<?php

namespace App\Services\Events;

use App\Models\Events\ProSubscription;
use App\Models\QrCode;
use App\Models\QrEventRegistration;
use App\Models\User;
use App\Services\Billing\BillingClient;
use Illuminate\Support\Carbon;
use Illuminate\Support\Facades\Schema;
use Illuminate\Support\Str;

class SubscriptionService
{
    public function __construct(private readonly BillingClient $billing) {}

    public function gatingActive(): bool
    {
        return (bool) config('events.pro.enabled', true) && $this->billing->configured();
    }

    public function priceMinor(): int
    {
        return (int) config('events.plans.pro.price_minor', config('events.pro.price_minor', 4900));
    }

    public function enterprisePriceMinor(): int
    {
        return (int) config('events.plans.enterprise.price_minor', 14900);
    }

    public function subscriptionFor(User $user): ?ProSubscription
    {
        if (! Schema::hasTable('events_pro_subscriptions')) {
            return null;
        }

        return ProSubscription::where('user_id', $user->id)->first();
    }

    public function planKey(User $user): string
    {
        if (! $this->gatingActive()) {
            return ProSubscription::PLAN_PRO;
        }

        $sub = $this->subscriptionFor($user);
        if (! $sub || ! $sub->entitled()) {
            return 'free';
        }

        return $sub->plan === ProSubscription::PLAN_ENTERPRISE
            ? ProSubscription::PLAN_ENTERPRISE
            : ProSubscription::PLAN_PRO;
    }

    public function hasPaidPlan(User $user): bool
    {
        if (! $this->gatingActive()) {
            return true;
        }

        return (bool) $this->subscriptionFor($user)?->entitled();
    }

    public function isEnterprise(User $user): bool
    {
        return $this->planKey($user) === ProSubscription::PLAN_ENTERPRISE;
    }

    public function isPro(User $user): bool
    {
        return $this->hasPaidPlan($user);
    }

    public function liveEventCount(User $user): int
    {
        return QrCode::query()
            ->where('user_id', $user->id)
            ->where('type', QrCode::TYPE_EVENT)
            ->count();
    }

    public function canCreateEvent(User $user): bool
    {
        if ($this->isPro($user)) {
            return true;
        }

        return $this->liveEventCount($user) < (int) config('events.free.max_live_events', 2);
    }

    public function ticketsThisMonth(User $user): int
    {
        return QrEventRegistration::query()
            ->where('user_id', $user->id)
            ->where('status', QrEventRegistration::STATUS_CONFIRMED)
            ->where('created_at', '>=', now()->startOfMonth())
            ->count();
    }

    public function canAcceptTicket(User $user): bool
    {
        if ($this->isPro($user)) {
            return true;
        }

        return $this->ticketsThisMonth($user) < (int) config('events.free.max_tickets_per_month', 100);
    }

    /** @return array{0:bool,1:string} */
    public function subscribe(User $user): array
    {
        $existing = $this->subscriptionFor($user);
        if ($existing && $existing->entitled() && $existing->status === ProSubscription::STATUS_ACTIVE) {
            return [true, 'You already have an active subscription.'];
        }

        if ($existing?->plan === ProSubscription::PLAN_ENTERPRISE) {
            return $this->subscribeEnterprise($user);
        }

        return $this->activateWalletPlan($user, ProSubscription::PLAN_PRO, $this->priceMinor(), 'Ladill Events Pro — monthly subscription', 'Welcome to Ladill Events Pro!');
    }

    /** @return array{0:bool,1:string} */
    public function subscribeEnterprise(User $user): array
    {
        $existing = $this->subscriptionFor($user);
        if ($existing && $existing->entitled() && $existing->status === ProSubscription::STATUS_ACTIVE) {
            return [true, 'You already have an active subscription.'];
        }

        return $this->activateWalletPlan(
            $user,
            ProSubscription::PLAN_ENTERPRISE,
            $this->enterprisePriceMinor(),
            'Ladill Events Business — monthly subscription',
            'Welcome to Ladill Events Business!',
        );
    }

    public function activatePrepaid(User $user, string $plan, int $months): void
    {
        $existing = $this->subscriptionFor($user);
        $price = $plan === ProSubscription::PLAN_ENTERPRISE
            ? $this->enterprisePriceMinor()
            : $this->priceMinor();

