using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media.Imaging;
using Comal.Classes;
using InABox.Clients;
using InABox.Core;
using InABox.DynamicGrid;
using InABox.WPF;

namespace PRSDesktop
{
    public class TimesheetGrid : DynamicDataGrid<TimeSheet>
    {
        private readonly BitmapImage leave = PRSDesktop.Resources.leave.AsBitmapImage();

        private LeaveRequestGrid leavegrid;

        private readonly BitmapImage post = PRSDesktop.Resources.post.AsBitmapImage();
        private readonly BitmapImage tick = PRSDesktop.Resources.tick.AsBitmapImage();
        private readonly BitmapImage warning = PRSDesktop.Resources.warning.AsBitmapImage();

        public TimesheetGrid()
        {
            Options.AddRange(
                DynamicGridOption.SelectColumns,
                DynamicGridOption.FilterRows,
                DynamicGridOption.MultiSelect,
                DynamicGridOption.RecordCount
            );

            ActionColumns.Add(new DynamicMenuColumn(BuildMenu) { Position = DynamicActionColumnPosition.Start });
            ActionColumns.Add(new DynamicMapColumn<TimeSheet>(this, x => x.StartLocation));
            //HiddenColumns.Add(x => x.StartLocation.Timestamp);
            //HiddenColumns.Add(x => x.StartLocation.Latitude);
            //HiddenColumns.Add(x => x.StartLocation.Longitude);

            ActionColumns.Add(new DynamicMapColumn<TimeSheet>(this, x => x.FinishLocation));
            //HiddenColumns.Add(x => x.FinishLocation.Timestamp);
            //HiddenColumns.Add(x => x.FinishLocation.Latitude);
            //HiddenColumns.Add(x => x.FinishLocation.Longitude);

            //ActionColumns.Add(new DynamicImageColumn() { Image = WarningImage });
            ActionColumns.Add(new DynamicTickColumn<TimeSheet, DateTime>(x => x.Approved, tick, tick, null));
            ActionColumns.Add(new DynamicTickColumn<TimeSheet, DateTime>(x => x.Processed, post, tick, null));

            HiddenColumns.Add(x => x.Date);

            HiddenColumns.Add(x => x.Start);
            HiddenColumns.Add(x => x.Finish);
            HiddenColumns.Add(x => x.Duration);

            HiddenColumns.Add(x => x.ApprovedStart);
            HiddenColumns.Add(x => x.ApprovedFinish);
            //HiddenColumns.Add(x => x.ApprovedHours);
            HiddenColumns.Add(x => x.ApprovedDuration);

            HiddenColumns.Add(x => x.EmployeeLink.ID);
            HiddenColumns.Add(x => x.LeaveRequestLink.ID);
            HiddenColumns.Add(x => x.JobLink.ID);
            HiddenColumns.Add(x => x.JobLink.Deleted);

            HiddenColumns.Add(x => x.Approved);

            if (Security.CanView<Employee>())
                AddButton("Employee", PRSDesktop.Resources.anonymous.AsBitmapImage(Color.White), EditEmployee);

            if (Security.IsAllowed<CanApproveTimesheets>())
            {
                AddButton("Approve", tick, ApproveTimeSheet);
                AddButton("UnApprove", warning, UnApproveTimeSheet);
            }

            if (Security.CanView<LeaveRequest>())
                AddButton("Create Leave", leave, CreateLeaveRequest);
        }

        public DateTime StartDate { get; set; } = DateTime.MinValue;
        public DateTime EndDate { get; set; } = DateTime.MaxValue;
        public string Search { get; set; } = "";

        public bool ApprovedOnly { get; set; } = false;

        private void BuildMenu(DynamicMenuColumn column, CoreRow row)
        {
            if (row == null) return;
            var formsItem = column.AddItem("Digital Forms", PRSDesktop.Resources.kanban, null);
            DynamicGridUtils.PopulateFormMenu<TimeSheetForm, TimeSheet, TimeSheetLink>(
                formsItem,
                row.Get<TimeSheet, Guid>(x => x.ID),
                () => row.ToObject<TimeSheet>());
        }
        protected override TimeSheet CreateItem()
        {
            var result = base.CreateItem();
            result.Date = DateTime.Today;
            return result;
        }
        
        private Tuple<Guid, DateTime, string>[] GroupTimeSheets(CoreRow[] rows)
        {
            var results = new List<Tuple<Guid, DateTime, string>>();
            foreach (var row in rows)
            {
                var date = row.Get<TimeSheet, DateTime>(x => x.Date);
                var empid = row.Get<TimeSheet, Guid>(x => x.EmployeeLink.ID);
                var name = row.Get<TimeSheet, string>(x => x.EmployeeLink.Name);

