import * as plugins from './smartdata.plugins.js';

import { SmartdataDb } from './smartdata.classes.db.js';
import { SmartdataDbCursor } from './smartdata.classes.cursor.js';
import { type IManager, SmartdataCollection } from './smartdata.classes.collection.js';
import { SmartdataDbWatcher } from './smartdata.classes.watcher.js';

export type TDocCreation = 'db' | 'new' | 'mixed';

/**
 * saveable - saveable decorator to be used on class properties
 */
export function svDb() {
  return (target: SmartDataDbDoc<unknown, unknown>, key: string) => {
    console.log(`called svDb() on >${target.constructor.name}.${key}<`);
    if (!target.saveableProperties) {
      target.saveableProperties = [];
    }
    target.saveableProperties.push(key);
  };
}

/**
 * unique index - decorator to mark a unique index
 */
export function unI() {
  return (target: SmartDataDbDoc<unknown, unknown>, key: string) => {
    console.log(`called unI on >>${target.constructor.name}.${key}<<`);

    // mark the index as unique
    if (!target.uniqueIndexes) {
      target.uniqueIndexes = [];
    }
    target.uniqueIndexes.push(key);

    // and also save it
    if (!target.saveableProperties) {
      target.saveableProperties = [];
    }
    target.saveableProperties.push(key);
  };
}

export const convertFilterForMongoDb = (filterArg: { [key: string]: any }) => {
  const convertedFilter: { [key: string]: any } = {};
  const convertFilterArgument = (keyPathArg2: string, filterArg2: any) => {
    if (typeof filterArg2 === 'object') {
      for (const key of Object.keys(filterArg2)) {
        if (key.startsWith('$')) {
          convertedFilter[keyPathArg2] = filterArg2;
          return;
        } else if (key.includes('.')) {
          throw new Error('keys cannot contain dots');
        }
      }
      for (const key of Object.keys(filterArg2)) {
        convertFilterArgument(`${keyPathArg2}.${key}`, filterArg2[key]);
      }
    } else {
      convertedFilter[keyPathArg2] = filterArg2;
    }
  };
  for (const key of Object.keys(filterArg)) {
    convertFilterArgument(key, filterArg[key]);
  }
  return convertedFilter;
};

export class SmartDataDbDoc<T extends TImplements, TImplements, TManager extends IManager = any> {
  /**
   * the collection object an Doc belongs to
   */
  public static collection: SmartdataCollection<any>;
  public collection: SmartdataCollection<any>;
  public static defaultManager;
  public static manager;
  public manager: TManager;

  // STATIC
  public static createInstanceFromMongoDbNativeDoc<T>(
    this: plugins.tsclass.typeFest.Class<T>,
    mongoDbNativeDocArg: any
  ): T {
    const newInstance = new this();
    (newInstance as any).creationStatus = 'db';
    for (const key of Object.keys(mongoDbNativeDocArg)) {
      newInstance[key] = mongoDbNativeDocArg[key];
    }
    return newInstance;
  }

  /**
   * gets all instances as array
   * @param this
   * @param filterArg
   * @returns
   */
  public static async getInstances<T>(
    this: plugins.tsclass.typeFest.Class<T>,
    filterArg: plugins.tsclass.typeFest.PartialDeep<T>
  ): Promise<T[]> {
    const foundDocs = await (this as any).collection.findAll(convertFilterForMongoDb(filterArg));
    const returnArray = [];
    for (const foundDoc of foundDocs) {
      const newInstance: T = (this as any).createInstanceFromMongoDbNativeDoc(foundDoc);
      returnArray.push(newInstance);
    }
    return returnArray;
  }

  /**
   * gets the first matching instance
   * @param this
   * @param filterArg
   * @returns
   */
  public static async getInstance<T>(
    this: plugins.tsclass.typeFest.Class<T>,
    filterArg: plugins.tsclass.typeFest.PartialDeep<T>
  ): Promise<T> {
    const foundDoc = await (this as any).collection.findOne(convertFilterForMongoDb(filterArg));
    if (foundDoc) {
      const newInstance: T = (this as any).createInstanceFromMongoDbNativeDoc(foundDoc);
      return newInstance;
    } else {
      return null;
    }
  }

  /**
   * get a unique id prefixed with the class name
   */
  public static async getNewId<T = any>(this: plugins.tsclass.typeFest.Class<T>, lengthArg: number = 20) {
    return `${(this as any).className}:${plugins.smartunique.shortId(lengthArg)}`;
  }

