feat: fallback text option and file conversion (#318)

Additionally fixes up some validation views that were not appearing.

.eslintrc.js

@@ -79,7 +79,6 @@ module.exports = {
     'react/jsx-props-no-spreading': 'off',
     'react/react-in-jsx-scope': 'off',
     'no-restricted-syntax': 'off',
-
     '@typescript-eslint/ban-types': 'warn',
     'import/no-extraneous-dependencies': [
       'warn',

apps/client-server/src/app/app.module.ts

@@ -7,6 +7,7 @@ import { AccountModule } from './account/account.module';
 import { AppController } from './app.controller';
 import { AppService } from './app.service';
 import { DirectoryWatchersModule } from './directory-watchers/directory-watchers.module';
+import { FileConverterModule } from './file-converter/file-converter.module';
 import { FileModule } from './file/file.module';
 import { FormGeneratorModule } from './form-generator/form-generator.module';
 import { PostParsersModule } from './post-parsers/post-parsers.module';
@@ -17,10 +18,10 @@ import { TagConvertersModule } from './tag-converters/tag-converters.module';
 import { TagGroupsModule } from './tag-groups/tag-groups.module';
 import { UpdateModule } from './update/update.module';
 import { UserSpecifiedWebsiteOptionsModule } from './user-specified-website-options/user-specified-website-options.module';
+import { ValidationModule } from './validation/validation.module';
 import { WebSocketModule } from './web-socket/web-socket.module';
 import { WebsiteOptionsModule } from './website-options/website-options.module';
 import { WebsitesModule } from './websites/websites.module';
-import { ValidationModule } from './validation/validation.module';
 
 @Module({
   imports: [
@@ -45,6 +46,7 @@ import { ValidationModule } from './validation/validation.module';
     PostModule,
     PostParsersModule,
     ValidationModule,
+    FileConverterModule,
   ],
   controllers: [AppController],
   providers: [AppService],

apps/client-server/src/app/database/entities/submission-file.entity.ts

@@ -59,7 +59,7 @@ export class SubmissionFile extends PostyBirbEntity implements ISubmissionFile {
     orphanRemoval: true,
     lazy: false,
     nullable: true,
-    serializer: (s) => s.id,
+    serializer: (s) => s?.id,
   })
   thumbnail: Rel<IFileBuffer>;
 
@@ -69,8 +69,9 @@ export class SubmissionFile extends PostyBirbEntity implements ISubmissionFile {
     orphanRemoval: true,
     lazy: false,
     nullable: true,
+    serializer: (s) => s?.id,
   })
-  altFile?: Rel<IFileBuffer>;
+  altFile: Rel<IFileBuffer>;
 
   @Property({ type: 'integer', nullable: false, default: 0 })
   size: number;
@@ -84,6 +85,9 @@ export class SubmissionFile extends PostyBirbEntity implements ISubmissionFile {
   @Property({ type: 'boolean', nullable: false, default: false })
   hasThumbnail: boolean;
 
+  @Property({ type: 'boolean', nullable: false, default: false })
+  hasAltFile: boolean;
+
   @Property({
     type: 'json',
     nullable: false,

apps/client-server/src/app/file-converter/converters/file-converter.ts

@@ -0,0 +1,24 @@
+import { IFileBuffer } from '@postybirb/types';
+
+export interface IFileConverter {
+  /**
+   * Determines if the file can be converted to any of the allowable output mime types.
+   *
+   * @param {IFileBuffer} file
+   * @param {string[]} allowableOutputMimeTypes
+   * @return {*}  {boolean}
+   */
+  canConvert(file: IFileBuffer, allowableOutputMimeTypes: string[]): boolean;
+
+  /**
+   * Converts the file to one of the allowable output mime types.
+   *
+   * @param {IFileBuffer} file
+   * @param {string[]} allowableOutputMimeTypes
+   * @return {*}  {Promise<IFileBuffer>}
+   */
+  convert(
+    file: IFileBuffer,
+    allowableOutputMimeTypes: string[],
+  ): Promise<IFileBuffer>;
+}

