/* Copyright (c) Citrix Systems Inc. 
 * All rights reserved. 
 * 
 * Redistribution and use in source and binary forms, 
 * with or without modification, are permitted provided 
 * that the following conditions are met: 
 * 
 * *   Redistributions of source code must retain the above 
 *     copyright notice, this list of conditions and the 
 *     following disclaimer. 
 * *   Redistributions in binary form must reproduce the above 
 *     copyright notice, this list of conditions and the 
 *     following disclaimer in the documentation and/or other 
 *     materials provided with the distribution. 
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 
 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, 
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR 
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 
 * SUCH DAMAGE.
 */

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Linq;
using System.Threading;
using System.Windows.Forms;
using XenAdmin.Actions;
using XenAdmin.Controls;
using XenAdmin.Core;
using XenAdmin.Diagnostics.Checks;
using XenAdmin.Diagnostics.Problems;
using XenAdmin.Diagnostics.Problems.HostProblem;
using XenAdmin.Dialogs;
using XenAdmin.Properties;
using XenAPI;
using XenAdmin.Diagnostics.Problems.VMProblem;

namespace XenAdmin.Wizards.PatchingWizard
{
    public partial class PatchingWizard_PrecheckPage : XenTabPage
    {
        private static readonly log4net.ILog log = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);

        private BackgroundWorker _worker = null;
        public List<Host> SelectedServers = new List<Host>();
        public List<Problem> ProblemsResolvedPreCheck = new List<Problem>();

        protected List<Pool> SelectedPools
        {
            get 
            { 
                return SelectedServers.Select(host => Helpers.GetPool(host.Connection)).Where(pool => pool != null).Distinct().ToList();
            }
        }

        public PatchingWizard_PrecheckPage()
        {
            InitializeComponent();
            dataGridView1.BackgroundColor = dataGridView1.DefaultCellStyle.BackColor;
            checkBoxViewPrecheckFailuresOnly.Checked = true;
        }

        public override string PageTitle
        {
            get
            {
                return Messages.PATCHINGWIZARD_PRECHECKPAGE_TITLE;
            }
        }

        public override string Text
        {
            get
            {
                return Messages.PATCHINGWIZARD_PRECHECKPAGE_TEXT;
            }
        }

        public override string HelpID
        {
            get { return "UpdatePrechecks"; }
        }

        public override bool EnablePrevious()
        {
            return _worker != null && !_worker.IsBusy;
        }
        
        void Connection_ConnectionStateChanged(object sender, EventArgs e)
        {
            Program.Invoke(Program.MainWindow, RefreshRechecks);
        }

        private void RegisterEventHandlers()
        {
            foreach (Host selectedServer in SelectedServers)
            {
                selectedServer.Connection.ConnectionStateChanged += Connection_ConnectionStateChanged;
            }            
        }

        private void DeregisterEventHandlers()
        {
            foreach (Host selectedServer in SelectedServers)
            {
                selectedServer.Connection.ConnectionStateChanged -= Connection_ConnectionStateChanged;
            }
        }

        public override void PageLoaded(PageLoadedDirection direction)
        {
            base.PageLoaded(direction);
            try
            {
                RegisterEventHandlers();
                if (direction == PageLoadedDirection.Back)
                    return;

                labelPrechecksFirstLine.Text = string.Format(Messages.PATCHINGWIZARD_PRECHECKPAGE_FIRSTLINE, Patch.Name);
                RefreshRechecks();
            }
            catch (Exception e)
            {
                log.Error(e, e);
                throw;//better throw an exception rather than closing the wizard suddenly and silently
            }
        }

        protected void RefreshRechecks()
        {
            buttonResolveAll.Enabled = buttonReCheckProblems.Enabled = false;
            _worker = null;
            _worker = new BackgroundWorker();
            _worker.DoWork += new DoWorkEventHandler(worker_DoWork);
            _worker.WorkerReportsProgress = true;
            _worker.WorkerSupportsCancellation = true;
            _worker.ProgressChanged += new ProgressChangedEventHandler(worker_ProgressChanged);
            _worker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(_worker_RunWorkerCompleted);
            _worker.RunWorkerAsync(Patch);
        }

