refactor: wip migrate ot nestjs

packages/server-nest/src/modules/Export/ExportService.ts

@@ -0,0 +1,228 @@
+// @ts-nocheck
+import xlsx from 'xlsx';
+import * as R from 'ramda';
+import { get } from 'lodash';
+import { sanitizeResourceName } from '../Import/_utils';
+import { ExportableResources } from './ExportResources';
+import { ServiceError } from '@/exceptions';
+import { Errors, ExportFormat } from './common';
+import { IModelMeta, IModelMetaColumn } from '@/interfaces';
+import { flatDataCollections, getDataAccessor } from './utils';
+import { ExportPdf } from './ExportPdf';
+import { ExportAls } from './ExportAls';
+import { Injectable } from '@nestjs/common';
+
+@Injectable()
+export class ExportResourceService {
+  constructor(
+    private readonly exportAls: ExportAls,
+    private readonly exportPdf: ExportPdf,
+    private readonly exportableResources: ExportableResources,
+    private readonly resourceService: ResourceService,
+  ) {}
+
+  /**
+   *
+   * @param {number} tenantId
+   * @param {string} resourceName
+   * @param {ExportFormat} format
+   * @returns
+   */
+  public async export(
+    tenantId: number,
+    resourceName: string,
+    format: ExportFormat = ExportFormat.Csv
+  ) {
+    return this.exportAls.run(() =>
+      this.exportAlsRun(tenantId, resourceName, format)
+    );
+  }
+
+  /**
+   * Exports the given resource data through csv, xlsx or pdf.
+   * @param {number} tenantId - Tenant id.
+   * @param {string} resourceName - Resource name.
+   * @param {ExportFormat} format - File format.
+   */
+  public async exportAlsRun(
+    tenantId: number,
+    resourceName: string,
+    format: ExportFormat = ExportFormat.Csv
+  ) {
+    const resource = sanitizeResourceName(resourceName);
+    const resourceMeta = this.getResourceMeta(tenantId, resource);
+    const resourceColumns = this.resourceService.getResourceColumns(
+      tenantId,
+      resource
+    );
+    this.validateResourceMeta(resourceMeta);
+
+    const data = await this.getExportableData(tenantId, resource);
+    const transformed = this.transformExportedData(tenantId, resource, data);
+
+    // Returns the csv, xlsx format.
+    if (format === ExportFormat.Csv || format === ExportFormat.Xlsx) {
+      const exportableColumns = this.getExportableColumns(resourceColumns);
+      const workbook = this.createWorkbook(transformed, exportableColumns);
+
+      return this.exportWorkbook(workbook, format);
+      // Returns the pdf format.
+    } else if (format === ExportFormat.Pdf) {
+      const printableColumns = this.getPrintableColumns(resourceMeta);
+
+      return this.exportPdf.pdf(
+        tenantId,
+        printableColumns,
+        transformed,
+        resourceMeta?.print?.pageTitle
+      );
+    }
+  }
+
+  /**
+   * Retrieves metadata for a specific resource.
+   * @param {number} tenantId - The tenant identifier.
+   * @param {string} resource - The name of the resource.
+   * @returns The metadata of the resource.
+   */
+  private getResourceMeta(tenantId: number, resource: string) {
+    return this.resourceService.getResourceMeta(tenantId, resource);
+  }
+
+  /**
+   * Validates if the resource metadata is exportable.
+   * @param {any} resourceMeta - The metadata of the resource.
+   * @throws {ServiceError} If the resource is not exportable or lacks columns.
+   */
+  private validateResourceMeta(resourceMeta: any) {
+    if (!resourceMeta.exportable || !resourceMeta.columns) {
+      throw new ServiceError(Errors.RESOURCE_NOT_EXPORTABLE);
+    }
+  }
+
+  /**
+   * Transforms the exported data based on the resource metadata.
+   * If the resource metadata specifies a flattening attribute (`exportFlattenOn`),
+   * the data will be flattened based on this attribute using the `flatDataCollections` utility function.
+   *
+   * @param {number} tenantId - The tenant identifier.
+   * @param {string} resource - The name of the resource.
