import { Controller, Get, NotFoundException, Param, Query, Req, Res } from '@nestjs/common';
import type { PageCommentsView } from '@dorfteich/shared';
import type { Response } from 'express';

import { AuthedRequest, Public } from '../auth/auth.guard';
import { InstanceSettingsService } from '../settings/instance-settings.service';
import { FeedService } from './feed.service';
import { PublicPageContent, PublicService } from './public.service';

/**
 * Public read endpoints (issue #56). `@Public()` so anonymous visitors reach
 * them; the service enforces the `public` grant through the shared resolver and
 * 404s otherwise (non-public pages never leak). Two shapes: JSON for the SPA's
 * read-only view, and a self-contained HTML document for crawlers / PDF export.
 */
@Controller('public')
export class PublicController {
  constructor(
    private readonly publicPages: PublicService,
    private readonly feeds: FeedService,
    private readonly settings: InstanceSettingsService,
  ) {}

  /** Feed master switch (issue #191): disabled ⇒ 404, existence hidden. */
  private async assertFeedsEnabled(): Promise<void> {
    if (!(await this.settings.get('feeds.enabled'))) throw new NotFoundException();
  }

  // The feed routes come FIRST: `:pondSlug/feed.xml` would otherwise be
  // swallowed by the `:pondSlug/:pageSlug` HTML route below (issue #149).
  @Get(':pondSlug/feed.xml')
  @Public()
  async pondFeed(
    @Param('pondSlug') pondSlug: string,
    @Query('token') token: string | undefined,
    @Req() request: AuthedRequest,
    @Res({ passthrough: true }) response: Response,
  ): Promise<string> {
    await this.assertFeedsEnabled();
    const viewer = await this.feeds.viewerFor(request.user ?? null, token);
    const xml = await this.feeds.pondFeed(viewer, pondSlug, baseUrlOf(request));
    response.set('Content-Type', 'application/atom+xml; charset=utf-8');
    return xml;
  }

  @Get(':pondSlug/:pageSlug/feed.xml')
  @Public()
  async pageFeed(
    @Param('pondSlug') pondSlug: string,
    @Param('pageSlug') pageSlug: string,
    @Query('token') token: string | undefined,
    @Req() request: AuthedRequest,
    @Res({ passthrough: true }) response: Response,
  ): Promise<string> {
    await this.assertFeedsEnabled();
    const viewer = await this.feeds.viewerFor(request.user ?? null, token);
    const xml = await this.feeds.pageFeed(viewer, pondSlug, pageSlug, baseUrlOf(request));
    response.set('Content-Type', 'application/atom+xml; charset=utf-8');
    return xml;
  }

  @Get(':pondSlug/:pageSlug/content')
  @Public()
  async content(
    @Param('pondSlug') pondSlug: string,
    @Param('pageSlug') pageSlug: string,
    @Req() request: AuthedRequest,
  ): Promise<PublicPageContent> {
    return this.publicPages.content(request.user ?? null, pondSlug, pageSlug);
  }

  @Get(':pondSlug/:pageSlug/comments')
  @Public()
  async comments(
    @Param('pondSlug') pondSlug: string,
    @Param('pageSlug') pageSlug: string,
    @Req() request: AuthedRequest,
  ): Promise<PageCommentsView> {
    return this.publicPages.comments(request.user ?? null, pondSlug, pageSlug);
  }

  @Get(':pondSlug/:pageSlug')
  @Public()
  async html(
    @Param('pondSlug') pondSlug: string,
    @Param('pageSlug') pageSlug: string,
    @Req() request: AuthedRequest,
    @Res({ passthrough: true }) response: Response,
  ): Promise<string> {
    const canonical = `${request.protocol}://${request.get('host') ?? ''}${request.originalUrl}`;
    const html = await this.publicPages.html(request.user ?? null, pondSlug, pageSlug, canonical);
    response.set('Content-Type', 'text/html; charset=utf-8');
    return html;
  }
}

function baseUrlOf(request: AuthedRequest): string {
  return `${request.protocol}://${request.get('host') ?? ''}`;
}