import type { WellSampleDropData } from '../types'

interface DroppedSampleTransfer {
  getData(format: string): string
}

export function parseDroppedSampleTransfer(transfer: DroppedSampleTransfer): WellSampleDropData | null {
  if (jsonPayload(transfer)) return parseDroppedSampleJson(transfer)
  return createTextDroppedSample(transfer.getData('text/plain'))
}

/** JSON payloads only — no `text/plain` fallback, so stray text drags are rejected. */
export function parseDroppedSampleJson(transfer: DroppedSampleTransfer): WellSampleDropData | null {
  const json = jsonPayload(transfer)
  if (!json) return null
  try {
    return normalizeDroppedSample(JSON.parse(json))
  } catch {
    return null
  }
}

function jsonPayload(transfer: DroppedSampleTransfer): string {
  return transfer.getData('application/json') || transfer.getData('text/json')
}

export function createTextDroppedSample(text: string | null | undefined): WellSampleDropData | null {
  const sampleName = text?.trim()
  if (!sampleName) return null

  return {
    sampleName,
    label: sampleName,
    raw: sampleName,
  }
}

export function normalizeDroppedSample(raw: unknown): WellSampleDropData | null {
  if (!raw || typeof raw !== 'object') return null

  const record = raw as Record<string, unknown>
  const sampleName =
    getString(record.sampleName) ??
    getString(record.sample_name) ??
    getString(record.name) ??
    getString(record.label)
  const label = getString(record.label) ?? sampleName
  const sampleType =
    getString(record.sampleType) ??
    getString(record.sample_type) ??
    (record.type === 'sample' ? 'sample' : undefined)

  if (!sampleName && !label && !getString(record.id)) return null

  return {
    id: getString(record.id),
    sampleName,
    label,
    sampleType,
    injectionVolume: getPositive(record.injectionVolume ?? record.injection_volume),
    injectionCount: getPositive(record.injectionCount ?? record.injection_count),
    customMethod: getString(record.customMethod ?? record.custom_method) ?? null,
    metadata: getRecord(record.metadata),
    raw,
  }
}

function getString(value: unknown): string | undefined {
  return typeof value === 'string' && value.trim() ? value.trim() : undefined
}

/** Volumes and counts from an untrusted drag payload: zero or less is dropped. */
function getPositive(value: unknown): number | undefined {
  return typeof value === 'number' && Number.isFinite(value) && value > 0 ? value : undefined
}

function getRecord(value: unknown): Record<string, unknown> | undefined {
  return value && typeof value === 'object' && !Array.isArray(value)
    ? value as Record<string, unknown>
    : undefined
}