  /**
   * get cursor
   * @returns
   */
  public static async getCursor<T>(
    this: plugins.tsclass.typeFest.Class<T>,
    filterArg: plugins.tsclass.typeFest.PartialDeep<T>
  ) {
    const collection: SmartdataCollection<T> = (this as any).collection;
    const cursor: SmartdataDbCursor<T> = await collection.getCursor(
      convertFilterForMongoDb(filterArg),
      this as any as typeof SmartDataDbDoc
    );
    return cursor;
  }

  /**
   * watch the collection
   * @param this
   * @param filterArg
   * @param forEachFunction
   */
  public static async watch<T>(
    this: plugins.tsclass.typeFest.Class<T>,
    filterArg: plugins.tsclass.typeFest.PartialDeep<T>
  ) {
    const collection: SmartdataCollection<T> = (this as any).collection;
    const watcher: SmartdataDbWatcher<T> = await collection.watch(
      convertFilterForMongoDb(filterArg),
      this as any
    );
    return watcher;
  }

  /**
   * run a function for all instances
   * @returns
   */
  public static async forEach<T>(
    this: plugins.tsclass.typeFest.Class<T>,
    filterArg: plugins.tsclass.typeFest.PartialDeep<T>,
    forEachFunction: (itemArg: T) => Promise<any>
  ) {
    const cursor: SmartdataDbCursor<T> = await (this as any).getCursor(filterArg);
    await cursor.forEach(forEachFunction);
  }

  // INSTANCE

  /**
   * how the Doc in memory was created, may prove useful later.
   */
  public creationStatus: TDocCreation = 'new';

  /**
   * updated from db in any case where doc comes from db
   */
  @svDb()
  _createdAt: number = Date.now();

  /**
   * will be updated everytime the doc is saved
   */
  @svDb()
  _updatedAt: number = Date.now();

  /**
   * unique indexes
   */
  public uniqueIndexes: string[];

  /**
   * an array of saveable properties of a doc
   */
  public saveableProperties: string[];

  /**
   * name
   */
  public name: string;

  /**
   * primary id in the database
   */
  public dbDocUniqueId: string;

  /**
   * class constructor
   */
  constructor() {}

  /**
   * saves this instance but not any connected items
   * may lead to data inconsistencies, but is faster
   */
  public async save() {
    // tslint:disable-next-line: no-this-assignment
    const self: any = this;
    let dbResult: any;

    this._updatedAt = Date.now();

    switch (this.creationStatus) {
      case 'db':
        dbResult = await this.collection.update(self);
        break;
      case 'new':
        dbResult = await this.collection.insert(self);
        this.creationStatus = 'db';
        break;
      default:
        console.error('neither new nor in db?');
    }
    return dbResult;
  }

  /**
   * deletes a document from the database
   */
  public async delete() {
    await this.collection.delete(this);
  }

  /**
   * also store any referenced objects to DB
   * better for data consistency
   */
  public saveDeep(savedMapArg: plugins.lik.ObjectMap<SmartDataDbDoc<any, any>> = null) {
    if (!savedMapArg) {
      savedMapArg = new plugins.lik.ObjectMap<SmartDataDbDoc<any, any>>();
    }
    savedMapArg.add(this);
    this.save();
    for (const propertyKey of Object.keys(this)) {
      const property: any = this[propertyKey];
      if (property instanceof SmartDataDbDoc && !savedMapArg.checkForObject(property)) {
        property.saveDeep(savedMapArg);
      }
    }
  }

  /**
   * updates an object from db
   */
  public async updateFromDb() {
    const mongoDbNativeDoc = await this.collection.findOne(await this.createIdentifiableObject());
    for (const key of Object.keys(mongoDbNativeDoc)) {
      this[key] = mongoDbNativeDoc[key];
    }
  }

  /**
   * creates a saveable object so the instance can be persisted as json in the database
   */
  public async createSavableObject(): Promise<TImplements> {
    const saveableObject: unknown = {}; // is not exposed to outside, so any is ok here
    for (const propertyNameString of this.saveableProperties) {
      saveableObject[propertyNameString] = this[propertyNameString];
    }
    return saveableObject as TImplements;
  }

  /**
   * creates an identifiable object for operations that require filtering
   */
  public async createIdentifiableObject() {
    const identifiableObject: any = {}; // is not exposed to outside, so any is ok here
    for (const propertyNameString of this.uniqueIndexes) {
      identifiableObject[propertyNameString] = this[propertyNameString];
    }
    return identifiableObject;
  }
}