using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;
using RyzStudio.IO;
using RyzStudio.Runtime.InteropServices;
using RyzStudio.Windows.Forms;

namespace RandomFileRunner
{
    public partial class MainForm : Form
    {
        private readonly FileSearcher _fileSearcher;
        private CancellationTokenSource _cancellationToken = new CancellationTokenSource();

        private List<string> _foundFiles = new List<string>();
        private Process _currentProcess = null;


        public MainForm()
        {
            InitializeComponent();

            _fileSearcher = new FileSearcher();
            _fileSearcher.OnDirectoryFound += fileSearcher_OnDirectoryFound;
            _fileSearcher.OnFileFound += fileSearcher_OnFileFound;
            _fileSearcher.OnSearchCompleted += fileSearcher_OnSearchCompleted;

            memoBox1.WordWrap = false;
            memoBox1.ScrollBars = ScrollBars.Vertical;
        }

        protected async override void OnLoad(EventArgs e)
        {
            base.OnLoad(e);

            this.ClearSession();

            var args = this.GetCommandLine();

            string jsonfigFilename = null;

            if (!args.TryGetValue("o", out jsonfigFilename))
            {
                if (!args.TryGetValue("open", out jsonfigFilename))
                {
                    jsonfigFilename = null;
                }
            }

            if (string.IsNullOrWhiteSpace(jsonfigFilename))
            {
                jsonfigFilename = Path.ChangeExtension(Application.ExecutablePath, "jsonfig");
            }

            if (System.IO.File.Exists(jsonfigFilename))
            {
                await LoadSessionFile(jsonfigFilename);

                UIControl.Invoke(button1, (x) => button1.Enabled = (this.CurrentSession.SearchItems.Count > 0));
            }
        }

        protected async override void OnShown(EventArgs e)
        {
            base.OnShown(e);

            memoBox1.Focus();
        }

        protected override void OnFormClosing(FormClosingEventArgs e)
        {
            base.OnFormClosing(e);

            if (this.IsBusy)
            {
                e.Cancel = true;
                return;
            }

            if (this.CurrentSession.ClosePrevOnNext)
            {
                CloseCurrentProcess(_currentProcess);
            }

            if (this.CurrentSession.NextHotKey != null)
            {
                if (this.CurrentSession.NextHotKey.KeyCode != Keys.None)
                {
                    //#if !DEBUG
                    User32.UnregisterHotKey((IntPtr)Handle, 1);
                    //#endif
                }
            }
        }

        protected override void WndProc(ref Message m)
        {
            switch (m.Msg)
            {
                case User32.WM_HOTKEY:
                    if (m.WParam.ToInt32() == 1)
                    {
                        dialogFooter1_OnButton1Click(null, null);
                    }

                    break;
                //case WM_QUERYENDSESSION:
                //    requestExit = true;
                //    //this.Close();
                //    Application.Exit();

                //    break;
                default:
                    break;
            }

            base.WndProc(ref m);
        }


        public bool IsBusy
        {
            get => field;
            private set
            {
                field = value;

                UIControl.Invoke(pictureBox1, (x) => pictureBox1.Image = (value ? RyzStudio.Resources.T3Resource.loading_block : null));
                UIControl.Invoke(textBox1, (x) => textBox1.Enabled = !value);
                UIControl.Invoke(button1, (x) => button1.LabelText = (value ? "&Cancel" : "&Search"));
                UIControl.Invoke(dialogFooter1, (x) => dialogFooter1.Button1Visible = !value);
            }
        }

        public AppSession CurrentSession
        {
            get
            {
                if (field == null) field = new AppSession();

                return field;
            }
            private set => field = value;
        } = new AppSession();

        private List<string> SearchPathList
        {
            get
            {
                return (memoBox1.Lines?.ToList() ?? new List<string>()).Where(x => !string.IsNullOrWhiteSpace(x)).ToList();
            }
        }

        private void menuStrip1_MenuActivate(object sender, EventArgs e)
        {
            saveAsToolStripMenuItem.Enabled = (!this.IsBusy && (this.SearchPathList.Count > 0));
            toolStripMenuItem2.Enabled = (!this.IsBusy && (_foundFiles.Count > 0));
        }

