export type CityPartnerScopeType = 'CITY_WIDE' | 'DISTRICT';
export type CityPartnerStatus = 'ACTIVE' | 'PAUSED';

export interface PartnerCityBindingInput {
  id?: string;
  partnerAccountId: string;
  scopeType: CityPartnerScopeType;
  districtCodes?: string[] | null;
  bindingStatus?: CityPartnerStatus;
}

export interface PartnerCityResolveRef {
  id: string;
  partnerAccountId: string;
  scopeType: CityPartnerScopeType;
  orderCommissionRate: number;
  redeemCommissionRate: number;
}

export interface PartnerCityValidationResult {
  ok: boolean;
  message?: string;
}

function normalizeDistrictCodes(codes?: string[] | null): string[] {
  if (!codes?.length) return [];
  return [...new Set(codes.map((c) => String(c).trim()).filter(Boolean))];
}

/** 区县 adcode 或名称命中区域合伙；否则全城合伙 */
export function resolveOrderCityPartner(
  bindings: Array<{
    id: string;
    partnerAccountId: string;
    scopeType: CityPartnerScopeType;
    districtCodes?: string[] | null;
    orderCommissionRate: number;
    redeemCommissionRate: number;
    bindingStatus?: CityPartnerStatus;
  }>,
  receiverDistrict?: string | null,
): PartnerCityResolveRef | null {
  const active = bindings.filter((b) => b.bindingStatus !== 'PAUSED');
  if (!active.length) return null;

  const districtKey = receiverDistrict?.trim();
  if (districtKey) {
    const districtHit = active.find((b) => {
      if (b.scopeType !== 'DISTRICT') return false;
      const codes = normalizeDistrictCodes(b.districtCodes);
      return codes.some((code) => code === districtKey || districtKey.includes(code) || code.includes(districtKey));
    });
    if (districtHit) {
      return {
        id: districtHit.id,
        partnerAccountId: districtHit.partnerAccountId,
        scopeType: districtHit.scopeType,
        orderCommissionRate: districtHit.orderCommissionRate,
        redeemCommissionRate: districtHit.redeemCommissionRate,
      };
    }
  }

  const cityWide = active.find((b) => b.scopeType === 'CITY_WIDE');
  if (cityWide) {
    return {
      id: cityWide.id,
      partnerAccountId: cityWide.partnerAccountId,
      scopeType: cityWide.scopeType,
      orderCommissionRate: cityWide.orderCommissionRate,
      redeemCommissionRate: cityWide.redeemCommissionRate,
    };
  }

  return null;
}

export function validatePartnerCityBinding(
  existing: PartnerCityBindingInput[],
  input: PartnerCityBindingInput,
  excludeId?: string,
): PartnerCityValidationResult {
  const others = existing.filter((b) => b.id !== excludeId);

  if (others.some((b) => b.partnerAccountId === input.partnerAccountId)) {
    return { ok: false, message: '该合伙人已绑定此城市' };
  }

  if (input.scopeType === 'CITY_WIDE') {
    if (others.some((b) => b.scopeType === 'CITY_WIDE')) {
      return { ok: false, message: '每城最多 1 名全城合伙人' };
    }
    return { ok: true };
  }

  const districts = normalizeDistrictCodes(input.districtCodes);
  if (!districts.length) {
    return { ok: false, message: '区域合伙人须至少选择一个区县' };
  }

  const occupied = new Set<string>();
  for (const row of others) {
    if (row.scopeType !== 'DISTRICT') continue;
    for (const code of normalizeDistrictCodes(row.districtCodes)) {
      occupied.add(code);
    }
  }

  for (const code of districts) {
    if (occupied.has(code)) {
      return { ok: false, message: `区县 ${code} 已被其他区域合伙人占用` };
    }
  }

  return { ok: true };
}

/** @deprecated use validatePartnerCityBinding */
export const validateCityPartnerBinding = validatePartnerCityBinding;

export const DEFAULT_MAX_PARTNER_COMMISSION_RATE = 0.05;

export function resolveMaxPartnerCommissionRate(maxRate?: number | null): number {
  if (maxRate == null || Number.isNaN(Number(maxRate))) {
    return DEFAULT_MAX_PARTNER_COMMISSION_RATE;
  }
  return Number(maxRate);
}

/** 订单佣金 + 核销佣金不得超过城市配置上限（默认 5%） */
export function validatePartnerCommissionRates(
  orderCommissionRate: number,
  redeemCommissionRate: number,
  maxSumRate = DEFAULT_MAX_PARTNER_COMMISSION_RATE,
): PartnerCityValidationResult {
  const sum = orderCommissionRate + redeemCommissionRate;
  const max = resolveMaxPartnerCommissionRate(maxSumRate);
  if (sum > max + 1e-9) {
    return {
      ok: false,
      message: `订单佣金与核销佣金合计不得超过 ${(max * 100).toFixed(2)}%（当前 ${(sum * 100).toFixed(2)}%）`,
    };
  }
  return { ok: true };
}