<?php

namespace Modules\EcommerceFinance\View;

use Illuminate\Pagination\LengthAwarePaginator;
use Illuminate\Support\Facades\DB;
use Throwable;

/**
 * 财务经营报表 › 账单明细。
 *
 * 数据源与「账单流水数据 › 店铺收款账户账单」同源（各平台已导入账单表），
 * 财务备注 / 财务类型 由科目映射表按「平台 + 账单项目（wx 去前缀）」带出。
 *
 * 查询按「分支下推」组织：每个平台各自带日期和筛选走自己的索引；
 * 京东账单 / 京东钱包 / 抖音 再按 periods 表的 active_generation 拆成单版本分支，
 * 避免同一账期多版本重复计数，同时让每个分支都能用 (generation, occurred_at, record_code)
 * 索引直接排序取前 N 行，不再把整月数据物化成临时表再排序。
 */
class BillingDetailsPageData
{
    /**
     * 各平台账单表；periods 非空表示该表按 active_generation 区分版本，必须用 periods 表锁定当前版本。
     */
    private const SOURCES = [
        '淘系支付宝' => ['table' => 'taobao_alipay_bill_rows', 'date' => 'occurred_at', 'income' => 'income_amount', 'expense' => 'expense_amount', 'online_order' => 'online_order_no', 'merchant_order' => 'merchant_order_no', 'type' => null, 'periods' => null],
        '淘系微信' => ['table' => 'taobao_wechat_bill_rows', 'date' => 'occurred_at', 'income' => 'income_amount', 'expense' => 'expense_amount', 'online_order' => 'online_order_no', 'merchant_order' => 'pay_serial_no', 'type' => null, 'periods' => null],
        '拼多多' => ['table' => 'pdd_settlement_bill_rows', 'date' => 'occurred_at', 'income' => 'income_amount', 'expense' => 'expense_amount', 'online_order' => 'online_order_no', 'merchant_order' => 'merchant_order_no', 'type' => 'account_name', 'periods' => null],
        '京东账单' => ['table' => 'jd_daily_bill_rows', 'date' => 'occurred_at', 'income' => 'income', 'expense' => 'expense', 'online_order' => null, 'merchant_order' => null, 'type' => null, 'periods' => 'jd_daily_bill_periods'],
        '京东钱包' => ['table' => 'jd_wallet_bill_rows', 'date' => 'occurred_at', 'income' => 'income', 'expense' => 'expense', 'online_order' => null, 'merchant_order' => null, 'type' => 'account_name', 'periods' => 'jd_wallet_bill_periods'],
        '抖音' => ['table' => 'douyin_authoritative_bills', 'date' => 'occurred_at', 'income' => 'income', 'expense' => 'expense', 'online_order' => null, 'merchant_order' => null, 'type' => null, 'periods' => 'douyin_authoritative_periods'],
        '得物' => ['table' => 'dewu_settlement_bill_rows', 'date' => 'bill_date', 'income' => 'income_amount', 'expense' => 'expense_amount', 'online_order' => 'online_order_no', 'merchant_order' => 'order_no', 'type' => null, 'periods' => null],
    ];

    private const PLATFORM_PREFIX = [
        '天猫' => '天猫', '淘宝' => '淘宝', '京东' => '京东', '京喜' => '京喜', '京喜小店' => '京喜',
        '拼多多' => '拼多多', '抖音' => '抖音', '头条放心购' => '抖音', '得物' => '得物',
        '阿里巴巴' => '阿里巴巴', '新佰广1688' => '阿里巴巴', '淘工厂' => '阿里巴巴',
        '唯品会MP' => '唯品会MP', '唯品会JX' => '唯品会JX', '支付宝' => '支付宝',
    ];

