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)
    {
        // 示例1：您账户8826于12月31日09:34在财付通-微信支付-这有电快捷支付1.00元，余额30.21
        // 示例2: 您账户8826于12月31日10:47入账款项，人民币1000.00，余额人民币1030.21。
        var pattern =
            "您账户(?<card>\\d+)" +                                   // 卡号
            "于(?<time>\\d{1,2}月\\d{1,2}日\\d{1,2}:\\d{2})" +        // 交易时间
            "(?:(?<type>收入|支出|消费|转入|转出|入账款项))?" +          // 交易类型（可选）
            "(?:在(?<reason>[^\\d，。]*?))?" +                        // 交易原因（可选）
            "，?(?:人民币)?(?<amount>\\d+\\.\\d{1,2})(?:元)?" +        // 金额，“元” 可有可无
            "，余额(?:人民币)?(?<balance>\\d+\\.\\d{1,2})" +           // 余额
            "。?";                                                   // 句号可有可无

        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 amountStr = match.Groups["amount"].Value;
            var balanceStr = match.Groups["balance"].Value;
            var typeStr = match.Groups["type"].Value;
            var reason = match.Groups["reason"].Value;
            if(string.IsNullOrEmpty(reason))
            {
                reason = typeStr;
            }

            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);
                var occurredAt = ParseOccurredAt(match.Groups["time"].Value);
                results.Add((card, reason, amount, balance, type, occurredAt));
            }
        }
        return results.ToArray();
    }

    private DateTime? ParseOccurredAt(string value)
    {
        // "12月31日09:34"
        var now = DateTime.Now;
        var dateTimeStr = $"{now.Year}年{value}";
        if (DateTime.TryParse(dateTimeStr, out var occurredAt))
        {
            // 如果解析结果在未来，说明是上一年的交易
            if (occurredAt > now)
            {
                occurredAt = occurredAt.AddYears(-1);
            }
            return occurredAt;
        }
        return null;
    }
}