using Newtonsoft.Json;
using SHH.CameraSdk;
using SHH.Contracts;

namespace SHH.CameraService
{
    /// <summary>
    /// 指令业务逻辑分发器 (纯逻辑层)
    /// <para>职责：解析业务参数 -> 调用 CameraManager -> 返回执行结果</para>
    /// <para>注意：本类不处理网络协议，也不负责 RequestId 的回填，只关注业务本身</para>
    /// </summary>
    public static class CommandBusProcessor
    {
        /// <summary>
        /// 核心业务入口
        /// </summary>
        /// <param name="manager">相机管理器实例</param>
        /// <param name="payload">已解析的指令包</param>
        /// <returns>执行结果 (不含 RequestId，由调用方补充)</returns>
        public static CommandResult ProcessBusinessLogic(CameraManager manager, CommandPayload payload)
        {
            string cmd = payload.CmdCode.ToUpper();

            // 忽略客户端发回的 ACK (如果是双向确认模式)
            if (cmd == "REGISTER_ACK") return CommandResult.Ok();

            // 解析 TargetId (CameraId)
            long deviceId = 0;
            // 只有非 SYSTEM 指令才需要解析设备ID
            if (payload.TargetId != "SYSTEM" && !long.TryParse(payload.TargetId, out deviceId))
            {
                return CommandResult.Fail($"Invalid Device ID: {payload.TargetId}");
            }

            try
            {
                switch (cmd)
                {
                    // ==========================================
                    // 1. PTZ 云台控制
                    // ==========================================
                    case "PTZ":
                        {
                            var device = manager.GetDevice(deviceId);
                            if (device == null) return CommandResult.Fail("Device Not Found");
                            if (!device.IsOnline) return CommandResult.Fail("Device Offline");

                            // 检查设备是否支持 PTZ 能力 (接口模式匹配)
                            if (device is IPtzFeature ptzFeature)
                            {
                                var ptzDto = JsonConvert.DeserializeObject<PtzControlDto>(payload.JsonParams);
                                if (ptzDto == null) return CommandResult.Fail("Invalid PTZ Params");

                                // 异步转同步执行 (Task.Wait 在后台线程是安全的)
                                if (ptzDto.Duration > 0)
                                {
                                    // 点动模式 (例如：向左转 500ms)
                                    ptzFeature.PtzStepAsync(ptzDto.Action, ptzDto.Duration, ptzDto.Speed).Wait();
                                }
                                else
                                {
                                    // 持续模式 (开始转/停止转)
                                    ptzFeature.PtzControlAsync(ptzDto.Action, ptzDto.Stop, ptzDto.Speed).Wait();
                                }
                                return CommandResult.Ok("PTZ Executed");
                            }
                            return CommandResult.Fail("Device does not support PTZ");
                        }

                    // ==========================================
                    // 2. 远程重启
                    // ==========================================
                    case "REBOOT":
                        {
                            var device = manager.GetDevice(deviceId);
                            if (device == null) return CommandResult.Fail("Device Not Found");

                            if (device is IRebootFeature rebootFeature)
                            {
                                rebootFeature.RebootAsync().Wait();
                                return CommandResult.Ok("Reboot command sent");
                            }
                            return CommandResult.Fail("Device does not support Reboot");
                        }

                    // ==========================================
                    // 3. 时间同步
                    // ==========================================
                    case "SYNC_TIME":
                        {
                            var device = manager.GetDevice(deviceId);
                            if (device == null) return CommandResult.Fail("Device Not Found");

                            if (device is ITimeSyncFeature timeFeature)
                            {
                                timeFeature.SetTimeAsync(DateTime.Now).Wait();
                                return CommandResult.Ok("Time synced");
                            }
                            return CommandResult.Fail("Device does not support TimeSync");
                        }

                    // ==========================================
                    // 4. 系统级指令 (心跳/诊断)
                    // ==========================================
                    case "PING":
                        return CommandResult.Ok("PONG");

                    default:
                        return CommandResult.Fail($"Unknown Command: {cmd}");
                }
            }
            catch (AggregateException ae)
            {
                // 捕获异步任务内部的异常
                return CommandResult.Fail($"Execution Error: {ae.InnerException?.Message}");
            }
            catch (Exception ex)
            {
                return CommandResult.Fail($"Execution Error: {ex.Message}");
            }
        }
    }
}