<?php

namespace Modules\EcommerceFinance\Repositories;

use Illuminate\Support\Facades\Schema;
use Modules\EcommerceFinance\Services\JushuitanCostPriceSnapshotDiffer;

class JushuitanCostPriceObservationRepository
{
    public function __construct(private readonly GenericBusinessMirrorRepository $mirror) {}

    /** 仅当前页每个源商品最近 20 条观测；不混入正式财务取价历史。 */
    public function attach(array $rows): void
    {
        foreach ($rows as $row) {
            $row->jushuitan_cost_price_observations = [];
        }
        $db = $this->mirror->connection();
        if ($rows === [] || ! Schema::connection($db->getName())->hasTable(JushuitanCostPriceSnapshotDiffer::OBSERVATIONS)) {
            return;
        }
        $keys = collect($rows)->pluck('_mirror_key')->filter()->unique()->values()->all();
        if ($keys === []) {
            return;
        }
        $ranked = $db->table(JushuitanCostPriceSnapshotDiffer::OBSERVATIONS)
            ->whereIn('source_key', $keys)
            ->select('*')->selectRaw('ROW_NUMBER() OVER (PARTITION BY source_key ORDER BY observed_at DESC, id DESC) AS observation_rank');
        $events = $db->query()->fromSub($ranked, 'ranked')->where('observation_rank', '<=', 20)
            ->orderBy('observed_at', 'desc')->get()->groupBy('source_key');
        foreach ($rows as $row) {
            $row->jushuitan_cost_price_observations = ($events->get($row->_mirror_key ?? '') ?? collect())->map(static fn ($event) => [
                'id' => $event->id, 'source' => '镜像价格观测（非完整改价历史）',
                'record_type_label' => '观测到成本价变化', 'effect_start_time' => $event->observed_at,
                'before_price' => $event->before_price, 'after_price' => $event->after_price,
                'diff_amount' => (float) $event->after_price - (float) $event->before_price,
                'operator' => '-', 'operation' => '镜像快照比较',
                'remark' => '上次观测：' . $event->previous_observed_at . '；本次为发现时间，不是真实改价时间。',
            ])->all();
        }
    }
}