        private void _worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            if (!e.Cancelled)
                OnPageUpdated();
            progressBar1.Value = 100;

            bool showResolveAllButton = false;
            foreach (PreCheckGridRow row in dataGridView1.Rows)
            {
                PreCheckHostRow hostRow = row as PreCheckHostRow;
                //CA-65508: if the problem cannot be solved immediately there's no point in enabling the Resolve All button
                //CA-136211: Changed the code below to enable the Resolve All button only when there is at least one problem and all the problems have solution/fix.
                if (hostRow != null && hostRow.IsProblem)
                {
                    if (!hostRow.IsFixable)
                    {
                        showResolveAllButton = false;
                        break;
                    }
                    else
                    {
                        showResolveAllButton = true;
                    }
                }
            }

            buttonResolveAll.Enabled = showResolveAllButton;
            buttonReCheckProblems.Enabled = true;
        }

        private void AddRowToGridView(DataGridViewRow row)
        {
            lock (_update_grid_lock)
            {
                dataGridView1.Rows.Add(row);
            }
        }

        private void worker_ProgressChanged(object sender, ProgressChangedEventArgs e)
        {
            try
            {
                PreCheckHostRow rowHost = e.UserState as PreCheckHostRow;
                if (rowHost != null)
                {
                    if (checkBoxViewPrecheckFailuresOnly.Checked && rowHost.Problem != null || !checkBoxViewPrecheckFailuresOnly.Checked)
                        AddRowToGridView(rowHost);
                }
                else
                {
                    var row = e.UserState as DataGridViewRow;
                    if (row != null && !dataGridView1.Rows.Contains(row))
                    {
                        AddRowToGridView(row);
                    }
                }
                int step = (int)((1.0 / ((float)_numberChecks)) * e.ProgressPercentage);
                progressBar1.Value += (step + progressBar1.Value) > 100 ? 0 : step;
            }
            catch (Exception) { }
        }

        private PreCheckHostRow ExecuteCheck(Check check)
        {
            Problem problem = check.RunCheck();
            if (problem != null)
            {
                if (problem is HostNotLive)
                {
                    // this host is no longer live -> remove all previous problems regarding this host
                    Problem curProblem = problem;
                    ProblemsResolvedPreCheck.RemoveAll(p => p.Check.Host == curProblem.Check.Host);
                }

                if (ProblemsResolvedPreCheck.Contains(problem))
                {
                    Problem curProblem = problem;
                    problem = ProblemsResolvedPreCheck.Find(p => p.Equals(curProblem));
                }
                else
                    ProblemsResolvedPreCheck.Add(problem);
                
                return new PreCheckHostRow(problem);
            }
            return new PreCheckHostRow(check);
        }

        private int _numberChecks = 0;
        private readonly object _lock = new object();
        private readonly object _update_grid_lock = new object();
        private void worker_DoWork(object sender, DoWorkEventArgs e)
        {
            lock (_lock)
            {
                Program.Invoke(this, () =>
                                         {
                                             dataGridView1.Rows.Clear();
                                             progressBar1.Value = 0;
                                         });
                Pool_patch patch = e.Argument as Pool_patch;

                List<KeyValuePair<string, List<Check>>> checks = GenerateChecks(patch);
                _numberChecks = checks.Count;
                for (int i = 0; i < checks.Count; i++)
                {
                    if (_worker.CancellationPending)
                    {
                        e.Cancel = true;
                        return;
                    }

                    List<Check> checkGroup = checks[i].Value;
                    PreCheckHeaderRow headerRow =
                        new PreCheckHeaderRow(string.Format(Messages.PATCHING_WIZARD_PRECHECK_STATUS, checks[i].Key));
                    _worker.ReportProgress(5, headerRow);

                    PreCheckResult precheckResult = PreCheckResult.OK;
                    for (int j = 0; j < checkGroup.Count; j++)
                    {
                        if (_worker.CancellationPending)
                        {
                            e.Cancel = true;
                            return;
                        }

