<?php

namespace App\Filament\Pages;

use App\Models\ScheduledGivingCampaign;
use App\Models\ScheduledGivingDonation;
use App\Models\ScheduledGivingPayment;
use Filament\Pages\Page;
use Illuminate\Support\Facades\DB;

/**
 * Scheduled Giving Command Centre.
 *
 * Three campaigns, three seasons, one dashboard.
 * Every number a supporter-care agent needs is on this page.
 */
class ScheduledGivingDashboard extends Page
{
    protected static ?string $navigationIcon = 'heroicon-o-calendar-days';

    protected static ?string $navigationGroup = 'Seasonal Campaigns';

    protected static ?int $navigationSort = 0;

    protected static ?string $navigationLabel = 'Campaign Dashboard';

    protected static ?string $title = 'Scheduled Giving';

    protected static string $view = 'filament.pages.scheduled-giving-dashboard';

    /**
     * Aggregate stats for every campaign, plus global totals.
     * Runs 3 efficient queries (not N+1).
     */
    public function getCampaignData(): array
    {
        $campaigns = ScheduledGivingCampaign::withCount([
            'donations',
            'donations as active_count' => fn ($q) => $q->where('is_active', true),
            'donations as cancelled_count' => fn ($q) => $q->where('is_active', false),
        ])->get();

        $result = [];

        foreach ($campaigns as $c) {
            $donationIds = $c->donations()->pluck('id');

            if ($donationIds->isEmpty()) {
                $result[] = [
                    'campaign' => $c,
                    'subscribers' => 0,
                    'active' => 0,
                    'cancelled' => 0,
                    'total_payments' => 0,
                    'paid_payments' => 0,
                    'pending_payments' => 0,
                    'failed_payments' => 0,
                    'collected' => 0,
                    'pending_amount' => 0,
                    'avg_per_night' => 0,
                    'completion_rate' => 0,
                    'dates' => $c->dates ?? [],
                    'next_payment' => null,
                    'last_payment' => null,
                ];
                continue;
            }

            $payments = DB::table('scheduled_giving_payments')
                ->whereIn('scheduled_giving_donation_id', $donationIds)
                ->whereNull('deleted_at')
                ->selectRaw("
                    COUNT(*) as total,
                    SUM(CASE WHEN is_paid = 1 THEN 1 ELSE 0 END) as paid,
                    SUM(CASE WHEN is_paid = 0 THEN 1 ELSE 0 END) as pending,
                    SUM(CASE WHEN is_paid = 0 AND attempts > 0 THEN 1 ELSE 0 END) as failed,
                    SUM(CASE WHEN is_paid = 1 THEN amount ELSE 0 END) as collected,
                    SUM(CASE WHEN is_paid = 0 THEN amount ELSE 0 END) as pending_amount,
                    AVG(CASE WHEN is_paid = 1 THEN amount ELSE NULL END) as avg_amount,
                    MIN(CASE WHEN is_paid = 0 AND expected_at > NOW() THEN expected_at ELSE NULL END) as next_payment,
                    MAX(CASE WHEN is_paid = 1 THEN expected_at ELSE NULL END) as last_payment
                ")
                ->first();

            // Completion: subscribers who paid ALL their payments
            $totalNights = count($c->dates ?? []);
            $fullyPaid = 0;
            if ($totalNights > 0 && $donationIds->isNotEmpty()) {
                $ids = $donationIds->implode(',');
                $row = DB::selectOne("SELECT COUNT(*) as cnt FROM (SELECT scheduled_giving_donation_id FROM scheduled_giving_payments WHERE scheduled_giving_donation_id IN ({$ids}) AND deleted_at IS NULL GROUP BY scheduled_giving_donation_id HAVING SUM(is_paid) >= {$totalNights}) sub");
                $fullyPaid = $row->cnt ?? 0;
            }

