using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Net;
using System.Security.Cryptography;
using System.Text;
using System.Text.RegularExpressions;
using System.Windows.Forms;
using System.Drawing.Imaging;

namespace Test
{
    public partial class Form2 : Form
    {
        // 摄像头配置信息
        private const string IP = "192.168.100.60";
        private const string SNAPSHOT_URI = "/snapshot.jpg";
        private const string USER = "admin";
        private const string PASSWD = "Yexian.net.168";
        
        // 保存路径
        private const string SAVE_DIRECTORY = @"D:\Projects";

        private string _authorization;

        public Form2()
        {
            InitializeComponent();
            
            // 确保保存目录存在
            if (!Directory.Exists(SAVE_DIRECTORY))
            {
                Directory.CreateDirectory(SAVE_DIRECTORY);
            }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Image image = GetCameraImage();
            pictureBox1.Image = image;
            
            // 自动保存图像到D:\Projects目录
            SaveImageToProjects(image);
        }

        /// <summary>
        /// 将图像保存到D:\Projects目录
        /// </summary>
        private void SaveImageToProjects(Image image)
        {
            try
            {
                if (image != null)
                {
                    // 生成带时间戳的文件名
                    string timestamp = DateTime.Now.ToString("yyyyMMdd_HHmmss_fff");
                    string fileName = $"CameraSnapshot_{timestamp}.jpg";
                    string filePath = Path.Combine(SAVE_DIRECTORY, fileName);
                    
                    // 保存图像
                    image.Save(filePath, ImageFormat.Jpeg);
                    
                    MessageBox.Show($"图像已保存到：{filePath}", "保存成功", 
                                  MessageBoxButtons.OK, MessageBoxIcon.Information);
                    
                    System.Diagnostics.Debug.WriteLine($"图像保存成功：{filePath}");
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show($"保存图像失败：{ex.Message}", "保存失败", 
                              MessageBoxButtons.OK, MessageBoxIcon.Error);
                System.Diagnostics.Debug.WriteLine($"图像保存失败：{ex.Message}");
            }
        }

        /// <summary>
        /// 手动保存当前显示的图像
        /// </summary>
        public void SaveCurrentImage()
        {
            if (pictureBox1.Image != null)
            {
                SaveImageToProjects(pictureBox1.Image);
            }
            else
            {
                MessageBox.Show("没有可保存的图像", "提示", 
                              MessageBoxButtons.OK, MessageBoxIcon.Warning);
            }
        }

        private Bitmap GetCameraImage()
        {
            string url = "http://" + IP + SNAPSHOT_URI;

            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
            request.Method = "GET";
            request.Headers.Add("Cache-Control", "no-cache");
            request.Headers.Add("Pragma", "no-cache");

            if (!string.IsNullOrEmpty(_authorization))
            {
                request.Headers.Add("Authorization", _authorization);
            }

            HttpWebResponse response = null;
            try
            {
                response = (HttpWebResponse)request.GetResponse();
            }
            catch (System.Net.WebException ex)
            {
                if (ex.Response != null && ((HttpWebResponse)ex.Response).StatusCode == HttpStatusCode.Unauthorized)
                {
                    response = (HttpWebResponse)ex.Response;
                    string authHeader = response.Headers["WWW-Authenticate"];
                    response.Close();

                    string realm = ExtractAuthParam(authHeader, "realm");
                    string nonce = ExtractAuthParam(authHeader, "nonce");

                    _authorization = GenerateDigestAuthorization(USER, PASSWD, realm, nonce, "GET", SNAPSHOT_URI);

                    request = (HttpWebRequest)WebRequest.Create(url);
                    request.Method = "GET";
                    request.Headers.Add("Authorization", _authorization);
                    response = (HttpWebResponse)request.GetResponse();
                }
                else
                {
                    throw;
                }
            }

            byte[] imageData;
            using (Stream stream = response.GetResponseStream())
            using (MemoryStream memoryStream = new MemoryStream())
            {
                stream.CopyTo(memoryStream);
                imageData = memoryStream.ToArray();
            }

            return new Bitmap(new MemoryStream(imageData));
        }

        /// <summary>
        /// 从WWW-Authenticate头中提取参数
        /// </summary>
        private string ExtractAuthParam(string authHeader, string paramName)
        {
            Regex regex = new Regex(paramName + "=\"([^\"]+)\"");
            Match match = regex.Match(authHeader);
            if (match.Success)
            {
                return match.Groups[1].Value;
            }
            return string.Empty;
        }
        /// <summary>
        /// 生成Digest认证的Authorization头
        /// </summary>
        private string GenerateDigestAuthorization(string username, string password, string realm, string nonce, string method, string uri)
        {
            string ha1 = CalculateMD5(username + ":" + realm + ":" + password);
            string ha2 = CalculateMD5(method + ":" + uri);
            string response = CalculateMD5(ha1 + ":" + nonce + ":" + ha2);

            return string.Format("Digest username=\"{0}\", realm=\"{1}\", nonce=\"{2}\", uri=\"{3}\", response=\"{4}\"",
                username, realm, nonce, uri, response);
        }
        /// <summary>
        /// 计算MD5哈希值
        /// </summary>
        private string CalculateMD5(string input)
        {
            using (MD5 md5 = MD5.Create())
            {
                byte[] inputBytes = System.Text.Encoding.UTF8.GetBytes(input);
                byte[] hashBytes = md5.ComputeHash(inputBytes);

                System.Text.StringBuilder sb = new System.Text.StringBuilder();
                for (int i = 0; i < hashBytes.Length; i++)
                {
                    sb.Append(hashBytes[i].ToString("x2"));
                }
                return sb.ToString();
            }
        }
    }
}