forms/${applicationForm.value.id}/versions`,
        exact: true
      }
    ],
    [
      {
        label: t('applicationForms.tabs.preview'),
        icon: 'i-lucide-file-text',
        to: `/api/application-forms/${applicationForm.value.id}/versions/${latestVersionNumber.value}/pdf`,
        target: '_blank',
        disabled: Boolean(versionsAsync.error.value) || latestVersionNumber.value === null
      }
    ]
  ])

  function updateApplicationForm(updatedForm: ApplicationFormDto) {
    applicationFormAsync.data.value = updatedForm
    // Refresh the versions list so the Preview link points to the latest version.
    void versionsAsync.refresh()
  }

  async function refresh() {
    await Promise.all([applicationFormAsync.refresh(), versionsAsync.refresh()])
  }

  return {
    applicationForm,
    navigationLinks,
    refresh,
    updateApplicationForm,
    error: applicationFormAsync.error
  }
}