<?php

namespace App\Business;

use App\Models\Business\CourierAgreementSignature;
use Illuminate\Pagination\LengthAwarePaginator;
use Illuminate\Support\Carbon;
use Illuminate\Support\Facades\Schema;
use Illuminate\Support\Facades\Storage;
use Throwable;

/** Read the signed snapshot directly: no duplicate contracts, attachment copies or archive backfill. */
class CourierContractPageData
{
    public const REMINDER_DAYS = 30;

    public const STATUSES = [
        'due' => '即将到期',
        'expired' => '约定期限已届满',
        'active' => '有效期内',
        'upcoming' => '未到开始日期',
        'unknown' => '期限待核对',
    ];

    public function page(bool $includeRows = true): array
    {
        $search = mb_substr(trim((string) request()->query('contract_search', '')), 0, 255);
        $status = (string) request()->query('contract_status', '');
        $status = array_key_exists($status, self::STATUSES) ? $status : '';
        $from = $this->date(request()->query('contract_end_from'));
        $to = $this->date(request()->query('contract_end_to'));
        if ($from && $to && $from > $to) {
            [$from, $to] = [$to, $from];
        }
        $filters = ['contract_search' => $search, 'contract_status' => $status,
            'contract_end_from' => $from ?? '', 'contract_end_to' => $to ?? ''];
        $limit = min(max((int) setting('default.list_limit', 25), 1), 100);
        $page = max((int) request()->query('page', 1), 1);
        $options = ['path' => request()->url(), 'query' => request()->except('page')];
        $data = [
            'courierContractFilters' => $filters,
            'courierContractRows' => new LengthAwarePaginator([], 0, $limit, $page, $options),
            'courierContractCounts' => array_fill_keys(array_keys(self::STATUSES), 0),
            'courierContractUnreadable' => 0,
            'courierContractError' => null,
        ];

        try {
            if (! Schema::hasTable('business_courier_agreement_signatures')) {
                $data['courierContractError'] = '协议签署数据表尚未建立，合同管理暂时无法读取。';
                return $data;
            }

            $matched = [];
            $today = Carbon::today(config('app.timezone'));
            // Dates and partner types are encrypted. Stream bounded chunks instead of SQL JSON queries
            // or persisting a second, potentially stale copy of the signed business snapshot.
            $signatures = CourierAgreementSignature::query()->where('company_id', (int) company_id())
                ->where('document_type', 'cooperation-contract')->where('status', CourierAgreementSignature::STATUS_ARCHIVED)
                ->select(['id', 'company_id', 'business_no', 'courier_name', 'payload', 'document_type', 'status',
                    'signed_pdf_path', 'certificate_path', 'archived_at', 'created_by', 'created_at'])
                ->lazyById(250);
            foreach ($signatures as $signature) {
                $payload = $signature->archivedCourierContractPayload();
                if ($payload === null) {
                    try {
                        $signature->payload;
                    } catch (Throwable) {
                        $data['courierContractUnreadable']++;
                    }
                    continue;
                }
                $row = $this->snapshot($signature, $payload, $today);
                $data['courierContractCounts'][$row['status']]++;
                if (! $includeRows || ($status !== '' && $status !== $row['status'])) {
                    continue;
                }
                if (($from && (! $row['end_date'] || $row['end_date'] < $from))
                    || ($to && (! $row['end_date'] || $row['end_date'] > $to))) {
                    continue;
                }
                if ($search !== '' && ! str_contains(mb_strtolower(implode(' ', [
                    $row['courier_name'], $row['number'], $row['business_no'], $row['party_a'], $row['party_b'],
                ])), mb_strtolower($search))) {
                    continue;
                }
                $matched[] = $row;
            }
            if ($includeRows) {
                $priority = ['due' => 0, 'expired' => 1, 'unknown' => 2, 'active' => 3, 'upcoming' => 4];
                usort($matched, static fn (array $a, array $b): int =>
                    [$priority[$a['status']], $a['end_date'] ?? '9999-12-31', -$a['id']]
                    <=> [$priority[$b['status']], $b['end_date'] ?? '9999-12-31', -$b['id']]);
                $total = count($matched);
                $items = array_slice($matched, ($page - 1) * $limit, $limit);
                $owners = user_model_class()::query()->whereIn('id', array_filter(array_column($items, 'created_by')))
                    ->pluck('name', 'id');
                foreach ($items as &$row) {
                    $row['creator'] = $owners[$row['created_by']] ?? '未记录';
                    $row['has_signed_file'] = $this->listedFileAvailable($row['signed_path']);
                    $row['has_certificate'] = $this->listedFileAvailable($row['certificate_path']);
                    unset($row['signed_path'], $row['certificate_path']);
                }
                unset($row);
                $data['courierContractRows'] = new LengthAwarePaginator($items, $total, $limit, $page, $options);
            }
        } catch (Throwable $exception) {
            report($exception);
            $data['courierContractCounts'] = array_fill_keys(array_keys(self::STATUSES), 0);
            $data['courierContractError'] = '归档合同暂时无法读取，请稍后重试。';
        }

        return $data;
    }

    private function snapshot(CourierAgreementSignature $signature, array $payload, Carbon $today): array
    {
        $start = $this->date($payload['cooperation_start_date'] ?? null);
        $end = $this->date($payload['cooperation_end_date'] ?? null);
        $days = $end ? (int) $today->diffInDays(Carbon::parse($end, config('app.timezone')), false) : null;
        $status = match (true) {
            ! $start || ! $end || $start > $end => 'unknown',
            $end < $today->toDateString() => 'expired',
            $start > $today->toDateString() => 'upcoming',
            $days <= self::REMINDER_DAYS => 'due',
            default => 'active',
        };
        $person = ($payload['counterparty_signer_type'] ?? 'organization') === 'person';

        return [
            'id' => (int) $signature->id,
            'courier_name' => (string) $signature->courier_name,
            'business_no' => (string) $signature->business_no,
            'number' => trim((string) ($payload['cooperation_contract_number'] ?? '')),
            'party_a' => trim((string) ($payload['cooperation_party_a_name'] ?? '')),
            'party_b' => trim((string) ($payload['cooperation_party_b_name'] ?? '')),
            'legal_representative' => $person ? '不适用（个人签署）' : trim((string) ($payload['cooperation_party_b_legal_representative'] ?? '')),
            'start_date' => $start, 'end_date' => $end, 'days' => $status === 'unknown' ? null : $days,
            'status' => $status, 'created_by' => $signature->created_by,
            'created_at' => $signature->created_at, 'archived_at' => $signature->archived_at,
            'signed_path' => $signature->signed_pdf_path, 'certificate_path' => $signature->certificate_path,
        ];
    }

    private function date(mixed $value): ?string
    {
        if (! is_string($value) || ! preg_match('/^\d{4}-\d{2}-\d{2}$/', $value)) {
            return null;
        }
        [$year, $month, $day] = array_map('intval', explode('-', $value));
        return checkdate($month, $day, $year) ? $value : null;
    }

    private function listedFileAvailable(?string $path): bool
    {
        if (blank($path)) {
            return false;
        }
        // Do not issue up to 50 sequential object-storage HEAD requests for one list page.
        // Downloads always verify the actual file; local files can be checked cheaply here.
        return config('filesystems.disks.uploads.driver') !== 'local' || Storage::disk('uploads')->exists($path);
    }
}