<?php

namespace App\Business;

use Illuminate\Database\DatabaseManager;
use InvalidArgumentException;
use RuntimeException;

/**
 * 聚水潭订单标签明细导入（从共享镜像 ops_jst_orders 拆标签写入 jst_order_labels）。
 *
 * 一个标签一行：一单有 N 个标签就写 N 行；订单不去重、标签不汇总。
 * 无标签的订单保留一行，标签记为「（无标签）」，方便与订单总数核对。
 */
class JstOrderLabelImporter
{
    public const NO_LABEL = '（无标签）';

    private const READ_CHUNK = 2000;

    private const INSERT_CHUNK = 2000;

    public function __construct(private readonly DatabaseManager $databases) {}

    /**
     * @return array{from:string,to:string,orders:int,rows:int,no_label_orders:int,labels:int,seconds:float}
     */
    public function import(string $from, string $to, int $companyId = 1, bool $replace = false, string $source = 'jst-order-label-import'): array
    {
        $from = $this->normalizeDate($from, '起始日期');
        $to = $this->normalizeDate($to, '结束日期');
        if ($from > $to) {
            throw new InvalidArgumentException('起始日期不能晚于结束日期。');
        }

        $start = $from . ' 00:00:00';
        $end = date('Y-m-d', strtotime($to . ' +1 day')) . ' 00:00:00';

        $mirror = $this->databases->connection(config('upstream_mirrors.connection', 'business_mirror'));
        if (! $mirror->getSchemaBuilder()->hasTable('ops_jst_orders')) {
            throw new RuntimeException('聚水潭订单镜像尚未建立（ops_jst_orders）。');
        }

        $target = $this->databases->connection();
        $startedAt = microtime(true);

        if ($replace) {
            $target->table('jst_order_labels')
                ->where('company_id', $companyId)
                ->where('ordered_at', '>=', $start)
                ->where('ordered_at', '<', $end)
                ->delete();
        }

        $now = now();
        $orders = 0;
        $rows = 0;
        $noLabelOrders = 0;
        $buffer = [];

        $flush = function () use (&$buffer, &$rows, $target): void {
            foreach (array_chunk($buffer, self::INSERT_CHUNK) as $chunk) {
                $target->table('jst_order_labels')->insert($chunk);
                $rows += count($chunk);
            }
            $buffer = [];
        };

        $mirror->table('ops_jst_orders')
            ->where('order_date', '>=', $start)
            ->where('order_date', '<', $end)
            ->orderBy('Id')
            ->chunkById(self::READ_CHUNK, function ($records) use (&$buffer, &$orders, &$noLabelOrders, $flush, $companyId, $source, $now): void {
                foreach ($records as $record) {
                    $orders++;
                    $orderedAt = $record->order_date === null ? null : substr((string) $record->order_date, 0, 19);
                    if ($orderedAt === null || $orderedAt === '') {
                        continue;
                    }

                    $labels = $this->splitLabels((string) ($record->labels ?? ''));
                    if ($labels === []) {
                        $labels = [self::NO_LABEL];
                        $noLabelOrders++;
                    }

                    foreach ($labels as $label) {
                        $buffer[] = [
                            'company_id' => $companyId,
                            'order_no' => mb_substr((string) $record->so_id, 0, 100),
                            'shop_name' => mb_substr((string) ($record->shop_name ?? ''), 0, 191),
                            'ordered_at' => $orderedAt,
                            'label' => $label,
                            'created_from' => $source,
                            'created_at' => $now,
                            'updated_at' => $now,
                        ];
                    }

                    if (count($buffer) >= self::INSERT_CHUNK * 2) {
                        $flush();
                    }
                }
            }, 'Id');

        $flush();

        $labels = $target->table('jst_order_labels')
            ->where('company_id', $companyId)
            ->where('ordered_at', '>=', $start)
            ->where('ordered_at', '<', $end)
            ->distinct()
            ->count('label');

        // 导入会改变筛选选项，重新预热缓存，避免页面下次打开时做几秒的 distinct 扫描。
        app(JstOrderLabelOptions::class)->forget($companyId);
        app(JstOrderLabelOptions::class)->warm($companyId);

        return [
            'from' => $from,
            'to' => $to,
            'orders' => $orders,
            'rows' => $rows,
            'no_label_orders' => $noLabelOrders,
            'labels' => (int) $labels,
            'seconds' => round(microtime(true) - $startedAt, 1),
        ];
    }

    /** @return list<string> */
    private function splitLabels(string $labels): array
    {
        $out = [];
        foreach (explode(',', $labels) as $label) {
            $label = trim($label);
            if ($label !== '') {
                $out[] = mb_substr($label, 0, 191);
            }
        }

        return array_values(array_unique($out));
    }

    private function normalizeDate(string $value, string $label): string
    {
        $value = trim($value);
        if (preg_match('/^\d{4}-\d{2}-\d{2}$/', $value) !== 1) {
            throw new InvalidArgumentException($label . '必须是 YYYY-MM-DD。');
        }

        [$year, $month, $day] = array_map('intval', explode('-', $value));
        if (! checkdate($month, $day, $year)) {
            throw new InvalidArgumentException($label . '不是有效日期。');
        }

        return $value;
    }
}