<?php

namespace App\Services\Draw;

use Carbon\Carbon;
use App\Models\Draw;
use App\Models\RiskPool;
use App\Lottery\DrawStatus;
use App\Models\DrawResultItem;
use App\Models\DrawResultBatch;
use App\Lottery\DrawResultBatchStatus;
use App\Services\Jackpot\JackpotSummaryService;

/**
 * `GET draw/current` 与大厅 WS 快照共用数据结构。
 *
 * @return array<string, mixed>|null
 */
final class DrawHallSnapshotBuilder
{
    public function __construct(
        private readonly JackpotSummaryService $jackpotSummary,
    ) {}

    /**
     * Tick 未及时跑时，DB 仍为 `open` 但已到封盘时刻；对外快照与界面应对齐真实可下注态（见 DrawTickService::openToClosingOrClosed）。
     *
     * 后台「当前大厅可见状态」预览可共用本方法。
     */
    public function effectiveHallDisplayStatus(Draw $target, Carbon $nowUtc): string
    {
        $db = (string) $target->status;
        if ($db !== DrawStatus::Open->value) {
            return $db;
        }

        $closeUtc = $target->close_time;
        if (! $closeUtc instanceof Carbon || $closeUtc > $nowUtc) {
            return $db;
        }

        $drawUtc = $target->draw_time;
        if ($drawUtc instanceof Carbon && $drawUtc <= $nowUtc) {
            return DrawStatus::Closed->value;
        }

        return DrawStatus::Closing->value;
    }

    private function showsPublishedResults(string $drawStatus): bool
    {
        return in_array($drawStatus, [
            DrawStatus::Cooldown->value,
            DrawStatus::Settling->value,
            DrawStatus::Settled->value,
        ], true);
    }

    /** 与 {@see build()} 使用同一套「大厅指向的当期行」 */
    public function resolveHallTarget(?Carbon $nowUtc = null): ?Draw
    {
        $nowUtc = ($nowUtc ?? Carbon::now())->utc();

        $bettingOpen = Draw::query()
            ->where('status', DrawStatus::Open->value)
            ->where(function ($q) use ($nowUtc): void {
                $q->whereNull('close_time')
                    ->orWhere('close_time', '>', $nowUtc);
            })
            ->orderBy('draw_time')
            ->first();

        $chronological = Draw::query()
            ->whereNotIn('status', [
                DrawStatus::Settled->value,
                DrawStatus::Cancelled->value,
            ])
            ->orderBy('draw_time')
            ->first();

        return $bettingOpen ?? $chronological;
    }

    /**
     * {@see DrawTickService} 发 `draw.status_change` 用：按 **数据库** `draw_no`+`status`，不用展示态规范化。
     *
     * @return array{draw_no: string, status: string}|null
     */
    public function hallTargetFingerprint(?Carbon $nowUtc = null): ?array
    {
        $target = $this->resolveHallTarget($nowUtc);
        if ($target === null) {
            return null;
        }

        return [
            'draw_no' => (string) $target->draw_no,
            'status' => (string) $target->status,
        ];
    }

    /**
     * @return array<string, mixed>|null
     */
    public function build(?Carbon $nowUtc = null): ?array
    {
        $nowUtc = ($nowUtc ?? Carbon::now())->utc();

        $target = $this->resolveHallTarget($nowUtc);

        if ($target === null) {
            return null;
        }

        $closeUtc = $target->close_time;
        $secsToClose = ($closeUtc !== null && $closeUtc > $nowUtc)
            ? max(0, (int) $closeUtc->getTimestamp() - (int) $nowUtc->getTimestamp())
            : 0;

        $secsToDraw = ($target->draw_time !== null && $target->draw_time > $nowUtc)
            ? max(0, (int) $target->draw_time->getTimestamp() - (int) $nowUtc->getTimestamp())
            : 0;

        $coolingRemain = null;
        if (
            $target->cooling_end_time instanceof Carbon
            && $target->cooling_end_time > $nowUtc
        ) {
            $coolingRemain = max(
                0,
                (int) $target->cooling_end_time->getTimestamp() - (int) $nowUtc->getTimestamp(),
            );
        }

        $effectiveStatus = $this->effectiveHallDisplayStatus($target, $nowUtc);

        $payload = [
            'draw_no' => $target->draw_no,
            'business_date' => $target->business_date instanceof Carbon
                ? $target->business_date->format('Y-m-d')
                : (string) $target->business_date,
            'sequence_no' => (int) $target->sequence_no,
            'status' => $effectiveStatus,
            'start_time' => $target->start_time?->toIso8601String(),
            'close_time' => $target->close_time?->toIso8601String(),
            'draw_time' => $target->draw_time?->toIso8601String(),
            'seconds_to_close' => $secsToClose,
            'seconds_to_draw' => $secsToDraw,
            'cooling_end_time' => $target->cooling_end_time?->toIso8601String(),
            'seconds_remaining_in_cooldown' => $coolingRemain,
            'jackpot' => $this->jackpotSummary->summary('NPR'),
        ];

        $riskAlerts = RiskPool::query()
            ->where('draw_id', $target->id)
            ->where(function ($q): void {
                $q->where('sold_out_status', 1)
                    ->orWhereRaw('(locked_amount * 1.0 / NULLIF(total_cap_amount, 0)) >= 0.8');
            })
            ->orderByRaw('(locked_amount * 1.0 / NULLIF(total_cap_amount, 0)) DESC')
            ->orderByDesc('locked_amount')
            ->orderBy('normalized_number')
            ->limit(500)
            ->get(['normalized_number', 'total_cap_amount', 'locked_amount', 'remaining_amount', 'sold_out_status'])
            ->map(fn ($row) => [
                'normalized_number' => (string) $row->normalized_number,
                'total_cap_amount' => (int) $row->total_cap_amount,
                'locked_amount' => (int) $row->locked_amount,
                'remaining_amount' => (int) $row->remaining_amount,
                'sold_out_status' => (int) $row->sold_out_status,
                'is_sold_out' => (int) $row->sold_out_status === 1,
                'usage_ratio' => (int) $row->total_cap_amount > 0
                    ? round(((int) $row->locked_amount) / (int) $row->total_cap_amount, 6)
                    : null,
            ])
            ->values()
            ->all();

        $payload['risk_pool_alerts'] = $riskAlerts;

        if ($this->showsPublishedResults((string) $target->status)) {
            $batchId = DrawResultBatch::query()
                ->where('draw_id', $target->id)
                ->where('result_version', (int) $target->current_result_version)
                ->where('status', DrawResultBatchStatus::Published->value)
                ->value('id');

            if ($batchId !== null) {
                $payload['result_items'] = DrawResultItem::query()
                    ->where('result_batch_id', $batchId)
                    ->orderBy('prize_type')
                    ->orderBy('prize_index')
                    ->get([
                        'prize_type', 'prize_index',
                        'number_4d', 'suffix_3d', 'suffix_2d', 'head_digit', 'tail_digit',
                    ])
                    ->map(fn ($row) => [
                        'prize_type' => $row->prize_type,
                        'prize_index' => (int) $row->prize_index,
                        'number_4d' => $row->number_4d,
                        'suffix_3d' => $row->suffix_3d,
                        'suffix_2d' => $row->suffix_2d,
                        'head_digit' => $row->head_digit,
                        'tail_digit' => $row->tail_digit,
                    ])
                    ->values()
                    ->all();
            }

            $payload['result_version'] = (int) $target->current_result_version;
            $payload['result_source'] = $target->result_source;
        }

        return $payload;
    }
}