<?php

namespace App\Services;

use App\Exceptions\RepositoryException;
use App\Exports\PurchaseOrderExport;
use App\Exports\SettlementExport;
use App\Exports\StatementExport;
use App\Models\PurchaseOrderModel;
use App\Models\SettlementModel;
use App\Models\StatementModel;
use Barryvdh\DomPDF\Facade\Pdf;
use Maatwebsite\Excel\Facades\Excel;
use Symfony\Component\HttpFoundation\Response;

/**
 * 导出统一入口：按业务类型 + format 分发到 app/Exports 导出类 / PDF 模板
 *
 * - Excel 分支：Excel::download(new XxxExport(...))
 * - PDF 分支：Pdf::loadView('exports.xxx', ...)->setPaper('a4')->download(...)，模板统一 font-family: SimHei
 * - 文件名规范：{单号}_{业务名}.{ext}，中文文件名由响应自动做 RFC 5987 编码
 */
class ExportService
{
    /** 导出格式：Excel */
    public const FORMAT_XLSX = 'xlsx';
    /** 导出格式：PDF */
    public const FORMAT_PDF = 'pdf';

    /**
     * 导出下载
     *
     * @param string $business 业务类型：purchase 采购单 / statement 门店对账单 / settlement 结算表
     * @param mixed $subject 业务主体（如 PurchaseOrderModel / StatementModel / SettlementModel 实例）
     * @param string $format 导出格式 xlsx|pdf，默认 xlsx，非法值报错
     * @param string|null $type 业务子类型（purchase 专用：all 全品类 / category 仅蔬果分类）
     * @return Response 文件流响应（blob）
     */
    public function download(
        string $business,
        mixed $subject,
        string $format = self::FORMAT_XLSX,
        ?string $type = null,
    ): Response {
        if (! in_array($format, [self::FORMAT_XLSX, self::FORMAT_PDF], true)) {
            throw new RepositoryException('导出格式参数不正确（仅支持 xlsx / pdf）');
        }

        return match ($business) {
            'purchase' => $this->exportPurchase($subject, $format, $type),
            'statement' => $this->exportStatement($subject, $format),
            'settlement' => $this->exportSettlement($subject, $format),
            default => throw new RepositoryException('不支持的导出业务类型：' . $business),
        };
    }

    /**
     * C2/C3 采购单导出
     */
    private function exportPurchase(PurchaseOrderModel $purchase, string $format, ?string $type): Response
    {
        $type = in_array($type, ['all', 'category'], true) ? $type : 'all';
        $extension = $format === self::FORMAT_PDF ? 'pdf' : 'xlsx';
        $filename = $purchase->purchase_no . '_采购单.' . $extension;

        $export = new PurchaseOrderExport($purchase, $type);
        if ($format === self::FORMAT_PDF) {
            return Pdf::loadView('exports.purchase', $export->viewData())
                ->setPaper('a4')
                ->download($filename);
        }

        return Excel::download($export, $filename);
    }

    /**
     * 门店对账单导出
     */
    private function exportStatement(StatementModel $statement, string $format): Response
    {
        $extension = $format === self::FORMAT_PDF ? 'pdf' : 'xlsx';
        $filename = $statement->statement_no . '_对账单.' . $extension;

        $export = new StatementExport($statement);
        if ($format === self::FORMAT_PDF) {
            return Pdf::loadView('exports.statement', $export->viewData())
                ->setPaper('a4')
                ->download($filename);
        }

        return Excel::download($export, $filename);
    }

    /**
     * D10 结算表导出
     */
    private function exportSettlement(SettlementModel $settlement, string $format): Response
    {
        $extension = $format === self::FORMAT_PDF ? 'pdf' : 'xlsx';
        $filename = $settlement->settlement_no . '_结算表.' . $extension;

        $export = new SettlementExport($settlement);
        if ($format === self::FORMAT_PDF) {
            return Pdf::loadView('exports.settlement', $export->viewData())
                ->setPaper('a4')
                ->download($filename);
        }

        return Excel::download($export, $filename);
    }
}