EmailBill/Service/EmailParseServices/EmailParseForm95555.cs

namespace Service.EmailParseServices;

public class EmailParseForm95555(
    ILogger<EmailParseForm95555> logger,
    IOpenAiService openAiService
) : EmailParseServicesBase(logger, openAiService)
{
    public override bool CanParse(string from, string subject, string body)
    {
        if (!from.Contains("95555@message.cmbchina.com"))
        {
            return false;
        }

        if (!subject.Contains("账户变动通知"))
        {
            return false;
        }

        // 不能包含HTML标签
        if (Regex.IsMatch(body, "<.*?>"))
        {
            return false;
        }

        return true;
    }

    public override async Task<(
        string card,
        string reason,
        decimal amount,
        decimal balance,
        TransactionType type,
        DateTime? occurredAt
    )[]> ParseEmailContentAsync(string emailContent)
    {
        var pattern =
            "您账户(?<card>\\d+)" +                        
            "于.*?" +                                    // 时间等信息统统吞掉
            "(?:(?<type>收入|支出|消费|转入|转出).*?)?" +   // 可选 type
            "(?:在(?<reason>.*?))?" +                    // 可选 reason（“财付通-微信支付-这有电快捷支付”）
            "(?<amount>\\d+\\.\\d{1,2})元，余额" +         
            "(?<balance>\\d+\\.\\d{1,2})";

        var matches = Regex.Matches(emailContent, pattern);

        if (matches.Count <= 0)
        {
            logger.LogWarning("未能从招商银行邮件内容中解析出交易信息");
            return [];
        }

        var results = new List<(
            string card,
            string reason,
            decimal amount,
            decimal balance,
            TransactionType type,
            DateTime? occurredAt
        )>();

        foreach (Match match in matches)
        {
            var card = match.Groups["card"].Value;
            var reason = match.Groups["reason"].Value;
            var amountStr = match.Groups["amount"].Value;
            var balanceStr = match.Groups["balance"].Value;
            var typeStr = match.Groups["type"].Value;

            if (!string.IsNullOrEmpty(card) &&
                !string.IsNullOrEmpty(reason) &&
                decimal.TryParse(amountStr, out var amount) &&
                decimal.TryParse(balanceStr, out var balance))
            {
                var type = DetermineTransactionType(typeStr, reason, amount);
                results.Add((card, reason, amount, balance, type, null));
            }
        }
        return results.ToArray();
    }
}