apps/client-server/src/app/file-converter/converters/text-file-converter.ts

@@ -0,0 +1,121 @@
+import { IFileBuffer } from '@postybirb/types';
+import { htmlToText } from 'html-to-text';
+import { TurndownService } from 'turndown';
+import { IFileConverter } from './file-converter';
+
+const supportedInputMimeTypes = ['text/html'] as const;
+const supportedOutputMimeTypes = [
+  'text/plain',
+  'text/html',
+  'text/markdown',
+] as const;
+
+type SupportedInputMimeTypes = (typeof supportedInputMimeTypes)[number];
+type SupportedOutputMimeTypes = (typeof supportedOutputMimeTypes)[number];
+
+type ConversionMap = {
+  [inputMimeType in SupportedInputMimeTypes]: {
+    [outputMimeType in SupportedOutputMimeTypes]: (
+      file: IFileBuffer,
+    ) => Promise<IFileBuffer>;
+  };
+};
+
+type ConversionWeights = {
+  [outputMimeType in SupportedOutputMimeTypes]: number;
+};
+
+// TODO - use this within the post service to convert alt files to acceptable format
+// TODO - use overall conversion check within the validator service to see if we can convert the file, this may be useful for the end user
+/**
+ * A class that converts text files to other text formats.
+ * Largely for use when converting AltFiles (text/html) to other desirable formats.
+ * @class TextFileConverter
+ * @implements {IFileConverter}
+ */
+export class TextFileConverter implements IFileConverter {
+  private readonly supportConversionMappers: ConversionMap = {
+    'text/html': {
+      'text/html': this.passThrough,
+      'text/plain': this.convertHtmlToPlaintext,
+      'text/markdown': this.convertHtmlToMarkdown,
+    },
+  };
+
+  /**
+   * Defines the preference of conversion, trying to convert to the most preferred format first.
+   */
+  private readonly conversionWeights: ConversionWeights = {
+    'text/plain': Number.MAX_SAFE_INTEGER,
+    'text/html': 1,
+    'text/markdown': 2,
+  };
+
+  canConvert(file: IFileBuffer, allowableOutputMimeTypes: string[]): boolean {
+    return (
+      supportedInputMimeTypes.includes(
+        file.mimeType as SupportedInputMimeTypes,
+      ) &&
+      supportedOutputMimeTypes.some((m) => allowableOutputMimeTypes.includes(m))
+    );
+  }
+
+  async convert(
+    file: IFileBuffer,
+    allowableOutputMimeTypes: string[],
+  ): Promise<IFileBuffer> {
+    const conversionMap =
+      this.supportConversionMappers[file.mimeType as SupportedInputMimeTypes];
+
+    const sortedOutputMimeTypes = allowableOutputMimeTypes
+      .filter((mimeType) => mimeType in conversionMap)
+      .sort(
+        (a, b) =>
+          this.conversionWeights[a as SupportedOutputMimeTypes] -
+          this.conversionWeights[b as SupportedOutputMimeTypes],
+      );
+
+    for (const outputMimeType of sortedOutputMimeTypes) {
+      const conversionFunction =
+        conversionMap[outputMimeType as SupportedOutputMimeTypes];
+      if (conversionFunction) {
+        return conversionFunction(file);
+      }
+    }
+
+    throw new Error(
+      `Cannot convert file ${file.fileName} with mime type: ${file.mimeType}`,
+    );
+  }
+
+  private async passThrough(file: IFileBuffer): Promise<IFileBuffer> {
+    return { ...file };
+  }
+
+  private async convertHtmlToPlaintext(
+    file: IFileBuffer,
+  ): Promise<IFileBuffer> {
+    const text = htmlToText(file.buffer.toString(), {
+      wordwrap: 120,
+    });
+    return this.toMergedBuffer(file, text, 'text/plain');
+  }
+
+  private async convertHtmlToMarkdown(file: IFileBuffer): Promise<IFileBuffer> {
+    const turndownService = new TurndownService();
+    const markdown = turndownService.turndown(file.buffer.toString());
+    return this.toMergedBuffer(file, markdown, 'text/markdown');
+  }
+
+  private toMergedBuffer(
+    fb: IFileBuffer,
+    str: string,
+    mimeType: string,
+  ): IFileBuffer {
+    return {
+      ...fb,
+      buffer: Buffer.from(str),
+      mimeType,
+    };
+  }
+}

apps/client-server/src/app/file-converter/file-converter.module.ts

@@ -0,0 +1,8 @@
+import { Module } from '@nestjs/common';
+import { FileConverterService } from './file-converter.service';
+
+@Module({
+  providers: [FileConverterService],
+  exports: [FileConverterService],
+})
+export class FileConverterModule {}

apps/client-server/src/app/file-converter/file-converter.service.spec.ts

@@ -0,0 +1,18 @@
+import { Test, TestingModule } from '@nestjs/testing';
+import { FileConverterService } from './file-converter.service';
+
+describe('FileConverterService', () => {
+  let service: FileConverterService;
+
+  beforeEach(async () => {
+    const module: TestingModule = await Test.createTestingModule({
+      providers: [FileConverterService],
+    }).compile();
+
+    service = module.get<FileConverterService>(FileConverterService);
+  });
+
+  it('should be defined', () => {
+    expect(service).toBeDefined();
+  });
+});

