<?php

namespace App\Services\Abo;

use App\Models\UserAbo;
use App\Models\UserAboOrder;
use App\Models\UserAboStatusHistory;
use App\Repositories\AboRepository;
use Carbon\Carbon;

/**
 * Uebersetzt Status, Grund und Zeitpunkte eines Abos in eine Aussage, die Admin,
 * Berater und Kunde ohne Rueckfrage verstehen (Ticket A3): "Pausiert bis
 * 24.10.2026 – vom Kunden am 12.09.2026", "Zahlung am 10.09.2026 fehlgeschlagen
 * (Karte abgelaufen) – das Abo laeuft nicht, bis die Zahlung nachgeholt ist",
 * "Gekuendigt am 01.08.2026 vom Berater".
 *
 * Quellen: `user_abos.status` / `status_reason` / `paused_until` (gepflegt
 * durch {@see UserAbo::applyStatusReasonDefaults()} und die Pause im
 * {@see AboRepository}), `user_abo_orders.error_message`
 * (Fehlertext des Zahlungsanbieters) und als Rueckfall fuer Bestandsdaten das
 * Statusprotokoll {@see UserAboStatusHistory}.
 */
class AboStatusExplainer
{
    public function explain(UserAbo $abo): AboStatusInfo
    {
        $status = (int) $abo->status;

        if ($abo->isPendingInitialPayment() || $status === 0) {
            return $this->pendingPayment($abo);
        }

        return match ($status) {
            3 => $this->paymentFailed($abo),
            4 => $this->cancelled($abo),
            5 => new AboStatusInfo(AboStatusInfo::STATE_FINISHED, __('abo.state_finished'), 'dark', __('abo.state_text_finished')),
            6 => $this->deactivated($abo),
            7 => new AboStatusInfo(AboStatusInfo::STATE_GRACE, __('abo.state_grace'), 'info', __('abo.state_text_grace')),
            8 => new AboStatusInfo(AboStatusInfo::STATE_EXTERN_DONE, __('abo.state_extern_done'), 'info', __('abo.state_text_extern_done')),
            2 => $abo->active ? $this->running($abo) : $this->deactivated($abo),
            default => new AboStatusInfo(AboStatusInfo::STATE_UNKNOWN, $abo->getStatusType() ?: __('abo.state_unknown'), $abo->getStatusColor(), ''),
        };
    }

    /**
     * Kurzer Fehlertext aus einer Payone-/Stripe-Antwort fuer
     * `user_abo_orders.error_message` — null, wenn die Antwort nichts Lesbares
     * enthaelt.
     *
     * @param  array<string, mixed>|null  $response
     */
    public static function paymentErrorMessage(?array $response): ?string
    {
        if (! $response) {
            return null;
        }

        $message = $response['customermessage'] ?? $response['errormessage'] ?? $response['message'] ?? null;
        $code = $response['errorcode'] ?? $response['decline_code'] ?? $response['code'] ?? null;

        if (! is_string($message) || trim($message) === '') {
            return null;
        }

        $text = trim($message);

        if (is_scalar($code) && (string) $code !== '') {
            $text = '['.$code.'] '.$text;
        }

        return mb_substr($text, 0, 255);
    }

    private function running(UserAbo $abo): AboStatusInfo
    {
        $pausedUntil = $abo->pausedUntil();

        if ($pausedUntil !== null && $pausedUntil->gte(Carbon::today())) {
            $actor = $this->actorFromReason($abo->status_reason, 'paused_by_')
                ?? $this->actorFromHistory($abo, UserAboStatusHistory::ACTION_PAUSED);
            $date = $abo->last_pause_date ? Carbon::parse($abo->getRawOriginal('last_pause_date')) : null;

            return new AboStatusInfo(
                AboStatusInfo::STATE_PAUSED,
                __('abo.state_paused'),
                'warning',
                __('abo.state_text_paused', [
                    'until' => $pausedUntil->format(\Util::formatDateDB()),
                    'actor' => $this->actorLabel($actor),
                    'date' => $date ? $date->format(\Util::formatDateDB()) : '-',
                ]),
                $date,
                $actor,
            );
        }

        $last = $this->rawDate($abo, 'last_date');
        $next = $this->rawDate($abo, 'next_date');

        $text = $last
            ? __('abo.state_text_active', ['last' => $last->format(\Util::formatDateDB()), 'next' => $next?->format(\Util::formatDateDB()) ?? '-'])
            : __('abo.state_text_active_first', ['next' => $next?->format(\Util::formatDateDB()) ?? '-']);

        return new AboStatusInfo(AboStatusInfo::STATE_ACTIVE, __('abo.state_active'), 'success', $text, $next);
    }

    private function paymentFailed(UserAbo $abo): AboStatusInfo
    {
        $date = $this->rawDate($abo, 'last_date');
        $error = $this->latestErrorMessage($abo);

