import { Injectable } from '@angular/core';
import { DbSvc } from '../db/db';

@Injectable()
export class Migration {

  constructor(public db: DbSvc) {

  }

  private list: any = [];
  private tableName: string = "app_migration";
  private idColumn: string = "app_migration_uu";

  public init() {
    let promise = new Promise((resolve, reject) => {
      this.db.query("Select * from " + this.tableName).then((result) => {
        this.list = this.db.fetchAll(result);
        resolve(this.list);
      }, (reject) => {
        reject(this.list);
      });
    });
    return promise;
  }

  public all() {
    return this.list;
  }

  public remove(appMigration) {
     let sql = "Delete from " + this.tableName + " WHERE " + this.idColumn + " = ? ";
    this.db.query(sql, [appMigration[this.idColumn]]).then((result) => {
      this.list.splice(this.list.indexOf(appMigration), 1);
    });
  }

  public get(AppMigrationsID) {
    for ( let i = 0; i < this.list.length; i++) {
      if (this.list[i][this.idColumn] == AppMigrationsID) {
        return this.list[i];
      }
    }
    return null;
  }

  add(row) {
    this.db.addTableRow(this.tableName, row, true).then((result) => {  //because of updation as default commit 21 pass true as demo or avoid error
      this.list.push(row);
    });
  }

  update(row) {
     let obj = row;
    if (obj) {
      this.db.updateTableRow(this.tableName, obj).then((result) => {
        for ( let i = 0; i < this.list.length; i++) {
          if (this.list[i][this.idColumn] == obj[this.idColumn]) {
            this.list[i] = obj;
            break;
          }
        }
      });
    }
  }

  addArray(objects) {
    objects.forEach(value => {
      if (this.get(value[this.idColumn]) == null) {
        this.add(value);
      } else {
        this.update(value);
      }
    });
  }

  getmigrationByVersion(version) {
    if (this.list.version = version)
      return this.list[0].app_migration_uu;
  }
}