import { Readable } from 'stream';
import * as bean from '../bean/index.js';
import * as model from '../model/index.js';
import * as types from '../model/types.js';
import * as sql from '../sql/index.js';
import IQuerySet from './IQuerySet.js';

class JoinQuerySet<T extends Object, U extends Object> extends IQuerySet<T & U> {
  private mainSet: IQuerySet<T>;
  private joinSet: IQuerySet<U>;

  stat: sql.Statement = new sql.Statement();

  constructor(mainSet: IQuerySet<T>, joinSet: IQuerySet<U>, joinType: sql.types.Join, expr: sql.Expression) {
    super();
    this.mainSet = mainSet;
    this.context = mainSet.context;

    this.joinSet = joinSet;

    this.stat = new sql.Statement();

    // this.stat.collection.leftColl = this.mainSet.stat.collection;
    // this.stat.collection.rightColl = this.joinSet.stat.collection;
    this.stat.collection.join = joinType;

    this.stat.where = this.stat.where.add(expr);
  }

  // getEntity(): T & U {
  // 	let mainObj = this.mainSet.getEntity();
  // 	let joinObj = this.joinSet.getEntity();
  // 	return Object.assign(mainObj, joinObj);
  // 	// return null;
  // }

  // Selection Functions
  async list(): Promise<Array<T & U>> {
    // this.stat.command = sql.types.Command.SELECT;

    // let tempObj = this.getEntity();
    // this.setStatColumns(tempObj);

    // let result = await this.context.execute(this.stat);
    // return this.mapData(result);
    //TODO: implementation
    return new Array();
  }

  stream(): Promise<Readable> {
    throw new Error('Method not implemented.');
  }

  listPlain(keys: (keyof T | keyof U)[]): Promise<Partial<T & U>[]> {
    throw new Error('Method not implemented.');
  }

  async mapData(input: bean.ResultSet): Promise<Array<T & U>> {
    // let resMain = await this.mainSet.mapData(input);
    // let resJoin = await this.joinSet.mapData(input);

    // let res = new Array<T & U>();
    // for (let i = 0; i < input.rowCount; i++) {
    // 	let objMain = resMain[i];
    // 	let objJoin = resJoin[i];
    // 	let objFinal = Object.assign(objMain, objJoin);
    // 	res.push(objFinal);
    // }
    // return res;
    //TODO: implement
    return new Array();
  }

  // select<V extends Object = types.SubEntityType<T & U>>(TargetType: types.IEntityType<V>): IQuerySet<V> {
  select<V extends Object>(EntityType: types.IEntityType<V>): IQuerySet<V> {
    // this.stat.command = sql.types.Command.SELECT;

    // let a = this.getEntity();
    // let tempObj = TargetType(a);
    // this.setStatColumns(tempObj);

    // let result = await this.context.execute(this.stat);
    // let temps = await this.mapData(result);
    // let res: V[] = [];
    // temps.forEach(t => {
    // 	let r = TargetType(t);
    // 	res.push(r);
    // });

    // return res;
    //TODO: implement
    throw new Error('Method not implemented.');
  }

  // selectPlain(keys: (keyof T & U)[]): Promise<types.SelectType<T & U>[]> {
  selectPlain(keys: (keyof T & U)[]): any {
    //TODO: implement
    return null;
  }

  // Conditional Functions
  where(param: types.IWhereFunc<model.WhereExprBuilder<T & U>>, ...args: any[]): IQuerySet<T & U> {
    // let res = null;
    // if (param && param instanceof Function) {
    // 	//TODO: fix join fieldMap
    // 	let mainFieldMap = this.context.tableSetMap.get(null).fieldMap;
    // 	let joinFieldMap = this.context.tableSetMap.get(null).fieldMap;
    // 	let finalFieldMap = new Map([...mainFieldMap, ...joinFieldMap]);

    // 	let op = new model.WhereExprBuilder<T & U>(finalFieldMap);
    // 	res = param(op, args);
    // }
    // if (res && res instanceof sql.Expression && res.exps.length > 0) {
    // 	this.stat.where = this.stat.where.add(res);
    // }
    return this;
  }

  groupBy(param: types.IArrFieldFunc<model.GroupExprBuilder<T & U>>): IQuerySet<T & U> {
    // let res = null;
    // if (param && param instanceof Function) {
    // 	//TODO: fix join fieldMap
    // 	let mainFieldMap = this.context.tableSetMap.get(Object)?.fieldMap;
    // 	let joinFieldMap = this.context.tableSetMap.get(Object)?.fieldMap;
    // 	let finalFieldMap = new Map([...mainFieldMap, ...joinFieldMap]);

    // 	let op = new model.GroupExprBuilder<T & U>(finalFieldMap);
    // 	res = param(op);
    // }
    // if (res && Array.isArray(res)) {
    // 	res.forEach(a => {
    // 		if (a instanceof sql.Expression && a.exps.length > 0) {
    // 			this.stat.groupBy.push(a);
    // 		}
    // 	});
    // }
    return this;
  }

  orderBy(param: types.IArrFieldFunc<model.OrderExprBuilder<T & U>>): IQuerySet<T & U> {
    // let res = null;
    // if (param && param instanceof Function) {
    // 	//TODO: fix join fieldMap
    // 	let mainFieldMap = this.context.tableSetMap.get(null)?.fieldMap;
    // 	let joinFieldMap = this.context.tableSetMap.get(null)?.fieldMap;
    // 	let finalFieldMap = new Map([...mainFieldMap, ...joinFieldMap]);

    // 	let op = new model.OrderExprBuilder<T & U>(finalFieldMap);
    // 	res = param(op);
    // }
    // if (res && Array.isArray(res)) {
    // 	res.forEach(expr => {
    // 		if (expr instanceof sql.Expression && expr.exps.length > 0) {
    // 			this.stat.orderBy.push(expr);
    // 		}
    // 	});
    // }
    return this;
  }

  limit(size: number, index?: number): IQuerySet<T & U> {
    this.stat.limit = new sql.Expression(null, sql.types.Operator.Limit);
    this.stat.limit.exps.push(new sql.Expression(size.toString()));
    if (index) {
      this.stat.limit.exps.push(new sql.Expression(index.toString()));
    }
    return this;
  }

  // join<A extends Object>(coll: IQuerySet<A>, param: types.IJoinFunc<model.WhereExprBuilder<T & U>, model.GroupExprBuilder<A>>, joinType?: sql.types.Join): IQuerySet<T & U & A> {
  // 	joinType = joinType || sql.types.Join.InnerJoin;

  // 	let temp: sql.Expression | null = null;
  // 	if (param && param instanceof Function) {
  // 		let mainObj = this.getEntity(); new model.WhereExprBuilder<T>(this.dbSet.fieldMap);
  // 		let joinObj = coll.getEntity();
  // 		temp = param(mainObj, joinObj);
  // 	}
  // 	let res: JoinQuerySet<T & U, A>;
  // 	if (temp instanceof sql.Expression && temp.exps.length > 0) {
  // 		res = new JoinQuerySet<T & U, A>(this, coll, joinType, temp);
  // 	} else {
  // 		throw new TypeError('Invalid Join');
  // 	}
  // 	return res;
  // }
}

export default JoinQuerySet;