using StackExchange.Redis;

namespace QYZH.InteractiveMagazine.Infrastructure.Cache;

/// <summary>
/// Redis操作封装
/// </summary>
public static class RedisHelper
{
    private static string? _keyPrefix;

    /// <summary>
    /// Redis连接实例
    /// </summary>
    public static IConnectionMultiplexer? Connection { get; set; }

    /// <summary>
    /// 设置键前缀
    /// </summary>
    /// <param name="prefix">前缀字符串</param>
    public static void SetKeyPrefix(string prefix)
    {
        _keyPrefix = prefix;
    }

    /// <summary>
    /// 获取Redis数据库实例
    /// </summary>
    /// <param name="db">数据库索引</param>
    /// <returns>IDatabase实例</returns>
    public static IDatabase GetDatabase(int db = -1)
    {
        if (Connection == null || !Connection.IsConnected)
        {
            throw new InvalidOperationException("Redis连接未初始化或已断开");
        }

        return Connection.GetDatabase(db);
    }

    /// <summary>
    /// 设置字符串值
    /// </summary>
    /// <param name="key">键</param>
    /// <param name="value">值</param>
    /// <param name="expiry">过期时间</param>
    /// <returns>是否成功</returns>
    public static async Task<bool> StringSetAsync(string key, string value, TimeSpan? expiry = null)
    {
        var db = GetDatabase();
        var prefixedKey = GetPrefixedKey(key);

        if (expiry.HasValue)
        {
            return await db.StringSetAsync(prefixedKey, value, (Expiration)expiry.Value);
        }

        return await db.StringSetAsync(prefixedKey, value);
    }

    /// <summary>
    /// 获取字符串值
    /// </summary>
    /// <param name="key">键</param>
    /// <returns>值</returns>
    public static async Task<string?> StringGetAsync(string key)
    {
        var db = GetDatabase();
        var prefixedKey = GetPrefixedKey(key);
        return await db.StringGetAsync(prefixedKey);
    }

    /// <summary>
    /// 删除键
    /// </summary>
    /// <param name="key">键</param>
    /// <returns>是否成功</returns>
    public static async Task<bool> KeyDeleteAsync(string key)
    {
        var db = GetDatabase();
        var prefixedKey = GetPrefixedKey(key);
        return await db.KeyDeleteAsync(prefixedKey);
    }

    /// <summary>
    /// 检查键是否存在
    /// </summary>
    /// <param name="key">键</param>
    /// <returns>是否存在</returns>
    public static async Task<bool> KeyExistsAsync(string key)
    {
        var db = GetDatabase();
        var prefixedKey = GetPrefixedKey(key);
        return await db.KeyExistsAsync(prefixedKey);
    }

    /// <summary>
    /// 设置键的过期时间
    /// </summary>
    /// <param name="key">键</param>
    /// <param name="expiry">过期时间</param>
    /// <returns>是否成功</returns>
    public static async Task<bool> KeyExpireAsync(string key, TimeSpan expiry)
    {
        var db = GetDatabase();
        var prefixedKey = GetPrefixedKey(key);
        return await db.KeyExpireAsync(prefixedKey, expiry);
    }

    /// <summary>
    /// 获取带前缀的键
    /// </summary>
    /// <param name="key">原始键</param>
    /// <returns>带前缀的键</returns>
    private static string GetPrefixedKey(string key)
    {
        return string.IsNullOrEmpty(_keyPrefix) ? key : $"{_keyPrefix}:{key}";
    }
}