type CalcSearchDraft = {
  from: string
  to: string
  cargo: string
  fromLat: number | null
  fromLng: number | null
  toLat: number | null
  toLng: number | null
}

type CalcSearchDraftPatch = Partial<CalcSearchDraft>

const initialCalcSearchDraft = (): CalcSearchDraft => ({
  from: '',
  to: '',
  cargo: '',
  fromLat: null,
  fromLng: null,
  toLat: null,
  toLng: null,
})

function stringParam(value: unknown) {
  return typeof value === 'string' ? value.trim() : ''
}

function numberParam(value: unknown) {
  const num = Number(value)
  return Number.isFinite(num) ? num : null
}

export function useCalcSearchDraft() {
  const draft = useState<CalcSearchDraft>('calc-search-draft', initialCalcSearchDraft)

  function hydrateFromQuery(query: Record<string, unknown>) {
    const nextDraft = { ...draft.value }
    const from = stringParam(query.from)
    const to = stringParam(query.to)
    const cargo = stringParam(query.cargo)
    const fromLat = numberParam(query.fromLat)
    const fromLng = numberParam(query.fromLng)
    const toLat = numberParam(query.toLat)
    const toLng = numberParam(query.toLng)

    if (from) nextDraft.from = from
    if (to) nextDraft.to = to
    if (cargo) nextDraft.cargo = cargo
    if (fromLat !== null) nextDraft.fromLat = fromLat
    if (fromLng !== null) nextDraft.fromLng = fromLng
    if (toLat !== null) nextDraft.toLat = toLat
    if (toLng !== null) nextDraft.toLng = toLng

    draft.value = nextDraft
  }

  function patchDraft(patch: CalcSearchDraftPatch) {
    draft.value = {
      ...draft.value,
      ...patch,
    }
  }

  function buildQuery(patch: CalcSearchDraftPatch = {}) {
    const nextDraft = {
      ...draft.value,
      ...patch,
    }

    return {
      ...(nextDraft.from.trim() ? { from: nextDraft.from.trim() } : {}),
      ...(nextDraft.to.trim() ? { to: nextDraft.to.trim() } : {}),
      ...(nextDraft.cargo.trim() ? { cargo: nextDraft.cargo.trim() } : {}),
      ...(nextDraft.fromLat !== null ? { fromLat: String(nextDraft.fromLat) } : {}),
      ...(nextDraft.fromLng !== null ? { fromLng: String(nextDraft.fromLng) } : {}),
      ...(nextDraft.toLat !== null ? { toLat: String(nextDraft.toLat) } : {}),
      ...(nextDraft.toLng !== null ? { toLng: String(nextDraft.toLng) } : {}),
    }
  }

  return {
    draft,
    hydrateFromQuery,
    patchDraft,
    buildQuery,
  }
}