import { Injectable } from "@angular/core";
import { TranslateService } from "@ngx-translate/core";
import { ColumnType, TableColumn} from "../../models";
import moment from 'moment';
import { TrueFalsePipe } from "../../pipes";

@Injectable()
export class CsvExportService {
    constructor(private translateService: TranslateService, private trueFalsePipe: TrueFalsePipe) {}

    private downloadCSV(csv: BlobPart, filename: string) {
        let csvFile: Blob;
        let downloadLink: HTMLAnchorElement;

        csvFile = new Blob([csv], { type: 'text/csv' });

        downloadLink = document.createElement('a');
        downloadLink.download = filename;
        downloadLink.href = window.URL.createObjectURL(csvFile);
        downloadLink.style.display = 'none';

        document.body.appendChild(downloadLink);
        downloadLink.click();
        document.body.removeChild(downloadLink);
    }

    exportTableToCsv(displayedColumns: TableColumn[], displayedRows: any[], exportFileName: string) {
        const csv = [];
        const date = new Date();
        const filename = `${exportFileName}_${moment().format(moment.HTML5_FMT.DATETIME_LOCAL_MS)}.csv`;

        for (let i = 0; i < displayedRows.length; i++) {
            let row = [];

            if (i === 0) {
                for (let m = 0; m < displayedColumns.length; m++) {
                    if (displayedColumns[m].label) {
                        row.push(this.getTranslatedText(displayedColumns[m].label));
                    } else {
                        row.push('')
                    }
                }
                csv.push(row.join(','));
                row = [];
            }
            
            for (let j = 0; j < displayedColumns.length; j++) {
                const val = displayedRows[i][displayedColumns[j].prop];
                const r = displayedRows[i];
                const c = displayedColumns[j];
                const temp = this.exportTableRow(r, c, val);
                row.push(`"${temp}"`);
            }

            csv.push(row.join(','))
        }

        this.downloadCSV(csv.join('\n'), filename);
    }

    private exportTableRow(row: any, column: TableColumn, value: any) {
        if (value == null) {
            return '';
        }

        switch (column.columnType) {
            case ColumnType.TEXT:
                return this.getTranslatedText(value);
            case ColumnType.NUMBER:
                return value;
            case ColumnType.BOOLEAN:
                return this.getTranslatedText(this.trueFalsePipe.transform(value, column.booleanFormat));
            default:
                return this.getTranslatedText(value);
        }
    }

    private getTranslatedText(value: string): string {
        if (value == null || value == '') {
            return '';
        }
        return this.translateService.instant(value)
    }
}