feat: add HelpText model, service, and controller for dynamic help text management

backend/src/help-texts/dto/upsert-help-text.dto.ts

@@ -0,0 +1,14 @@
+import { IsBoolean, IsOptional, IsString, MaxLength } from 'class-validator';
+
+export class UpsertHelpTextDto {
+  @IsString()
+  @MaxLength(120)
+  title!: string;
+
+  @IsString()
+  content!: string;
+
+  @IsOptional()
+  @IsBoolean()
+  isActive?: boolean;
+}

backend/src/help-texts/help-texts.controller.ts

@@ -0,0 +1,28 @@
+import { Body, Controller, Get, Param, Put } from '@nestjs/common';
+import { CurrentUser } from '../auth/decorators/current-user.decorator';
+import { Roles } from '../auth/decorators/roles.decorator';
+import { UpsertHelpTextDto } from './dto/upsert-help-text.dto';
+import { HelpTextsService } from './help-texts.service';
+
+@Controller('help-texts')
+export class HelpTextsController {
+  constructor(private readonly helpTextsService: HelpTextsService) {}
+
+  @Get(':key')
+  getByKey(
+    @Param('key') key: string,
+    @CurrentUser() user: { role?: string },
+  ) {
+    return this.helpTextsService.getResolvedByKey(key, user?.role);
+  }
+
+  @Roles('admin')
+  @Put(':key/:scope')
+  upsert(
+    @Param('key') key: string,
+    @Param('scope') scope: string,
+    @Body() dto: UpsertHelpTextDto,
+  ) {
+    return this.helpTextsService.upsert(key, scope, dto);
+  }
+}

backend/src/help-texts/help-texts.module.ts

@@ -0,0 +1,11 @@
+import { Module } from '@nestjs/common';
+import { PrismaModule } from '../prisma/prisma.module';
+import { HelpTextsController } from './help-texts.controller';
+import { HelpTextsService } from './help-texts.service';
+
+@Module({
+  imports: [PrismaModule],
+  controllers: [HelpTextsController],
+  providers: [HelpTextsService],
+})
+export class HelpTextsModule {}

backend/src/help-texts/help-texts.service.ts

@@ -0,0 +1,99 @@
+import { BadRequestException, Injectable, NotFoundException } from '@nestjs/common';
+import { PrismaService } from '../prisma/prisma.service';
+import { UpsertHelpTextDto } from './dto/upsert-help-text.dto';
+
+type HelpTextScope = 'default' | 'user' | 'admin';
+
+@Injectable()
+export class HelpTextsService {
+  private readonly allowedScopes: HelpTextScope[] = ['default', 'user', 'admin'];
+
+  constructor(private readonly prisma: PrismaService) {}
+
+  async getResolvedByKey(keyRaw: string, roleRaw?: string) {
+    const key = this.normalizeKey(keyRaw);
+    const role = (roleRaw ?? 'user').toLowerCase();
+    const scopePriority: HelpTextScope[] = role === 'admin'
+      ? ['admin', 'user', 'default']
+      : ['user', 'default'];
+
+    const rows = await this.prisma.helpText.findMany({
+      where: {
+        key,
+        isActive: true,
+        scope: { in: scopePriority },
+      },
+      select: {
+        key: true,
+        scope: true,
+        title: true,
+        content: true,
+        updatedAt: true,
+      },
+    });
+
+    for (const scope of scopePriority) {
+      const hit = rows.find((row) => row.scope === scope);
+      if (hit) {
+        return {
+          'key': hit.key,
+          'scope': hit.scope,
+          'title': hit.title,
+          'content': hit.content,
+          'updatedAt': hit.updatedAt,
+        };
+      }
+    }
+
+    throw new NotFoundException(`Ingen aktiv hjälptext hittades för key '${key}'.`);
+  }
+
+  async upsert(keyRaw: string, scopeRaw: string, dto: UpsertHelpTextDto) {
+    const key = this.normalizeKey(keyRaw);
+    const scope = this.normalizeScope(scopeRaw);
+
+    return this.prisma.helpText.upsert({
+      where: {
+        key_scope: { key, scope },
+      },
+      update: {
+        title: dto.title.trim(),
+        content: dto.content.trim(),
+        isActive: dto.isActive ?? true,
+      },
+      create: {
+        key,
+        scope,
+        title: dto.title.trim(),
+        content: dto.content.trim(),
+        isActive: dto.isActive ?? true,
+      },
+      select: {
+        key: true,
+        scope: true,
+        title: true,
+        content: true,
+        isActive: true,
+        updatedAt: true,
+      },
+    });
+  }
+
+  private normalizeKey(value: string): string {
+    const normalized = value.trim().toLowerCase();
+    if (!normalized) {
+      throw new BadRequestException('Hjälptext-nyckel måste anges.');
+    }
+    return normalized;
+  }
+
+  private normalizeScope(value: string): HelpTextScope {
+    const normalized = value.trim().toLowerCase() as HelpTextScope;
+    if (!this.allowedScopes.includes(normalized)) {
+      throw new BadRequestException(
+        `Ogiltig scope '${value}'. Tillåtna scopes: ${this.allowedScopes.join(', ')}`,
+      );
+    }
+    return normalized;
+  }
+}