    /**
     * 平台筛选：按「账户 / 数据来源」分类，与「店铺收款账户账单」各页签一致。
     * source 对应 self::SOURCES 的分支；prefix 非空时再按店铺前缀切分（京东账单 / 京喜账单同属一张表）。
     */
    private const PLATFORM_FILTERS = [
        '淘系支付宝' => ['source' => '淘系支付宝', 'prefix' => null],
        '淘系微信' => ['source' => '淘系微信', 'prefix' => null],
        '拼多多' => ['source' => '拼多多', 'prefix' => null],
        '京东账单' => ['source' => '京东账单', 'prefix' => '京东'],
        '京喜账单' => ['source' => '京东账单', 'prefix' => '京喜'],
        '京东网银钱包' => ['source' => '京东钱包', 'prefix' => null],
        '抖音' => ['source' => '抖音', 'prefix' => null],
        '得物' => ['source' => '得物', 'prefix' => null],
    ];

    public function page(): array
    {
        return [
            'view' => 'business.pages.financial-operations.billing-details',
            'options' => $this->options(),
            'columns' => self::COLUMNS,
        ] + $this->data();
    }

    /**
     * 页面与导出的列定义（顺序即默认显示顺序）：key => [标签, 类型]。
     */
    public const COLUMNS = [
        'record_code' => ['记录编码', 'text'],
        'store_name' => ['店铺', 'text'],
        'finance_remark' => ['财务备注', 'text'],
        'online_order_no' => ['线上单号', 'text'],
        'amount' => ['金额', 'num'],
        'bill_item' => ['账单项目', 'tag'],
        'merchant_order_no' => ['商户订单号', 'text'],
        'custom_remark' => ['自定义备注', 'text'],
        'finance_type' => ['财务类型', 'tag'],
        'type_text' => ['类型', 'text'],
        'occurred_at' => ['发生时间', 'text'],
        'income' => ['收入金额', 'num'],
        'expense' => ['支出金额', 'num'],
        'remark' => ['备注', 'text'],
    ];

    /** 导出用：按请求解析筛选条件（与页面同一套口径） */
    public function exportFilters(array $input): array
    {
        return $this->parseFilters($input);
    }

    /** 导出用：当前筛选下的总行数（进度百分比用） */
    public function exportTotal(array $filters): int
    {
        if ($filters === []) {
            return 0;
        }

        $parts = [];
        $bind = [];
        foreach (self::SOURCES as $label => $meta) {
            $branch = $this->branch($label, $meta, $filters);
            foreach ($branch['scopes'] as $scope) {
                $parts[] = 'SELECT COUNT(*) AS c FROM ' . $branch['table'] . ' WHERE ' . $scope['where'];
                $bind = array_merge($bind, $scope['bind']);
            }
        }

        $total = 0;
        foreach ($this->connection()->select(implode(' UNION ALL ', $parts), $bind) as $row) {
            $total += (int) $row->c;
        }

        return $total;
    }

    /**
     * 导出用：按 key 过滤列；不传即全部列。
     *
     * @param  list<string>  $keys
     * @return array<string,array{0:string,1:string}>
     */
    public function exportColumns(array $keys): array
    {
        if ($keys === []) {
            return self::COLUMNS;
        }
        $wanted = array_flip(array_map(static fn ($key): string => trim((string) $key), $keys));
        $columns = [];
        foreach (self::COLUMNS as $key => $definition) {
            if (isset($wanted[$key])) {
                $columns[$key] = $definition;
            }
        }

        return $columns === [] ? self::COLUMNS : $columns;
    }

    /**
     * 导出用：逐分支流式产出「页面同款」行（财务备注/财务类型已按科目映射表带出）。
     *
     * @param  array<string,mixed>  $filters
     * @return \Generator<array<string,string>>
     */
    public function exportRows(array $filters, array $columns = []): \Generator
    {
        $connection = $this->connection();
        $rules = $this->rules();

        foreach (self::SOURCES as $label => $meta) {
            $branch = $this->branch($label, $meta, $filters);
            // 只查导出要用的列：备注这类长文本不查，从镜像库搬的数据量能少好几倍
            $select = $columns === [] ? $branch['cols'] : $this->exportSelectList($meta, $columns);
            foreach ($branch['scopes'] as $scope) {
                // 用游标（非缓冲查询）逐行产出，避免上百万行一次性读进内存
                foreach ($connection->cursor(
                    'SELECT ' . $select . ' FROM ' . $branch['table'] . ' WHERE ' . $scope['where']
                    . ' ORDER BY ' . $branch['date'] . ' DESC, record_code DESC',
                    $scope['bind']
                ) as $raw) {
                    yield $this->presentRow((array) $raw, $rules);
                }
            }
        }
    }

