/** Contract / quote product package_spec codec — mirror backend `crm_package_spec.py`. */

export const MAX_PACKAGE_SPECS_PER_LINE = 20

export interface PackageQtyBreakdownItem {
  packageSpec?: string
  archivedQty?: number | null
  arrangedUnarchivedQty?: number | null
  arrangedTotalQty?: number | null
}

export function normalizePackageSpecs(values?: Iterable<unknown> | null): string[] {
  const out: string[] = []
  const seen = new Set<string>()
  for (const raw of values || []) {
    const s = String(raw ?? '').trim()
    if (!s || seen.has(s)) continue
    seen.add(s)
    out.push(s)
    if (out.length >= MAX_PACKAGE_SPECS_PER_LINE) break
  }
  return out
}

/** JSON array or legacy scalar → string[] */
export function decodePackageSpecs(value: unknown): string[] {
  if (value == null) return []
  if (Array.isArray(value)) return normalizePackageSpecs(value)
  const text = String(value).trim()
  if (!text) return []
  if (text.startsWith('[')) {
    try {
      const parsed = JSON.parse(text)
      if (Array.isArray(parsed)) return normalizePackageSpecs(parsed)
    } catch {
      // fall through to scalar
    }
  }
  return [text]
}

/** Prefer API `packageSpecs` when present; fallback to scalar `packageSpec`. */
export function resolvePackageSpecsFromPayload(data?: {
  packageSpecs?: string[] | null
  packageSpec?: string | null
} | null): string[] {
  if (!data) return []
  if (data.packageSpecs != null) return normalizePackageSpecs(data.packageSpecs)
  return decodePackageSpecs(data.packageSpec)
}

export function formatPackageSpecsJoin(
  data?: { packageSpecs?: string[] | null; packageSpec?: string | null } | null,
  separator = '、'
): string {
  const specs = resolvePackageSpecsFromPayload(data)
  return specs.length ? specs.join(separator) : ''
}

export function hasMultiPackageQtyBreakdown(product?: {
  packageQtyBreakdown?: PackageQtyBreakdownItem[] | null
} | null): boolean {
  return (product?.packageQtyBreakdown?.length ?? 0) > 1
}

export function resolveLineRemainingQty(product?: {
  remainingQty?: number | null
  quantity?: number | null
  arrangedTotalQty?: number | null
} | null): number | null {
  if (product?.remainingQty != null && !Number.isNaN(Number(product.remainingQty))) {
    return Number(product.remainingQty)
  }
  const qty = Number(product?.quantity)
  const arranged = Number(product?.arrangedTotalQty ?? 0)
  if (!Number.isNaN(qty) && qty > 0) {
    return qty - arranged
  }
  return null
}

/** Collect union of all line package specs (dedupe, preserve order). */
export function collectAllContractPackageSpecs(
  products?: Array<{ packageSpecs?: string[] | null; packageSpec?: string | null }> | null
): string[] {
  const out: string[] = []
  const seen = new Set<string>()
  for (const p of products || []) {
    for (const spec of resolvePackageSpecsFromPayload(p)) {
      if (seen.has(spec)) continue
      seen.add(spec)
      out.push(spec)
    }
  }
  return out
}

export function normalizeContractProductPackageFields<
  T extends { packageSpecs?: string[] | null; packageSpec?: string | null }
>(product: T): T {
  const specs = resolvePackageSpecsFromPayload(product)
  product.packageSpecs = specs
  product.packageSpec = specs[0] || ''
  return product
}

export function buildPackageSpecsPayload(product: {
  packageSpecs?: string[] | null
  packageSpec?: string | null
}) {
  const specs = product.packageSpecs?.length
    ? normalizePackageSpecs(product.packageSpecs)
    : resolvePackageSpecsFromPayload(product)
  return {
    packageSpecs: specs,
    packageSpec: specs[0] || ''
  }
}

export function validateContractProductPackageSpecs(
  products: Array<{
    productId?: string | number | null
    packageSpecs?: string[] | null
    packageSpec?: string | null
  }>
): { ok: true } | { ok: false; message: string } {
  const seenByProduct = new Map<string, Set<string>>()
  for (let i = 0; i < products.length; i++) {
    const product = products[i]
    const rowNum = i + 1
    const specs = resolvePackageSpecsFromPayload(product)
    if (!specs.length) {
      return { ok: false, message: `第${rowNum}行产品的包装规格不能为空` }
    }
    const pid = String(product.productId || '').trim()
    if (!pid) continue
    if (!seenByProduct.has(pid)) seenByProduct.set(pid, new Set())
    const seen = seenByProduct.get(pid)!
    for (const spec of specs) {
      if (seen.has(spec)) {
        return { ok: false, message: `同一产品的包装规格不能重复：${spec}` }
      }
      seen.add(spec)
    }
  }
  return { ok: true }
}