import {Injectable} from '@angular/core';
import {
  RecordCollection, IRecord,
  ISerializedRecordCollection
} from '../record-collection';
import _ from 'lodash';
import {IRecordTransformer} from './record-transformer.interface';

@Injectable()
export class OwsRecordTransformer
  implements IRecordTransformer<IOwsSearchResult> {
  constructor() {}

  transform(
    data: IOwsSearchResult,
    opts: ISerializedRecordCollection = {})
  : RecordCollection {
    return new RecordCollection(
      _.defaults(
        {
          fields: data.columns,
          records: _.map(
            data.data,
            record => this.transformRecord(record, opts, data.columns)
          ),
          geoTransformStrategy: 'owsKml'
        },
        opts
      )
    );
  }

  private transformRecord(
    recordValues: string[],
    opts: ISerializedRecordCollection,
    fields: IOwsSearchResultColumn[])
  : IRecord {
    const record = _(recordValues)
      .transform(
        (record, val, idx) => {
          this._copyFieldValueToRecord(record, val, idx, fields);
        },
        {}
      ).value();

    record['record-type'] = opts.name;
    record['timespan'] = {begin: this._getRecordMapDate(record)};

    return record;
  }

  private _copyFieldValueToRecord(
    record: {},
    fieldValue: any,
    idx: number,
    fields: IOwsSearchResultColumn[])
  : any {
    const field = fields[idx];
    record[field.name] = fieldValue;

    return record;
  }

  private _getRecordMapDate(record: any): {begin: string} {
    return record['map_date'] || record['completion_date'];
  }
}

export interface IOwsSearchResult {
  columns: IOwsSearchResultColumn[];
  data: string[][];
}

export interface IOwsSearchResultColumn {
  name: string;
  label: string;
  type: string;
  visible: boolean;
}