    /**
     * 按导出列拼最小查询列表（别名与页面列一致）。
     *
     * @param  array<string,mixed>  $meta
     * @param  array<string,array{0:string,1:string}>  $columns
     */
    private function exportSelectList(array $meta, array $columns): string
    {
        $table = (string) $meta['table'];
        $has = fn (string $column): bool => in_array($column, $this->columns($table), true);
        $pick = static fn (?string $column): ?string => $column !== null && $column !== '' ? $column : null;
        $want = array_flip(array_keys($columns));
        $finance = isset($want['finance_remark']) || isset($want['finance_type']);

        $select = [];
        $add = static function (string $alias, ?string $expr) use (&$select): void {
            if ($expr === null || isset($select[$alias])) {
                return;
            }
            $select[$alias] = $expr === $alias ? $alias : $expr . ' AS ' . $alias;
        };

        if (isset($want['record_code'])) { $add('record_code', 'record_code'); }
        if (isset($want['store_name']) || $finance) { $add('store_name', 'store_name'); }
        if (isset($want['bill_item']) || $finance) { $add('bill_item', 'bill_item'); }
        if (isset($want['online_order_no'])) { $add('online_order_no', $pick(is_string($meta['online_order']) ? (string) $meta['online_order'] : null)); }
        if (isset($want['merchant_order_no'])) { $add('merchant_order_no', $pick(is_string($meta['merchant_order']) ? (string) $meta['merchant_order'] : null)); }
        if (isset($want['custom_remark'])) { $add('custom_remark', $has('custom_remark') ? 'custom_remark' : null); }
        if (isset($want['remark'])) { $add('remark', $has('remark') ? 'remark' : null); }
        if (isset($want['type_text'])) { $add('type_text', $pick(is_string($meta['type']) ? (string) $meta['type'] : null)); }
        if (isset($want['occurred_at'])) { $add('occurred_at', (string) $meta['date']); }
        if (isset($want['income']) || isset($want['amount'])) { $add('income', (string) $meta['income']); }
        if (isset($want['expense']) || isset($want['amount'])) { $add('expense', (string) $meta['expense']); }

        // 一列都没选到时至少取主键列，保证 SQL 合法
        return $select === [] ? 'record_code' : implode(', ', $select);
    }

    /**
     * 筛选下拉候选：店铺与账单项目（账单项目统一成去 wx 前缀后的名称，与带出财务备注/类型同一口径）。
     * 镜像每天只会新增数据，候选清单按 6 小时缓存，避免每次开页都做一次索引扫描。
     *
     * @return array{stores:list<string>,items:list<string>}
     */
    public function options(): array
    {
        try {
            return cache()->remember('billing-details-filter-options-v1', now()->addHours(6), function (): array {
                $stores = [];
                $items = [];
                foreach (self::SOURCES as $meta) {
                    $table = (string) $meta['table'];
                    try {
                        foreach ($this->connection()->select('SELECT DISTINCT store_name FROM ' . $table) as $row) {
                            $store = trim((string) $row->store_name);
                            if ($store !== '') { $stores[$store] = true; }
                        }
                        foreach ($this->connection()->select('SELECT DISTINCT bill_item FROM ' . $table) as $row) {
                            $item = $this->normalizeItem((string) $row->bill_item);
                            if ($item !== '') { $items[$item] = true; }
                        }
                    } catch (Throwable) {
                        continue;
                    }
                }

                $stores = array_keys($stores);
                $items = array_keys($items);
                sort($stores, SORT_NATURAL | SORT_FLAG_CASE);
                sort($items, SORT_NATURAL | SORT_FLAG_CASE);

                return ['stores' => $stores, 'items' => $items];
            });
        } catch (Throwable $exception) {
            report($exception);

            return ['stores' => [], 'items' => []];
        }
    }

    /** @return array<string,mixed> */
    public function data(?array $input = null): array
    {
        $input ??= request()->all();
        $filters = $this->parseFilters($input);

        $rows = [];
        $total = 0;
        $income = 0.0;
        $expense = 0.0;
        $status = null;
        $error = null;
        $limit = $this->perPage($input);
        $page = max((int) ($input['page'] ?? request('page', 1)), 1);
        $offset = ($page - 1) * $limit;

        try {
            $conn = DB::connection((string) config('upstream_mirrors.connection', 'business_mirror'));