                if (!results.Any(x => x.Item1.Equals(empid) && x.Item2.Equals(date)))
                    results.Add(new Tuple<Guid, DateTime, string>(empid, date, name));
            }

            return results.OrderBy(x => x.Item3).ThenBy(x => x.Item2).ToArray();
        }

        private bool CheckApproval(TimeSheet time)
        {
            time.ApprovedStart = time.Start.Round(new TimeSpan(0, 15, 0));
            time.ApprovedFinish = time.Finish.Round(new TimeSpan(0, 15, 0));
            time.Approved = DateTime.Now;
            return true;
        }

        private bool ApproveTimeSheet(Button sender, CoreRow[] rows)
        {
            if (!rows.Any())
            {
                MessageBox.Show("Please select at least one row to process!");
                return false;
            }

            Progress.Show("");
            Progress.SetMessage("Loading Time Sheets");

            var employeedays = GroupTimeSheets(rows);

            var updates = new List<TimeSheet>();

            var lastemp = Guid.Empty;
            Employee emp = null;
            foreach (var day in employeedays)
            {
                var date = day.Item2;
                var empid = day.Item1;
                var name = day.Item3;


                if (empid != lastemp)
                {
                    Progress.SetMessage("Processing: " + name);
                    emp = new Client<Employee>().Load(new Filter<Employee>(x => x.ID).IsEqualTo(empid)).FirstOrDefault();
                    lastemp = empid;
                }

                if (emp != null)
                {
                    
                    var times = new Client<TimeSheet>().Load(new Filter<TimeSheet>(x => x.Date).IsEqualTo(date)
                        .And(x => x.EmployeeLink.ID).IsEqualTo(empid)
                        .And(x => x.Approved).IsEqualTo(DateTime.MinValue)
                        .And(x => x.Finish).IsNotEqualTo(new TimeSpan(0))
                    );

                    if (times.Length > 0)
                    {
                        // Rules: 
                        // if the employee has a usual start / usual end set, it will be treated as salary, 
                        //    and the approved times will always reflect the usual, eather than the actual times
                        // Then, it will go through each timesheet, and wind back the start / finish time IF
                        //    a: timesheet is joblinked
                        //    b: job has a usual start / end
                        //    b: timesheet activity == job.usual activity


                        var first = times.OrderBy(x => x.Start).First();
                        var start = first.Start.Round(new TimeSpan(0, 15, 0));
                        
                        var last = times.OrderBy(x => x.Finish).Last();
                        var finish = last.Finish.Round(new TimeSpan(0, 15, 0));

                        var jobfilter = new Filter<Job>(x => x.ID).IsEqualTo(Guid.Empty);
                        Array.ForEach(times, t => jobfilter.Ors.Add(new Filter<Job>(j => j.ID).IsEqualTo(t.JobLink.ID)));
                        var jobs = new Client<Job>().Query(jobfilter,
                            new Columns<Job>(x => x.ID, x => x.UsualStart, x => x.UsualFinish, x => x.UsualActivity.ID));

                        for (var i = 0; i < times.Length; i++)
                        {
                            //Progress.SetMessage(String.Format("Checking Time Sheet({0:F2}% complete)", (i * 100.0F) / (double)times.Length));
                            var time = times[i];

                            time.ApprovedStart = time == first || time.Start < start ? start : time.Start;
                            time.ApprovedFinish = time == last || time.Finish > finish ? finish : time.Finish;

                            var job = jobs.Rows.Where(r => r.Get<Job, Guid>(c => c.ID).Equals(time.JobLink.ID)
                                                           && Entity.IsEntityLinkValid<Job, ActivityLink>(x => x.UsualActivity, r)
                                                           && r.Get<Job, Guid>(c => c.UsualActivity.ID).Equals(time.ActivityLink.ID)
                            ).FirstOrDefault();

                            if (job != null)
                            {
                                var jobstart = job.Get<Job, TimeSpan>(x => x.UsualStart);
                                if (jobstart > new TimeSpan(0) && time.Start < jobstart)
                                    time.ApprovedStart = jobstart;

                                var jobend = job.Get<Job, TimeSpan>(x => x.UsualFinish);
                                if (jobend > new TimeSpan(0) && time.Finish > jobend)
                                    time.ApprovedFinish = jobend;
                            }

                            if (time.ApprovedFinish < time.ApprovedStart)
                                time.ApprovedFinish = time.ApprovedStart;

