<?php

namespace App\Http\Controllers;

use App\Services\Billing\PlanCatalogue;
use Illuminate\Contracts\View\View;
use Illuminate\Support\Facades\Log;
use Throwable;

/**
 * The public price sheet.
 *
 * Prices, storage and seat counts are read from the catalogue rather than
 * written into the page. They were hard-coded here once, and the page and the
 * catalogue had already drifted apart on three of four plans — a visitor was
 * quoted 249 € for a plan that charged 399 € at checkout. The marketing site is
 * a reader of the catalogue like every other caller.
 *
 * The catalogue fails loudly by design: an empty or overlapping catalogue is an
 * outage for commerce, not something to paper over. But a public website is not
 * commerce — a mistyped availability window must not take the company's front
 * page down with it. So the failure is caught HERE and only here: the page
 * still renders, the price sheet is replaced by "on request", and nobody is
 * shown a number the checkout would not honour.
 */
class LandingController extends Controller
{
    /** Presentation that belongs to the marketing page, not to the catalogue. */
    private const COPY = [
        'start' => ['audience' => 'Für kleine Teams', 'note' => 'Einstieg für Büros, die heute noch Dateien per Mail schicken.'],
        'team' => ['audience' => 'Für wachsende Teams', 'note' => 'Der Regelfall — Einschulung des gesamten Teams inklusive.'],
        'business' => ['audience' => 'Für dokumentenlastige Betriebe', 'note' => 'Mehr Speicher, längere Aufbewahrung, bevorzugte Reaktionszeit.'],
        'enterprise' => ['audience' => 'Individuell für Ihr Unternehmen', 'note' => 'Umfang, Einrichtung und Reaktionszeiten nach Vereinbarung.'],
    ];

    /** Catalogue feature keys, in the words a customer uses. */
    private const FEATURES = [
        'managed_updates' => 'Updates & Wartung',
        'daily_backups' => 'Tägliche Sicherung',
        'monitoring' => 'Überwachung rund um die Uhr',
        'subdomain' => 'Adresse auf clupilot.cloud',
        'custom_domain' => 'Eigene Domain',
        'office' => 'Office im Browser',
        'branding' => 'Ihr Logo & Ihre Farben',
        'priority_support' => 'Bevorzugter Support',
        'premium_sla' => 'Vereinbarte Reaktionszeiten',
        'extended_retention' => 'Verlängerte Aufbewahrung',
        'audit_log' => 'Protokollierung der Zugriffe',
        'onboarding' => 'Begleitete Einführung',
    ];

    public function __invoke(): View
    {
        $plans = $this->plans();

        return view('landing', [
            'plans' => $plans,
            'featureRows' => $this->featureRows($plans),
        ]);
    }

    /**
     * Every feature any sellable plan carries, in the catalogue's narrative
     * order — the row headings of the price sheet.
     *
     * Built from what is on sale rather than from the full list, so a feature
     * no current plan offers does not appear as an empty row.
     *
     * @param  array<int, array<string, mixed>>  $plans
     * @return array<int, string>
     */
    private function featureRows(array $plans): array
    {
        $offered = array_merge(...array_column($plans, 'features')) ?: [];

        return array_values(array_filter(
            self::FEATURES,
            fn (string $label) => in_array($label, $offered, true),
        ));
    }

    /**
     * @return array<int, array<string, mixed>>  empty when the catalogue cannot be read
     */
    private function plans(): array
    {
        try {
            $sellable = app(PlanCatalogue::class)->sellable();
        } catch (Throwable $e) {
            // Deliberately swallowed: see the class docblock. Logged at error
            // level because a shop that cannot list its plans is not selling.
            Log::error('Landing page could not read the plan catalogue', ['exception' => $e]);

            return [];
        }

        $plans = [];

        foreach ($sellable as $key => $plan) {
            $plans[] = [
                'key' => $key,
                'name' => $plan['name'],
                'audience' => self::COPY[$key]['audience'] ?? '',
                'note' => self::COPY[$key]['note'] ?? '',
                'price' => $this->money((int) $plan['price_cents'], (string) $plan['currency']),
                'storage' => $this->storage((int) $plan['quota_gb']),
                'traffic' => $this->storage((int) $plan['traffic_gb']),
                'seats' => (int) $plan['seats'],
                'features' => $this->features($plan['features'] ?? []),
                'recommended' => (bool) ($plan['recommended'] ?? false),
            ];
        }

        return $plans;
    }

    /** Currencies we have a symbol for; anything else prints its ISO code. */
    private const SYMBOLS = ['EUR' => '€', 'CHF' => 'CHF', 'USD' => '$', 'GBP' => '£'];

    /**
     * A price as the sheet prints it, currency included.
     *
     * The symbol comes from the catalogue rather than from the template: the
     * currency is configurable (CLUPILOT_CURRENCY), and a page that says "€"
     * while the checkout charges francs is the same two-sources-of-truth
     * mistake as a hard-coded amount, only harder to notice.
     *
     * Whole units when the amount is whole — a price sheet reads "179", not
     * "179,00".
     */
    private function money(int $cents, string $currency): string
    {
        $amount = $cents % 100 === 0
            ? number_format($cents / 100, 0, ',', '.')
            : number_format($cents / 100, 2, ',', '.');

        // Non-breaking: in a narrow table column "49 €" otherwise wraps, and the
        // currency ends up on a line of its own under the number.
        return $amount."\u{00A0}".(self::SYMBOLS[strtoupper($currency)] ?? strtoupper($currency));
    }

    private function storage(int $gb): string
    {
        return $gb >= 1000 && $gb % 1000 === 0
            ? ($gb / 1000).' TB'
            : $gb.' GB';
    }

    /**
     * @param  array<int, string>  $keys
     * @return array<int, string>
     */
    private function features(array $keys): array
    {
        // Unknown keys are dropped rather than printed raw: a feature added to
        // the catalogue without a translation would otherwise appear on the
        // public page as "premium_sla".
        return array_values(array_filter(array_map(
            fn (string $key) => self::FEATURES[$key] ?? null,
            $keys,
        )));
    }
}