using System.Collections.Generic;
using UnityEngine;
using Unity.Cinemachine;

public class CameraManager : MonoBehaviour
{
    public static CameraManager Instance { get; private set; }

    [System.Serializable]
    public class CameraEntry
    {
        public string id;
        public CinemachineVirtualCameraBase camera;
        public int activePriority = 20;
        public int inactivePriority = 10;
    }

    [Header("Setup")]
    public bool dontDestroyOnLoad = true;
    public bool disableInactiveCameras = false;
    public CinemachineBrain brain;

    [Header("Cameras")]
    public List<CameraEntry> cameras = new List<CameraEntry>();

    private readonly Dictionary<string, CameraEntry> cameraLookup = new Dictionary<string, CameraEntry>();
    private CameraEntry current;

    private void Awake()
    {
        if (Instance != null && Instance != this)
        {
            Destroy(gameObject);
            return;
        }

        Instance = this;
        if (dontDestroyOnLoad)
        {
            DontDestroyOnLoad(gameObject);
        }

        RebuildLookup();
        if (brain == null)
        {
            brain = FindAnyObjectByType<CinemachineBrain>();
        }
    }

    private void OnValidate()
    {
        for (int i = 0; i < cameras.Count; i++)
        {
            CameraEntry entry = cameras[i];
            if (entry != null && string.IsNullOrEmpty(entry.id) && entry.camera != null)
            {
                entry.id = entry.camera.name;
            }
        }
    }

    public void RebuildLookup()
    {
        cameraLookup.Clear();
        foreach (CameraEntry entry in cameras)
        {
            if (entry == null || entry.camera == null || string.IsNullOrEmpty(entry.id))
            {
                continue;
            }

            if (!cameraLookup.ContainsKey(entry.id))
            {
                cameraLookup.Add(entry.id, entry);
            }
        }
    }

    public void SwitchTo(string id)
    {
        if (string.IsNullOrEmpty(id)) return;
        if (!cameraLookup.TryGetValue(id, out CameraEntry entry) || entry.camera == null)
        {
            Debug.LogWarning($"CameraManager: No camera registered with id '{id}'.", gameObject);
            return;
        }

        SwitchTo(entry.camera);
    }

    public void SwitchTo(CinemachineVirtualCameraBase targetCamera)
    {
        if (targetCamera == null) return;

        foreach (CameraEntry entry in cameras)
        {
            if (entry == null || entry.camera == null) continue;

            bool isActive = entry.camera == targetCamera;
            entry.camera.Priority = isActive ? entry.activePriority : entry.inactivePriority;

            if (disableInactiveCameras)
            {
                entry.camera.gameObject.SetActive(isActive);
            }

            if (isActive)
            {
                current = entry;
            }
        }
    }

    public CinemachineVirtualCameraBase GetActiveCamera()
    {
        return current != null ? current.camera : null;
    }

    public void SetFollow(Transform followTarget)
    {
        CinemachineVirtualCameraBase cam = GetActiveCamera();
        if (cam != null)
        {
            cam.Follow = followTarget;
        }
    }

    public void SetLookAt(Transform lookTarget)
    {
        CinemachineVirtualCameraBase cam = GetActiveCamera();
        if (cam != null)
        {
            cam.LookAt = lookTarget;
        }
    }

    public void SetDefaultBlend(string style, float time)
    {
        if (brain == null)
        {
            brain = FindAnyObjectByType<CinemachineBrain>();
        }

        if (brain != null && System.Enum.TryParse<CinemachineBlendDefinition.Styles>(style, out var blendStyle))
        {
            brain.DefaultBlend = new CinemachineBlendDefinition(blendStyle, time);
        }
    }

    public void RegisterCamera(string id, CinemachineVirtualCameraBase cam, int activePriority = 20, int inactivePriority = 10)
    {
        if (cam == null || string.IsNullOrEmpty(id)) return;

        CameraEntry entry = new CameraEntry
        {
            id = id,
            camera = cam,
            activePriority = activePriority,
            inactivePriority = inactivePriority
        };

        cameras.Add(entry);
        RebuildLookup();
    }

    public void UnregisterCamera(string id)
    {
        if (string.IsNullOrEmpty(id)) return;

        for (int i = cameras.Count - 1; i >= 0; i--)
        {
            if (cameras[i] != null && cameras[i].id == id)
            {
                cameras.RemoveAt(i);
            }
        }

        RebuildLookup();
    }
}