import {
  Body,
  Controller,
  Delete,
  ForbiddenException,
  Get,
  NotFoundException,
  Param,
  Patch,
  Post,
  Put,
  Query,
  Req,
} from '@nestjs/common';
import { Role } from '@prisma/client';
import { Request } from 'express';
import { Roles } from '../auth/decorators/roles.decorator';
import { UseModule } from '../module-registry/module.guard';
import { PrismaService } from '../prisma/prisma.service';
import { UpdateNotificationPrefDto } from './dto/notification-pref.dto';
import { CreateSavedSearchDto, UpdateSavedSearchDto } from './dto/saved-search.dto';
import { SourceConfigDto } from './dto/source-config.dto';
import { TenderQueryDto } from './dto/tender-query.dto';
import { TenderTriageDto } from './dto/tender-triage.dto';
import { TenderNotificationPrefService } from './tender-notification-pref.service';
import { TenderSavedSearchService } from './tender-saved-search.service';
import { TenderSchedulerService } from './tender-scheduler.service';
import { TenderTriageService } from './tender-triage.service';
import { buildOrderBy, buildTenderWhere } from './tender-query.builder';

/**
 * T-11-11 (DoS): bounds the `ids` batch-triage query param — same
 * defensive intent as MAX_FAV_IDS in tender-query.builder.ts.
 */
const MAX_TRIAGE_BATCH_IDS = 200;

const DOE_SOURCE_TYPE = 'doe-opendata';

/**
 * TendersController — `/modules/tender-radar/*` routes.
 *
 * Deliberate structural divergence from DkvController (RESEARCH.md V4,
 * PATTERNS.md): `GET /` and `GET /:id` read the GLOBAL `Tender` catalog,
 * gated only by `@UseModule('tender-radar')` (module activation) — NEVER
 * row-scoped by the tenant's id. The tender catalog is platform-wide data
 * (D-03); "tenant-gated" (can this tenant see the feature at all) and
 * "tenant-scoped" (filter rows by tenant) are genuinely different things
 * here, unlike every other module in this codebase.
 *
 * Admin source-config routes (`GET`/`PUT /source-config`) are, like
 * DkvController, per-handler `@Roles(Role.ADMIN, Role.SUPER_ADMIN)`-guarded
 * (T-10-13) and are NOT gated by @UseModule — an admin configuring the
 * shared platform-wide poll schedule is a platform-admin action, not a
 * per-tenant module feature.
 */
@Controller('modules/tender-radar')
export class TendersController {
  constructor(
    private readonly prisma: PrismaService,
    private readonly tenderScheduler: TenderSchedulerService,
    private readonly tenderTriage: TenderTriageService,
    private readonly tenderSavedSearch: TenderSavedSearchService,
    private readonly tenderNotificationPref: TenderNotificationPrefService,
  ) {}

  /**
   * Extracts (userId, tenantId) for the per-user Triage routes — same
   * pattern as FavoritesController.extractContext (T-08-06): userId/
   * tenantId are ALWAYS read from the authenticated request context, never
   * from a client-supplied body/query field (T-11-10 / V4 — IDOR).
   */
  private extractTriageContext(req: Request) {
    const userId = (req as any).user?.id;
    const tenantId = (req as any).tenantId ?? (req as any).user?.tenantId;

