using System;
using System.Collections.Generic;
using System.IO;
using UnityEngine;
using ZXing;
using ZXing.Common;
using ZXing.QrCode;
using ZXing.QrCode.Internal;

namespace GeneralTools
{
    public class QRTool
    {

        ///// <summary>
        ///// 将内容转换到二维码并写入文件
        ///// </summary>
        ///// <param name="path"></param>
        //public static void WriteToFile(string path, TexStyle style, string content, int qrWidth, int qrHeight, Texture2D middleTex = null)
        //{
        //    byte[] bytes = TexConvertBytes(GeneQRwithString2(content, qrWidth, qrHeight, middleTex), style);
        //    using (FileStream fs = new FileStream(path, FileMode.OpenOrCreate, FileAccess.ReadWrite))
        //    {
        //        fs.Write(bytes, 0, bytes.Length);
        //    }
        //}

        /// <summary>
        /// 创建二维码,不能添加小图片，不需要图标时推荐
        /// </summary>
        /// <param name="content">二维码的内容</param>
        /// <param name="qrWidth">二维码的宽度</param>
        /// <param name="qrHeight">二维码的高度</param>
        /// <returns>二维码生成的Texture2D</returns>
        public static Texture2D GeneQRwithString1(string content, int qrWidth, int qrHeight)
        {
            // 创建 BarcodeWriter 并设置条件
            QrCodeEncodingOptions options = new QrCodeEncodingOptions()
            {
                CharacterSet = "UTF-8",
                Width = qrWidth,
                Height = qrHeight,
                // 边缘宽度
                Margin = 2,
            };
            BarcodeWriter barcodeWriter = new BarcodeWriter()
            {
                Format = BarcodeFormat.QR_CODE,
                Options = options
            };
            Color32[] colors = barcodeWriter.Write(content);
            // 创建一张和二维码一样像素的 Texture2D
            Texture2D tex = new Texture2D(qrWidth, qrHeight);
            tex.SetPixels32(colors);
            tex.Apply();
            return tex;
        }


        /// <summary>
        /// 创建二维码,添加小图标,可以不添加
        /// </summary>
        /// <param name="content">二维码的内容</param>
        /// <param name="qrWidth">二维码的宽度</param>
        /// <param name="qrHeight">二维码的高度</param>
        /// <param name="middleTex">添加的小图标</param>
        /// <returns>二维码生成的Texture2D</returns>
        public static Texture2D GeneQRwithString2(string content, int qrWidth, int qrHeight, Texture2D middleTex = null)
        {
            // 将 content 编码成 bit矩阵
            Dictionary<EncodeHintType, object> hints = new Dictionary<EncodeHintType, object>();
            hints.Add(EncodeHintType.CHARACTER_SET, "UTF-8");                    // 编码
            hints.Add(EncodeHintType.MARGIN, 2);                                 // 边缘距离
            hints.Add(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);  // 纠错方式
            MultiFormatWriter writer = new MultiFormatWriter();
            BitMatrix bitMatrix = writer.encode(content, BarcodeFormat.QR_CODE, qrWidth, qrHeight, hints); // bit 矩阵

            Texture2D tex = new Texture2D(qrWidth, qrHeight);
            for (int y = 0; y < qrHeight; y++)
            {
                for (int x = 0; x < qrWidth; x++)
                {
                    if (bitMatrix[x, y])
                    {
                        tex.SetPixel(x, y, Color.black);   // true 的地方 不能用白色
                    }
                    else
                    {
                        tex.SetPixel(x, y, Color.white);    // false 的位置 不能用黑色
                    }
                }
            }
            // 在 Tex2D的中间添加图片，是不会影响检测的
            if (middleTex != null)
            {
                AddTex(middleTex, tex.width / 2f, tex.height / 2f, tex);
            }
            tex.Apply();
            return tex;
        }


        /// <summary>
        /// 在二维码中插入小图标
        ///                         在 Tex2D的中间添加小的图片，是不会影响检测的
        /// </summary>
        /// <param name="addTex">添加的Texture2D</param>
        /// <param name="centerX">添加的图的中心点 ==> 大图左下角为起始点</param>
        /// <param name="centerY">添加的图的中心点 ==> 大图左下角为起始点</param>
        /// <param name="qrTex">源二维码的图片</param>
        private static void AddTex(Texture2D addTex, float centerX, float centerY, Texture2D qrTex)
        {
            float addTexWidth = addTex.width;
            float addTexHeight = addTex.height;
            // 小图片左下角 在 大图中的坐标(因为 Texture2D的坐标原点在左下角 )
            Vector2 localAddTexOriginal = new Vector2((int)(centerX - addTexWidth / 2f), (int)(centerY - addTexHeight / 2));
            for (int x = 0; x < qrTex.width; x++)
            {
                for (int y = 0; y < qrTex.height; y++)
                {
                    // 坐标在 添加的图内部，就改成添加图的像素信息
                    if (Mathf.Abs(x - centerX) <= addTexWidth / 2 && Mathf.Abs(y - centerY) <= addTexHeight / 2)
                    {
                        // 获取添加图的像素
                        Vector2 local = new Vector2(x, y) - localAddTexOriginal; // x,y 相对于下图左下角的向量(坐标)
                        Color color = addTex.GetPixel((int)local.x, (int)local.y);
                        // 将像素赋给二维码图像
                        qrTex.SetPixel(x, y, color);
                    }
                }
            }
        }
    }
}