dorfteich/apps/api/src/settings/instance-settings.service.ts

import { BadRequestException, Injectable } from '@nestjs/common';
import { DEFAULT_ATTACHMENT_EXTENSIONS } from '@dorfteich/shared';
import { Prisma } from '@prisma/client';
import { PinoLogger } from 'nestjs-pino';
import { z } from 'zod';

import { AuditService } from '../audit/audit.service';
import { PrismaService } from '../prisma/prisma.service';

/**
 * The typed registry of instance settings. Adding a setting = adding a
 * line here; readers get parsed, defaulted values and writers get
 * validation for free. Secrets never go through this table
 * (security.md §Secrets).
 */
export const INSTANCE_SETTINGS = {
  'auth.registrationMode': z.enum(['open', 'closed']).default('open'),
  'instance.name': z.string().trim().min(1).max(60).default('Dorfteich'),
  'instance.defaultLocale': z.enum(['de', 'en']).default('en'),
  // Instance-default quotas (ADR 0011); per-user/per-pond overrides live
  // in quota_overrides and win over these (QuotaService, issue #22).
  'quota.editorsPerPond': z.number().int().min(0).default(5),
  'quota.readersPerPond': z.number().int().min(0).default(50),
  'quota.additionalPonds': z.number().int().min(0).default(0),
  'quota.storageBytes': z
    .number()
    .int()
    .min(0)
    .default(1024 * 1024 * 1024),
  'quota.maxFileBytes': z
    .number()
    .int()
    .min(0)
    .default(25 * 1024 * 1024),
  // Trash retention (ADR 0013, issue #31): days a soft-deleted page stays
  // restorable before the daily purge job removes it for good.
  'trash.retentionDays': z.number().int().min(1).default(30),
  // Non-image upload allowlist (ADR 0011, issue #61): lowercase extensions
  // without the dot. Images are always allowed regardless; SVG is governed
  // by `upload.svgPolicy`. Normalized (lowercased, dot-stripped, deduped) so
  // an admin can paste `.PDF` or `pdf` interchangeably.
  'upload.allowedExtensions': z
    .array(z.string())
    .transform((exts) => [
      ...new Set(exts.map((e) => e.trim().replace(/^\./, '').toLowerCase()).filter(Boolean)),
    ])
    .pipe(z.array(z.string().regex(/^[a-z0-9]+$/)))
    .default([...DEFAULT_ATTACHMENT_EXTENSIONS]),
  // SVG upload handling (security.md §Uploads): sanitize strips scripts and
  // event handlers with a maintained library; reject refuses SVG outright.
  'upload.svgPolicy': z.enum(['reject', 'sanitize']).default('sanitize'),
  // Public REST API master switch (issue #104, default off): every
  // /api/public/v1 route answers 404 while disabled. Individual ponds
  // additionally opt in through their pond settings (`apiEnabled`).
  'api.enabled': z.boolean().default(false),
  // Built-in MCP endpoint master switch (issue #105, default off) —
  // independent of the REST switch; ponds opt in via `mcpEnabled`.
  'mcp.enabled': z.boolean().default(false),
  // Backup targets (ADR 0015, issue #103). The backup sidecar reads these
  // rows directly (apps/backup settings.ts — keep the schemas in sync); the
  // Nextcloud app password is NOT here, it lives in the secret store
  // (security.md §Secrets). localRetentionDays `null` = no admin override,
  // the sidecar's BACKUP_RETENTION_DAYS env stays authoritative.
  'backup.localRetentionDays': z.number().int().min(1).nullable().default(null),
  'backup.remoteRetentionDays': z.number().int().min(1).default(30),
  'backup.nextcloud.enabled': z.boolean().default(false),
  'backup.nextcloud.baseUrl': z.string().trim().url().or(z.literal('')).default(''),
  'backup.nextcloud.username': z.string().trim().max(200).default(''),
  'backup.nextcloud.folder': z
    .string()
    .trim()
    .max(500)
    .refine((folder) => !folder.split('/').some((s) => s === '.' || s === '..'), {
      message: 'validation.invalid',
    })
    .default('dorfteich-backups'),
  'backup.nextcloud.uploadSchedule': z.enum(['off', 'daily', 'weekly']).default('daily'),
  // Instance legal pages (issue #82, security.md §Privacy): Markdown texts
  // for imprint and privacy policy, rendered publicly at /legal/<kind>.
  // Empty = not configured yet (the legal pages then show a notice and
  // Site Admins a warning banner instead of silently missing).
  'legal.imprint': z.string().max(100_000).default(''),
  'legal.privacyPolicy': z.string().max(100_000).default(''),
  // Landing-page body: the Site Admin's Markdown for the public home page
  // (`/`), rendered through the same sanitizing pipeline as the legal pages.
  // Empty = the built-in default welcome text is shown instead.
  'home.content': z.string().max(100_000).default(''),
  // When the first-run setup wizard completed (issue #80). Null = the
  // instance still requires setup and only /setup/* is reachable; once set
  // the wizard is locked for good (SetupStateService). Written by the wizard,
  // env pre-seeding, the fixture seed, and a backfill migration for
  // instances that predate the wizard.
  'setup.completedAt': z.string().nullable().default(null),
} as const;