        #region Main Menu

        /// <summary>
        /// New
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private async void newToolStripMenuItem_Click(object sender, EventArgs e)
        {
            await Task.Run(() =>
            {
                if (this.IsBusy)
                {
                    return;
                }

                if (this.CurrentSession.ClosePrevOnNext)
                {
                    CloseCurrentProcess(_currentProcess);
                }

                ClearSession();
            });
        }

        /// <summary>
        /// Open
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private async void openToolStripMenuItem_Click(object sender, EventArgs e)
        {
            if (this.IsBusy)
            {
                return;
            }

            if (openFileDialog2.ShowDialog() == DialogResult.OK)
            {
                await LoadSessionFile(openFileDialog2.FileName);
            }
        }

        /// <summary>
        /// Save as
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private async void saveAsToolStripMenuItem_Click(object sender, EventArgs e)
        {
            if (this.IsBusy)
            {
                return;
            }

            saveFileDialog1.Title = "Save session";
            saveFileDialog1.Filter = "Session files (*.jsonfig)|*.jsonfig";
            saveFileDialog1.DefaultExt = "jsonfig";

            if (saveFileDialog1.ShowDialog() == DialogResult.OK)
            {
                await SaveSessionFile(saveFileDialog1.FileName);
            }
        }

        /// <summary>
        /// Export file list
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private async void toolStripMenuItem2_Click(object sender, EventArgs e)
        {
            if (this.IsBusy)
            {
                return;
            }

            if (_foundFiles.Count <= 0)
            {
                return;
            }

            saveFileDialog1.Title = "Save File List";
            saveFileDialog1.Filter = "Text files (*.txt)|*.txt";
            saveFileDialog1.DefaultExt = "txt";

            if (saveFileDialog1.ShowDialog() == DialogResult.OK)
            {
                try
                {
                    await System.IO.File.WriteAllTextAsync(saveFileDialog1.FileName, string.Join(Environment.NewLine, _foundFiles.ToArray()));
                }
                catch (Exception exc)
                {
                    RyzStudio.Forms.T3MessageBox.Show(this, exc.Message, "Save File List", MessageBoxButtons.OK, MessageBoxIcon.Error);
                }
            }
        }

        /// <summary>
        /// Close
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void exitToolStripMenuItem2_Click(object sender, EventArgs e)
        {
            this.Close();
        }


        /// <summary>
        /// Export File List
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private async void toolStripMenuItem1_Click(object sender, EventArgs e)
        {
        }

        /// <summary>
        /// Options
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void optionsToolStripMenuItem_Click(object sender, EventArgs e)
        {
            if (this.IsBusy)
            {
                return;
            }

            var optionsForm = new OptionsForm(this.CurrentSession);
            if (optionsForm.ShowDialog() == DialogResult.OK)
            {
                this.CurrentSession = optionsForm.Result;

                InvalidateHotKey();
            }
        }


        /// <summary>
        /// Help
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void viewHelpToolStripMenuItem1_Click(object sender, EventArgs e)
        {
            RyzStudio.Diagnostics.Process.Execute(AppResource.AppHelpURL);
        }

        /// <summary>
        /// About
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void aboutToolStripMenuItem1_Click(object sender, EventArgs e)
        {
            var form = new RyzStudio.Forms.T3AboutForm();
            form.ProductURL = AppResource.AppProductURL;
            form.AuthorURL = AppResource.AppAuthorURL;
            form.CompanyURL = AppResource.AppCompanyURL;
            form.ProductCopyrightStartYear = 2021;
            form.ProductLogo = AppResource.icon_64;

            form.ShowDialog();
        }

        #endregion

        #region Search Engine

        private async Task fileSearcher_OnFileFound(FileSearcher sender, string searchPath, string fileName)
        {
            await Task.Run(() =>
            {
                _foundFiles.Add(fileName);

