import {
  Body,
  Controller,
  Delete,
  ForbiddenException,
  Get,
  Param,
  ParseUUIDPipe,
  Patch,
  Post,
  Put,
  Query,
  Req,
  Res,
  UploadedFile,
  UseInterceptors,
} from '@nestjs/common';
import { FileInterceptor } from '@nestjs/platform-express';
import { Response } from 'express';
import type { AuthenticatedRequest, UploadedFileLike } from '../auth/types/auth-user';
import { CreateFavoriteDto } from './dto/create-favorite.dto';
import { ReorderFavoritesDto } from './dto/reorder-favorites.dto';
import { UpdateFavoriteDto } from './dto/update-favorite.dto';
import { FAVORITE_ICON_MAX_BYTES } from './favorite-icon-files';
import { FavoritesService } from './favorites.service';

/**
 * REST controller for per-user, per-widget favorite links.
 *
 * All routes are protected by the global JwtAuthGuard + TenantGuard.
 *
 * Mandantenquelle (260911-gwh): `extractContext` liest `req.tenantId ??
 * req.user?.tenantId` — WORTGLEICH mit `dashboard.controller.ts`, unter
 * dessen Bindung `WidgetInstance` liegt. `FavoriteLink` haengt ueber
 * `widgetId` an `WidgetInstance`; eine andere Quelle (z. B. das Claim, wie
 * bei `auth` fuer Selbstbedienung) wuerde Widget und Link unter einem
 * `x-tenant-id`-Wechsel eines SUPER_ADMIN in verschiedenen Mandanten
 * auseinanderreissen. Das Favoriten-Frontend sendet die `x-tenant-id`-
 * Kopfzeile heute nicht — die Entscheidung haengt an der Bauform, nicht am
 * heutigen Aufrufer.
 *
 * Routes:
 * - GET  /favorites?widgetId=   — list favorites for a widget instance
 * - POST /favorites             — create a favorite (triggers server-side icon discovery)
 * - PUT  /favorites/order       — reorder favorites for a widget instance (260917-jdd)
 * - GET  /favorites/:id/icon    — stream a favorite's stored icon bytes (append `?v=<iconVersion>`
 *   client-side to bust the 24h cache after any change to the icon source, 260923-lrr)
 * - POST /favorites/:id/icon    — upload a custom icon (multipart field `icon`, ≤512 KB, 260923-lrr)
 * - DELETE /favorites/:id/icon  — remove a previously uploaded icon (260923-lrr)
 * - PATCH /favorites/:id        — update a favorite (ownership verified in service)
 * - DELETE /favorites/:id       — delete a favorite (ownership verified in service)
 */
@Controller('favorites')
export class FavoritesController {
  constructor(private readonly favoritesService: FavoritesService) {}

  private extractContext(req: AuthenticatedRequest) {
    const userId = req.user?.id;
    const tenantId =
      req.tenantId ?? req.user?.tenantId;

    if (!tenantId) {
      throw new ForbiddenException('No tenant context');
    }
    if (!userId) {
      throw new ForbiddenException('No user context');
    }

    return { userId, tenantId };
  }

  @Get()
  async list(
    @Query('widgetId', ParseUUIDPipe) widgetId: string,
    @Req() req: AuthenticatedRequest,
  ) {
    const { userId, tenantId } = this.extractContext(req);

    return this.favoritesService.list(tenantId, userId, widgetId);
  }

  @Post()
  async create(
    @Body() dto: CreateFavoriteDto,
    @Req() req: AuthenticatedRequest,
  ) {
    const { userId, tenantId } = this.extractContext(req);

    return this.favoritesService.create(tenantId, userId, dto);
  }

  /**
   * PUT /favorites/order — persists the display order for a widget's
   * favorites (260917-jdd). Declared BEFORE the `:id` routes below on
   * purpose (NestJS route order — a later `:id` route would otherwise
   * shadow the literal segment "order"; precedent tenders.controller.ts
   * Z. 636-648).
   */
  @Put('order')
  async reorder(
    @Body() dto: ReorderFavoritesDto,
    @Req() req: AuthenticatedRequest,
  ) {
    const { userId, tenantId } = this.extractContext(req);