                        Check check = checkGroup[j];
                        PreCheckHostRow row = ExecuteCheck(check);
                        if (precheckResult != PreCheckResult.Failed && row.Problem != null)
                            precheckResult = row.IsProblem ? PreCheckResult.Failed : PreCheckResult.Warning;
                        _worker.ReportProgress(PercentageSelectedServers(j + 1), row);
                    }

                    lock (_update_grid_lock)
                    {
                        headerRow.UpdateDescription(precheckResult);
                    }
                }
            }
        }

        protected virtual List<KeyValuePair<string, List<Check>>> GenerateChecks(Pool_patch patch)
        {
            List<KeyValuePair<string, List<Check>>> checks = new List<KeyValuePair<string, List<Check>>>();

            //HostLivenessCheck checks
            checks.Add(new KeyValuePair<string, List<Check>>(Messages.CHECKING_HOST_LIVENESS_STATUS, new List<Check>()));
            List<Check> checkGroup = checks[checks.Count - 1].Value;
            foreach (Host host in SelectedServers)
            {
                checkGroup.Add(new HostLivenessCheck(host));
            }

            //HA checks
            checks.Add(new KeyValuePair<string, List<Check>>(Messages.CHECKING_HA_STATUS, new List<Check>()));
            checkGroup = checks[checks.Count - 1].Value;
            foreach (Host host in SelectedServers)
            {
                if (Helpers.HostIsMaster(host))
                    checkGroup.Add(new HAOffCheck(host));
            }

            //Checking can evacuate host
            //CA-97061 - evacuate host -> suspended VMs. This is only needed for restartHost
            if (patch != null && patch.after_apply_guidance.Contains(after_apply_guidance.restartHost))
            {
                checks.Add(new KeyValuePair<string, List<Check>>(Messages.CHECKING_CANEVACUATE_STATUS, new List<Check>()));
                checkGroup = checks[checks.Count - 1].Value;
                foreach (Host host in SelectedServers)
                {
                        checkGroup.Add(new AssertCanEvacuateCheck(host));
                }
            }

            //PBDsPluggedCheck
            checks.Add(new KeyValuePair<string, List<Check>>(Messages.CHECKING_STORAGE_CONNECTIONS_STATUS, new List<Check>()));
            checkGroup = checks[checks.Count - 1].Value;
            foreach (Host host in SelectedServers)
            {
                checkGroup.Add(new PBDsPluggedCheck(host));
            }

            //Checking other things
            checks.Add(new KeyValuePair<string, List<Check>>(Messages.CHECKING_SERVER_SIDE_STATUS, new List<Check>()));
            checkGroup = checks[checks.Count - 1].Value;
            foreach (Host host in SelectedServers)
            {
                List<Pool_patch> poolPatches = new List<Pool_patch>(host.Connection.Cache.Pool_patches);
                Pool_patch poolPatchFromHost = poolPatches.Find(otherPatch => otherPatch.uuid == patch.uuid);
                checkGroup.Add(new PatchPrecheckCheck(host, poolPatchFromHost));
            }
            return checks;
        }

        [DefaultValue(true)]
        protected bool ManualUpgrade { set; get; }

        private int PercentageSelectedServers(int i)
        {
            return (int)(((float)i / (float)(SelectedServers.Count)) * 100);
        }

        public override void PageCancelled()
        {
            DeregisterEventHandlers();
            if (_worker != null)
                _worker.CancelAsync();
        }

        public override void PageLeave(PageLoadedDirection direction, ref bool cancel)
        {
            DeregisterEventHandlers();
            if (direction == PageLoadedDirection.Back && _worker != null)
            {
                _worker.CancelAsync();
                _worker = null;
            }

            base.PageLeave(direction, ref cancel);
        }

        public override bool EnableNext()
        {
            bool problemsFound = false;
            foreach (DataGridViewRow row in dataGridView1.Rows)
            {
                PreCheckHostRow preCheckHostRow = row as PreCheckHostRow;
                if (preCheckHostRow != null && preCheckHostRow.IsProblem)
                {
                    problemsFound = true;
                    break;
                }