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

    return { userId, tenantId };
  }

  // ─── Global read (ModuleGuard-gated, NOT tenant-scoped) ────────────────────

  /**
   * GET /modules/tender-radar — paginated, filtered + sorted global
   * tender catalog. Gated by @UseModule('tender-radar'): only tenants
   * with the module active can read. Deliberately NOT filtered by the
   * tenant's id — the catalog is platform-global (D-03).
   *
   * Filter/sort composition is delegated to tender-query.builder.ts
   * (buildTenderWhere/buildOrderBy) — kept out of the controller so the
   * where/orderBy logic is independently unit-testable (T-11-01/03).
   * Pagination bounds (limit @Max(100), page @Min(1)) are unchanged
   * (T-10-15, Don't Hand-Roll).
   *
   * favOnly (UI-04, T-11-10): when set, this user's favorited tenderIds
   * are resolved server-side via TenderTriageService.favoriteIds(userId)
   * — derived from the auth context, NOT from the query string — and
   * passed into buildTenderWhere so an empty favorites list yields zero
   * matches rather than the unfiltered catalog.
   */
  @Get()
  @UseModule('tender-radar')
  async listTenders(@Query() query: TenderQueryDto, @Req() req?: Request) {
    const page = query.page ?? 1;
    const limit = query.limit ?? 20;
    const skip = (page - 1) * limit;

    let favIds: string[] | undefined;
    if (query.favOnly) {
      // req is always present in production (NestJS @Req() DI) — the
      // optional type only accommodates unit tests that call this method
      // directly without favOnly set (T-11-10: extractTriageContext
      // throws ForbiddenException if req/user context is genuinely absent).
      const { userId } = this.extractTriageContext(req as Request);
      favIds = await this.tenderTriage.favoriteIds(userId);
    }

    const where = buildTenderWhere(query, favIds);
    const orderBy = buildOrderBy(query.sort);

    const [items, total] = await Promise.all([
      this.prisma.tender.findMany({
        where,
        orderBy,
        skip,
        take: limit,
      }),
      this.prisma.tender.count({ where }),
    ]);

    return { items, total, page, limit };
  }

  /**
   * GET /modules/tender-radar/source-config — read the singleton
   * doe-opendata poll config.
   *
   * MUST be declared before the `:id` route below — NestJS matches routes
   * in declaration order, so a `@Get(':id')` placed first would capture
   * "source-config" as an id and shadow this handler (404 on GET).
   */
  @Get('source-config')
  @Roles(Role.ADMIN, Role.SUPER_ADMIN)
  async getSourceConfig() {
    const config = await this.prisma.tenderSourcePollConfig.findUnique({
      where: { sourceType: DOE_SOURCE_TYPE },
    });
    if (!config) {
      throw new NotFoundException('Tender source config not yet seeded');
    }
    return config;
  }

  /**
   * GET /modules/tender-radar/coverage — distribution of active tenders
   * by sourcePortal (D-12, UI-05). Feeds the frontend CoverageBanner so a
   * thin/single-source result list (currently only 'doe-opendata',
   * Oberschwelle-lastig) is not misread as a defect.
   *
   * MUST be declared before `@Get(':id')` below — same route-order
   * pitfall as `source-config` above (Pitfall 5, Phase-10 regression).
   * Read-surface, gated by @UseModule (not an admin-only route).
   */
  @Get('coverage')
  @UseModule('tender-radar')
  async getCoverage() {
    const [bySource, total] = await Promise.all([
      this.prisma.tender.groupBy({
        by: ['sourcePortal'],
        _count: true,
        where: { status: 'active' },
      }),
      this.prisma.tender.count({ where: { status: 'active' } }),
    ]);

    return {
      total,
      sources: bySource.map((s) => ({
        sourcePortal: s.sourcePortal,
        count: s._count,
      })),
    };
  }

  /**
   * GET /modules/tender-radar/triage?ids=<csv> — batch-fetch the current
   * user's triage state (gelesen/ungelesen, Favorit) for the given
   * tenderIds (UI-03/04). Used by the Trefferliste to merge triage state
   * into the visible page in one round-trip instead of per-row requests.
   *
   * MUST be declared before `@Get(':id')` below — same route-order
   * pitfall as `source-config`/`coverage` above (Pitfall 5).
   *
   * Scoped strictly by userId (T-11-10 / V4 — IDOR): userId is derived
   * from the auth context, never from `ids`. `ids` is a client-supplied
   * comma-separated list of tenderIds to look up — bounded to
   * MAX_TRIAGE_BATCH_IDS entries (T-11-11, DoS).
   */
  @Get('triage')
  @UseModule('tender-radar')
  async listTriage(@Query('ids') ids: string | undefined, @Req() req: Request) {
    const { userId } = this.extractTriageContext(req);
    const tenderIds = (ids ?? '')
      .split(',')
      .map((id) => id.trim())
      .filter(Boolean)
      .slice(0, MAX_TRIAGE_BATCH_IDS);

