<?php

namespace App\Filament\Pages;

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

/**
 * Scheduled Giving Command Centre.
 *
 * Campaigns are seasonal (Ramadan). Each subscription belongs to a specific year.
 * "Current season" = has future payments. "Expired" = all payments in the past.
 * Only shows REAL subscribers (has customer + payments + amount > 0 + not soft-deleted).
 */
class ScheduledGivingDashboard extends Page
{
    protected static ?string $navigationIcon = 'heroicon-o-calendar-days';

    protected static ?string $navigationGroup = 'Giving';

    protected static ?int $navigationSort = 0;

    protected static ?string $navigationLabel = 'Dashboard';

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

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

    /** Real subscriber IDs (has customer + payments + amount > 0 + not soft-deleted) */
    private function realSubscriberIds(?int $campaignId = null)
    {
        $q = DB::table('scheduled_giving_donations as d')
            ->whereNotNull('d.customer_id')
            ->where('d.total_amount', '>', 0)
            ->whereNull('d.deleted_at')
            ->whereExists(function ($sub) {
                $sub->select(DB::raw(1))
                    ->from('scheduled_giving_payments as p')
                    ->whereColumn('p.scheduled_giving_donation_id', 'd.id')
                    ->whereNull('p.deleted_at');
            });

        if ($campaignId) {
            $q->where('d.scheduled_giving_campaign_id', $campaignId);
        }

        return $q->pluck('d.id');
    }

    /** IDs with at least one future payment = current season */
    private function currentSeasonIds(?int $campaignId = null)
    {
        $realIds = $this->realSubscriberIds($campaignId);
        if ($realIds->isEmpty()) return collect();

        return DB::table('scheduled_giving_donations as d')
            ->whereIn('d.id', $realIds)
            ->whereExists(function ($sub) {
                $sub->select(DB::raw(1))
                    ->from('scheduled_giving_payments as p')
                    ->whereColumn('p.scheduled_giving_donation_id', 'd.id')
                    ->whereNull('p.deleted_at')
                    ->whereRaw('p.expected_at > NOW()');
            })
            ->pluck('d.id');
    }

    public function getCampaignData(): array
    {
        $campaigns = ScheduledGivingCampaign::all();
        $result = [];

        foreach ($campaigns as $c) {
            $realIds = $this->realSubscriberIds($c->id);
            if ($realIds->isEmpty()) {
                $result[] = $this->emptyCampaign($c);
                continue;
            }

            $currentIds = $this->currentSeasonIds($c->id);
            $expiredIds = $realIds->diff($currentIds);

            // Current season payment stats — separate due vs future
            $currentPayments = null;
            if ($currentIds->isNotEmpty()) {
                $currentPayments = DB::table('scheduled_giving_payments')
                    ->whereIn('scheduled_giving_donation_id', $currentIds)
                    ->whereNull('deleted_at')
                    ->selectRaw("
                        COUNT(*) as total,
                        SUM(is_paid = 1) as paid,
                        SUM(is_paid = 0 AND expected_at <= NOW()) as failed,
                        SUM(is_paid = 0 AND expected_at > NOW()) as scheduled,
                        SUM(expected_at <= NOW()) as due,
                        SUM(CASE WHEN is_paid = 1 THEN amount ELSE 0 END) as collected,
                        SUM(CASE WHEN is_paid = 0 AND expected_at <= NOW() THEN amount ELSE 0 END) as failed_amount,
                        SUM(CASE WHEN is_paid = 0 AND expected_at > NOW() THEN amount ELSE 0 END) as scheduled_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
                    ")
                    ->first();
            }

            // All-time payment stats (for totals)
            $allPayments = DB::table('scheduled_giving_payments')
                ->whereIn('scheduled_giving_donation_id', $realIds)
                ->whereNull('deleted_at')
                ->selectRaw("
                    SUM(CASE WHEN is_paid = 1 THEN amount ELSE 0 END) as collected,
                    SUM(CASE WHEN is_paid = 1 THEN 1 ELSE 0 END) as paid,
                    COUNT(*) as total
                ")
                ->first();

            // Completion for current season
            $totalNights = count($c->dates ?? []);
            $fullyPaid = 0;
            if ($totalNights > 0 && $currentIds->isNotEmpty()) {
                $ids = $currentIds->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;
            }

            $due = (int) ($currentPayments->due ?? 0);
            $paid = (int) ($currentPayments->paid ?? 0);

            $result[] = [
                'campaign' => $c,
                'all_time_subscribers' => $realIds->count(),
                'all_time_collected' => ($allPayments->collected ?? 0) / 100,
                'all_time_payments' => (int) ($allPayments->total ?? 0),
                'all_time_paid' => (int) ($allPayments->paid ?? 0),
                // Current season
                'current_subscribers' => $currentIds->count(),
                'expired_subscribers' => $expiredIds->count(),
                'total_payments' => (int) ($currentPayments->total ?? 0),
                'due_payments' => $due,
                'paid_payments' => $paid,
                'failed_payments' => (int) ($currentPayments->failed ?? 0),
                'scheduled_payments' => (int) ($currentPayments->scheduled ?? 0),
                'collected' => ($currentPayments->collected ?? 0) / 100,
                'failed_amount' => ($currentPayments->failed_amount ?? 0) / 100,
                'scheduled_amount' => ($currentPayments->scheduled_amount ?? 0) / 100,
                'avg_per_night' => ($currentPayments->avg_amount ?? 0) / 100,
                'collection_rate' => $due > 0 ? round($paid / $due * 100, 1) : 0,
                'fully_completed' => $fullyPaid,
                'dates' => $c->dates ?? [],
                'total_nights' => $totalNights,
                'next_payment' => $currentPayments->next_payment ?? null,
            ];
        }

        return $result;
    }

    public function getGlobalStats(): array
    {
        $realIds = $this->realSubscriberIds();
        $currentIds = $this->currentSeasonIds();