            // 每个平台一个分支，日期与筛选已下推到分支内，可各自命中 (日期, record_code) 索引
            $branches = [];
            foreach (self::SOURCES as $label => $meta) {
                $branches[] = $this->branch($label, $meta, $filters);
            }

            // 汇总：按分支聚合并，避免把整月数据物化成临时表
            $summaryParts = [];
            $summaryBind = [];
            foreach ($branches as $branch) {
                foreach ($branch['scopes'] as $scope) {
                    $summaryParts[] = 'SELECT COUNT(*) AS c, COALESCE(SUM(' . $branch['income'] . '),0) AS inc, '
                        . 'COALESCE(SUM(' . $branch['expense'] . '),0) AS exp FROM ' . $branch['table']
                        . ' WHERE ' . $scope['where'];
                    $summaryBind = array_merge($summaryBind, $scope['bind']);
                }
            }
            foreach ($conn->select(implode(' UNION ALL ', $summaryParts), $summaryBind) as $part) {
                $total += (int) $part->c;
                $income += (float) $part->inc;
                $expense += (float) $part->exp;
            }

            // 明细：每个分支先用索引取自己的前 offset+limit 行，再合并排序，避免全量排序
            if ($total > 0 && $offset < $total) {
                $need = $offset + $limit;
                $rowParts = [];
                $rowBind = [];
                foreach ($branches as $branch) {
                    foreach ($branch['scopes'] as $scope) {
                        $rowParts[] = '(SELECT ' . $branch['cols'] . ' FROM ' . $branch['table']
                            . ' WHERE ' . $scope['where']
                            . ' ORDER BY ' . $branch['date'] . ' DESC, record_code DESC LIMIT ' . $need . ')';
                        $rowBind = array_merge($rowBind, $scope['bind']);
                    }
                }
                $rows = $conn->select(
                    implode(' UNION ALL ', $rowParts) . ' ORDER BY occurred_at DESC, record_code DESC LIMIT ' . $limit . ' OFFSET ' . $offset,
                    $rowBind
                );
            }
        } catch (Throwable $exception) {
            report($exception);
            $error = '账单明细数据暂时无法读取：' . $exception->getMessage();
        }

        $rules = $this->rules();
        $rows = array_map(fn ($row): array => $this->presentRow((array) $row, $rules), $rows);

        return [
            'filters' => $filters,
            'rows' => new LengthAwarePaginator($rows, $total, $limit, $page, [
                'path' => request()->url(),
                'query' => request()->except('page'),
            ]),
            'summary' => ['rows' => $total, 'income' => round($income, 2), 'expense' => round($expense, 2), 'net' => round($income - $expense, 2)],
            'platforms' => array_keys(self::PLATFORM_FILTERS),
            'types' => $this->types(),
            'error' => $error,
            'status' => $status,
        ];
    }

    /**
     * 组装单个平台分支：统一的输出列 + 每个账期版本一份「筛选已下推」的 WHERE。
     *
     * @param  array<string,mixed>  $meta
     * @param  array<string,string>  $filters
     * @return array{table:string,date:string,income:string,expense:string,cols:string,scopes:list<array{where:string,bind:list<mixed>}>}
     */
    private function branch(string $label, array $meta, array $filters): array
    {
        $table = (string) $meta['table'];
        $dateCol = (string) $meta['date'];
        $has = fn (string $column): bool => in_array($column, $this->columns($table), true);
        // 各平台账单表列不完全一致（京东/抖音没有 custom_remark、remark），缺的列统一留空
        $customRemark = $has('custom_remark') ? 'custom_remark' : "''";
        $remark = $has('remark') ? 'remark' : "''";
        $online = is_string($meta['online_order']) && $has((string) $meta['online_order']) ? (string) $meta['online_order'] : "''";
        $merchant = is_string($meta['merchant_order']) && $has((string) $meta['merchant_order']) ? (string) $meta['merchant_order'] : "''";
        $typeCol = is_string($meta['type']) && $has((string) $meta['type']) ? (string) $meta['type'] : "''";

