[POC] add graphql query runner (#6747)

## Context
The goal is to replace pg_graphql with our own ORM wrapper (TwentyORM).
This PR tries to add some parsing logic to convert graphql requests to
send to the ORM to replace pg_graphql implementation.

---------

Co-authored-by: Charles Bochet <charles@twenty.com>

packages/twenty-server/src/engine/api/graphql/graphql-query-runner/graphql-query-runner.service.ts

@@ -0,0 +1,130 @@
+import { Injectable } from '@nestjs/common';
+
+import graphqlFields from 'graphql-fields';
+import { FindManyOptions, ObjectLiteral } from 'typeorm';
+
+import {
+  Record as IRecord,
+  RecordFilter,
+  RecordOrderBy,
+} from 'src/engine/api/graphql/workspace-query-builder/interfaces/record.interface';
+import { IConnection } from 'src/engine/api/graphql/workspace-query-runner/interfaces/connection.interface';
+import { WorkspaceQueryRunnerOptions } from 'src/engine/api/graphql/workspace-query-runner/interfaces/query-runner-option.interface';
+import { FindManyResolverArgs } from 'src/engine/api/graphql/workspace-resolver-builder/interfaces/workspace-resolvers-builder.interface';
+
+import { QUERY_MAX_RECORDS } from 'src/engine/api/graphql/graphql-query-runner/constants/query-max-records.constant';
+import {
+  GraphqlQueryRunnerException,
+  GraphqlQueryRunnerExceptionCode,
+} from 'src/engine/api/graphql/graphql-query-runner/errors/graphql-query-runner.exception';
+import { GraphqlQueryParser } from 'src/engine/api/graphql/graphql-query-runner/parsers/graphql-query.parser';
+import { applyRangeFilter } from 'src/engine/api/graphql/graphql-query-runner/utils/apply-range-filter.util';
+import {
+  createConnection,
+  decodeCursor,
+} from 'src/engine/api/graphql/graphql-query-runner/utils/connection.util';
+import { convertObjectMetadataToMap } from 'src/engine/api/graphql/graphql-query-runner/utils/convert-object-metadata-to-map.util';
+import { LogExecutionTime } from 'src/engine/decorators/observability/log-execution-time.decorator';
+import { TwentyORMGlobalManager } from 'src/engine/twenty-orm/twenty-orm-global.manager';
+
+@Injectable()
+export class GraphqlQueryRunnerService {
+  constructor(
+    private readonly twentyORMGlobalManager: TwentyORMGlobalManager,
+  ) {}
+
+  @LogExecutionTime()
+  async findManyWithTwentyOrm<
+    ObjectRecord extends IRecord = IRecord,
+    Filter extends RecordFilter = RecordFilter,
+    OrderBy extends RecordOrderBy = RecordOrderBy,
+  >(
+    args: FindManyResolverArgs<Filter, OrderBy>,
+    options: WorkspaceQueryRunnerOptions,
+  ): Promise<IConnection<ObjectRecord>> {
+    const { authContext, objectMetadataItem, info, objectMetadataCollection } =
+      options;
+
+    const repository =
+      await this.twentyORMGlobalManager.getRepositoryForWorkspace(
+        authContext.workspace.id,
+        objectMetadataItem.nameSingular,
+      );
+
+    const selectedFields = graphqlFields(info);
+
+    const objectMetadataMap = convertObjectMetadataToMap(
+      objectMetadataCollection,
+    );
+
+    const objectMetadata = objectMetadataMap[objectMetadataItem.nameSingular];
+
+    if (!objectMetadata) {
+      throw new Error(
+        `Object metadata for ${objectMetadataItem.nameSingular} not found`,
+      );
+    }
+
+    const fieldMetadataMap = objectMetadata.fields;
+
+    const graphqlQueryParser = new GraphqlQueryParser(
+      fieldMetadataMap,
+      objectMetadataMap,
+    );
+
+    const { select, relations } = graphqlQueryParser.parseSelectedFields(
+      objectMetadataItem,
+      selectedFields,
+    );
+
+    const order = args.orderBy
+      ? graphqlQueryParser.parseOrder(args.orderBy)
+      : undefined;
+
+    const where = args.filter
+      ? graphqlQueryParser.parseFilter(args.filter)
+      : {};
+
+    let cursor: Record<string, any> | undefined;
+
+    if (args.after) {
+      cursor = decodeCursor(args.after);
+    } else if (args.before) {
+      cursor = decodeCursor(args.before);
+    }
+
+    if (args.first && args.last) {
+      throw new GraphqlQueryRunnerException(
+        'Cannot provide both first and last',
+        GraphqlQueryRunnerExceptionCode.ARGS_CONFLICT,
+      );
+    }
+
+    const take = args.first ?? args.last ?? QUERY_MAX_RECORDS;
+
+    const findOptions: FindManyOptions<ObjectLiteral> = {
+      where,
+      order,
+      select,
+      relations,
+      take,
+    };
+
+    const totalCount = await repository.count({
+      where,
+    });
+
+    if (cursor) {
+      applyRangeFilter(where, order, cursor);
+    }
+
+    const objectRecords = await repository.find(findOptions);
+
+    return createConnection(
+      (objectRecords as ObjectRecord[]) ?? [],
+      take,
+      totalCount,
+      order,
+    );
+  }
+}