        $text = __('abo.state_text_payment_failed', ['date' => $date ? $date->format(\Util::formatDateDB()) : '-']);

        if ($error !== null) {
            $text .= ' '.__('abo.state_text_payment_error', ['error' => $error]);
        }

        return new AboStatusInfo(AboStatusInfo::STATE_PAYMENT_FAILED, __('abo.state_payment_failed'), 'danger', $text, $date, null, $error);
    }

    private function cancelled(UserAbo $abo): AboStatusInfo
    {
        $actor = $this->actorFromReason($abo->status_reason, 'cancelled_by_')
            ?? $this->actorFromHistory($abo, UserAboStatusHistory::ACTION_CANCELLED);
        $date = $this->rawDate($abo, 'cancel_date') ?? $this->historyDate($abo, UserAboStatusHistory::ACTION_CANCELLED);

        return new AboStatusInfo(
            AboStatusInfo::STATE_CANCELLED,
            __('abo.state_cancelled'),
            'dark',
            __('abo.state_text_cancelled', [
                'date' => $date ? $date->format(\Util::formatDateDB()) : '-',
                'actor' => $this->actorLabel($actor),
            ]),
            $date,
            $actor,
        );
    }

    private function deactivated(UserAbo $abo): AboStatusInfo
    {
        $actor = $this->actorFromReason($abo->status_reason, 'deactivated_by_')
            ?? $this->actorFromHistory($abo, UserAboStatusHistory::ACTION_DEACTIVATED);
        $date = $this->historyDate($abo, UserAboStatusHistory::ACTION_DEACTIVATED);

        $text = $date
            ? __('abo.state_text_deactivated', ['date' => $date->format(\Util::formatDateDB()), 'actor' => $this->actorLabel($actor)])
            : __('abo.state_text_deactivated_no_date', ['actor' => $this->actorLabel($actor)]);

        return new AboStatusInfo(AboStatusInfo::STATE_DEACTIVATED, __('abo.state_deactivated'), 'secondary', $text, $date, $actor);
    }

    private function pendingPayment(UserAbo $abo): AboStatusInfo
    {
        if ($abo->hasFailedInitialPayment()) {
            $text = __('abo.pending_payment_failed_copy');
        } elseif ($abo->hasInitialPaymentStatus()) {
            $text = __('abo.pending_payment_processing_copy');
        } else {
            $text = __('abo.pending_payment_waiting_copy');
        }

        return new AboStatusInfo(AboStatusInfo::STATE_PENDING_PAYMENT, __('abo.state_pending_payment'), 'warning', $text);
    }

    private function latestErrorMessage(UserAbo $abo): ?string
    {
        $order = $abo->relationLoaded('user_abo_orders')
            ? $abo->user_abo_orders->sortByDesc('id')->first(fn (UserAboOrder $order) => (int) $order->status === 3)
            : $abo->user_abo_orders()->where('status', 3)->orderByDesc('id')->first();

        $message = $order?->error_message;

        return is_string($message) && trim($message) !== '' ? $message : null;
    }

    private function actorFromReason(?string $reason, string $prefix): ?string
    {
        if (! $reason || ! str_starts_with($reason, $prefix)) {
            return null;
        }

        return substr($reason, strlen($prefix)) ?: null;
    }

    private function actorFromHistory(UserAbo $abo, string $action): ?string
    {
        $entry = $this->latestHistory($abo, $action);

        return $entry ? UserAbo::reasonActorFromView($entry->view) : null;
    }

    private function historyDate(UserAbo $abo, string $action): ?Carbon
    {
        return $this->latestHistory($abo, $action)?->created_at?->copy();
    }

    /**
     * Letzter Protokolleintrag je Aktion — pro Abo und Aktion nur einmal geladen,
     * aus der vorgeladenen Relation, wenn vorhanden (Listen: `with('status_histories')`).
     *
     * @var array<string, UserAboStatusHistory|null>
     */
    private array $historyMemo = [];

    private function latestHistory(UserAbo $abo, string $action): ?UserAboStatusHistory
    {
        $key = $abo->id.':'.$action;

        if (array_key_exists($key, $this->historyMemo)) {
            return $this->historyMemo[$key];
        }

        if ($abo->relationLoaded('status_histories')) {
            $entry = $abo->status_histories
                ->filter(fn (UserAboStatusHistory $history) => $history->action === $action)
                ->sortByDesc('id')
                ->first();
        } else {
            $entry = $abo->status_histories()->where('action', $action)->orderByDesc('id')->first();
        }

        return $this->historyMemo[$key] = $entry;
    }

    private function actorLabel(?string $actor): string
    {
        return __('abo.actor_by_'.($actor ?: UserAbo::ACTOR_SYSTEM));
    }

    private function rawDate(UserAbo $abo, string $column): ?Carbon
    {
        $raw = $abo->getRawOriginal($column);

        return $raw ? Carbon::parse($raw) : null;
    }
}