apps/client-server/src/app/file-converter/file-converter.service.ts

@@ -0,0 +1,33 @@
+import { Injectable } from '@nestjs/common';
+import { IFileBuffer } from '@postybirb/types';
+import { IFileConverter } from './converters/file-converter';
+import { TextFileConverter } from './converters/text-file-converter';
+
+@Injectable()
+export class FileConverterService {
+  private readonly converters: IFileConverter[] = [new TextFileConverter()];
+
+  public async convert(
+    file: IFileBuffer,
+    allowableOutputMimeTypes: string[],
+  ): Promise<IFileBuffer> {
+    const converter = this.converters.find((c) =>
+      c.canConvert(file, allowableOutputMimeTypes),
+    );
+
+    if (!converter) {
+      throw new Error('No converter found for file');
+    }
+
+    return converter.convert(file, allowableOutputMimeTypes);
+  }
+
+  public async canConvert(
+    mimeType: string,
+    allowableOutputMimeTypes: string[],
+  ): Promise<boolean> {
+    return this.converters.some((c) =>
+      c.canConvert({ mimeType } as IFileBuffer, allowableOutputMimeTypes),
+    );
+  }
+}

apps/client-server/src/app/file/file.service.spec.ts

@@ -6,6 +6,7 @@ import { readFileSync } from 'fs';
 import { join } from 'path';
 import { AccountService } from '../account/account.service';
 import { DatabaseModule } from '../database/database.module';
+import { FileConverterService } from '../file-converter/file-converter.service';
 import { FormGeneratorService } from '../form-generator/form-generator.service';
 import { DescriptionParserService } from '../post-parsers/parsers/description-parser.service';
 import { TagParserService } from '../post-parsers/parsers/tag-parser.service';
@@ -92,6 +93,7 @@ describe('FileService', () => {
         TagConvertersService,
         SettingsService,
         FormGeneratorService,
+        FileConverterService,
       ],
     }).compile();
 
@@ -116,7 +118,10 @@ describe('FileService', () => {
     const path = setup();
     const submission = await createSubmission();
     const fileInfo = createMulterData(path);
-    const file = await service.create(fileInfo, submission as FileSubmission);
+    const file = await service.create(
+      fileInfo,
+      submission as unknown as FileSubmission,
+    );
     expect(file.file).toBeDefined();
     expect(file.thumbnail).toBeDefined();
     expect(file.fileName).toBe(fileInfo.originalname);
@@ -137,7 +142,10 @@ describe('FileService', () => {
     const path = setup();
     const submission = await createSubmission();
     const fileInfo = createMulterData(path);
-    const file = await service.create(fileInfo, submission as FileSubmission);
+    const file = await service.create(
+      fileInfo,
+      submission as unknown as FileSubmission,
+    );
     expect(file.file).toBeDefined();
 
     const path2 = setup();

apps/client-server/src/app/file/file.service.ts

@@ -3,13 +3,14 @@ import { InjectRepository } from '@mikro-orm/nestjs';
 import { BadRequestException, Injectable } from '@nestjs/common';
 import { read } from '@postybirb/fs';
 import { Logger } from '@postybirb/logger';
-import { FileSubmission } from '@postybirb/types';
+import { EntityId, FileSubmission } from '@postybirb/types';
 import type { queueAsPromised } from 'fastq';
 import fastq from 'fastq';
 import { readFile } from 'fs/promises';
 import { cpus } from 'os';
-import { SubmissionFile } from '../database/entities';
+import { AltFile, SubmissionFile } from '../database/entities';
 import { PostyBirbRepository } from '../database/repositories/postybirb-repository';
+import { UpdateAltFileDto } from '../submission/dtos/update-alt-file.dto';
 import { MulterFileInfo, TaskOrigin } from './models/multer-file-info';
 import { CreateTask, Task, UpdateTask } from './models/task';
 import { TaskType } from './models/task-type.enum';
@@ -34,6 +35,8 @@ export class FileService {
     private readonly updateFileService: UpdateFileService,
     @InjectRepository(SubmissionFile)
     private readonly fileRepository: PostyBirbRepository<SubmissionFile>,
+    @InjectRepository(AltFile)
+    private readonly altFileRepository: PostyBirbRepository<AltFile>,
   ) {}
 
   /**
@@ -137,4 +140,28 @@ export class FileService {
   public async findFile(id: string): Promise<SubmissionFile> {
     return this.fileRepository.findById(id, { failOnMissing: true });
   }
+
+  /**
+   * Gets the raw text of an alt text file.
+   * @param {string} id
+   */
+  async getAltText(id: EntityId): Promise<string> {
+    const altFile = await this.altFileRepository.findOneOrFail({ id });
+    if (altFile.size) {
+      return altFile.buffer.toString();
+    }
+
+    return '';
+  }
+
+  /**
+   * Updates the raw text of an alt text file.
+   * @param {string} id
+   * @param {UpdateAltFileDto} update
+   */
+  async updateAltText(id: string, update: UpdateAltFileDto) {
+    const altFile = await this.altFileRepository.findOneOrFail({ id });
+    altFile.buffer = Buffer.from(update.html ?? '');
+    await this.altFileRepository.persistAndFlush(altFile);
+  }
 }