<?php

namespace App\Service\common;

/**
 * 表格导出辅助：报价给结构化列/行（前端 ExcelJS 画 xlsx），小程序继续用 text。
 * 仍保留 toCsv / parseUpload，避免旧调用立刻断掉。
 */
class ExcelCsvService
{
    private static mixed $_instance;

    public static function getInstance(): null|static
    {
        $name = get_called_class();
        if (!isset(self::$_instance[$name])) {
            self::$_instance[$name] = new static();
        }
        return self::$_instance[$name];
    }

    /**
     * 行数组转带 BOM 的 CSV 文本
     */
    public function toCsv(array $header, array $rows): string
    {
        $fp = fopen('php://temp', 'r+');
        fprintf($fp, chr(0xEF) . chr(0xBB) . chr(0xBF));
        fputcsv($fp, $header);
        foreach ($rows as $row) {
            $line = [];
            foreach ($header as $key) {
                $line[] = $row[$key] ?? '';
            }
            fputcsv($fp, $line);
        }
        rewind($fp);
        $csv = stream_get_contents($fp);
        fclose($fp);
        return $csv === false ? '' : $csv;
    }

    /**
     * 解析上传文件（csv / 文本）
     */
    public function parseUpload($file): array
    {
        if (empty($file)) {
            UtilsService::getInstance()->errorThrow('请上传表格文件');
        }
        $path = is_string($file) ? $file : $file->getRealPath();
        $raw = file_get_contents($path);
        if ($raw === false) {
            UtilsService::getInstance()->errorThrow('文件读取失败');
        }
        if (str_starts_with($raw, "\xEF\xBB\xBF")) {
            $raw = substr($raw, 3);
        }
        $fp = fopen('php://temp', 'r+');
        fwrite($fp, $raw);
        rewind($fp);
        $header = fgetcsv($fp);
        if (empty($header)) {
            fclose($fp);
            UtilsService::getInstance()->errorThrow('表格没有表头');
        }
        $header = array_map(static fn ($v) => trim((string) $v), $header);
        $rows = [];
        while (($cols = fgetcsv($fp)) !== false) {
            if ($this->rowEmpty($cols)) {
                continue;
            }
            $item = [];
            foreach ($header as $i => $key) {
                $item[$key] = isset($cols[$i]) ? trim((string) $cols[$i]) : '';
            }
            $rows[] = $item;
        }
        fclose($fp);
        return $rows;
    }

    /**
     * 清单报价：后台用 ExcelJS 画 xlsx，小程序继续用 text 分享
     */
    public function quoteFromList(array $info): array
    {
        $rows = [];
        $lines = [];
        $name = (string) ($info['name'] ?? $info['list_no'] ?? '报价');
        $lines[] = $name;
        foreach ($info['items'] ?? [] as $item) {
            $title = (string) ($item['title'] ?? $item['catalogue']['title'] ?? $item['product']['title'] ?? '');
            $spec = (string) ($item['specification'] ?? $item['price_sheet']['specification'] ?? '');
            $qty = (int) ($item['quantity'] ?? 1);
            $unit = (string) ($item['unit_price_text'] ?? '');
            $total = (string) ($item['total_price_text'] ?? '');
            $rows[] = [
                'title' => $title,
                'specification' => $spec,
                'quantity' => $qty,
                'unit_price' => $unit,
                'total_price' => $total,
            ];
            $lines[] = trim($title . ' ' . $spec . ' x' . $qty . ($unit !== '' ? ' ¥' . $unit : ''));
        }
        $payable = (string) ($info['payable_amount_text'] ?? $info['total_amount_text'] ?? '');
        if ($payable !== '') {
            $lines[] = '合计 ¥' . $payable;
        }
        $no = (string) ($info['list_no'] ?? 'quote');
        return [
            'filename' => 'quote-' . $no . '.xlsx',
            'title' => $name,
            'sheet' => '报价',
            'subtitle' => '清单号 ' . $no,
            'columns' => [
                ['key' => 'title', 'header' => '商品', 'width' => 28],
                ['key' => 'specification', 'header' => '规格', 'width' => 22],
                ['key' => 'quantity', 'header' => '数量', 'width' => 10, 'align' => 'center'],
                ['key' => 'unit_price', 'header' => '单价', 'width' => 14, 'align' => 'right'],
                ['key' => 'total_price', 'header' => '小计', 'width' => 14, 'align' => 'right'],
            ],
            'rows' => $rows,
            'summary' => [
                'title' => '合计',
                'total_price' => $payable === '' ? '' : ('¥' . $payable),
            ],
            'text' => implode("\n", $lines),
        ];
    }

    private function rowEmpty(array $cols): bool
    {
        foreach ($cols as $col) {
            if (trim((string) $col) !== '') {
                return false;
            }
        }
        return true;
    }
}