    return this.tenderTriage.listForUser(userId, tenderIds);
  }

  /**
   * PUT /modules/tender-radar/triage — upsert the current user's triage
   * state (isRead/isFavorite) for one tender (UI-03/04). Idempotent
   * (TenderTriageService.setTriage upserts on @@unique([userId,tenderId])).
   *
   * MUST be declared before `@Get(':id')` below (Pitfall 5).
   *
   * userId/tenantId come exclusively from the auth context — `dto` (body)
   * carries only `tenderId`/`isRead`/`isFavorite`, never a userId field
   * (T-11-10 / V4 — IDOR).
   */
  @Put('triage')
  @UseModule('tender-radar')
  async setTriage(@Body() dto: TenderTriageDto, @Req() req: Request) {
    const { userId, tenantId } = this.extractTriageContext(req);

    return this.tenderTriage.setTriage(userId, tenantId, dto.tenderId, {
      isRead: dto.isRead,
      isFavorite: dto.isFavorite,
    });
  }

  // ─── Saved Searches (per-user, FILTER-06, D-08/D-11) ───────────────────────

  /**
   * GET /modules/tender-radar/saved-searches — list the current user's
   * saved search profiles (FILTER-06). Scoped strictly by userId
   * (T-11-14 / V4 — IDOR), derived from the auth context, never from a
   * query param.
   *
   * MUST be declared before `@Get(':id')` below — same route-order pitfall
   * as `source-config`/`coverage`/`triage` above (Pitfall 5, T-11-16).
   */
  @Get('saved-searches')
  @UseModule('tender-radar')
  async listSavedSearches(@Req() req: Request) {
    const { userId } = this.extractTriageContext(req);
    return this.tenderSavedSearch.list(userId);
  }

  /**
   * POST /modules/tender-radar/saved-searches — create a new saved search
   * profile. userId/tenantId come exclusively from the auth context
   * (T-11-14 / V4 — IDOR); `dto` carries only name/filters, never a
   * userId field.
   */
  @Post('saved-searches')
  @UseModule('tender-radar')
  async createSavedSearch(
    @Body() dto: CreateSavedSearchDto,
    @Req() req: Request,
  ) {
    const { userId, tenantId } = this.extractTriageContext(req);
    return this.tenderSavedSearch.create(userId, tenantId, dto);
  }

  /**
   * PATCH /modules/tender-radar/saved-searches/:searchId — rename and/or
   * update the filters of an existing saved search. Ownership is verified
   * in TenderSavedSearchService.update() (T-11-14). Uses `:searchId`
   * (not `:id`) so this route can never be confused with the Tender
   * `:id` param below (Pitfall 5).
   */
  @Patch('saved-searches/:searchId')
  @UseModule('tender-radar')
  async updateSavedSearch(
    @Param('searchId') searchId: string,
    @Body() dto: UpdateSavedSearchDto,
    @Req() req: Request,
  ) {
    const { userId } = this.extractTriageContext(req);
    return this.tenderSavedSearch.update(searchId, userId, dto);
  }

  /**
   * DELETE /modules/tender-radar/saved-searches/:searchId — delete a saved
   * search. Ownership verified in TenderSavedSearchService.remove()
   * (T-11-14).
   */
  @Delete('saved-searches/:searchId')
  @UseModule('tender-radar')
  async removeSavedSearch(
    @Param('searchId') searchId: string,
    @Req() req: Request,
  ) {
    const { userId } = this.extractTriageContext(req);
    await this.tenderSavedSearch.remove(searchId, userId);
    return { success: true };
  }

