export enum QueryType {
  DIRECT = 'direct',
  GRAFANA = 'grafana',
}

export enum DatasourceType {
  INFLUXDB = 'influxdb',
  GRAPHITE = 'graphite',
  PROMETHEUS = 'prometheus',
  POSTGRES = 'postgres',
  ELASTICSEARCH = 'elasticsearch',
  MYSQL = 'mysql',
}

export declare type Datasource = {
  url: string;
  type: DatasourceType;
  params?: {
    db: string;
    q: string;
    epoch: string;
  };
  data?: any;
  datasourceId?: string;
};

export type DatasourceQuery = {
  url: string;
  method: string;
  schema: any;
  headers?: any;
}

export type DataTable = {
  values: (number | null)[][];
  columns: string[];
}

export abstract class DatasourceConnector {
  constructor(
    public datasource: Datasource,
    // TODO: Target type
    public targets: any[],
  ) {};
  /*
    from / to - timestamp in ms
    limit - max number of items in result
    offset - number of items to skip from timerange start
  */
  abstract getQuery(from: number, to: number, limit: number, offset: number): DatasourceQuery;
  abstract parseResponse(res): DataTable;
}