        ProSubscription::updateOrCreate(
            ['user_id' => $user->id],
            [
                'plan' => $plan,
                'status' => ProSubscription::STATUS_ACTIVE,
                'price_minor' => $price,
                'currency' => (string) config('events.pro.currency', 'GHS'),
                'auto_renew' => false,
                'started_at' => $existing?->started_at ?? now(),
                'current_period_end' => Carbon::now()->addMonths($months),
                'last_charged_at' => now(),
                'canceled_at' => null,
                'last_reference' => null,
                'last_error' => null,
            ],
        );
    }

    /** @return array{0:bool,1:string} */
    public function cancel(User $user): array
    {
        $sub = $this->subscriptionFor($user);
        if (! $sub || ! $sub->entitled()) {
            return [false, 'You do not have an active subscription.'];
        }

        $sub->forceFill([
            'status' => ProSubscription::STATUS_CANCELED,
            'auto_renew' => false,
            'canceled_at' => now(),
        ])->save();

        $until = optional($sub->current_period_end)->format('d M Y');

        return [true, "Auto-renew is off. You keep access until {$until}."];
    }

    public function renewIfDue(ProSubscription $sub): void
    {
        if (! $sub->auto_renew || $sub->status !== ProSubscription::STATUS_ACTIVE) {
            return;
        }
        if ($sub->current_period_end && $sub->current_period_end->isFuture()) {
            return;
        }

        $user = $sub->user;
        if (! $user) {
            return;
        }

        $planLabel = $sub->plan === ProSubscription::PLAN_ENTERPRISE ? 'Business' : 'Pro';
        $reference = 'events-'.$sub->plan.'-'.$user->id.'-'.now()->format('YmdHis').'-'.Str::random(6);
        $result = $this->billing->charge($user, $sub->price_minor, $reference, "Ladill Events {$planLabel} — renewal");

        if ($result['ok']) {
            $sub->forceFill([
                'current_period_end' => Carbon::now()->addDays((int) config('events.pro.period_days', 30)),
                'last_charged_at' => now(),
                'last_reference' => $reference,
                'last_error' => null,
            ])->save();

            return;
        }

        $graceEnd = optional($sub->current_period_end)->addDays((int) config('events.pro.grace_days', 3));
        if ($graceEnd && $graceEnd->isPast()) {
            $sub->forceFill(['status' => ProSubscription::STATUS_PAST_DUE, 'last_error' => $result['error']])->save();
        } else {
            $sub->forceFill(['last_error' => $result['error']])->save();
        }
    }

    /** @return array{0:bool,1:string} */
    private function activateWalletPlan(User $user, string $plan, int $price, string $description, string $successMessage): array
    {
        $existing = $this->subscriptionFor($user);
        $reference = 'events-'.$plan.'-'.$user->id.'-'.now()->format('YmdHis').'-'.Str::random(6);
        $result = $this->billing->charge($user, $price, $reference, $description);

        if (! $result['ok']) {
            if ($result['insufficient']) {
                $bal = number_format(((int) $result['balance_minor']) / 100, 2);

                return [false, "Your wallet balance (GHS {$bal}) is too low. Top up, then subscribe."];
            }

            return [false, $result['error'] ?? 'Could not start your subscription. Please try again.'];
        }

        $periodEnd = Carbon::now()->addDays((int) config('events.pro.period_days', 30));
        ProSubscription::updateOrCreate(
            ['user_id' => $user->id],
            [
                'plan' => $plan,
                'status' => ProSubscription::STATUS_ACTIVE,
                'price_minor' => $price,
                'currency' => (string) config('events.pro.currency', 'GHS'),
                'auto_renew' => true,
                'started_at' => $existing?->started_at ?? now(),
                'current_period_end' => $periodEnd,
                'last_charged_at' => now(),
                'canceled_at' => null,
                'last_reference' => $reference,
                'last_error' => null,
            ],
        );

        return [true, $successMessage.' Your subscription is active.'];
    }
}