using System;
using UnityModManagerNet;

namespace S3.Core;

/// <summary>
/// Thin static wrapper over the UMM mod logger so every module can log without
/// holding a ModEntry reference. Initialized once from <see cref="Main.Load"/>.
/// </summary>
public static class Log
{
    private const int RingN = 200;
    private static readonly object RingLock = new();
    private static readonly string[] Ring = new string[RingN];
    private static int _ringCount;

    private static UnityModManager.ModEntry.ModLogger? _logger;

    public static void Init(UnityModManager.ModEntry modEntry) => _logger = modEntry.Logger;

    public static void Info(string msg)
    {
        Push("INF", msg);
        _logger?.Log(msg);
    }

    public static void Warn(string msg)
    {
        Push("WRN", msg);
        _logger?.Warning(msg);
    }

    public static void Error(string msg)
    {
        Push("ERR", msg);
        _logger?.Error(msg);
    }

    public static string[] Tail(int count)
    {
        if (count < 1) count = 1;
        if (count > RingN) count = RingN;
        lock (RingLock)
        {
            int have = Math.Min(_ringCount, RingN);
            int take = Math.Min(count, have);
            var result = new string[take];
            int start = _ringCount - take;
            for (int i = 0; i < take; i++)
                result[i] = Ring[(start + i) % RingN];
            return result;
        }
    }

    static void Push(string level, string msg)
    {
        string line = DateTime.Now.ToString("HH:mm:ss") + " [" + level + "] " + msg;
        lock (RingLock)
        {
            Ring[_ringCount % RingN] = line;
            _ringCount++;
        }
    }
}