feat: Individual page export in Markdown and HTML formats (#80)

* fix maths node

* render default html width

* Add page export module
* with support for html and markdown exports

* Page export UI
* Add PDF print too

* remove unused import

apps/server/src/integrations/export/export.controller.ts

@@ -0,0 +1,69 @@
+import {
+  Body,
+  Controller,
+  ForbiddenException,
+  HttpCode,
+  HttpStatus,
+  NotFoundException,
+  Post,
+  Res,
+  UseGuards,
+} from '@nestjs/common';
+import { ExportService } from './export.service';
+import { ExportPageDto } from './dto/export-dto';
+import { AuthUser } from '../../common/decorators/auth-user.decorator';
+import { User } from '@docmost/db/types/entity.types';
+import SpaceAbilityFactory from '../../core/casl/abilities/space-ability.factory';
+import { JwtAuthGuard } from '../../common/guards/jwt-auth.guard';
+import { PageRepo } from '@docmost/db/repos/page/page.repo';
+import {
+  SpaceCaslAction,
+  SpaceCaslSubject,
+} from '../../core/casl/interfaces/space-ability.type';
+import { FastifyReply } from 'fastify';
+import { sanitize } from 'sanitize-filename-ts';
+import { getExportExtension } from './utils';
+import { getMimeType } from '../../common/helpers';
+
+@Controller()
+export class ImportController {
+  constructor(
+    private readonly importService: ExportService,
+    private readonly pageRepo: PageRepo,
+    private readonly spaceAbility: SpaceAbilityFactory,
+  ) {}
+
+  @UseGuards(JwtAuthGuard)
+  @HttpCode(HttpStatus.OK)
+  @Post('pages/export')
+  async exportPage(
+    @Body() dto: ExportPageDto,
+    @AuthUser() user: User,
+    @Res() res: FastifyReply,
+  ) {
+    const page = await this.pageRepo.findById(dto.pageId, {
+      includeContent: true,
+    });
+
+    if (!page) {
+      throw new NotFoundException('Page not found');
+    }
+
+    const ability = await this.spaceAbility.createForUser(user, page.spaceId);
+    if (ability.cannot(SpaceCaslAction.Read, SpaceCaslSubject.Page)) {
+      throw new ForbiddenException();
+    }
+
+    const rawContent = await this.importService.exportPage(dto.format, page);
+
+    const fileExt = getExportExtension(dto.format);
+    const fileName = sanitize(page.title || 'Untitled') + fileExt;
+
+    res.headers({
+      'Content-Type': getMimeType(fileExt),
+      'Content-Disposition': 'attachment; filename="' + fileName + '"',
+    });
+
+    res.send(rawContent);
+  }
+}