import Dexie from 'dexie';
import { createUUID, isNilOrEmpty } from 'qx-util';
import { IContext, IEntityBase } from '../../interface';
import { DBService } from './db-service';

/**
 * 数据对象基类 前端应用实体存储主键，统一为srfSessionKey
 *
 * @export
 * @class EntityDBService<T>
 */
export class EntityDBService<T extends IEntityBase> {
	/**
	 * 当前表
	 *
	 * @type {Dexie.Table<T, string>}
	 */
	readonly tab!: Dexie.Table<T, string>;

	/**
	 * Creates an instance of EntityDBService.
	 *
	 * @param {string} entityName
	 * @param {(data: any) => T} newEntity
	 * @param {(entity: T) => any} filterEntityData
	 */
	constructor(
		protected entityName: string,
		protected newEntity: (data: any) => T,
		protected filterEntityData: (entity: T) => any
	) {
		const db = DBService.getInstance();
		try {
			this.tab = db.table(entityName);
		} catch (err) {
			console.error(err);
		}
	}

	/**
	 * 新增数据
	 *
	 * @param {IContext} _context
	 * @param {T} entity
	 * @return {*}  {Promise<T>}
	 */
	async create(_context: IContext, entity: T): Promise<T> {
		try {
			if (isNilOrEmpty(entity.srfkey)) {
				entity.srfkey = createUUID();
			}
			const key = await this.tab.add(this.filterEntityData(entity));
			if (key) {
				return entity;
			}
		} catch (err) {
			console.error(err);
		}
		return null!;
	}

	/**
	 * 更新数据
	 *
	 * @param {IContext} _context
	 * @param {T} entity
	 * @return {*}  {Promise<T>}
	 */
	async update(_context: IContext, entity: T): Promise<T> {
		try {
			const res = await this.tab.put(
				this.filterEntityData(entity),
				entity.srfkey!
			);
			if (res) {
				return entity;
			}
		} catch (err) {
			console.error(err);
		}
		return null!;
	}

	/**
	 * 获取数据
	 *
	 * @param {IContext} _context
	 * @param {string} key
	 * @return {*}  {Promise<T>}
	 */
	async get(_context: IContext, key: string): Promise<T> {
		try {
			const data = await this.tab.get(key);
			if (data) {
				return this.newEntity(data);
			}
		} catch (err) {
			console.error(err);
		}
		return null!;
	}

	/**
	 * 数据是否存在
	 *
	 * @param {IContext} _context
	 * @param {string} key
	 * @return {*}  {Promise<boolean>}
	 */
	async checkData(_context: IContext, key: string): Promise<boolean> {
		try {
			const data = await this.tab.get(key);
			if (data) {
				return true;
			}
		} catch (err) {
			console.error(err);
		}
		return false;
	}

	/**
	 * 根据索引查询数据
	 *
	 * @param {IContext} _context
	 * @param {string} val 索引属性值
	 * @param {string} indexName 索引属性
	 * @return {*}  {Promise<T>}
	 */
	async getByIndex(
		_context: IContext,
		val: string,
		indexName: string
	): Promise<T> {
		try {
			const data = await this.tab.where(indexName).equals(val).first();
			if (data) {
				return this.newEntity(data);
			}
		} catch (err) {
			console.error(err);
		}
		return null!;
	}

	/**
	 * 删除数据
	 *
	 * @param {IContext} _context
	 * @param {string} key
	 * @return {*}  {Promise<boolean>}
	 */
	async remove(_context: IContext, key: string): Promise<boolean> {
		try {
			await this.tab.delete(key);
			return true;
		} catch (err) {
			console.error(err);
		}
		return false;
	}

	/**
	 * 搜索
	 *
	 * @param {IContext} _context
	 * @return {*}  {Promise<T[]>}
	 */
	async search(_context: IContext): Promise<T[]> {
		const items = await this.tab.toArray();
		return items.map((item) => this.newEntity(item));
	}

	/**
	 * 清空存储
	 *
	 * @return {*}  {boolean}
	 */
	async clear(): Promise<boolean> {
		try {
			await this.tab.clear();
			return true;
		} catch (err) {
			console.error(err);
		}
		return false;
	}
}