import areaData from 'china-area-data';

export interface CascadeOption {
  value: string;
  label: string;
  children?: CascadeOption[];
}

/**
 * 将 china-area-data 原始数据转换为 antd Cascader 所需的 options 格式
 *
 * 原始数据格式: { '86': { '110000': '北京' }, '110000': { '110100': '市辖区' }, ... }
 * 目标格式: [{ value: '110000', label: '北京', children: [...] }]
 */
function buildTree(parentCode: string): CascadeOption[] {
  const nodes = areaData[parentCode];
  if (!nodes) return [];

  return Object.entries(nodes).map(([code, name]) => {
    const node: CascadeOption = {
      value: code,
      label: name as string,
    };
    const children = buildTree(code);
    if (children.length > 0) {
      node.children = children;
    }
    return node;
  });
}

/** 省市区三级联动数据 */
export const regionOptions: CascadeOption[] = buildTree('86');

// ============================================================
// 省市选项（精确到市，直辖市仅市名）
// ============================================================

/** 直辖市代码 */
const MUNICIPALITY_CODES = ['110000', '120000', '310000', '500000'];

/** 省市选项 */
export interface ProvinceCityOption {
  value: string;
  label: string;
}

/**
 * 获取"省-市"格式的选项列表
 * - 普通省份：格式为 "省名-市名"，如 "广东省-深圳市"
 * - 直辖市：直接使用市名，如 "北京市"
 */
export function getProvinceCityOptions(): ProvinceCityOption[] {
  const options: ProvinceCityOption[] = [];
  const provinces = areaData['86'];
  if (!provinces) return options;

  for (const [provinceCode, provinceName] of Object.entries(provinces)) {
    const pname = provinceName as string;

    if (MUNICIPALITY_CODES.includes(provinceCode)) {
      options.push({ value: pname, label: pname });
    } else {
      const cities = areaData[provinceCode];
      if (cities) {
        for (const [, cityName] of Object.entries(cities)) {
          const fullName = `${pname}-${cityName}`;
          options.push({ value: fullName, label: fullName });
        }
      }
    }
  }

  return options;
}

/** Cascader 节点 */
export interface CascaderNode {
  value: string;
  label: string;
  children?: CascaderNode[];
}

/**
 * 获取省市两级 Cascader 选项
 * - 普通省份：省 → 市，选中值 ["省名", "市名"]
 * - 直辖市：直接叶子节点，选中值 ["市名"]
 */
export function getProvinceCityCascaderOptions(): CascaderNode[] {
  const nodes: CascaderNode[] = [];
  const provinces = areaData['86'];
  if (!provinces) return nodes;

  for (const [provinceCode, provinceName] of Object.entries(provinces)) {
    const pname = provinceName as string;

    if (MUNICIPALITY_CODES.includes(provinceCode)) {
      // 直辖市：直接作为叶子节点
      nodes.push({ value: pname, label: pname });
    } else {
      const cities = areaData[provinceCode];
      if (cities) {
        const cityNodes: CascaderNode[] = Object.entries(cities).map(([, cname]) => ({
          value: cname as string,
          label: cname as string,
        }));
        nodes.push({ value: pname, label: pname, children: cityNodes });
      }
    }
  }

  return nodes;
}

/**
 * 将 Cascader 选中的路径数组转为存储用的区域字符串
 * ["广东省", "深圳市"] → "广东省-深圳市"
 * ["北京市"] → "北京市"
 */
export function formatCascaderArea(path: string[]): string {
  if (!path || path.length === 0) return '';
  return path.join('-');
}

/**
 * 将存储的区域字符串反向解析为 Cascader 路径数组
 * "广东省-深圳市" → ["广东省", "深圳市"]
 * "北京市" → ["北京市"]
 */
export function parseAreaToCascaderPath(area: string): string[] {
  if (!area) return [];
  return area.split('-');
}

// ============================================================
// 城市级别选项（仅市名，加"全国"）
// ============================================================

/** 城市 Select 选项 */
export interface CityOption {
  value: string;
  label: string;
}

/**
 * 获取仅城市名的选项列表，第一项为"全国"
 * 用于 Banner 弹窗中"所属区域"下拉选择
 * - 直辖市：直接取市名（如"北京市"）
 * - 普通省份：取市名（如"深圳市"）
 */
export function getCityOnlyOptions(): CityOption[] {
  const options: CityOption[] = [{ value: '全国', label: '全国' }];
  const provinces = areaData['86'];
  if (!provinces) return options;

  for (const [provinceCode, provinceName] of Object.entries(provinces)) {
    if (MUNICIPALITY_CODES.includes(provinceCode)) {
      options.push({ value: provinceName as string, label: provinceName as string });
    } else {
      const cities = areaData[provinceCode];
      if (cities) {
        for (const [, cityName] of Object.entries(cities)) {
          options.push({ value: cityName as string, label: cityName as string });
        }
      }
    }
  }

  return options;
}

/**
 * 根据城市名反查 Cascader 路径数组
 * "深圳市" → ["广东省", "深圳市"]
 * "北京市" → ["北京市"]
 * "全国" → ["全国"]
 */
export function cityNameToCascaderPath(cityName: string): string[] {
  if (!cityName || cityName === '全国') return ['全国'];

  const provinces = areaData['86'];
  if (!provinces) return [cityName];

  for (const [provinceCode, provinceName] of Object.entries(provinces)) {
    const pname = provinceName as string;

    if (MUNICIPALITY_CODES.includes(provinceCode)) {
      if (pname === cityName) return [pname];
    } else {
      const cities = areaData[provinceCode];
      if (cities) {
        for (const [, cname] of Object.entries(cities)) {
          if ((cname as string) === cityName) {
            return [pname, cname as string];
          }
        }
      }
    }
  }

  // 兜底：找不到省份隶属，直接用市名
  return [cityName];
}