        $cols = "'{$label}' AS source, record_code, store_name, {$customRemark} AS custom_remark, {$online} AS online_order_no, "
            . "bill_item, {$merchant} AS merchant_order_no, {$typeCol} AS type_text, {$dateCol} AS occurred_at, "
            . "{$meta['income']} AS income, {$meta['expense']} AS expense, {$remark} AS remark";

        // 公共筛选（不含日期）逐条下推到分支，让各表尽量用自己的索引
        $conditions = [];
        $bind = [];
        if ($filters['platform'] !== []) {
            // 平台按账户来源筛：先看这个分支被哪几个平台命中，没命中就直接排除整个分支
            $matched = [];
            foreach ($filters['platform'] as $platform) {
                $mapping = self::PLATFORM_FILTERS[$platform] ?? null;
                if ($mapping !== null && $mapping['source'] === $label) {
                    $matched[] = $mapping;
                }
            }

            if ($matched === []) {
                $conditions[] = '1 = 0';
            } else {
                $parts = [];
                foreach ($matched as $mapping) {
                    if ($mapping['prefix'] === null) {
                        $parts[] = '1 = 1';
                        continue;
                    }
                    $parts[] = 'store_name LIKE ?';
                    $bind[] = $mapping['prefix'] . '%';
                }
                $conditions[] = '(' . implode(' OR ', $parts) . ')';
            }
        }
        if ($filters['store'] !== []) {
            $conditions[] = 'store_name IN (' . $this->literals($filters['store']) . ')';
        }
        if ($filters['item'] !== []) {
            // 候选取自下拉清单（已去 wx 前缀），这里用同一套归一化表达式比对
            $conditions[] = $this->normalizedItemSql() . ' IN (' . $this->literals($filters['item']) . ')';
        }
        if ($filters['keyword'] !== '') {
            $keyword = '%' . $filters['keyword'] . '%';
            $haystack = [];
            foreach (array_unique(['record_code', $online, $merchant, 'bill_item', $customRemark, $remark]) as $column) {
                $haystack[] = $column . ' LIKE ?';
                $bind[] = $keyword;
            }
            $conditions[] = '(' . implode(' OR ', $haystack) . ')';
        }
        if ($filters['type'] !== []) {
            $allowed = $this->itemsForTypes($filters['type']);
            if ($allowed === []) {
                $conditions[] = '1 = 0';
            } else {
                // 与页面带出财务备注/类型时一致：wx 前缀的账单项目按去前缀后的名称归类。
                // 项目名以字面量内联：MySQL 对字面量 IN 列表会排序后二分查找，
                // 参数化 IN 会逐行线性比对，161 个项目 × 130 万行会退化到 30 秒以上。
                $conditions[] = $this->normalizedItemSql() . ' IN (' . $this->literals($allowed) . ')';
            }
        }

        $dateBind = $dateCol === 'bill_date'
            ? [$filters['start'], $filters['end']]
            : [$filters['start'] . ' 00:00:00', $filters['end'] . ' 23:59:59'];

        $scopes = [];
        foreach ($this->generations($meta['periods'] === null ? null : (string) $meta['periods'], $filters['start'], $filters['end']) as $generation) {
            $where = [];
            $scopeBind = [];
            if ($generation !== null) {
                $where[] = 'generation = ?';
                $scopeBind[] = $generation;
            }
            $where[] = "{$dateCol} >= ? AND {$dateCol} <= ?";
            $scopeBind = array_merge($scopeBind, $dateBind);
            foreach ($conditions as $condition) {
                $where[] = $condition;
            }
            $scopes[] = ['where' => implode(' AND ', $where), 'bind' => array_merge($scopeBind, $bind)];
        }

        return [
            'table' => $table,
            'date' => $dateCol,
            'income' => (string) $meta['income'],
            'expense' => (string) $meta['expense'],
            'cols' => $cols,
            'scopes' => $scopes,
        ];
    }

    /** @var array<string,list<string|null>> */
    private array $generationCache = [];

    private function connection(): \Illuminate\Database\Connection
    {
        return DB::connection((string) config('upstream_mirrors.connection', 'business_mirror'));
    }

