/*
 * Tencent is pleased to support the open source community by making TMagicEditor available.
 *
 * Copyright (C) 2023 THL A29 Limited, a Tencent company.  All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import EventEmitter from 'events';

import { cloneDeep } from 'lodash-es';

import type { DataSourceSchema, default as TMagicApp, DisplayCond, Id, MNode, NODE_CONDS_KEY } from '@tmagic/core';
import { compiledNode } from '@tmagic/core';

import { SimpleObservedData } from './observed-data/SimpleObservedData';
import { DataSource, HttpDataSource } from './data-sources';
import { getDeps } from './depsCache';
import type { ChangeEvent, DataSourceManagerData, DataSourceManagerOptions, ObservedDataClass } from './types';
import { compiledNodeField, compliedConditions, compliedIteratorItem, createIteratorContentData } from './utils';

class DataSourceManager extends EventEmitter {
  private static dataSourceClassMap = new Map<string, typeof DataSource>();
  private static ObservedDataClass: ObservedDataClass = SimpleObservedData;

  public static register<T extends typeof DataSource = typeof DataSource>(type: string, dataSource: T) {
    DataSourceManager.dataSourceClassMap.set(type, dataSource);
  }

  public static getDataSourceClass(type: string) {
    return DataSourceManager.dataSourceClassMap.get(type);
  }

  public static registerObservedData(ObservedDataClass: ObservedDataClass) {
    DataSourceManager.ObservedDataClass = ObservedDataClass;
  }

  public app: TMagicApp;

  public dataSourceMap = new Map<string, DataSource & Record<string, any>>();

  public data: DataSourceManagerData = {};
  public useMock?: boolean = false;

  constructor({ app, useMock, initialData }: DataSourceManagerOptions) {
    super();

    this.app = app;
    this.useMock = useMock;

    if (initialData) {
      this.data = initialData;
    }

    app.dsl?.dataSources?.forEach((config) => {
      this.addDataSource(config);
    });

    const dataSourceList = Array.from(this.dataSourceMap);

    if (typeof Promise.allSettled === 'function') {
      Promise.allSettled<Record<string, any>>(dataSourceList.map(([, ds]) => this.init(ds))).then((values) => {
        const data: DataSourceManagerData = {};
        const errors: Record<string, Error> = {};

        values.forEach((value, index) => {
          const dsId = dataSourceList[index][0];
          if (value.status === 'fulfilled') {
            if (this.data[dsId]) {
              data[dsId] = this.data[dsId];
            } else {
              delete data[dsId];
            }
          } else if (value.status === 'rejected') {
            delete data[dsId];
            errors[dsId] = value.reason;
          }
        });

        this.emit('init', data, errors);
      });
    } else {
      Promise.all<Record<string, any>>(dataSourceList.map(([, ds]) => this.init(ds)))
        .then(() => {
          this.emit('init', this.data);
        })
        .catch(() => {
          this.emit('init', this.data);
        });
    }
  }

  public async init(ds: DataSource) {
    if (ds.isInit) {
      return;
    }

    if (this.app.jsEngine && ds.schema.disabledInitInJsEngine?.includes(this.app.jsEngine)) {
      return;
    }

    for (const method of ds.methods) {
      if (typeof method.content !== 'function') return;
      if (method.timing === 'beforeInit') {
        await method.content({ params: {}, dataSource: ds, app: this.app });
      }
    }

    await ds.init();

    for (const method of ds.methods) {
      if (typeof method.content !== 'function') return;
      if (method.timing === 'afterInit') {
        await method.content({ params: {}, dataSource: ds, app: this.app });
      }
    }
  }

  public get(id: string) {
    return this.dataSourceMap.get(id);
  }

  public async addDataSource(config?: DataSourceSchema) {
    if (!config) return;

    const DataSourceClass = DataSourceManager.dataSourceClassMap.get(config.type) || DataSource;

    const ds = new DataSourceClass({
      app: this.app,
      schema: config,
      request: this.app.request,
      useMock: this.useMock,
      initialData: this.data[config.id],
      ObservedDataClass: DataSourceManager.ObservedDataClass,
    });

    this.dataSourceMap.set(config.id, ds);

    this.data[ds.id] = ds.data;

    ds.on('change', (changeEvent: ChangeEvent) => {
      this.setData(ds, changeEvent);
    });
  }

  public setData(ds: DataSource, changeEvent: ChangeEvent) {
    this.data[ds.id] = ds.data;
    this.emit('change', ds.id, changeEvent);
  }

  public removeDataSource(id: string) {
    this.get(id)?.destroy();
    delete this.data[id];
    this.dataSourceMap.delete(id);
  }

