import { Injectable } from '@nestjs/common';

import { makeExecutableSchema } from '@graphql-tools/schema';
import { GraphQLSchema } from 'graphql';
import { gql } from 'graphql-tag';
import { isDefined } from 'twenty-shared/utils';

import { ScalarsExplorerService } from 'src/engine/api/graphql/services/scalars-explorer.service';
import { WorkspaceGraphqlSchemaSDLService } from 'src/engine/api/graphql/workspace-graphql-schema-sdl/workspace-graphql-schema-sdl.service';
import { workspaceResolverBuilderMethodNames } from 'src/engine/api/graphql/workspace-resolver-builder/factories/factories';
import { WorkspaceResolverFactory } from 'src/engine/api/graphql/workspace-resolver-builder/workspace-resolver.factory';
import { FlatWorkspace } from 'src/engine/core-modules/workspace/types/flat-workspace.type';
import { buildObjectIdByNameMaps } from 'src/engine/metadata-modules/flat-object-metadata/utils/build-object-id-by-name-maps.util';

@Injectable()
export class WorkspaceSchemaFactory {
  constructor(
    private readonly scalarsExplorerService: ScalarsExplorerService,
    private readonly workspaceResolverFactory: WorkspaceResolverFactory,
    private readonly workspaceGraphqlSchemaSDLService: WorkspaceGraphqlSchemaSDLService,
  ) {}

  async createGraphQLSchema(
    workspace: FlatWorkspace,
    applicationId?: string,
  ): Promise<GraphQLSchema> {
    const schemaSDLResult =
      await this.workspaceGraphqlSchemaSDLService.getOrComputeSchemaSDL(
        workspace,
        applicationId,
      );

    if (!isDefined(schemaSDLResult)) {
      return new GraphQLSchema({});
    }

    const {
      sdl,
      usedScalarNames,
      flatObjectMetadataMaps,
      flatFieldMetadataMaps,
      flatIndexMaps,
    } = schemaSDLResult;

    const { idByNameSingular } = buildObjectIdByNameMaps(
      flatObjectMetadataMaps,
    );

    const autoGeneratedResolvers = await this.workspaceResolverFactory.create(
      flatObjectMetadataMaps,
      flatFieldMetadataMaps,
      flatIndexMaps,
      idByNameSingular,
      workspaceResolverBuilderMethodNames,
    );
    const scalarsResolvers =
      this.scalarsExplorerService.getScalarResolvers(usedScalarNames);

    const executableSchema = makeExecutableSchema({
      typeDefs: gql`
        ${sdl}
      `,
      resolvers: {
        ...scalarsResolvers,
        ...autoGeneratedResolvers,
      },
    });

    return executableSchema;
  }
}