finance_app/app/Services/GmailParserService.php

<?php

namespace App\Services;

use Illuminate\Support\Str;
use Illuminate\Support\Facades\Log;
use Carbon\Carbon;

class GmailParserService
{

    protected array $parserMatrix = [
        [
            'keywords' => ['國泰世華銀行消費彙整通知'],
            'method'   => 'parseCathaySummary'
        ],
        [
            'keywords' => ['永豐銀行信用卡消費通知'],
            'method'   => 'parseSinoPacNotification'
        ],
        [
            'keywords' => ['電子發票', '載具', '發票開立通知'],
            'method'   => 'parseElectronicInvoice'
        ],
        [
            'keywords' => ['消費通知', '刷卡', '卡片消費'],
            'method'   => 'parseCreditCardNotification'
        ],
    ];

    public function parse(string $subject, string $body): ?array
    {
        // 🔄 遍歷矩陣，尋找第一個命中的規則
        foreach ($this->parserMatrix as $rule) {
            if (Str::contains($subject, $rule['keywords'])) {
                $method = $rule['method'];

                // 動態呼叫對應的方法 (例如 $this->parseCathaySummary($body) )
                return $this->{$method}($body);
            }
        }

        Log::info("【Parser】忽略信件，主旨未命中任何對照規則: [{$subject}]");
        return null;
    }

    /**
     * 🟢 國泰世華消費彙整信件專屬解析
     */
    private function parseCathaySummary(string $body): ?array
    {
        $cleanBody = preg_replace('/\s+/', ' ', $body);

        if (preg_match('/(\d{4}\/\d{2}\/\d{2})/u', $cleanBody, $dateMatches)) {
            $date = Carbon::createFromFormat('Y/m/d', $dateMatches[1])->format('Y-m-d');
        } else {
            $date = now()->format('Y-m-d');
        }

        $pattern = '/NT\$\s*([0-9,]+)\s*<\/td>\s*<td[^>]*>\s*([^<\s&]+)\s*<\/td>/u';
        
        if (!preg_match_all($pattern, $cleanBody, $matches, PREG_SET_ORDER)) {
            Log::error("【Parser】國泰信件未命中消費明細。");
            return null;
        }

        $results = [];
        foreach ($matches as $match) {
            $sellerName = $this->convertFullWidthToHalfWidth(trim($match[2]));
            $results[] = [
                'amount'      => floatval(str_replace(',', '', $match[1])),
                'item_name'   => "信用卡消費: {$sellerName}",
                'seller_name' => $sellerName,
                'date'        => $date,
                'category_id' => null,
            ];
        }

        return $results;
    }

    /**
     * 永豐銀行信用卡消費通知（單筆制）
     */
    private function parseSinoPacNotification(string $body): ?array
    {
        $cleanBody = preg_replace('/\s+/', ' ', $body);
        $amount = 0;
        $sellerName = '永豐刷卡消費';

        if (preg_match('/(?:新臺幣|TWD)\s*([0-9,]+)/u', $cleanBody, $amountMatches)) {
            $amount = floatval(str_replace(',', '', $amountMatches[1]));
        }

        if (preg_match('/特約商店[:：]\s*([^<\s]+)/u', $cleanBody, $merchantMatches)) {
            $sellerName = trim($merchantMatches[1]);
        }

        if ($amount === 0) return null;

        if (preg_match('/(\d{4}\/\d{2}\/\d{2})/u', $cleanBody, $dateMatches)) {
            $date = Carbon::createFromFormat('Y/m/d', $dateMatches[1])->format('Y-m-d');
        } else {
            $date = now()->format('Y-m-d');
        }

        $sellerName = $this->convertFullWidthToHalfWidth($sellerName);

        return [
            'amount'      => $amount,
            'item_name'   => "信用卡消費: {$sellerName}",
            'seller_name' => $sellerName,
            'date'        => $date,
            'category_id' => null,
        ];
    }

    /**
     * 解析電子發票信件
     */
    private function parseElectronicInvoice(string $body): ?array
    {
        $amount = 0;
        $sellerName = '未知商家';

        if (preg_match('/(總計|金額|總金額)[:：]\s*?\$?([0-9,]+)/u', $body, $matches)) {
            $amount = floatval(str_replace(',', '', $matches[2]));
        }
        if (preg_match('/(賣方|開立店家|商店名稱)[:：]\s*?([^\n<\s]+)/u', $body, $matches)) {
            $sellerName = trim($matches[2]);
        }

        if ($amount === 0) return null;

        return [
            'amount'      => $amount,
            'item_name'   => '電子發票消費',
            'seller_name' => $sellerName,
            'date'        => now()->format('Y-m-d'),
            'category_id' => null,
        ];
    }

    /**
     * 解析信用卡消費通知（泛用型備援）
     */
    private function parseCreditCardNotification(string $body): ?array
    {
        $amount = 0;
        $sellerName = '一般刷卡消費';

        if (preg_match('/(NT\$|元|TWD)\s*?([0-9,]+)/u', $body, $matches)) {
            $amount = floatval(str_replace(',', '', $matches[2]));
        } elseif (preg_match('/([0-9,]+)\s*?(元)/u', $body, $matches)) {
            $amount = floatval(str_replace(',', '', $matches[1]));
        }

        if (preg_match('/於\s*?([^\n\]（(]+?)\s*?消費/u', $body, $matches)) {
            $sellerName = trim($matches[1]);
        } elseif (preg_match('/(特約商店|消費商店|商店)[:：]\s*?([^\n<\s]+)/u', $body, $matches)) {
            $sellerName = trim($matches[2]);
        }

        if ($amount === 0) return null;

        return [
            'amount'      => $amount,
            'item_name'   => "刷卡消費: {$sellerName}",
            'seller_name' => $sellerName,
            'date'        => now()->format('Y-m-d'),
            'category_id' => null,
        ];
    }

    private function convertFullWidthToHalfWidth(string $str): string
    {
        $str = str_replace('&nbsp;', '', $str);
        return mb_convert_kana($str, 'asKV', 'UTF-8');
    }
}