  /**
   * 更新数据源dsl，在编辑器中修改配置后需要更新，一般在其他环境下不需要更新dsl
   * @param {DataSourceSchema[]} schemas 所有数据源配置
   */
  public updateSchema(schemas: DataSourceSchema[]) {
    schemas.forEach((schema) => {
      const ds = this.get(schema.id);
      if (!ds) {
        return;
      }

      this.removeDataSource(schema.id);

      this.addDataSource(schema);
      const newDs = this.get(schema.id);
      if (newDs) {
        this.init(newDs);
      }
    });
  }

  /**
   * 将组件dsl中所有key中数据源相关的配置编译成对应的值
   * @param {MNode} node 组件dsl
   * @param {string | number} sourceId 数据源ID
   * @param {boolean} deep 是否编译子项（items)，默认为false
   * @returns {MNode} 编译后的组件dsl
   */
  public compiledNode({ items, ...node }: MNode, sourceId?: Id, deep = false) {
    const newNode = cloneDeep(node);

    if (items) {
      newNode.items =
        Array.isArray(items) && deep ? items.map((item) => this.compiledNode(item, sourceId, deep)) : items;
    }

    if (node.condResult === false) return newNode;
    if (node.visible === false) return newNode;

    // 编译函数这里作为参数，方便后续支持自定义编译
    return compiledNode(
      (value: any) => compiledNodeField(value, this.data),
      newNode,
      this.app.dsl?.dataSourceDeps || {},
      sourceId,
    );
  }

  /**
   * 编译组件条件组配置（用于配置组件显示时机）
   * @param {{ [NODE_CONDS_KEY]?: DisplayCond[] }} node 显示条件组配置
   * @returns {boolean} 是否显示
   */
  public compliedConds(node: { [NODE_CONDS_KEY]?: DisplayCond[] }) {
    return compliedConditions(node, this.data);
  }

  /**
   * 编译迭代器容器的迭代项的显示条件
   * @param {any[]} itemData 迭代数据
   * @param {{ [NODE_CONDS_KEY]?: DisplayCond[] }} node 显示条件组配置
   * @param {string[]} dataSourceField 迭代数据在数据源中的字段，格式如['dsId', 'key1', 'key2']
   * @returns {boolean}是否显示
   */
  public compliedIteratorItemConds(
    itemData: any,
    node: { [NODE_CONDS_KEY]?: DisplayCond[] },
    dataSourceField: string[] = [],
  ) {
    const [dsId, ...keys] = dataSourceField;
    const ds = this.get(dsId);
    if (!ds) return true;

    const ctxData = createIteratorContentData(itemData, ds.id, keys, this.data);
    return compliedConditions(node, ctxData);
  }

  public compliedIteratorItems(itemData: any, nodes: MNode[], dataSourceField: string[] = []): MNode[] {
    const [dsId, ...keys] = dataSourceField;
    const ds = this.get(dsId);
    if (!ds) return nodes;

    const inEditor = this.app.platform === 'editor';

    const ctxData = createIteratorContentData(itemData, ds.id, keys, this.data);

    const { deps = {}, condDeps = {} } = getDeps(ds.schema, nodes, inEditor);

    if (!Object.keys(deps).length && !Object.keys(condDeps).length) {
      return nodes;
    }

    return nodes.map((item) =>
      compliedIteratorItem({
        compile: (value: any) => compiledNodeField(value, ctxData),
        dsId: ds.id,
        item,
        deps,
        condDeps,
        inEditor,
        ctxData,
      }),
    );
  }

  public destroy() {
    this.removeAllListeners();
    this.data = {};
    this.dataSourceMap.forEach((ds) => {
      ds.destroy();
    });
    this.dataSourceMap.clear();
  }

  public onDataChange(id: string, path: string, callback: (newVal: any) => void) {
    return this.get(id)?.onDataChange(path, callback);
  }

  public offDataChange(id: string, path: string, callback: (newVal: any) => void) {
    return this.get(id)?.offDataChange(path, callback);
  }
}

DataSourceManager.register('http', HttpDataSource as any);

export default DataSourceManager;