    /**
     * 筛选值统一成字符串列表（表单提交的多选是数组；空值丢弃）。
     *
     * @return list<string>
     */
    private function values(mixed $raw): array
    {
        $list = is_array($raw) ? $raw : [$raw];
        $values = [];
        foreach ($list as $value) {
            $value = trim((string) $value);
            if ($value !== '' && ! in_array($value, $values, true)) {
                $values[] = $value;
            }
        }

        return array_slice($values, 0, 500);
    }

    /**
     * IN 列表以字面量内联（已按驱动转义）。
     * MySQL 对字面量 IN 会排序后二分查找，参数化 IN 会逐行线性比对；
     * 财务类型动辄上百个项目 × 上百万行，参数化会退化到 30 秒以上。
     *
     * @param  list<string>  $values
     */
    private function literals(array $values): string
    {
        $pdo = $this->connection()->getPdo();

        return implode(',', array_map(static fn (string $value): string => $pdo->quote($value), array_values(array_unique($values))));
    }

    /** 账单项目归一化：去掉 wx 前缀（与页面带出财务备注/类型时一致） */
    private function normalizeItem(string $item): string
    {
        $item = trim($item);

        return preg_match('/^wx/i', $item) === 1 ? ltrim(substr($item, 2)) : $item;
    }

    /**
     * 解析筛选条件（页面与导出共用同一套口径）。
     *
     * @param  array<string,mixed>  $input
     * @return array<string,mixed>
     */
    private function parseFilters(array $input): array
    {
        $now = now();
        $month = trim((string) ($input['month'] ?? '')) ?: $now->format('Y-m');
        $start = trim((string) ($input['start'] ?? '')) ?: $month . '-01';
        $end = trim((string) ($input['end'] ?? '')) ?: date('Y-m-t', strtotime($start));
        // 日期只接受 Y-m-d，避免拼进 SQL 的字符串被注入
        $start = preg_match('/^\d{4}-\d{2}-\d{2}$/', $start) === 1 ? $start : $now->format('Y-m-01');
        $end = preg_match('/^\d{4}-\d{2}-\d{2}$/', $end) === 1 ? $end : date('Y-m-t', strtotime($start));
        if ($end < $start) { $end = $start; }

        return [
            'month' => substr($start, 0, 7),
            'start' => $start,
            'end' => $end,
            'platform' => $this->values($input['platform'] ?? []),
            'store' => $this->values($input['store'] ?? []),
            'item' => $this->values($input['item'] ?? []),
            'type' => $this->values($input['type'] ?? []),
            'keyword' => trim((string) ($input['keyword'] ?? '')),
            'per_page' => $this->perPage($input),
        ];
    }

    /** 每页条数：只接受 10 / 20 / 50，缺省 20 */
    private function perPage(array $input): int
    {
        $size = (int) ($input['per_page'] ?? 20);

        return in_array($size, [10, 20, 50], true) ? $size : 20;
    }

    /**
     * 行展示口径：带出平台、财务备注、财务类型（页面与导出一致）。
     *
     * @param  array<string,mixed>  $row
     * @param  array<string,array{memo:string,category:string,catch:bool}>  $rules
     * @return array<string,mixed>
     */
    private function presentRow(array $row, array $rules): array
    {
        $shop = (string) ($row['store_name'] ?? '');
        $prefix = $shop === '' ? '' : explode('-', $shop)[0];
        $platform = self::PLATFORM_PREFIX[$prefix] ?? '';
        $item = trim((string) ($row['bill_item'] ?? ''));
        $normalized = $this->normalizeItem($item);
        $rule = $rules[$platform . '|' . $normalized] ?? ($rules[$platform . '|' . $item] ?? null);

        $row['platform'] = $platform;
        $row['finance_remark'] = $rule['memo'] ?? '';
        $row['finance_type'] = $rule['category'] ?? '';
        $row['matched'] = $rule !== null;

        return $row;
    }

    private function normalizedItemSql(): string
    {
        return "(CASE WHEN bill_item LIKE 'wx%' THEN LTRIM(SUBSTRING(bill_item, 3)) ELSE bill_item END)";
    }

