using dodohold.core;
using System.Security.Cryptography;
using System.Text;

namespace molilian.core
{
    public static class TaobaoGeneralLinkParseCacheCore
    {
        public const int CacheExpireSeconds = 7 * 86400;

        // 统计跨天保留，每次通知领取上次通知后的全部次数；同一天只允许领取一次。
        private const string ClaimNotificationScript = @"
local count = redis.call('HINCRBY', KEYS[1], 'pending', 1)
local lastDate = redis.call('HGET', KEYS[1], 'last_notify_date')
if lastDate and lastDate >= ARGV[1] then
    return 0
end
redis.call('HSET', KEYS[1], 'last_notify_date', ARGV[1])
redis.call('HSET', KEYS[1], 'pending', 0)
return count";

        public static async Task<TaobaoGeneralLinkParseCacheDTO?> GetAsync(string content)
        {
            try
            {
                return await CenterHub.Redis.GetAsync<TaobaoGeneralLinkParseCacheDTO>(GetCacheKey(content));
            }
            catch (Exception ex)
            {
                LogFailure("cache_read_error", ex);
                return null;
            }
        }

        public static async Task SaveAsync(TaobaoGeneralLinkParseCacheDTO record)
        {
            try
            {
                await CenterHub.Redis.SetAsync(GetCacheKey(record.RequestContent), record, CacheExpireSeconds);
            }
            catch (Exception ex)
            {
                LogFailure("cache_write_error", ex);
            }
        }

        public static async Task NotifyFailureOnceAsync(string reason, int parseAccountId, int consumerAccountId)
        {
            reason = string.IsNullOrWhiteSpace(reason) ? "未知错误" : reason.Trim();
            string key = $"notify:taobao:general_link_parse:v1:{Hash(reason)}";
            long count = 0;
            try
            {
                count = Convert.ToInt64(await CenterHub.Redis.EvalAsync(ClaimNotificationScript, key, DateTime.Now.ToString("yyyyMMdd")));
                if (count <= 0) return;

                await NotifyCore.NotifyAsync(
                    $"【淘宝万能解析失败】\n错误信息：{reason}\n" +
                    $"自上次相同错误通知以来发生：{count} 次（含本次）\n" +
                    $"使用账号：{consumerAccountId}，解析账号：{parseAccountId}\n已回退原短链解析逻辑。");
            }
            catch (Exception ex)
            {
                if (count > 0)
                {
                    try
                    {
                        // 发送失败的次数留给下一次通知，同一天不重复尝试发送。
                        await CenterHub.Redis.HIncrByAsync(key, "pending", count);
                    }
                    catch (Exception restoreException)
                    {
                        LogFailure("notify_count_restore_error", restoreException);
                    }
                }
                LogFailure("notify_error", ex);
            }
        }

        private static string GetCacheKey(string content)
        {
            return $"cache:taobao:general_link_parse:v1:{Hash(content.Trim())}";
        }

        private static string Hash(string value)
        {
            return Convert.ToHexString(SHA256.HashData(Encoding.UTF8.GetBytes(value)));
        }

        private static void LogFailure(string operation, Exception ex)
        {
            _ = new LoggerLibrary("tbk_dg_general_link_parse", operation)
                .Info(ex.Message, ex.StackTrace)
                .SaveAsync();
        }
    }
}