<?php

namespace App\Support;

use App\Models\Business\CourierQuoteVersion;
use DateTimeInterface;
use Illuminate\Support\Collection;

/**
 * 按「快递编码 + 发货日期」找到当天生效的报价版本，用结构化计费规则算一票的运费。
 *
 * 计费重量 = max(实重, 体积重, 起算重量) 再按取整方式处理；超过限重不计算。
 *
 * 生效版本的判断与报价管理页一致（CourierRequoteService::resolveAt：未作废、已审核或已签署归档、
 * 执行期间覆盖发货日期，短期变价优先）。没有结构化规则的版本（按体积、按条码等特殊计费）返回原因，交人工核算。
 */
class CourierQuoteFreightCalculator
{
    /** @var array<string,Collection<int,CourierQuoteVersion>> */
    private array $versions = [];

    /**
     * @param string $courierExpcode 快递编码；没有编码的存量报价可传快递名称（如「沐野竹木顺丰」）
     * @return array{
     *   version_code:?string,company_name:?string,region:?string,gross_weight:float,volume_weight:?float,
     *   billable_weight:?float,base_amount:?float,surcharge:float,amount:?float,formula:?string,reason:?string
     * }
     */
    public function calculate(
        string $courierExpcode,
        DateTimeInterface $shipDate,
        string $province,
        float $grossWeight,
        ?float $length = null,
        ?float $width = null,
        ?float $height = null,
        ?string $city = null,
        ?string $quoteType = null,
    ): array {
        $result = [
            'version_code' => null, 'company_name' => null, 'region' => null, 'gross_weight' => $grossWeight,
            'volume_weight' => null, 'billable_weight' => null, 'base_amount' => null, 'surcharge' => 0.0,
            'amount' => null, 'formula' => null, 'reason' => null,
        ];
        if (! is_finite($grossWeight) || $grossWeight < 0
            || collect([$length, $width, $height])->contains(static fn ($v) => $v !== null && (! is_finite($v) || $v < 0))) {
            return ['reason' => '重量和尺寸必须是有效非负数字'] + $result;
        }

        $version = $this->versionAt(trim($courierExpcode), $shipDate, $quoteType);
        if ($version === null) {
            return ['reason' => '发货日期没有生效的报价'] + $result;
        }
        $result['version_code'] = $version->version_code;
        $result['company_name'] = $version->company_name;
        if (! $version->hasBillingRules()) {
            return ['reason' => '该报价为特殊计费或尚未设置计费规则，需人工核算'] + $result;
        }

        $structure = (array) $version->billing_structure;
        $row = $this->matchRow((array) $version->billing_rows, $province, $city);
        if ($row === null) {
            return ['reason' => '报价未覆盖目的地「' . trim($province . ' ' . $city) . '」或该地区不发'] + $result;
        }
        $result['region'] = (string) $row['region'];

        $divisor = (float) ($structure['volumetric_divisor'] ?? 0);
        $volume = $divisor > 0 && $length > 0 && $width > 0 && $height > 0 ? round($length * $width * $height / $divisor, 4) : null;
        $settlement = max($grossWeight, (float) $volume);
        $result['volume_weight'] = $volume;
        if ($settlement <= 0) {
            return ['reason' => '缺少重量，无法计算运费'] + $result;
        }

        $limit = (float) ($structure['weight_limit'] ?? 0);
        if ($limit > 0 && $settlement > $limit + 1e-9) {
            return ['reason' => '超出限重 ' . CourierQuoteStructure::kg($limit) . 'kg'] + $result;
        }

        // 起算重量：不足按起算重量计（如菏泽顺帆顺丰不足 5kg 按 5kg）
        $minimum = (float) ($structure['min_weight'] ?? 0);
        $billable = CourierQuoteStructure::roundWeight(max($settlement, $minimum), (string) ($structure['rounding'] ?? 'none'));
        $result['billable_weight'] = $billable;
        $freight = CourierQuoteStructure::freight($structure, $row, $billable);
        if ($freight['amount'] === null) {
            return ['reason' => $freight['reason']] + $result;
        }

        $surcharge = (float) ($structure['per_ticket_surcharge'] ?? 0);
        $result['base_amount'] = round($freight['amount'], 2);
        $result['surcharge'] = $surcharge;
        $result['amount'] = round($freight['amount'] + $surcharge, 2);
        $result['formula'] = $freight['formula'] . ($surcharge > 0 ? '+每票' . CourierQuoteStructure::kg($surcharge) : '');

        return $result;
    }

    /** 省份名统一：去掉省/市/自治区后缀，黑龙→黑龙江、内蒙→内蒙古。 */
    public static function regionKey(string $name): string
    {
        $text = (string) preg_replace('/\s+/u', '', $name);
        $text = (string) preg_replace('/(维吾尔自治区|壮族自治区|回族自治区|自治区|特别行政区|省|市)$/u', '', $text);

        return match ($text) {
            '黑龙' => '黑龙江',
            '内蒙' => '内蒙古',
            default => $text,
        };
    }

    private function versionAt(string $courierExpcode, DateTimeInterface $date, ?string $quoteType): ?CourierQuoteVersion
    {
        if ($courierExpcode === '') {
            return null;
        }
        // 先按快递编码；部分存量版本没有编码，按快递名称（与报价管理页的分组口径一致）
        $cacheKey = company_id() . ':' . $courierExpcode;
        $versions = $this->versions[$cacheKey] ??= CourierQuoteVersion::query()
            ->with(['signature', 'change'])
            ->where(static fn ($query) => $query->where('courier_expcode', $courierExpcode)
                ->orWhere(static fn ($q) => $q->where(static fn ($e) => $e->whereNull('courier_expcode')->orWhere('courier_expcode', ''))
                    ->where('company_name', $courierExpcode)))
            ->get();

        return CourierRequoteService::resolveAt(
            $quoteType === null ? $versions : $versions->where('quote_type', $quoteType),
            $date,
        );
    }

    /**
     * 先按城市匹配单列的城市行（如「深圳(广东)」），再按省份匹配。
     *
     * @param list<array<string,mixed>> $rows
     * @return array<string,mixed>|null
     */
    private function matchRow(array $rows, string $province, ?string $city): ?array
    {
        $cityKey = self::regionKey((string) $city);
        if ($cityKey !== '') {
            foreach ($rows as $row) {
                if (is_array($row) && preg_match('/^(.+?)[（(](.+?)[）)]$/u', trim((string) ($row['region'] ?? '')), $parts)
                    && self::regionKey($parts[1]) === $cityKey && self::regionKey($parts[2]) === self::regionKey($province)) {
                    return $row;
                }
            }
        }
        $key = self::regionKey($province);
        foreach ($rows as $row) {
            if (is_array($row) && self::regionKey((string) ($row['region'] ?? '')) === $key) {
                return $row;
            }
        }

        return null;
    }
}