                UIControl.Invoke(label3, (x) => label3.Text = Path.GetFileName(fileName));

                progressBar2.Maximum = (sender.FileCount + sender.NoAccessFileCount);
                progressBar2.Value = sender.FileCount;
            });
        }

        private async Task fileSearcher_OnDirectoryFound(FileSearcher sender, string searchPath, string directoryName)
        {
            await Task.Run(() =>
            {
                UIControl.Invoke(label4, (x) => label4.Text = Path.GetFileName(directoryName));

                progressBar1.Maximum = sender.DirectoryCount;
                progressBar1.Value = sender.BufferLevel;
            });
        }

        private async Task fileSearcher_OnSearchCompleted(FileSearcher sender, TimeSpan elapsedTime)
        {
            await Task.Run(() =>
            {
                if (!_cancellationToken.IsCancellationRequested)
                {
                    UIControl.Invoke(label4, (x) => label4.Text = $"Done ({Math.Floor(elapsedTime.TotalMinutes)}m {elapsedTime.Seconds}s)");
                }
                else
                {
                    UIControl.Invoke(label4, (x) => label4.Text = $"Cancelled ({Math.Floor(elapsedTime.TotalMinutes)}m {elapsedTime.Seconds}s)");

                    _cancellationToken = new CancellationTokenSource();
                }

                UIControl.Invoke(label3, (x) => label3.Text = ((_foundFiles.Count <= 0) ? "0" : _foundFiles.Count.ToString("#,#", System.Globalization.CultureInfo.CurrentCulture)) + " File" + ((_foundFiles.Count == 1) ? "" : "s") + " Found");

                progressBar1.Value = sender.BufferLevel;
                progressBar2.Value = sender.FileCount;

                UIControl.Invoke(dialogFooter1, (x) => dialogFooter1.Button1Visible = (_foundFiles.Count > 0));

                this.IsBusy = false;
            });
        }

        #endregion


        /// <summary>
        /// Search
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private async void button2_MouseClick(object sender, MouseEventArgs e)
        {
            if (this.IsBusy)
            {
                button1.LabelText = "&Cancelling...";
                _cancellationToken.Cancel();

                return;
            }

            this.IsBusy = true;

            progressBar1.ShowText = true;
            progressBar2.ShowText = true;

            _foundFiles = new List<string>();
            _cancellationToken = new CancellationTokenSource();
            _currentProcess = null;

            var paths = this.SearchPathList;

            _fileSearcher.FileSearchPattern = textBox1.Text;
            _fileSearcher.SearchPath = new List<string>();

            UIControl.Invoke(label4, (x) => label4.Text = $"Peeking...");
            UIControl.Invoke(label3, (x) => label3.Text = "");

            await Task.Run(() =>
            {
                foreach (var item in paths)
                {
                    if (_cancellationToken.IsCancellationRequested)
                    {
                        break;
                    }

                    if (System.IO.File.Exists(item))
                    {
                        _foundFiles.Add(item);

                        UIControl.Invoke(label3, (x) => label3.Text = item);
                        continue;
                    }

                    if (System.IO.Directory.Exists(item))
                    {
                        _fileSearcher.SearchPath.Add(item);

                        UIControl.Invoke(label3, (x) => label3.Text = item);
                        continue;
                    }
                }

                UIControl.Invoke(label4, (x) => label4.Text = $"Peeking... {paths.Count}");
                UIControl.Invoke(label3, (x) => label3.Text = ((_foundFiles.Count <= 0) ? "0" : _foundFiles.Count.ToString("#,#", System.Globalization.CultureInfo.CurrentCulture)) + " File" + ((_foundFiles.Count == 1) ? "" : "s") + " Found");
            });

            if (_fileSearcher.SearchPath.Count <= 0)
            {
                UIControl.Invoke(label4, (x) => label4.Text = $"Done");
                UIControl.Invoke(label3, (x) => label3.Text = ((_foundFiles.Count <= 0) ? "0" : _foundFiles.Count.ToString("#,#", System.Globalization.CultureInfo.CurrentCulture)) + " File" + ((_foundFiles.Count == 1) ? "" : "s") + " Found");
            }
            else
            {
                UIControl.Invoke(label4, (x) => label4.Text = $"Searching...");

                await _fileSearcher.Search(_cancellationToken.Token);
            }

            //this.IsBusy = false;
        }

        /// <summary>
        /// Close
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button1_MouseClick(object sender, MouseEventArgs e)
        {
            this.Close();
        }


        private void CloseCurrentProcess(Process p)
        {
            if (p == null)
            {
                return;
            }

            try
            {
                p.CloseMainWindow();
            }
            catch (Exception)
            {
                // do nothing
            }
        }

        private void InvalidateHotKey()
        {
            //#if !DEBUG
            UIControl.Invoke(this, (x) =>
            {
                User32.UnregisterHotKey((IntPtr)Handle, 1);
            });
            //#endif

            if (this.CurrentSession.NextHotKey != null)
            {
                if (this.CurrentSession.NextHotKey.KeyCode != Keys.None)
                {
                    //#if !DEBUG
                    UIControl.Invoke(this, (x) =>
                    {
                        User32.RegisterHotKey((IntPtr)Handle, 1, this.CurrentSession.NextHotKey.ModifierCode, this.CurrentSession.NextHotKey.Key);
                    });
                    //#endif
                }
            }
        }

        private void ClearSession()
        {
            _foundFiles = new List<string>();
            _currentProcess = null;

