using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Net;
using System.IO;
using System.Threading;
using System.Net.NetworkInformation;
using System.Diagnostics;

namespace WindowsFormsApplication1 {
    public partial class Viewer : Form {
        string[] IMAGE_FORMATS = new string[] { ".JPG", ".JPEG", ".PNG", ".BMP", ".GIF", ".TIFF" };
        const string hostMain = "http://rghost.ru/main";
        const string hostRu = "http://rghost.ru";
        const string proxyConfPath = "proxy.conf";

        public Viewer() {
            InitializeComponent();
            panel1.Dock = DockStyle.Fill;
            flowLayoutPanel1.Dock = DockStyle.Top;
            flowLayoutPanel1.Height = 2000;
            LoadProxy();
        }

        void UpdateConnectedState() {
            PingHost(hostRu);
        }

        WebProxy _proxy;
        bool _connected = false;
        bool Connected {
            get { return _connected; }
            set {
                if(!value) {
                    toolStripStatusLabel1.Text = "Disconnected";
                }
                else {
                    toolStripStatusLabel1.Text = "Connected";
                }
                toolStripButton1.Enabled = true;
                _connected = value;
            }
        }

        void DoRefresh() {
            if(!Connected) {
                UpdateConnectedState();
                return;
            }
            List<string> urlsToLoad = new List<string>();
            try {
                toolStripStatusLabel1.Text = "Getting images from host...";
                toolStripButton1.Enabled = false;
                Application.DoEvents();
                WebRequest request = WebRequest.Create(hostMain);
                using(var response = request.GetResponse()) {
                    using(var stream = response.GetResponseStream()) {
                        string html;
                        using(StreamReader sr = new StreamReader(stream)) {
                            html = sr.ReadToEnd();
                            int startInd = html.IndexOf(@"class=""main-column""");
                            int endInd = html.IndexOf(@"<a href=""/files"">Далее");
                            if(endInd <= startInd) return;
                            html = html.Substring(startInd, endInd - startInd);
                            List<string> lis = html.Split(new string[] { "<li>" }, StringSplitOptions.RemoveEmptyEntries).ToList();
                            LeaveOnlyImages(lis);
                            foreach(string li in lis) {
                                List<string> splits = li.Split(new string[] { @"""" }, StringSplitOptions.RemoveEmptyEntries).ToList();
                                if(splits.Count > 1) urlsToLoad.Add(splits[1]);
                            }
                        }
                    }
                }
            }
            catch { Connected = false; }
            finally {
                ClearPix();
                urlsToLoad = urlsToLoad.Distinct().ToList();
                ProceedURLs(urlsToLoad);
            }
        }

        void LeaveOnlyImages(List<string> lis) {
            List<string> lisToRemove = new List<string>();
            foreach(string li in lis) {
                string upperli = li.ToUpper();
                string[] splits = upperli.Split(IMAGE_FORMATS, StringSplitOptions.RemoveEmptyEntries);
                if(splits.Length <= 1) lisToRemove.Add(li);
            }
            foreach(string liToRemove in lisToRemove) {
                lis.Remove(liToRemove);
            }
        }

        void ClearPix() {
            while(flowLayoutPanel1.Controls.Count > 0) {
                Control c = flowLayoutPanel1.Controls[0];
                flowLayoutPanel1.Controls.Remove(c);
                c.MouseDoubleClick -= new MouseEventHandler(pic_MouseDoubleClick);
                c.Dispose();
                c = null;
            }
        }

        private void ProceedURLs(List<string> urlsToLoad) {
            if(urlsToLoad.Count == 0) { toolStripButton1.Enabled = true; return; }
            foreach(string url in urlsToLoad) {
                bool last = urlsToLoad.IndexOf(url) == urlsToLoad.Count - 1;
                Thread t = new Thread(() => {
                    LoadImage(url, last);
                });
                t.Start();
            }
        }

        void LoadImage(string url, bool last) {
            WebRequest request = WebRequest.Create(hostRu + url + "/thumb.png");
            try {
                using(var response = request.GetResponse()) {
                    using(var stream = response.GetResponseStream()) {
                        Image img = Bitmap.FromStream(stream);
                        if(img == null) return;
                        PictureBox pic = new PictureBox() { Size = img.Size, Image = img, Tag = hostRu + url };
                        pic.MouseDoubleClick += new MouseEventHandler(pic_MouseDoubleClick);
                        flowLayoutPanel1.Invoke(new Action(() => {
                            flowLayoutPanel1.Controls.Add(pic);
                        }));
                    }
                }
            }
            catch { }
            finally {
                if(last) {
                    toolStrip1.Invoke(new Action(() => {
                        toolStripButton1.Enabled = true;
                        toolStripStatusLabel1.Text = "Done!";
                    }));
                }
            }
        }

        void pic_MouseDoubleClick(object sender, MouseEventArgs e) {
            Control c = sender as Control;
            string url = (string) c.Tag;
            Process.Start(url);
        }

        public void PingHost(string nameOrAddress) {
            toolStripStatusLabel1.Text = "Ping host...";
            Thread tr = new Thread(() => { RequestPing(nameOrAddress, this); });
            tr.Start();
        }

        void RequestPing(string nameOrAddress, Viewer control) {
            try {
                WebRequest request = WebRequest.Create(nameOrAddress);
                using(var response = request.GetResponse()) {
                    control.Invoke(new Action(() => {
                        control.Connected = true;
                    }));
                }
            }
            catch {
                control.Invoke(new Action(() => {
                    control.Connected = false;
                }));
            }
        }

        private void toolStripButton1_Click(object sender, EventArgs e) {
            DoRefresh();
        }

        private void checkBox1_CheckedChanged(object sender, EventArgs e) {
            if(checkBox1.Checked)
                WebRequest.DefaultWebProxy = _proxy;
            else
                WebRequest.DefaultWebProxy = null;
        }

        private void textBox1_TextChanged(object sender, EventArgs e) {
            try {
                string str = textBox1.Text.Trim();
                _proxy = new WebProxy(@"http://" + str);
                if(checkBox1.Checked) {
                    WebRequest.DefaultWebProxy = _proxy;
                    this.Connected = false;
                }
                SaveProxy();
            }
            catch { }
        }

        void SaveProxy() {
            try {
                string str = textBox1.Text.Trim();
                File.WriteAllText(proxyConfPath, str);
            }
            catch { }
        }
        void LoadProxy() {
            try {
                if(File.Exists(proxyConfPath))
                    textBox1.Text = File.ReadAllText(proxyConfPath);
            }
            catch { }
        }
    }
}