            }

            bool result = _worker != null && !_worker.IsBusy && !problemsFound;
            panelErrorsFound.Visible = problemsFound;
            return result;
        }

        public UpdateType SelectedUpdateType { private get; set; }
        public Pool_patch Patch { private get; set; }
        public List<Pool_patch> NewUploadedPatches { private get; set; }

        internal enum PreCheckResult { OK, Warning, Failed }

        private abstract class PreCheckGridRow : DataGridViewRow
        {
            protected DataGridViewImageCell _iconCell = new DataGridViewImageCell();
            protected DataGridViewTextBoxCell _descriptionCell = new DataGridViewTextBoxCell();
            protected DataGridViewCell _solutionCell = null;
            protected PreCheckGridRow(DataGridViewCell solutionCell)
            {
                _solutionCell = solutionCell;
                Cells.Add(_iconCell);
                Cells.Add(_descriptionCell);
                Cells.Add(_solutionCell);
            }
        }

        private class PreCheckHeaderRow : PreCheckGridRow
        {
            private string description;

            public PreCheckHeaderRow(string text)
                : base(new DataGridViewTextBoxCell())
            {
                _iconCell.Value = new Bitmap(1, 1);
                description = text;
                _descriptionCell.Value = text;
                _descriptionCell.Style.Font = new Font(Program.DefaultFont, FontStyle.Bold);
            }

            public void UpdateDescription(PreCheckResult precheckResult)
            {
                string result = precheckResult == PreCheckResult.OK
                                    ? Messages.OK
                                    : precheckResult == PreCheckResult.Warning ? Messages.WARNING : Messages.FAILED;

                _descriptionCell.Value = string.Format("{0} {1}", description, result);
            }
        }

        private class PreCheckHostRow : PreCheckGridRow
        {
            private Problem _problem = null;
            private Check _check = null;
            public PreCheckHostRow(Problem problem)
                : base(new DataGridViewTextBoxCell())
            {
                _problem = problem;
                _check = problem.Check;
                UpdateRowFields();
            }

            public PreCheckHostRow(Check check)
                : base(new DataGridViewTextBoxCell())
            {
                _check = check;
                UpdateRowFields();
            }

            public bool IsFixable 
            {
                get
                {
                    return Problem != null && Problem.IsFixable && !string.IsNullOrEmpty(this.Solution);
                }
            }

            private void UpdateRowFields()
            {
                _iconCell.Value = Problem == null
                    ? Resources._000_Tick_h32bit_16
                    : Problem is Warning ? Resources._000_Alert2_h32bit_16 : Resources._000_Abort_h32bit_16;

                string description = string.Empty;

                if (Problem != null)
                    description = Problem.Description;
                else if (_check != null)
                    description = String.Format(Messages.PATCHING_WIZARD_HOST_CHECK_OK, _check.Host.Name, _check.Description);
                
                if (description != string.Empty)
                    _descriptionCell.Value = String.Format(Messages.PATCHING_WIZARD_DESC_CELL_INDENT, null, description);

                _solutionCell.Value = Problem == null ? string.Empty : Problem.HelpMessage;

                if (Problem is WarningWithInformationUrl)
                    _solutionCell.Value = (Problem as WarningWithInformationUrl).LinkText;

                if (Problem is ProblemWithInformationUrl)
                    _solutionCell.Value = (Problem as ProblemWithInformationUrl).LinkText;

                _solutionCell.Style.Font = new Font(Program.DefaultFont, FontStyle.Underline);
                _solutionCell.Style.ForeColor = Color.Blue;
            }

            public Problem Problem
            {
                get
                {
                    return _problem;
                }
            }

            public string Solution
            {
                get { return (string)_solutionCell.Value; }
            }
            
            public bool IsProblem
            {
                get { return _problem != null && !(_problem is Warning); }
            }

            public override bool Equals(object obj)
            {
                PreCheckHostRow other = obj as PreCheckHostRow;
                if (other != null && other.Problem != null && _problem != null)
                    return _problem.CompareTo(other.Problem) == 0;
                return false;
            }

            public override int GetHashCode()
            {
                return (_problem != null ? _problem.GetHashCode() : 0);
            }

