import * as plugins from "./smartdata.plugins";
import { Db } from "./smartdata.classes.db";
import { DbDoc } from "./smartdata.classes.dbdoc";

// RethinkDb Interfaces
import { WriteResult, Cursor } from "rethinkdb";

export interface IFindOptions {
  limit?: number;
}

/**
 *
 */
export interface IDocValidationFunc<T> {
  (doc: T): boolean;
}

/**
 * This is a decorator that will tell the decorated class what dbTable to use
 * @param db
 */
export function Table(db: Db) {
  return function(constructor) {
    constructor["dbTable"] = new DbTable(constructor, db);
  };
}

export class DbTable<T> {
  /**
   * the collection that is used
   */
  table: plugins.rethinkDb.Table;
  objectValidation: IDocValidationFunc<T> = null;
  tableName: string;
  db: Db;

  constructor(collectedClassArg: T & DbDoc<T>, dbArg: Db) {
    // tell the collection where it belongs
    this.tableName = collectedClassArg.name;
    this.db = dbArg;

    // tell the db class about it (important since Db uses different systems under the hood)
    this.db.addTable(this);
  }

  async init() {
    if (!this.table) {
      // connect this instance to a RethinkDB table
      const availableTables = await plugins.rethinkDb
        .db(this.db.dbName)
        .tableList()
        .run(this.db.dbConnection);
      if (availableTables.indexOf(this.tableName)) {
        await plugins.rethinkDb
          .db(this.db.dbName)
          .tableCreate(this.tableName)
          .run(this.db.dbConnection);
      }
    }
    this.table = plugins.rethinkDb.table(this.tableName);
  }

  /**
   * adds a validation function that all newly inserted and updated objects have to pass
   */
  addDocValidation(funcArg: IDocValidationFunc<T>) {
    this.objectValidation = funcArg;
  }

  /**
   * finds an object in the DbCollection
   */
  async find(filterObject: any): Promise<any> {
    await this.init();
    let cursor = await plugins.rethinkDb
      .table(this.tableName)
      .filter(filterObject)
      .run(this.db.dbConnection);
    return await cursor.toArray();
  }

  /**
   * create an object in the database
   */
  async insert(dbDocArg: T & DbDoc<T>): Promise<WriteResult> {
    await this.init();
    await this.checkDoc(dbDocArg);
    return await plugins.rethinkDb
      .table(this.tableName)
      .insert(dbDocArg.createSavableObject())
      .run(this.db.dbConnection);
  }

  /**
   * inserts object into the DbCollection
   */
  async update(dbDocArg: T & DbDoc<T>): Promise<WriteResult> {
    await this.init();
    await this.checkDoc(dbDocArg);
    console.log(this.tableName, dbDocArg.createSavableObject());
    return await plugins.rethinkDb
      .table(this.tableName)
      .update(dbDocArg.createSavableObject())
      .run(this.db.dbConnection);
  }

  /**
   * checks a Doc for constraints
   * if this.objectValidation is not set it passes.
   */
  private checkDoc(docArg: T): Promise<void> {
    let done = plugins.smartq.defer<void>();
    let validationResult = true;
    if (this.objectValidation) {
      validationResult = this.objectValidation(docArg);
    }
    if (validationResult) {
      done.resolve();
    } else {
      done.reject("validation of object did not pass");
    }
    return done.promise;
  }

  extractKey(writeResult: WriteResult) {}
}