        $allTime = DB::table('scheduled_giving_payments')
            ->whereIn('scheduled_giving_donation_id', $realIds)
            ->whereNull('deleted_at')
            ->selectRaw("
                SUM(CASE WHEN is_paid = 1 THEN amount ELSE 0 END) / 100 as collected,
                SUM(CASE WHEN is_paid = 1 THEN 1 ELSE 0 END) as paid,
                COUNT(*) as total
            ")
            ->first();

        $currentStats = null;
        if ($currentIds->isNotEmpty()) {
            $currentStats = DB::table('scheduled_giving_payments')
                ->whereIn('scheduled_giving_donation_id', $currentIds)
                ->whereNull('deleted_at')
                ->selectRaw("
                    SUM(is_paid = 1) as paid,
                    SUM(expected_at <= NOW()) as due,
                    SUM(is_paid = 0 AND expected_at <= NOW()) as failed,
                    SUM(is_paid = 0 AND expected_at > NOW()) as scheduled,
                    SUM(CASE WHEN is_paid = 1 THEN amount ELSE 0 END) / 100 as collected,
                    SUM(CASE WHEN is_paid = 0 AND expected_at <= NOW() THEN amount ELSE 0 END) / 100 as failed_amount,
                    SUM(CASE WHEN is_paid = 0 AND expected_at > NOW() THEN amount ELSE 0 END) / 100 as scheduled_amount
                ")
                ->first();
        }

        $due = (int) ($currentStats->due ?? 0);
        $paid = (int) ($currentStats->paid ?? 0);

        return [
            'total_subscribers' => $realIds->count(),
            'current_subscribers' => $currentIds->count(),
            'expired_subscribers' => $realIds->count() - $currentIds->count(),
            'all_time_collected' => (float) ($allTime->collected ?? 0),
            'collected' => (float) ($currentStats->collected ?? 0),
            'failed_amount' => (float) ($currentStats->failed_amount ?? 0),
            'scheduled_amount' => (float) ($currentStats->scheduled_amount ?? 0),
            'failed_count' => (int) ($currentStats->failed ?? 0),
            'scheduled_count' => (int) ($currentStats->scheduled ?? 0),
            'due_payments' => $due,
            'paid_payments' => $paid,
            'collection_rate' => $due > 0 ? round($paid / $due * 100, 1) : 0,
        ];
    }

    public function getFailedPayments(): array
    {
        $currentIds = $this->currentSeasonIds();
        if ($currentIds->isEmpty()) return [];

        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')
            ->whereIn('d.id', $currentIds)
            ->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();
    }

    public function getUpcomingPayments(): array
    {
        $currentIds = $this->currentSeasonIds();
        if ($currentIds->isEmpty()) return [];

        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')
            ->whereIn('d.id', $currentIds)
            ->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();
    }

    public function getDataQuality(): array
    {
        $total = DB::table('scheduled_giving_donations')->count();
        $softDeleted = DB::table('scheduled_giving_donations')->whereNotNull('deleted_at')->count();
        $noCustomer = DB::table('scheduled_giving_donations')->whereNull('customer_id')->whereNull('deleted_at')->count();
        $noPayments = DB::table('scheduled_giving_donations as d')
            ->whereNull('d.deleted_at')
            ->whereNotNull('d.customer_id')
            ->whereNotExists(function ($q) {
                $q->select(DB::raw(1))
                    ->from('scheduled_giving_payments as p')
                    ->whereColumn('p.scheduled_giving_donation_id', 'd.id')
                    ->whereNull('p.deleted_at');
            })->count();
        $zeroAmount = DB::table('scheduled_giving_donations')
            ->whereNull('deleted_at')
            ->where('total_amount', '<=', 0)
            ->count();

        return [
            'total_records' => $total,
            'soft_deleted' => $softDeleted,
            'no_customer' => $noCustomer,
            'no_payments' => $noPayments,
            'zero_amount' => $zeroAmount,
        ];
    }

    private function emptyCampaign($c): array
    {
        return [
            'campaign' => $c,
            'all_time_subscribers' => 0, 'all_time_collected' => 0, 'all_time_payments' => 0, 'all_time_paid' => 0,
            'current_subscribers' => 0, 'expired_subscribers' => 0,
            'current_payments' => 0, 'current_paid' => 0, 'current_pending' => 0, 'current_failed' => 0,
            'current_collected' => 0, 'current_pending_amount' => 0, 'avg_per_night' => 0,
            'fully_completed' => 0, 'dates' => $c->dates ?? [], 'total_nights' => count($c->dates ?? []),
            'next_payment' => null,
        ];
    }
}