using System;
using System.Collections.Generic;
using System.IO;
using System.Threading;
using System.Threading.Tasks;
using log4net;

namespace DeviceBroker
{
    /// <summary>
    /// DeviceBroker 宿主入口。
    /// 用法: DeviceBroker.exe [--db data.db路径] [--arb arb.db路径] [--broker broker-b01]
    /// 默认路径与集成测试环境一致（%LOCALAPPDATA%\PluginIntegrationTest）。
    /// </summary>
    public static class Program
    {
        private static readonly ILog Log = LogManager.GetLogger(typeof(Program));

        public static async Task Main(string[] args)
        {
            var map = ParseArgs(args);
            string appData = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
            string defaultDir = Path.Combine(appData, "PluginIntegrationTest");
            string dbPath = Get(map, "--db", Path.Combine(defaultDir, "data.db"));
            string arbPath = Get(map, "--arb", Path.Combine(defaultDir, "arb.db"));
            string brokerId = Get(map, "--broker", "broker-b01");

            Console.WriteLine($"DeviceBroker [{brokerId}]");
            Console.WriteLine($"  配置库: {dbPath}");
            Console.WriteLine($"  仲裁库: {arbPath}");

            if (!File.Exists(dbPath))
            {
                Console.WriteLine($"[FATAL] 配置库不存在，请先在注册页保存设备配置。{dbPath}");
                Environment.ExitCode = 2;
                return;
            }

            using var cts = new CancellationTokenSource();
            Console.CancelKeyPress += (_, e) =>
            {
                e.Cancel = true;   // 优雅退出：租约靠 TTL 过期 + 人工回收，不做进程内强放
                cts.Cancel();
                Console.WriteLine("[Broker] 收到退出请求，在途片段按 deadline 收口…");
            };

            try
            {
                var server = new BrokerServer(dbPath, arbPath, brokerId);
                server.LoadDevices();
                Console.WriteLine($"[Broker] epoch={server.Epoch}，Ctrl+C 退出");
                await server.RunAsync(cts.Token).ConfigureAwait(false);
            }
            catch (Exception ex)
            {
                Log.Fatal("[Broker] 宿主异常退出", ex);
                Console.WriteLine($"[FATAL] {ex.Message}");
                Environment.ExitCode = 1;
            }
        }

        private static string Get(Dictionary<string, string> map, string key, string fallback)
            => map.TryGetValue(key, out var v) && !string.IsNullOrWhiteSpace(v) ? v : fallback;

        private static Dictionary<string, string> ParseArgs(string[] args)
        {
            var map = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
            for (int i = 0; i + 1 < args.Length; i++)
            {
                if (args[i].StartsWith("--"))
                {
                    map[args[i]] = args[i + 1];
                    i++;
                }
            }
            return map;
        }
    }
}