            UIControl.Invoke(textBox1, (_) => textBox1.Text = "*.*");
            UIControl.Invoke(memoBox1, (_) => memoBox1.Clear());

            progressBar1.Clear(0);
            progressBar2.Clear(0);

            UIControl.Invoke(label4, (x) => label4.Text = "");
            UIControl.Invoke(label3, (x) => label3.Text = "");
            UIControl.Invoke(button1, (x) => button1.Enabled = false);
            UIControl.Invoke(dialogFooter1, (x) => dialogFooter1.Button1Visible = false);
        }

        protected async Task LoadSessionFile(string filename)
        {
            await Task.Run(async () =>
            {
                this.CurrentSession = await RyzStudio.Text.Json.JsonSerialiser.DeserialiseFile<AppSession>(filename);

                ClearSession();

                textBox1.Text = (string.IsNullOrWhiteSpace(this.CurrentSession.SearchFilePattern) ? "*" : this.CurrentSession.SearchFilePattern?.Trim());

                foreach (var item in this.CurrentSession?.SearchItems)
                {
                    if (string.IsNullOrWhiteSpace(item))
                    {
                        continue;
                    }

                    UIControl.Invoke(memoBox1, (_) => memoBox1.AddLine(item));
                }

                UIControl.Invoke(label4, (x) => label4.Text = "Ready");
                UIControl.Invoke(button1, (x) => button1.Enabled = (this.CurrentSession?.SearchItems.Count > 0));

                // hotkey
                InvalidateHotKey();
            });
        }

        protected async Task SaveSessionFile(string filename)
        {
            if (string.IsNullOrWhiteSpace(filename))
            {
                return;
            }

            if (this.CurrentSession == null)
            {
                this.CurrentSession = new AppSession();
            }

            await Task.Run(() =>
            {
                this.CurrentSession.SearchFilePattern = textBox1.Text;
                this.CurrentSession.SearchItems = this.SearchPathList;

                var result = RyzStudio.Text.Json.JsonSerialiser.SerialiseFile(filename, this.CurrentSession);
                if (result.Success)
                {
                    RyzStudio.Forms.T3MessageBox.Show(this, "Session saved!", "Save session");
                }
                else
                {
                    RyzStudio.Forms.T3MessageBox.Show(this, result.Message, "Save session", MessageBoxButtons.OK, MessageBoxIcon.Error);
                }
            });
        }


        /// <summary>
        /// Run Next
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private async void dialogFooter1_OnButton1Click(object sender, MouseEventArgs e)
        {
            if (this.IsBusy)
            {
                return;
            }

            if (_foundFiles.Count <= 0)
            {
                return;
            }

            await Task.Run(() =>
            {
                this.IsBusy = true;

                if (this.CurrentSession.ClosePrevOnNext)
                {
                    CloseCurrentProcess(_currentProcess);
                }

                string filename = null;

                // retry 8 times
                for (int i = 0; i < this.CurrentSession.RetryOnError; i++)
                {
                    filename = _foundFiles[Random.Shared.Next(0, (_foundFiles.Count - 1))];
                    if (System.IO.File.Exists(filename))
                    {
                        continue;
                    }

                    filename = null;
                }

                if (!string.IsNullOrWhiteSpace(filename))
                {
                    _currentProcess = RyzStudio.Diagnostics.Process.Execute(filename);
                }

                this.IsBusy = false;
            });
        }

        /// <summary>
        /// Close
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void dialogFooter1_OnButton2Click(object sender, MouseEventArgs e)
        {
            this.Close();
        }

        private void memoBox1_TextChanged(object sender, EventArgs e)
        {
            UIControl.Invoke(button1, (x) => button1.Enabled = !string.IsNullOrWhiteSpace(memoBox1.Text));
        }

    }
}