    return this.favoritesService.reorder(tenantId, userId, dto);
  }

  /**
   * GET /favorites/:id/icon — streams the stored icon bytes for a favorite
   * owned by the caller, from Tessera's own origin. This avoids the browser
   * blocking a cross-origin <img> hotlink when the external site sends
   * Cross-Origin-Resource-Policy: same-origin (e.g. claude.ai).
   *
   * Takes only a FavoriteLink id — never a client-supplied URL — so this
   * cannot be used as an arbitrary-URL SSRF proxy (T-QFIP-01).
   */
  @Get(':id/icon')
  async getIcon(
    @Param('id') id: string,
    @Req() req: AuthenticatedRequest,
    @Res() res: Response,
  ) {
    const { userId, tenantId } = this.extractContext(req);
    const { contentType, body } = await this.favoritesService.getIconBytes(
      tenantId,
      id,
      userId,
    );

    res.setHeader('Content-Type', contentType);
    // 260923-lrr: private statt public — kein gemeinsamer Zwischenspeicher
    // (Nginx Proxy Manager) haelt benutzerbezogene Symbole vor. Die Adresse
    // traegt clientseitig `?v=<iconVersion>` (T-LRR-05), damit der lange
    // 24h-Browser-Zwischenspeicher nach einer Aenderung trotzdem sofort
    // ungueltig wird.
    res.setHeader('Cache-Control', 'private, max-age=86400');
    // 260917-jdd: die Bytes kommen jetzt auch von Hosts ohne gueltiges
    // Zertifikat. Als <img>-Unterressource ignoriert der Browser diese
    // Header, aber ein direkt im Tab geoeffnetes SVG laeuft damit ohne
    // Skript und ohne Tessera-Origin (T-JDD-02).
    res.setHeader('X-Content-Type-Options', 'nosniff');
    res.setHeader('Content-Security-Policy', "default-src 'none'; sandbox");
    res.send(body);
  }

  /**
   * POST /favorites/:id/icon — laedt ein eigenes Symbol fuer einen
   * Favoriten hoch (260923-lrr). Groessengrenze JE ROUTE (Muster
   * `dashboard-images.controller.ts` T-PI9-02): `FileInterceptor` nimmt
   * genau eine Datei bis 512 KB; multers `LIMIT_FILE_SIZE` bildet Nest auf
   * 413 ab. Typ und Besitzpruefung laufen im Dienst (T-LRR-01/T-LRR-03).
   */
  @Post(':id/icon')
  @UseInterceptors(
    FileInterceptor('icon', { limits: { fileSize: FAVORITE_ICON_MAX_BYTES, files: 1 } }),
  )
  async uploadIcon(
    @Param('id', ParseUUIDPipe) id: string,
    @Req() req: AuthenticatedRequest,
    @UploadedFile() file?: UploadedFileLike,
  ) {
    const { userId, tenantId } = this.extractContext(req);

    return this.favoritesService.uploadIcon(tenantId, id, userId, file);
  }

  /**
   * DELETE /favorites/:id/icon — entfernt ein zuvor hochgeladenes Symbol
   * wieder; die Kachel faellt danach auf `iconUrl` bzw. automatische
   * Erkennung zurueck (260923-lrr).
   */
  @Delete(':id/icon')
  async removeUploadedIcon(
    @Param('id', ParseUUIDPipe) id: string,
    @Req() req: AuthenticatedRequest,
  ) {
    const { userId, tenantId } = this.extractContext(req);

    return this.favoritesService.removeUploadedIcon(tenantId, id, userId);
  }

  @Patch(':id')
  async update(
    @Param('id') id: string,
    @Body() dto: UpdateFavoriteDto,
    @Req() req: AuthenticatedRequest,
  ) {
    const { userId, tenantId } = this.extractContext(req);

    return this.favoritesService.update(tenantId, id, userId, dto);
  }

  @Delete(':id')
  async remove(
    @Param('id') id: string,
    @Req() req: AuthenticatedRequest,
  ) {
    const { userId, tenantId } = this.extractContext(req);

    return this.favoritesService.remove(tenantId, id, userId);
  }
}