                            time.Approved = DateTime.Now;
                            updates.Add(time);
                        }
                    }
                }
            }

            if (updates.Any())
            {
                Progress.SetMessage("Updating Database");
                new Client<TimeSheet>().Save(updates, "Approving Time Sheets");
            }

            Progress.Close();
            MessageBox.Show("All Done");
            return true;
        }

        private bool UnApproveTimeSheet(Button sender, CoreRow[] rows)
        {
            if (!rows.Any())
            {
                MessageBox.Show("Please select at least one row to process!");
                return false;
            }

            Progress.Show("");
            Progress.SetMessage("Processing Time Sheets");

            var employeedays = GroupTimeSheets(rows);

            var updates = new List<TimeSheet>();

            foreach (var day in employeedays)
            {
                var date = day.Item2;
                var empid = day.Item1;
                var name = day.Item3;

                Progress.SetMessage("Clearing Approvals for " + name);
                var times = new Client<TimeSheet>().Load(new Filter<TimeSheet>(x => x.Date).IsEqualTo(date)
                    .And(x => x.EmployeeLink.ID).IsEqualTo(empid)
                );

                for (var i = 0; i < times.Length; i++)
                {
                    //Progress.SetMessage(String.Format("Clearing Approval ({0:F2}% complete)", (i * 100.0F) / (double)times.Length));
                    var time = times[i];
                    time.ApprovedStart = new TimeSpan(0);
                    time.ApprovedFinish = new TimeSpan(0);
                    time.Approved = DateTime.MinValue;
                    updates.Add(time);
                }
            }

            if (updates.Any())
            {
                Progress.SetMessage("Updating Database");
                new Client<TimeSheet>().Save(updates, "Clearing Approvals");
            }

            Progress.Close();
            MessageBox.Show("All Done");

            return true;
        }


        private bool EditEmployee(Button btn, CoreRow[] rows)
        {
            if (rows.Length != 1)
            {
                MessageBox.Show("Please select a single employee!");
                return false;
            }

            var row = rows.First();

            var employee = new Client<Employee>().Load(new Filter<Employee>(x => x.ID).IsEqualTo(row.Get<TimeSheet, Guid>(c => c.EmployeeLink.ID)))
                .FirstOrDefault();
            if (employee == null)
            {
                MessageBox.Show("Cannot Locate Employee!");
                return false;
            }

            var employeegrid = new EmployeeGrid();
            return employeegrid.EditItems(new[] { employee });
        }

        private bool CreateLeaveRequest(Button arg1, CoreRow[] arg2)
        {
            var leave = new LeaveRequest();
            leave.From = DateTime.Today;
            leave.To = DateTime.Today;
            if (leavegrid == null)
                leavegrid = new LeaveRequestGrid();
            return leavegrid.EditItems(new[] { leave });
        }

        public override bool EditItems(TimeSheet[] items, Func<Type, CoreTable> PageDataHandler = null, bool PreloadPages = false)
        {
            var leaveids = items.Select(x => x.LeaveRequestLink.ID).Distinct().ToArray();
            if (leaveids.Length > 1 && leaveids.Contains(Guid.Empty))
            {
                MessageBox.Show(
                    "At least one of these timesheets is linked to a leave request!\nPlease select either regular or leave timesheets and try again.");
                return false;
            }

            if (!leaveids.Contains(Guid.Empty))
            {
                if (!Security.CanView<LeaveRequest>())
                {
                    MessageBox.Show("Editing leave requests is not permitted here");
                    return false;
                }

                LeaveRequest[] leaves = null;
                using (new WaitCursor())
                {
                    leaves = new Client<LeaveRequest>().Load(new Filter<LeaveRequest>(x => x.ID).InList(leaveids));
                    if (leavegrid == null)
                        leavegrid = new LeaveRequestGrid();
                }

                return leavegrid.EditItems(leaves);
            }

            return base.EditItems(items, PageDataHandler, PreloadPages);
        }

        protected override Dictionary<string, object> EditorValueChanged(IDynamicEditorForm editor, TimeSheet[] items, string name, object value)
        {
            var result = base.EditorValueChanged(editor, items, name, value);

            if (name == "ActivityLink.ID")
            {
                ReloadForms<TimeSheet, TimeSheetForm, ActivityForm>(editor, items.FirstOrDefault(), x => x.Activity.ID,
                    value != null ? (Guid)value : Guid.Empty);
            }
            else if (name.Equals("EmployeeLink.ID"))
            {
                var activity = editor.FindEditor("ActivityLink.ID") as ILookupEditorControl;
                if (activity != null)
                    DefineLookups(activity, items);
            }

            return result;
        }

        protected override void AfterLoad(IDynamicEditorForm editor, TimeSheet[] items)
        {
            base.AfterLoad(editor, items);
            if (items.FirstOrDefault().ID == Guid.Empty)
                ReloadForms<TimeSheet, TimeSheetForm, ActivityForm>(editor, items.FirstOrDefault(), x => x.Activity.ID,
                    items.FirstOrDefault().ActivityLink.ID);
        }