        }


        private ActionProgressDialog _progressDialog = null;
        private void dataGridView1_CellContentClick(object sender, DataGridViewCellEventArgs e)
        {
            PreCheckHostRow preCheckHostRow = dataGridView1.Rows[e.RowIndex] as PreCheckHostRow;
            if (preCheckHostRow != null && e.ColumnIndex == 2)
            {
                ExecuteSolution(preCheckHostRow);
            }
        }

        private void dataGridView1_KeyPress(object sender, KeyPressEventArgs e)
        {
            if (e.KeyChar == (char)Keys.Enter && dataGridView1.CurrentCell != null)
            {
                PreCheckHostRow preCheckHostRow = dataGridView1.CurrentCell.OwningRow as PreCheckHostRow;
                int columnIndex = dataGridView1.CurrentCell.ColumnIndex;

                if (preCheckHostRow != null && columnIndex == 2)
                    ExecuteSolution(preCheckHostRow);
            }
        }

        private void ExecuteSolution(PreCheckHostRow preCheckHostRow)
        {
            bool cancelled;
            AsyncAction action = preCheckHostRow.Problem.SolveImmediately(out cancelled);

            if (action != null)
            {
                action.Completed += action_Completed;
                _progressDialog = new ActionProgressDialog(action, ProgressBarStyle.Blocks);
                _progressDialog.ShowDialog(this);
            }
            else
            {
                if (preCheckHostRow.Problem is WarningWithInformationUrl)
                    (preCheckHostRow.Problem as WarningWithInformationUrl).LaunchUrlInBrowser();
                else if (preCheckHostRow.Problem is ProblemWithInformationUrl)
                    (preCheckHostRow.Problem as ProblemWithInformationUrl).LaunchUrlInBrowser();
                    
                else if (!cancelled)
                    new ThreeButtonDialog(new ThreeButtonDialog.Details(SystemIcons.Information,
                                                                        string.Format(Messages.PATCHING_WIZARD_SOLVE_MANUALLY, preCheckHostRow.Problem.Description).Replace("\\n", "\n"),
                                                                        Messages.PATCHINGWIZARD_PRECHECKPAGE_TEXT)).ShowDialog(this);
            }
        }

        private void action_Completed(ActionBase sender)
        {
            Thread.Sleep(1000);
            Program.Invoke(Program.MainWindow, RefreshRechecks);
        }


        private void buttonReCheckProblems_Click(object sender, EventArgs e)
        {
            RefreshRechecks();
        }

        private void buttonResolveAll_Click(object sender, EventArgs e)
        {
            List<AsyncAction> actions = new List<AsyncAction>();
            foreach (DataGridViewRow row in dataGridView1.Rows)
            {
                PreCheckHostRow preCheckHostRow = row as PreCheckHostRow;
                if (preCheckHostRow != null && preCheckHostRow.Problem != null)
                {
                    bool cancelled;
                    AsyncAction action = preCheckHostRow.Problem.SolveImmediately(out cancelled);
                    
                    if (action != null)
                        actions.Add(action);
                }
            }
            foreach (var asyncAction in actions)
            {
                _progressDialog = new ActionProgressDialog(asyncAction, ProgressBarStyle.Blocks);
                _progressDialog.ShowDialog(this);
                Program.Invoke(Program.MainWindow, RefreshRechecks);
            }
            Program.Invoke(Program.MainWindow, RefreshRechecks);
        }

        private void checkBox1_CheckedChanged(object sender, EventArgs e)
        {
            RefreshRechecks();
        }

        private void dataGridView1_CellMouseMove(object sender, DataGridViewCellMouseEventArgs e)
        {
            PreCheckHostRow preCheckHostRow = dataGridView1.Rows[e.RowIndex] as PreCheckHostRow;
            if (preCheckHostRow != null && e.ColumnIndex == 2 && !string.IsNullOrEmpty(preCheckHostRow.Solution))
            {
                Cursor = Cursors.Hand;
            }
            else
                Cursor = Cursors.Arrow;
        }
    }
}