export type InstanceSettingKey = keyof typeof INSTANCE_SETTINGS;
export type InstanceSettingValue<K extends InstanceSettingKey> = z.infer<
  (typeof INSTANCE_SETTINGS)[K]
>;
export type InstanceSettings = { [K in InstanceSettingKey]: InstanceSettingValue<K> };

/**
 * Typed, cached access to instance_settings. The in-process cache is
 * invalidated on every write; with one api container per stage
 * (ADR 0002) that is sufficient — no cross-instance bus needed yet.
 */
@Injectable()
export class InstanceSettingsService {
  private cache = new Map<InstanceSettingKey, unknown>();

  constructor(
    private readonly prisma: PrismaService,
    private readonly audit: AuditService,
    private readonly logger: PinoLogger,
  ) {
    this.logger.setContext(InstanceSettingsService.name);
  }

  async get<K extends InstanceSettingKey>(key: K): Promise<InstanceSettingValue<K>> {
    if (this.cache.has(key)) return this.cache.get(key) as InstanceSettingValue<K>;
    const row = await this.prisma.instanceSetting.findUnique({ where: { key } });
    const parsed = INSTANCE_SETTINGS[key].safeParse(row?.value);
    // Unknown/invalid stored values fall back to the schema default
    // instead of breaking the instance.
    const value = parsed.success ? parsed.data : INSTANCE_SETTINGS[key].parse(undefined);
    this.cache.set(key, value);
    return value as InstanceSettingValue<K>;
  }

  async getAll(): Promise<InstanceSettings> {
    const entries = await Promise.all(
      (Object.keys(INSTANCE_SETTINGS) as InstanceSettingKey[]).map(
        async (key) => [key, await this.get(key)] as const,
      ),
    );
    return Object.fromEntries(entries) as InstanceSettings;
  }

  async set<K extends InstanceSettingKey>(
    key: K,
    value: unknown,
    actorUserId: string,
  ): Promise<InstanceSettingValue<K>> {
    const parsed = INSTANCE_SETTINGS[key].safeParse(value);
    if (!parsed.success) {
      throw new BadRequestException({
        code: 'bad_request',
        details: { [key]: parsed.error.issues.map((i) => i.message) },
      });
    }
    // Nullable settings (setup.completedAt) store JSON null explicitly —
    // Prisma requires the sentinel for that.
    const stored = parsed.data === null ? Prisma.JsonNull : parsed.data;
    await this.prisma.instanceSetting.upsert({
      where: { key },
      create: { key, value: stored },
      update: { value: stored },
    });
    this.cache.set(key, parsed.data);
    // Values stay out of the trail: legal texts are long, and future keys
    // could be sensitive — the key names what changed, the log has the actor.
    await this.audit.record({
      action: 'settings.changed',
      actorId: actorUserId,
      targetType: 'setting',
      targetId: key,
    });
    return parsed.data as InstanceSettingValue<K>;
  }
}