using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Text.Json;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;
using RyzStudio.IO;
using RyzStudio.Runtime.InteropServices;
using RyzStudio.Windows.Forms;
using Application = System.Windows.Forms.Application;

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

        private bool _isBusy = false;

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


        public MainForm()
        {
            InitializeComponent();

            textBox2.SetIcon("search");
            textBox2.TextBox.ReadOnly = true;

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

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

            this.ClearSession();
        }

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

            var args = RyzStudio.Windows.Forms.Application.GetCommandLine();

            string jsonfigFilename = args.Where(x => (x.Key.Equals("o") || x.Key.Equals("open"))).Select(x => x.Value).FirstOrDefault();
            if (string.IsNullOrWhiteSpace(jsonfigFilename))
            {
                jsonfigFilename = Path.ChangeExtension(Application.ExecutablePath, "jsonfig");
            }

            if (!string.IsNullOrWhiteSpace(jsonfigFilename) && System.IO.File.Exists(jsonfigFilename))
            {
                await LoadSessionFile(jsonfigFilename);
            }
        }

        protected override void OnClosing(CancelEventArgs e)
        {
            base.OnClosing(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)
                    {
                        button5_MouseClick(null, null);
                    }

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

                //    break;
                default:
                    break;
            }

            base.WndProc(ref m);
        }


        public bool IsBusy
        {
            get => _isBusy;
            set
            {
                _isBusy = value;

                UIControl.SetValue(pictureBox1, (_isBusy ? UIResource.loading_block : null));
                UIControl.SetEnable(textBox1, !_isBusy);
                button2.LabelText = (_isBusy ? "&Cancel" : "&Search");
                UIControl.SetEnable(button5, !_isBusy);
                UIControl.SetEnable(button4, !_isBusy);
            }
        }

        public AppSession CurrentSession { get; set; } = new AppSession();

        public List<string> SearchPaths
        {
            get => _searchPaths;
            set
            {
                _searchPaths = value;

                textBox2.Text = string.Join(", ", _searchPaths.ToArray());
            }
        }


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

        /// <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.Session;

                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)
        {
            MessageBox.Show(Application.ProductName + " v" + Application.ProductVersion, "About", MessageBoxButtons.OK, MessageBoxIcon.Information);
        }

        #endregion

        #region Search Engine

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

                UIControl.SetText(label3, 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.SetText(label4, Path.GetFileName(directoryName));

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

        private async Task fileSearcher_OnSearchCompleted(FileSearcher sender, TimeSpan elapsedTime)
        {
            await Task.Run(() =>
            {
                UIControl.SetText(label4, $"Done in {Math.Floor(elapsedTime.TotalMinutes)}m {elapsedTime.Seconds}s");
                UIControl.SetText(label3, ((_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;
            });
        }

        #endregion


        private void textBox2_OnButtonClick(object sender, EventArgs e)
        {
            if (this.IsBusy)
            {
                return;
            }

            var form = new MemoBoxForm();

            form.Lines = SearchPaths;

            if (form.ShowDialog() == DialogResult.OK)
            {
                SearchPaths = form.Lines;
            }
        }

        /// <summary>
        /// Search
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private async void button2_MouseClick(object sender, MouseEventArgs e)
        {
            if (this.IsBusy)
            {
                button2.LabelText = "&Cancelling...";
                _cancellationToken.Cancel();

                return;
            }

            this.IsBusy = true;

            progressBar1.ShowProgressText = true;
            progressBar2.ShowProgressText = true;

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

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

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

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

                        continue;
                    }

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

                        continue;
                    }
                }

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

            if (_fileSearcher.SearchPath.Count > 0)
            {
                await _fileSearcher.Search(_cancellationToken.Token);
            }

            this.IsBusy = false;

            _cancellationToken = new CancellationTokenSource();
        }

        /// <summary>
        /// Run next
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private async void button5_MouseClick(object sender, MouseEventArgs e)
        {
            if (this.IsBusy)
            {
                return;
            }

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

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

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

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

                string filename = null;

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

                    filename = null;
                }

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

                //this.IsBusy = false;
            });
        }

        /// <summary>
        /// Save File List
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private async void button4_MouseClick(object sender, MouseEventArgs 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)
                {
                    MessageBox.Show(exc.Message, "Save File List");
                }
            }
        }

        /// <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;

            textBox1.Text = "*.*";

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

            UIControl.SetText(label4, "");
            UIControl.SetText(label3, "");
        }

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

                ClearSession();

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

                SearchPaths = this.CurrentSession?.SearchItems ?? new List<string>();

                // 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 = new List<string>();

                foreach (var item in SearchPaths)
                {
                    if (string.IsNullOrWhiteSpace(item))
                    {
                        continue;
                    }

                    this.CurrentSession.SearchItems.Add(item.Trim());
                }

                string sourceCode = null;

                try
                {
                    sourceCode = JsonSerializer.Serialize(this.CurrentSession);
                }
                catch (Exception)
                {
                    MessageBox.Show("Unable to write session", "Save session");
                    return;
                }

                try
                {
                    System.IO.File.WriteAllText(filename, sourceCode);
                }
                catch (Exception exc)
                {
                    MessageBox.Show(exc.Message, "Save session");
                    return;
                }
            });
        }

    }
}