<?php

declare(strict_types=1);

namespace App\Http\Controllers\Api\PublicApi\V1;

use App\Http\Requests\PublicApi\ReportMissingUrlRequest;
use App\Http\Requests\PublicApi\ReportViewsRequest;
use App\Models\ContentView;
use App\Models\MissingUrl;
use App\Models\Redirect;
use App\Support\ContentTypes;
use Illuminate\Http\JsonResponse;
use Symfony\Component\HttpFoundation\Response;

/**
 * The frontend reporting back.
 *
 * Everything else this API does is answer questions. These two endpoints are
 * the direction nothing else travels in: the site telling the panel what
 * happened out there, which is the half of every editorial decision that has
 * been missing.
 *
 * Two things are worth knowing and neither can be discovered from here: which
 * addresses failed, because a broken link only ever fails in front of a
 * visitor, and which records were read, because the panel can say what is
 * published and never whether anybody opened it.
 *
 * What is deliberately not collected in either: anything about a person. No
 * address, no session, no user agent, no time of day. A failed URL and a daily
 * tally per record answer the questions; a visitor log would answer different
 * ones nobody here asked.
 */
class TelemetryController extends PublicController
{
    /**
     * POST /api/public/v1/telemetry/not-found
     *
     * Answers 202 rather than 201: nothing here is a resource the caller owns,
     * and reports that were merged into an existing count or dropped as noise
     * are still perfectly successful. The count of what was actually recorded
     * comes back so the frontend can tell whether its filter matches ours.
     */
    public function notFound(ReportMissingUrlRequest $request): JsonResponse
    {
        $recorded = 0;

        foreach ($request->hits() as $hit) {
            // Normalised exactly as a redirect is, because that is what these
            // are eventually compared against: "/x/" and "/x?ref=1" are the
            // same broken address and must not become two rows.
            $path = Redirect::normalise((string) $hit['path']);

            if ($this->isNoise($path)) {
                continue;
            }

            MissingUrl::report(
                $path,
                // The frontend usually knows which language it was rendering.
                // When it does not, the negotiated locale is the same answer:
                // it comes from the Accept-Language the frontend forwarded.
                filled($hit['locale'] ?? null) ? (string) $hit['locale'] : app()->getLocale(),
                filled($hit['referrer'] ?? null) ? (string) $hit['referrer'] : null,
            );

            $recorded++;
        }

        return response()->json([
            'data' => [
                'received' => count($request->hits()),
                'recorded' => $recorded,
            ],
        ], Response::HTTP_ACCEPTED)
            ->header('Cache-Control', 'no-store, private');
    }

    /**
     * POST /api/public/v1/telemetry/views
     *
     * What was read. The panel has always known what exists and what is
     * published, and never whether any of it gets opened — which is the fact
     * behind most editorial decisions: what to translate next, whether the
     * featured project is one anybody looks at, whether a page earns the work
     * of keeping it accurate.
     *
     * There is no visitor in any of this. A report says a record was rendered
     * in a language; what is stored is a daily total per record. No address,
     * no session, no user agent, no time of day — nothing that could be
     * assembled back into a person.
     */
    public function views(ReportViewsRequest $request): JsonResponse
    {
        $recorded = 0;

        foreach ($request->views() as $view) {
            $locale = filled($view['locale'] ?? null)
                ? (string) $view['locale']
                : app()->getLocale();

            $record = ContentTypes::resolve((string) $view['type'], (string) $view['slug'], $locale);

            // A slug that no longer resolves is a 404, and the endpoint next
            // door exists to hear about those. Counting it here would attach
            // somebody's reading to nothing.
            if ($record === null) {
                continue;
            }

            ContentView::record($record, $locale, (int) ($view['count'] ?? 1));

            $recorded++;
        }

        return response()->json([
            'data' => [
                'received' => count($request->views()),
                'recorded' => $recorded,
            ],
        ], Response::HTTP_ACCEPTED)
            ->header('Cache-Control', 'no-store, private');
    }

    /**
     * A scan for something that was never here.
     *
     * Dropped rather than stored, and dropped on this side rather than left to
     * the frontend: the list is only useful while a person is willing to read
     * it, and one afternoon of a bot looking for WordPress would end that.
     */
    protected function isNoise(string $path): bool
    {
        foreach ((array) config('site.telemetry.ignore', []) as $pattern) {
            if (fnmatch((string) $pattern, $path, FNM_CASEFOLD)) {
                return true;
            }
        }

        return false;
    }
}