using System.Text;

namespace NewLife.Log;

/// <summary>复合日志提供者，多种方式输出</summary>
public class CompositeLog : Logger
{
    /// <summary>日志提供者集合</summary>
    public List<ILog> Logs { get; set; } = new List<ILog>();

    /// <summary>日志等级，只输出大于等于该级别的日志，默认Info，打开NewLife.Debug时默认为最低的Debug</summary>
    public override LogLevel Level
    {
        get => base.Level; set
        {
            base.Level = value;

            foreach (var item in Logs)
            {
                // 使用外层层级
                item.Level = Level;
            }
        }
    }

    /// <summary>实例化</summary>
    public CompositeLog() { }

    /// <summary>实例化</summary>
    /// <param name="log"></param>
    public CompositeLog(ILog log) { Logs.Add(log); Level = log.Level; }

    /// <summary>实例化</summary>
    /// <param name="log1"></param>
    /// <param name="log2"></param>
    public CompositeLog(ILog log1, ILog log2)
    {
        Add(log1).Add(log2);
        Level = log1.Level;
        if (Level > log2.Level) Level = log2.Level;
    }

    /// <summary>添加一个日志提供者</summary>
    /// <param name="log"></param>
    /// <returns></returns>
    public CompositeLog Add(ILog log) { Logs.Add(log); return this; }

    /// <summary>删除日志提供者</summary>
    /// <param name="log"></param>
    /// <returns></returns>
    public CompositeLog Remove(ILog log) { if (Logs.Contains(log)) Logs.Remove(log); return this; }

    /// <summary>写日志</summary>
    /// <param name="level"></param>
    /// <param name="format"></param>
    /// <param name="args"></param>
    protected override void OnWrite(LogLevel level, String format, params Object?[] args)
    {
        if (Logs != null)
        {
            foreach (var item in Logs)
            {
                item.Write(level, format, args);
            }
        }
    }

    /// <summary>从复合日志提供者中提取指定类型的日志提供者</summary>
    /// <typeparam name="TLog"></typeparam>
    /// <returns></returns>
    public TLog? Get<TLog>() where TLog : class
    {
        foreach (var item in Logs)
        {
            if (item != null)
            {
                if (item is TLog) return item as TLog;

                // 递归获取内层日志
                if (item is CompositeLog cmp)
                {
                    var log = cmp.Get<TLog>();
                    if (log != null) return log;
                }
            }
        }

        return null;
    }

    /// <summary>已重载。</summary>
    /// <returns></returns>
    public override String ToString()
    {
        var sb = new StringBuilder();
        sb.Append(GetType().Name);

        foreach (var item in Logs)
        {
            sb.Append(' ');
            sb.Append(item + "");
        }

        return sb.ToString();
    }
}