+   * @param {Array<Record<string, any>>} data - The original data to be transformed.
+   * @returns {Array<Record<string, any>>} - The transformed data.
+   */
+  private transformExportedData(
+    tenantId: number,
+    resource: string,
+    data: Array<Record<string, any>>
+  ): Array<Record<string, any>> {
+    const resourceMeta = this.getResourceMeta(tenantId, resource);
+
+    return R.when<Array<Record<string, any>>, Array<Record<string, any>>>(
+      R.always(Boolean(resourceMeta.exportFlattenOn)),
+      (data) => flatDataCollections(data, resourceMeta.exportFlattenOn),
+      data
+    );
+  }
+  /**
+   * Fetches exportable data for a given resource.
+   * @param {number} tenantId - The tenant identifier.
+   * @param {string} resource - The name of the resource.
+   * @returns A promise that resolves to the exportable data.
+   */
+  private async getExportableData(tenantId: number, resource: string) {
+    const exportable =
+      this.exportableResources.registry.getExportable(resource);
+
+    return exportable.exportable(tenantId, {});
+  }
+
+  /**
+   * Extracts columns that are marked as exportable from the resource metadata.
+   * @param {IModelMeta} resourceMeta - The metadata of the resource.
+   * @returns An array of exportable columns.
+   */
+  private getExportableColumns(resourceColumns: any) {
+    const processColumns = (
+      columns: { [key: string]: IModelMetaColumn },
+      parent = ''
+    ) => {
+      return Object.entries(columns)
+        .filter(([_, value]) => value.exportable !== false)
+        .flatMap(([key, value]) => {
+          if (value.type === 'collection' && value.collectionOf === 'object') {
+            return processColumns(value.columns, key);
+          } else {
+            const group = parent;
+            return [
+              {
+                name: value.name,
+                type: value.type || 'text',
+                accessor: value.accessor || key,
+                group,
+              },
+            ];
+          }
+        });
+    };
+    return processColumns(resourceColumns);
+  }
+
+  private getPrintableColumns(resourceMeta: IModelMeta) {
+    const processColumns = (
+      columns: { [key: string]: IModelMetaColumn },
+      parent = ''
+    ) => {
+      return Object.entries(columns)
+        .filter(([_, value]) => value.printable !== false)
+        .flatMap(([key, value]) => {
+          if (value.type === 'collection' && value.collectionOf === 'object') {
+            return processColumns(value.columns, key);
+          } else {
+            const group = parent;
+            return [
+              {
+                name: value.name,
+                type: value.type || 'text',
+                accessor: value.accessor || key,
+                group,
+              },
+            ];
+          }
+        });
+    };
+    return processColumns(resourceMeta.columns);
+  }
+
+  /**
+   * Creates a workbook from the provided data and columns.
+   * @param {any[]} data - The data to be included in the workbook.
+   * @param {any[]} exportableColumns - The columns to be included in the workbook.
+   * @returns The created workbook.
+   */
+  private createWorkbook(data: any[], exportableColumns: any[]) {
+    const workbook = xlsx.utils.book_new();
+    const worksheetData = data.map((item) =>
+      exportableColumns.map((col) => get(item, getDataAccessor(col)))
+    );
+    worksheetData.unshift(exportableColumns.map((col) => col.name));
+
+    const worksheet = xlsx.utils.aoa_to_sheet(worksheetData);
+    xlsx.utils.book_append_sheet(workbook, worksheet, 'Exported Data');
+
+    return workbook;
+  }
+
+  /**
+   * Exports the workbook in the specified format.
+   * @param {any} workbook - The workbook to be exported.
+   * @param {string} format - The format to export the workbook in.
+   * @returns The exported workbook data.
+   */
+  private exportWorkbook(workbook: any, format: string) {
+    if (format.toLowerCase() === 'csv') {
+      return xlsx.write(workbook, { type: 'buffer', bookType: 'csv' });
+    } else if (format.toLowerCase() === 'xlsx') {
+      return xlsx.write(workbook, { type: 'buffer', bookType: 'xlsx' });
+    }
+  }
+}