using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class UIModelUtil : MonoBehaviour
{
  public Animator animator;
  public int id;
  public int index;

}

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class UIModelControl : MonoBehaviour
{
  public Transform modelsParent;
  public Transform centerPos;
  public float interval;
  public bool loop;

  List<UIModelUtil> models;
  bool isPressing;
  public UIDrag dragComp;


  Vector3 mousePos;

  private void Awake()
  {
    if(models == null)
    {
      int i = 0;
      models = new List<UIModelUtil>();
      foreach(UIModelUtil util in modelsParent.GetComponentsInChildren<UIModelUtil>())
      {
        models.Add(util);
        //util.index = i;
        Vector3 pos = Vector3.zero;
        pos.x = i * interval;
        util.transform.localPosition = pos;
        i++;
      }
    }
  }

  private void Start()
  {
    JumpToSelect();
  }

  
  private void Update()
  {
    //接受拖拽事件
    if (isPressing)
    {
      float x = GetInputDeltaX();
      int dir = 0;
      if (x > 0) dir = 1;
      else if (x < 0) dir = -1;

      //分辨率修正
      if (dir == 0) return;
      x = Mathf.Abs(x) / (Screen.width) * 800f;
      if (x > 800f) x = 800f;

      //偏移
      float currectX = Mathf.Lerp(0, interval, x / 800f) * dir;
      Vector3 pos = modelsParent.position;
      pos.x += currectX;



        Transform right = GetRight().transform;
        Transform left = GetLeft().transform;
      //不循環(huán)時(shí)候設(shè)置邊框
      if (models.Count > 2 || !loop || models.Count == 1)
      {
    

        if (right.localPosition.x + interval / 10 < -pos.x) pos.x = -(right.localPosition.x + interval / 10);
        else if (left.localPosition.x - interval / 10 > -pos.x) pos.x = -(left.localPosition.x - interval / 10);

        //modelsParent.position = pos;
      }
      //只有兩個(gè)循環(huán)的時(shí)候
      else if (models.Count == 2 && loop)
      {

        Transform selected = GetSelect().transform;
        //當(dāng)前是右邊那個(gè)且向右拖拽
        if (selected == right && dir < 0)
        {
          
          Vector3 leftPos = left.localPosition;
          leftPos.x = right.localPosition.x + interval;
          left.localPosition = leftPos;
        }
        //當(dāng)前是左邊那個(gè)且向左拖拽
        else if (selected == left && dir > 0)
        {
          Vector3 rightPos = right.localPosition;
          rightPos.x = left.localPosition.x - interval;
          right.localPosition = rightPos;
        }
      }
      modelsParent.position = pos;
      
      AfterSelect();
    }
  }


  void AfterSelect()
  {
    foreach(UIModelUtil util in models)
    {
      float dis = GetXDis(util);
      //設(shè)置顯示
      if (dis > interval)
        util.gameObject.SetActive(false);
      else
      { 
        //越靠近中間越前
        util.gameObject.SetActive(true);
        float t = Mathf.Abs(dis) / interval;
        float y = Mathf.Lerp(centerPos.position.z, modelsParent.position.z, t);
        Vector3 pos = util.transform.position;
        pos.z = y;
        util.transform.position = pos;
      }

    }
    //循環(huán)時(shí)候位置修正
    if (loop && models.Count > 2)
    {
      Transform right = GetRight().transform;
      Transform left = GetLeft().transform;
      Transform selected = GetSelect().transform;
      if (selected == right)
      {
        Vector3 pos = right.position;
        pos.x += interval;
        left.position = pos;
      }
      else if (selected == left)
      {
        Vector3 pos = left.position;
        pos.x -= interval;
        right.position = pos;
      }
    }
    //設(shè)置UI選中狀況
    dragComp.OnSelected(GetSelect().id, GetSelect().index);
  }

  //通過id選中
   UIModelUtil GetById(int id)
  {
    if (models == null) return null;
    UIModelUtil target = null;

    foreach (UIModelUtil util in models)
    {
      if (util.id == id) return util;
    }
    return target;
  }

  //獲取當(dāng)前選中
   UIModelUtil GetSelect()
  {
    if (models == null) return null;
    float min = 9999;

    UIModelUtil target = null;

    foreach(UIModelUtil util in models)
    {
      float dis = Mathf.Abs( GetXDis(util));
      if(dis < min)
      {
        target = util;
        min = dis;
      }
    }
    return target;
  }

  //所有模型最右邊的那個(gè)
   UIModelUtil GetRight()
  {
    if (models == null) return null;
    float max = -9999;

    UIModelUtil target = null;

    foreach(UIModelUtil util in models)
    {
      float dis = util.transform.localPosition.x;
      if(dis > max)
      {
        target = util;
        max = dis;
      }
    }

    return target;
  }

  //所有模型最左邊的那個(gè)
   UIModelUtil GetLeft()
  {
    if (models == null) return null;
    float min = 9999;

    UIModelUtil target = null;

    foreach(UIModelUtil util in models)
    {
      float dis = util.transform.localPosition.x;
      if(dis < min)
      {
        target = util;
        min = dis;
      }
    }


    return target;
  }

  //UI控件按下觸發(fā)
  public void OnPress()
  {
    if (isPressing) return;
    isPressing = true;

    if (Application.isEditor)
      mousePos = Input.mousePosition;
    else
      mousePos = Input.GetTouch(0).position;
    if (backing != null) StopCoroutine(backing);
  }

  //UI控件釋放觸發(fā)
  public void OnRelease()
  {
    backing = StartCoroutine(ToSelect());
    isPressing = false;
  }


  Coroutine backing;
  //釋放后偏移
  IEnumerator ToSelect()
  {


    UIModelUtil selected = GetSelect();
    float dis = GetXDis(selected);
    float time = Mathf.Lerp (0, 1f, Mathf.Abs(dis) / interval);
    float timer = 0;
    Vector3 from = modelsParent.localPosition;
    Vector3 to = from;
    to.x = -selected.transform.localPosition.x;

    while(timer < time)
    {
      timer += Time.deltaTime;
      float t = timer / time;
      Vector3 pos = Vector3.Lerp(from, to, t);
      modelsParent.localPosition = pos;
      AfterSelect();
      yield return null;
    }
    backing = null;

  }

  //獲取手指偏移量
  float GetInputDeltaX()
  {
    Vector3 pos;
    if (Application.isEditor)
      pos = Input.mousePosition;
    else
      pos = Input.GetTouch(0).position;
    Vector3 delta = pos - mousePos;
    //Debug.Log(pos +"/"+mousePos +"/"+ delta.x);
    mousePos = pos;
    return delta.x;
      
  }

  //計(jì)算偏移中心位置的X軸距離
  float GetXDis(UIModelUtil util)
  {
    return util.transform.position.x - centerPos.position.x;
  }

  // 跳轉(zhuǎn)到選中的id
  public void JumpToSelect()
  {
    int id = CharacterManager.characterId;
    Vector3 pos = modelsParent.localPosition;
    UIModelUtil selected = GetById(id);
    pos.x = -selected.transform.localPosition.x;
    modelsParent.localPosition = pos;

    AfterSelect();
  }


}

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.EventSystems;
public class UIDrag : MonoBehaviour,IPointerDownHandler, IPointerUpHandler
{
  public UIModelControl control;

  virtual public void OnPointerDown(PointerEventData data)
  {
    control.OnPress();
  }

  virtual public void OnPointerUp(PointerEventData data)
  {
    control.OnRelease();
  }

  virtual public void OnSelected(int id, int index)
  {

  }
}