using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.SceneManagement;
using GeoSus.Client;

namespace Subsystems
{
    /// <summary>
    /// Round-robin task-to-minigame assignment, proximity detection, additive scene launch.
    /// </summary>
    public class GameManager_Tasks
    {
        private class TaskEntry
        {
            public GeoSus.Client.GameTask ServerTask;
            public string MinigameScene;
            public bool Completed;
        }

        private GameClient _gameClient;
        private string[] _minigameScenes;
        private MonoBehaviour _host; // GameManager MonoBehaviour for coroutines
        private List<TaskEntry> _tasks = new List<TaskEntry>();
        private bool _minigameOpen;
        private string _loadedMinigameScene;

        // Proximity state (checked every frame in UpdateProximity)
        public GeoSus.Client.GameTask NearbyTask { get; private set; }

        private const float ProximityRadius = 5f; // metres / Unity units

        public GameManager_Tasks(GameClient gameClient, string[] minigameScenes, MonoBehaviour host)
        {
            _gameClient = gameClient;
            _minigameScenes = minigameScenes ?? new string[0];
            _host = host;
        }

        /// <summary>Called by Network subsystem when RoleAssigned fires.</summary>
        public void Initialize(List<GeoSus.Client.GameTask> serverTasks)
        {
            _tasks.Clear();
            if (_minigameScenes.Length == 0) return;

            for (int i = 0; i < serverTasks.Count; i++)
            {
                _tasks.Add(new TaskEntry
                {
                    ServerTask  = serverTasks[i],
                    MinigameScene = _minigameScenes[i % _minigameScenes.Length],
                    Completed   = false
                });
            }

            // Create map markers
            GameManager.Instance?.mapSubsystem?.CreateTaskMarkers(serverTasks);
            Debug.Log($"[Tasks] Initialized {_tasks.Count} tasks.");
        }

        /// <summary>Called every frame from GameManager.Update().</summary>
        public void UpdateProximity()
        {
            if (_minigameOpen) return;

            NearbyTask = null;
            var myPos = _gameClient.MyPosition;
            if (myPos.Lat == 0 && myPos.Lon == 0) return;

            foreach (var entry in _tasks)
            {
                if (entry.Completed) continue;
                double dist = myPos.DistanceTo(entry.ServerTask.Location);
                if (dist <= ProximityRadius)
                {
                    NearbyTask = entry.ServerTask;
                    break;
                }
            }

            // Drive the action button in UI
            var ui = GameManager.Instance?.uiSubsystem;
            if (ui == null || ui.IsPlayerDead) return;

            bool isImpostor = _gameClient.MyRole == GeoSus.Client.PlayerRole.Impostor;

            if (!isImpostor && NearbyTask != null)
            {
                ui.SetActionButton("USE", true, () => GameManager.Instance?.PerformAction());
                return;
            }

            // Check body proximity
            if (!ui.IsCommsBlackout)
            {
                var body = _gameClient.FindNearbyBody(ProximityRadius);
                if (body != null)
                {
                    ui.SetActionButton("REPORT", true, () => GameManager.Instance?.PerformAction());
                    return;
                }

                // Emergency meeting proximity
                if (_gameClient.CurrentLobbyState?.MapData != null)
                {
                    double dist = myPos.DistanceTo(_gameClient.CurrentLobbyState.MapData.Center);
                    if (dist <= ProximityRadius)
                    {
                        ui.SetActionButton("EMERGENCY", true, () => GameManager.Instance?.PerformAction());
                        return;
                    }
                }
            }

            // Impostor kill
            if (isImpostor)
            {
                var target = _gameClient.FindNearbyPlayer(ProximityRadius);
                if (!string.IsNullOrEmpty(target))
                {
                    ui.SetActionButton("KILL", true, () => GameManager.Instance?.PerformAction());
                    return;
                }
            }

            // Nothing nearby
            ui.SetActionButton("", false);
        }

        /// <summary>Called externally (e.g., GameManager.PerformAction) to launch the nearby task.</summary>
        public void TriggerNearbyTask()
        {
            OnUsePressed();
        }

        private void OnUsePressed()
        {
            if (NearbyTask == null || _minigameOpen) return;
            var entry = _tasks.Find(t => t.ServerTask.TaskId == NearbyTask.TaskId);
            if (entry != null) _host.StartCoroutine(LaunchMinigame(entry));
        }

        private IEnumerator LaunchMinigame(TaskEntry entry)
        {
            _minigameOpen = true;
            Debug.Log($"[Tasks] Launching minigame '{entry.MinigameScene}' for task '{entry.ServerTask.Name}'");

            // Inform server that task started
            _gameClient.Send(new TaskStart { TaskId = entry.ServerTask.TaskId });

            var op = SceneManager.LoadSceneAsync(entry.MinigameScene, LoadSceneMode.Additive);
            yield return op;

            _loadedMinigameScene = entry.MinigameScene;

            // Find the ITask component in the newly loaded scene
            Scene scene = SceneManager.GetSceneByName(entry.MinigameScene);
            ITask taskComponent = null;
            foreach (var root in scene.GetRootGameObjects())
            {
                taskComponent = root.GetComponentInChildren<ITask>();
                if (taskComponent != null) break;
            }

            if (taskComponent == null)
            {
                Debug.LogWarning($"[Tasks] No ITask found in '{entry.MinigameScene}'. Auto-completing.");
                yield return FinishMinigame(entry, true);
                yield break;
            }

            // Set task metadata
            taskComponent.TaskID = entry.ServerTask.TaskId;
            taskComponent.TaskName = entry.ServerTask.Name;
            taskComponent.TaskLocation = (entry.ServerTask.Location.Lat, entry.ServerTask.Location.Lon);

            bool done = false;
            taskComponent.Initialize(t => { done = true; });

            // Wait for completion or exit
            yield return new WaitUntil(() => done);

            yield return FinishMinigame(entry, done);
        }

        private IEnumerator FinishMinigame(TaskEntry entry, bool completed)
        {
            if (completed)
            {
                entry.Completed = true;
                _gameClient.CompleteTask(entry.ServerTask.TaskId);
                Debug.Log($"[Tasks] Task '{entry.ServerTask.Name}' completed.");
            }
            else
            {
                Debug.Log($"[Tasks] Task '{entry.ServerTask.Name}' exited without completion.");
            }

            // Unload minigame scene
            if (!string.IsNullOrEmpty(_loadedMinigameScene))
            {
                var unload = SceneManager.UnloadSceneAsync(_loadedMinigameScene);
                yield return unload;
                _loadedMinigameScene = null;
            }

            _minigameOpen = false;
        }
    }
}