import { Middleware, IMiddleware } from '@midwayjs/core';
import { NextFunction, Context } from '@midwayjs/koa';
import * as qs from 'qs';

@Middleware()
  export class QueryNormalizeMiddleware implements IMiddleware<Context, NextFunction> {
    // 数值与布尔转换函数,用于将字符串转换为合适的类型
    private toPrimitive(value: any): any {
      const s = String(value);
      if (s === 'true') return true;
      if (s === 'false') return false;
      const n = Number(s);
      return Number.isFinite(n) && s !== '' ? n : value;
    }

    // 深度遍历对象并对字符串进行trim
    private trimDeep(input: any): any {
      if (input === null || input === undefined) return input;
      if (typeof input === 'string') return input.trim();
      if (Array.isArray(input)) return input.map(v => this.trimDeep(v));
      if (typeof input === 'object') {
        const out: Record<string, any> = {};
        for (const key of Object.keys(input)) {
          out[key] = this.trimDeep((input as any)[key]);
        }
        return out;
      }
      return input;
    }

  // 将路径数组对应的值赋到对象中,支持构建嵌套结构与数组
  private assignByPath(target: Record<string, any>, path: string[], value: any): void {
    let cur: any = target;
    for (let i = 0; i < path.length; i++) {
      const key = path[i];
      const isLast = i === path.length - 1;
      if (isLast) {
        if (key === '') {
          if (!Array.isArray(cur)) return;
          cur.push(value);
        } else {
          if (cur[key] === undefined) cur[key] = value;
          else if (Array.isArray(cur[key])) cur[key].push(value);
          else cur[key] = [cur[key], value];
        }
      } else {
        if (!cur[key] || typeof cur[key] !== 'object') cur[key] = {};
        cur = cur[key];
      }
    }
  }

  // 解析可能为 JSON 字符串或鍵值串的输入为对象
  private parseLooseObject(input: any): Record<string, any> {
    if (!input) return {};
    if (typeof input === 'object') return input as Record<string, any>;
    const str = String(input).trim();
    try {
      if (str.startsWith('{') || str.startsWith('[')) {
        const json = JSON.parse(str);
        if (json && typeof json === 'object') return json as Record<string, any>;
      }
    } catch {}
    const obj: Record<string, any> = {};
    const pairs = str.split(/[&;,]/).map(s => s.trim()).filter(Boolean);
    for (const pair of pairs) {
      const idxEq = pair.indexOf('=');
      const idxColon = pair.indexOf(':');
      const idx = idxEq >= 0 ? idxEq : idxColon;
      if (idx < 0) continue;
      const key = decodeURIComponent(pair.slice(0, idx)).trim();
      const valueRaw = decodeURIComponent(pair.slice(idx + 1)).trim();
      obj[key] = this.toPrimitive(valueRaw);
    }
    return obj;
  }

  resolve() {
    return async (ctx: Context, next: NextFunction) => {
      const raw = String((ctx.request as any).querystring || '');
      const parsed = qs.parse(raw, { allowDots: true, depth: 10, ignoreQueryPrefix: false, comma: true });
      const query = { ...(ctx.request.query || {}), ...(parsed as any) } as Record<string, any>;
      const trimmedTop: Record<string, any> = {};
      for (const k of Object.keys(query)) {
        const v = (query as any)[k];
        trimmedTop[k] = typeof v === 'string' ? String(v).trim() : v;
      }
      Object.assign(query, trimmedTop);

      // 解析 where 对象,支持 JSON 字符串与括号或点号语法
      const hasWhereInput = (query as any).where !== undefined;
      let whereObj: Record<string, any> = this.parseLooseObject((query as any).where);
      for (const k of Object.keys(query)) {
        if (k === 'where') continue;
        if (k.startsWith('where[') || k.startsWith('where.')) {
          const pathStr = k.replace(/^where\.?/, '').replace(/\]/g, '').replace(/\[/g, '.');
          const path = pathStr.split('.');
          const val = this.toPrimitive((query as any)[k]);
          this.assignByPath(whereObj, path, val);
        }
      }
      const hasWhereBracketKeys = Object.keys(query).some(k => k.startsWith('where[') || k.startsWith('where.'));
      if (hasWhereInput || hasWhereBracketKeys) (query as any).where = this.trimDeep(whereObj);

      // 解析 order 对象,支持 JSON 字符串与括号或点号语法
      const hasOrderInput = (query as any).order !== undefined;
      let orderObj: Record<string, any> = this.parseLooseObject((query as any).order);
      for (const k of Object.keys(query)) {
        if (k === 'order') continue;
        if (k.startsWith('order[') || k.startsWith('order.')) {
          const pathStr = k.replace(/^order\.?/, '').replace(/\]/g, '').replace(/\[/g, '.');
          const path = pathStr.split('.');
          const val = this.toPrimitive((query as any)[k]);
          this.assignByPath(orderObj, path, val);
        }
      }
      const hasOrderBracketKeys = Object.keys(query).some(k => k.startsWith('order[') || k.startsWith('order.'));
      if (hasOrderInput || hasOrderBracketKeys) (query as any).order = this.trimDeep(orderObj);

      // 将常见分页参数转换为数字类型
      if (query.page !== undefined) (query as any).page = Number(query.page);
      if ((query as any).page_size !== undefined) (query as any).page_size = Number((query as any).page_size);
      if ((query as any).per_page !== undefined) (query as any).per_page = Number((query as any).per_page);
      if ((query as any).customer_id !== undefined) (query as any).customer_id = Number((query as any).customer_id);

      ctx.request.query = query as any;
      (ctx as any).query = query as any;
      return await next();
    };
  }

  static getName(): string {
    return 'queryNormalize';
  }

  static getPriority(): number {
    // 优先级靠前,优先处理查询参数
    return -1;
  }
}