    /**
     * 取与查询区间有交集的账期的 active_generation（与 JD / 抖音账单页仓储同一口径）。
     *
     * 只取相交账期，可保证分支数量不随镜像历史累积增长；
     * 账期信息不可用时退回 [null]，表示该分支不区分版本。
     *
     * @return list<string|null>
     */
    private function generations(?string $periodsTable, string $start, string $end): array
    {
        if ($periodsTable === null) {
            return [null];
        }
        $cacheKey = $periodsTable . '|' . $start . '|' . $end;
        if (array_key_exists($cacheKey, $this->generationCache)) {
            return $this->generationCache[$cacheKey];
        }
        try {
            $connection = $this->connection();
            $columns = array_map(static fn ($column): string => (string) $column->Field, $connection->select('SHOW COLUMNS FROM ' . $periodsTable));
            $active = $connection->table($periodsTable)->distinct()->orderBy('active_generation');
            if (in_array('period_start', $columns, true) && in_array('period_end', $columns, true)) {
                $active->where('period_start', '<=', $end)->where('period_end', '>=', $start);
            }
            $generations = $active->pluck('active_generation')
                ->filter(static fn ($generation): bool => is_string($generation) && $generation !== '')
                ->values()
                ->all();
            if ($generations === []) {
                // 查询区间与任何账期都不相交时，退回全部在用版本，保证不漏数
                $generations = $connection->table($periodsTable)->distinct()->orderBy('active_generation')
                    ->pluck('active_generation')
                    ->filter(static fn ($generation): bool => is_string($generation) && $generation !== '')
                    ->values()
                    ->all();
            }
        } catch (Throwable) {
            $generations = [];
        }

        return $this->generationCache[$cacheKey] = ($generations === [] ? [null] : $generations);
    }

    /** @var array<string,list<string>> */
    private array $columnCache = [];

    /** @return list<string> */
    private function columns(string $table): array
    {
        if (! isset($this->columnCache[$table])) {
            try {
                $this->columnCache[$table] = array_map(
                    static fn ($c): string => (string) $c->Field,
                    DB::connection((string) config('upstream_mirrors.connection', 'business_mirror'))->select('SHOW COLUMNS FROM ' . $table)
                );
            } catch (Throwable) {
                $this->columnCache[$table] = [];
            }
        }
        return $this->columnCache[$table];
    }

    /** 科目映射表：平台|账单项目 → [memo, category] */
    private function rules(): array
    {
        static $cache = null;
        if ($cache !== null) { return $cache; }
        $cache = [];
        $path = storage_path('app/account-mapping/rules.json');
        if (! is_file($path)) { return $cache; }
        $raw = json_decode((string) file_get_contents($path), true);
        foreach (($raw['rules'] ?? $raw) as $rule) {
            $key = trim((string) ($rule['platform'] ?? '')) . '|' . trim((string) ($rule['item'] ?? ''));
            $prev = $cache[$key] ?? null;
            $isCatchAll = trim((string) ($rule['memo'] ?? '')) === '' && trim((string) ($rule['goods'] ?? '')) === '';
            if ($prev === null || ($isCatchAll && ! $prev['catch'])) {
                $cache[$key] = ['memo' => (string) ($rule['memo'] ?? ''), 'category' => (string) ($rule['category'] ?? ''), 'catch' => $isCatchAll];
            }
        }
        return $cache;
    }

    /** @return list<string> */
    private function types(): array
    {
        $types = [];
        foreach ($this->rules() as $rule) {
            if ($rule['category'] !== '' && ! in_array($rule['category'], $types, true)) { $types[] = $rule['category']; }
        }
        sort($types);
        return $types;
    }

    /** 财务类型 → 该类型下的账单项目集合（用于按类型筛选时保持分页正确） */
    private function itemsForType(string $type): array
    {
        return $this->itemsForTypes([$type]);
    }

    /**
     * 多个财务类型 → 其下所有账单项目的并集。
     *
     * @param  list<string>  $types
     * @return list<string>
     */
    private function itemsForTypes(array $types): array
    {
        $wanted = array_flip($types);
        $items = [];
        foreach ($this->rules() as $key => $rule) {
            if (isset($wanted[$rule['category']])) {
                $items[explode('|', $key, 2)[1]] = true;
            }
        }

        return array_keys($items);
    }
}