  // ─── Notification preference (per-user, NOTIFY-01, D-01/D-03) ─────────────

  /**
   * GET /modules/tender-radar/notification-pref — this user's digest
   * interval preference (daily/weekly/off). Scoped strictly by userId
   * (T-12-14 / V4 — IDOR), derived from the auth context, never from a
   * query param.
   *
   * MUST be declared before `@Get(':id')` below — same route-order pitfall
   * as `source-config`/`coverage`/`triage`/`saved-searches` above
   * (Pitfall 5).
   */
  @Get('notification-pref')
  @UseModule('tender-radar')
  async getNotificationPref(@Req() req: Request) {
    const { userId } = this.extractTriageContext(req);
    return this.tenderNotificationPref.getForUser(userId);
  }

  /**
   * PUT /modules/tender-radar/notification-pref — upsert this user's digest
   * interval preference. userId/tenantId come exclusively from the auth
   * context (T-12-14 / V4 — IDOR); `dto` carries only `digestInterval`,
   * never a userId field.
   */
  @Put('notification-pref')
  @UseModule('tender-radar')
  async setNotificationPref(
    @Body() dto: UpdateNotificationPrefDto,
    @Req() req: Request,
  ) {
    const { userId, tenantId } = this.extractTriageContext(req);
    return this.tenderNotificationPref.setForUser(userId, tenantId, dto.digestInterval);
  }

  /**
   * GET /modules/tender-radar/:id — single tender detail.
   * Gated by @UseModule('tender-radar'); NOT scoped by the tenant's id
   * (global row).
   *
   * D-03/SCHEMA-03 (13-06): includes the `sources` relation (TenderSource
   * rows) so a cross-source-deduplicated tender surfaces links to ALL of
   * its source portals, not just the single primary `sourceUrl` column.
   * `select` is scoped to the three display fields the frontend needs —
   * no `id`/`createdAt` leak, same minimal-surface convention as
   * `getCoverage`'s groupBy projection.
   */
  @Get(':id')
  @UseModule('tender-radar')
  async getTender(@Param('id') id: string) {
    const tender = await this.prisma.tender.findUnique({
      where: { id },
      include: {
        sources: {
          select: { sourcePortal: true, sourceUrl: true, sourceNoticeId: true },
        },
      },
    });
    if (!tender) {
      throw new NotFoundException('Tender not found');
    }
    return tender;
  }

  // ─── Admin source-config (Roles-guarded, live scheduler apply) ────────────
  // NOTE: GET /source-config is declared above the `:id` route (route-order
  // matters in NestJS). The PUT below is not shadowed — there is no @Put(':id').

  /**
   * PUT /modules/tender-radar/source-config — upsert the singleton
   * doe-opendata poll config, then apply the change live to the scheduler
   * (INGEST-06: admin-configurable interval, no restart required).
   *
   * Divergence from DkvController.saveConfig: no tenant-id argument to
   * setInterval()/stopJob() — this config is a platform-wide singleton.
   */
  @Put('source-config')
  @Roles(Role.ADMIN, Role.SUPER_ADMIN)
  async saveSourceConfig(@Body() dto: SourceConfigDto) {
    const result = await this.prisma.tenderSourcePollConfig.upsert({
      where: { sourceType: DOE_SOURCE_TYPE },
      update: { ...dto },
      create: {
        sourceType: DOE_SOURCE_TYPE,
        pollIntervalMin: dto.pollIntervalMin ?? 60,
        isActive: dto.isActive ?? false,
      },
    });

    if (dto.isActive && dto.pollIntervalMin) {
      this.tenderScheduler.setInterval(dto.pollIntervalMin);
    } else if (dto.isActive === false) {
      this.tenderScheduler.stopJob();
    }

    return result;
  }
}