using UnityEngine;
using System.Collections;
using UnityEngine.UI;
using UnityEngine.EventSystems;
using System.Collections.Generic;
using System.Linq;

[RequireComponent(typeof(Text))]
public class RotateText : UIBehaviour, IMeshModifier
{
    private Text textComponent;
    private string text = null;
    private char[] characters;

    // 回転させない文字群
    [SerializeField] private List<char> NonRotatableCharacters;
    [SerializeField] static int ShiftChar = 0;
    [SerializeField] private char[] ShiftCharacters = new char[ShiftChar];
    [SerializeField] private float[] ShiftXPixels = new float[ShiftChar];
    [SerializeField] private float[] ShiftYPixels = new float[ShiftChar];

    void Update()
    {
        if (textComponent == null)
        {
            textComponent = this.GetComponent<Text>();
        }
        else
        {
            if (textComponent.text != "")
            {
                if (textComponent.text != text)
                {
                    text = textComponent.text;
                    var graphics = base.GetComponent<Graphic>();
                    if (graphics != null)
                    {
                        graphics.SetVerticesDirty();
                    }
                }
            }
        }
    }

    void OnValidate()
    {
        textComponent = this.GetComponent<Text>();
        if (textComponent.text != null && textComponent.text != "")
        {
            if (textComponent.text != text)
            {
                text = textComponent.text;
                var graphics = base.GetComponent<Graphic>();
                if (graphics != null)
                {
                    graphics.SetVerticesDirty();
                }
            }
        }
    }

    public void ModifyMesh(Mesh mesh) { }
    public void ModifyMesh(VertexHelper verts)
    {
        if (!this.IsActive())
        {
            return;
        }

        List<UIVertex> vertexList = new List<UIVertex>();
        verts.GetUIVertexStream(vertexList);

        ModifyVertices(vertexList);

        verts.Clear();
        verts.AddUIVertexTriangleStream(vertexList);
    }

    void ModifyVertices(List<UIVertex> vertexList)
    {
        if (textComponent != null)
        {
            if (textComponent.text != null && textComponent.text != "")
            {
                characters = textComponent.text.ToCharArray();
                if (characters.Length == 0)
                {
                    return;
                }

                for (int i = 0, vertexListCount = vertexList.Count; i < vertexListCount; i += 6)
                {
                    int index = i / 6;
                    //文字の回転の制御
                    if (!IsNonrotatableCharactor(characters[index]))
                    {
                        var center = Vector2.Lerp(vertexList[i].position, vertexList[i + 3].position, 0.5f);
                        for (int r = 0; r < 6; r++)
                        {
                            var element = vertexList[i + r];
                            var pos = element.position - (Vector3)center;
                            var newPos = new Vector2(
                                            pos.x * Mathf.Cos(90 * Mathf.Deg2Rad) - pos.y * Mathf.Sin(90 * Mathf.Deg2Rad),
                                            pos.x * Mathf.Sin(90 * Mathf.Deg2Rad) + pos.y * Mathf.Cos(90 * Mathf.Deg2Rad)
                                        );
                            element.position = (Vector3)(newPos + center);
                            vertexList[i + r] = element;
                        }
                    }
                    //文字の位置の制御
                    float[] shiftPixel = GetPixelShiftCharactor(characters[index]);
                    if (shiftPixel[0] != 0 || shiftPixel[1] != 0)
                    {
                        var center = Vector2.Lerp(vertexList[i].position, vertexList[i + 3].position, 0.5f);
                        for (int r = 0; r < 6; r++)
                        {
                            var element = vertexList[i + r];
                            Debug.Log("before：" + element.position.x + "," + element.position.y);
                            var pos = element.position - (Vector3)center;
                            var newPos = new Vector2(
                                            pos.x + shiftPixel[0],
                                            pos.y + shiftPixel[1]
                                        );
                            element.position = (Vector3)(newPos + center);
                            Debug.Log("after：" + element.position.x + "," + element.position.y);
                            vertexList[i + r] = element;
                        }
                    }
                }
            }
        }
    }

    bool IsNonrotatableCharactor(char character)
    {
        return NonRotatableCharacters.Any(x => x == character);
    }

    float[] GetPixelShiftCharactor(char character)
    {
        int index = System.Array.IndexOf(ShiftCharacters, character);
        float[] pixel = new float[2];
        if (0 <= index && index < ShiftXPixels.Length && index < ShiftYPixels.Length)
        {
            pixel[0] = ShiftXPixels[index];
            pixel[1] = ShiftYPixels[index];
        }
        return pixel;
    }
}