using System;
using System.IO;
using System.Text.Json;
using JXHelper.Core;

namespace JXHelper.Common;

public record TelemetryEvent(
    string Timestamp,
    string EventName,
    string State,
    int TargetPid,
    string Details
);

/// <summary>
/// Ghi nhận nhật ký có cấu trúc và viễn trắc (Telemetry) ra đĩa.
/// Tuân thủ bất biến: INV-STRUCTURED-LOG-STREAM.
/// Sử dụng FileShare.ReadWrite để dev/agent có thể đọc stream live liên tục không bị lock file.
/// </summary>
public static class TelemetryLogger
{
    private static readonly object LockObj = new();
    private static readonly string LogDir;
    private static readonly string JsonlPath;
    private static readonly string ActionsLogPath;

    static TelemetryLogger()
    {
        // Thư mục logs nằm tại root workspace hoặc cạnh binary
        string baseDir = AppDomain.CurrentDomain.BaseDirectory;
        // Thử tìm root workspace nếu đang chạy trong src/JXHelper/bin...
        string candidate = Path.GetFullPath(Path.Combine(baseDir, "..", "..", "..", "..", "..", "logs"));
        if (Directory.Exists(Path.GetDirectoryName(candidate)))
        {
            LogDir = candidate;
        }
        else
        {
            LogDir = Path.Combine(baseDir, "logs");
        }

        Directory.CreateDirectory(LogDir);
        JsonlPath = Path.Combine(LogDir, "telemetry.jsonl");
        ActionsLogPath = Path.Combine(LogDir, "actions.log");
    }

    public static void LogEvent(string eventName, BotState state, int targetPid, string details)
    {
        var evt = new TelemetryEvent(
            DateTime.UtcNow.ToString("o"),
            eventName,
            state.ToString(),
            targetPid,
            details
        );

        string jsonLine = JsonSerializer.Serialize(evt) + Environment.NewLine;
        string textLine = $"[{DateTime.Now:yyyy-MM-dd HH:mm:ss.fff}] [{state}] (PID:{targetPid}) {eventName}: {details}{Environment.NewLine}";

        lock (LockObj)
        {
            try
            {
                using var jsonStream = new FileStream(JsonlPath, FileMode.Append, FileAccess.Write, FileShare.ReadWrite);
                using var writer = new StreamWriter(jsonStream);
                writer.Write(jsonLine);
            }
            catch { /* non-blocking */ }

            try
            {
                using var textStream = new FileStream(ActionsLogPath, FileMode.Append, FileAccess.Write, FileShare.ReadWrite);
                using var writer = new StreamWriter(textStream);
                writer.Write(textLine);
            }
            catch { /* non-blocking */ }
        }
    }

    public static void LogAction(string action)
    {
        lock (LockObj)
        {
            try
            {
                using var fs = new FileStream(ActionsLogPath, FileMode.Append, FileAccess.Write, FileShare.ReadWrite);
                using var sw = new StreamWriter(fs);
                sw.WriteLine($"[{DateTime.Now:yyyy-MM-dd HH:mm:ss.fff}] {action}");
            }
            catch { /* non-blocking */ }
        }
    }
}