            $result[] = [
                'campaign' => $c,
                'subscribers' => $c->donations_count,
                'active' => $c->active_count,
                'cancelled' => $c->cancelled_count,
                'total_payments' => (int) $payments->total,
                'paid_payments' => (int) $payments->paid,
                'pending_payments' => (int) $payments->pending,
                'failed_payments' => (int) $payments->failed,
                'collected' => ($payments->collected ?? 0) / 100,
                'pending_amount' => ($payments->pending_amount ?? 0) / 100,
                'avg_per_night' => ($payments->avg_amount ?? 0) / 100,
                'completion_rate' => $c->active_count > 0
                    ? round($fullyPaid / $c->active_count * 100, 1)
                    : 0,
                'fully_completed' => $fullyPaid,
                'dates' => $c->dates ?? [],
                'total_nights' => $totalNights,
                'next_payment' => $payments->next_payment,
                'last_payment' => $payments->last_payment,
            ];
        }

        return $result;
    }

    /**
     * Global totals across all campaigns.
     */
    public function getGlobalStats(): array
    {
        $row = DB::table('scheduled_giving_payments')
            ->whereNull('deleted_at')
            ->selectRaw("
                COUNT(*) as total,
                SUM(CASE WHEN is_paid = 1 THEN 1 ELSE 0 END) as paid,
                SUM(CASE WHEN is_paid = 0 AND attempts > 0 THEN 1 ELSE 0 END) as failed,
                SUM(CASE WHEN is_paid = 1 THEN amount ELSE 0 END) / 100 as collected,
                SUM(CASE WHEN is_paid = 0 THEN amount ELSE 0 END) / 100 as pending
            ")
            ->first();

        $totalSubs = ScheduledGivingDonation::count();
        $activeSubs = ScheduledGivingDonation::where('is_active', true)->count();

        return [
            'total_subscribers' => $totalSubs,
            'active_subscribers' => $activeSubs,
            'total_payments' => (int) ($row->total ?? 0),
            'paid_payments' => (int) ($row->paid ?? 0),
            'failed_payments' => (int) ($row->failed ?? 0),
            'collected' => (float) ($row->collected ?? 0),
            'pending' => (float) ($row->pending ?? 0),
            'collection_rate' => $row->total > 0
                ? round($row->paid / $row->total * 100, 1)
                : 0,
        ];
    }

    /**
     * Recent failed payments needing attention.
     */
    public function getFailedPayments(): array
    {
        return DB::table('scheduled_giving_payments as p')
            ->join('scheduled_giving_donations as d', 'd.id', '=', 'p.scheduled_giving_donation_id')
            ->join('scheduled_giving_campaigns as c', 'c.id', '=', 'd.scheduled_giving_campaign_id')
            ->leftJoin('customers as cu', 'cu.id', '=', 'd.customer_id')
            ->where('p.is_paid', false)
            ->where('p.attempts', '>', 0)
            ->whereNull('p.deleted_at')
            ->orderByDesc('p.updated_at')
            ->limit(15)
            ->get([
                'p.id as payment_id',
                'p.amount',
                'p.expected_at',
                'p.attempts',
                'd.id as donation_id',
                'c.title as campaign',
                DB::raw("CONCAT(cu.first_name, ' ', cu.last_name) as donor_name"),
                'cu.email as donor_email',
            ])
            ->toArray();
    }

    /**
     * Upcoming payments in the next 48 hours.
     */
    public function getUpcomingPayments(): array
    {
        return DB::table('scheduled_giving_payments as p')
            ->join('scheduled_giving_donations as d', 'd.id', '=', 'p.scheduled_giving_donation_id')
            ->join('scheduled_giving_campaigns as c', 'c.id', '=', 'd.scheduled_giving_campaign_id')
            ->where('p.is_paid', false)
            ->where('p.attempts', 0)
            ->where('d.is_active', true)
            ->whereNull('p.deleted_at')
            ->whereBetween('p.expected_at', [now(), now()->addHours(48)])
            ->selectRaw("
                c.title as campaign,
                COUNT(*) as payment_count,
                SUM(p.amount) / 100 as total_amount,
                MIN(p.expected_at) as earliest
            ")
            ->groupBy('c.title')
            ->orderBy('earliest')
            ->get()
            ->toArray();
    }
}