        //private BitmapImage WarningImage(DataRow row)
        //{
        //    if (row == null)
        //        return warning;

        //    if (row.Get<TimeSheet, DateTime>(x => x.Approved) != DateTime.MinValue)
        //        return null;


        //    TimeSpan start = row.Get<TimeSheet, TimeSpan>(x => x.Start);
        //    if (start.Equals(new TimeSpan(0)))
        //        return warning;

        //    TimeSpan finish = row.Get<TimeSheet, TimeSpan>(x => x.Finish);
        //    if (finish.Equals(new TimeSpan(0)))
        //        return warning;

        //    TimeSpan actual = row.Get<TimeSheet, TimeSpan>(x => x.Duration);
        //    TimeSpan approved = row.Get<TimeSheet, TimeSpan>(x => x.ApprovedDuration);

        //    if (!actual.Equals(approved))
        //        return warning;

        //    return null;
        //}

        //private bool ApproveClick(DataRow row)
        //{
        //    if (row == null)
        //        return false;
        //    Guid id = row.Get<TimeSheet, Guid>(x => x.ID);
        //    TimeSheet timesheet = new Client<TimeSheet>().Load(new Filter<TimeSheet>(x => x.ID).IsEqualTo(id)).FirstOrDefault();
        //    if (timesheet != null)
        //    {
        //        timesheet.Approved = timesheet.Approved.IsEmpty() ? DateTime.Now : DateTime.MinValue;
        //        new Client<TimeSheet>().Save(timesheet, "Toggled Approval flag");
        //        return true;
        //    }
        //    return false;
        //}

        protected override void Reload(Filters<TimeSheet> criteria, Columns<TimeSheet> columns, ref SortOrder<TimeSheet> sort,
            Action<CoreTable, Exception> action)
        {
            var filter = new Filter<TimeSheet>(x => x.Processed).IsEqualTo(DateTime.MinValue);
            if (!string.IsNullOrWhiteSpace(Search))
                filter = filter.TextSearch(Search, x => x.EmployeeLink.Name, x => x.Address, x => x.Notes);
            criteria.Add(filter);
            criteria.Add(new Filter<TimeSheet>(x => x.EmployeeLink.FinishDate).IsEqualTo(DateTime.MinValue).Or(x => x.EmployeeLink.FinishDate)
                .IsGreaterThanOrEqualTo(DateTime.Today));
            criteria.Add(new Filter<TimeSheet>(x => x.Date).IsGreaterThanOrEqualTo(StartDate.Date));
            criteria.Add(new Filter<TimeSheet>(x => x.Date).IsLessThan(EndDate == DateTime.MaxValue ? DateTime.MaxValue : EndDate.AddDays(1)));

            if (ApprovedOnly)
                criteria.Add(new Filter<TimeSheet>(x => x.Approved).IsNotEqualTo(DateTime.MinValue));

            base.Reload(criteria, columns, ref sort, action);
        }

        protected override bool CanDeleteItems(CoreRow[] rows)
        {
            var result = true;
            foreach (var row in rows)
            {
                if (row.IsEntityLinkValid<TimeSheet, LeaveRequestLink>(x => x.LeaveRequestLink))
                    result = false;
            }

            if (!result)
                MessageBox.Show(
                    "You cannot delete timesheets linked to Leave Requests!\n\nPlease un-approve or delete the related Leave Request instead.");
            return result;
        }

        protected override BaseEditor? GetEditor(object item, DynamicGridColumn column)
        {
            var result = base.GetEditor(item, column);
            if (result == null)
                return null;

            if (!Security.IsAllowed<CanApproveTimesheets>() &&
                (column.ColumnName.Equals("ApprovedStart") || column.ColumnName.Equals("ApprovedFinish") ||
                 column.ColumnName.Equals("Approved")))
                result.Editable = Editable.Disabled;
            if (!Security.IsAllowed<CanChangeStartFinishTimes>() &&
                (column.ColumnName.Equals("Date") || column.ColumnName.Equals("Start") || column.ColumnName.Equals("Finish")))
                result.Editable = Editable.Disabled;
            if (!Security.IsAllowed<CanArchiveTimesheets>() && column.ColumnName.Equals("Processed"))
                result.Editable = Editable.Disabled;

            return result;
        }
    }
}