using System;
using System.Collections.Generic;
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
{
    internal class JobEmployeeGrid : DynamicManyToManyDataGrid<JobEmployee, Job>, IJobControl
    {
        private CoreTable EmployeeQualifications;
        private CoreTable JobQualifications;
        private readonly Dictionary<Guid, Tuple<List<string>, List<string>>> warnings = new();

        public JobEmployeeGrid()
        {
            Options.Add(DynamicGridOption.MultiSelect);
            HiddenColumns.Add(x => x.EmployeeLink.ID);
            HiddenColumns.Add(x => x.JobLink.ID);
            ActionColumns.Add(new DynamicImageColumn(QualificationImage, QualificationsCheck) { Position = DynamicActionColumnPosition.Start });
            AddButton("Edit Employee", PRSDesktop.Resources.employee.AsBitmapImage(), EditEmployee);
        }

        public Guid ParentID
        {
            get => ID;
            set => ID = value;
        }
        
        public JobPanelSettings Settings { get; set; }

        private bool EditEmployee(Button arg1, CoreRow[] arg2)
        {
            if (arg2 != null && arg2.Length == 1)
            {
                var emps = new Client<Employee>().Query(
                    new Filter<Employee>(x => x.ID).IsEqualTo(arg2.First().Get<JobEmployee, Guid>(x => x.EmployeeLink.ID)));
                if (emps.Rows.Count == 1)
                {
                    var emp = emps.Rows.First().ToObject<Employee>();
                    var grid = new EmployeeGrid();
                    return grid.EditItems(new[] { emp });
                }

                MessageBox.Show("Unable to Load Employee Card");
            }
            else
            {
                MessageBox.Show("Please select a single employee to edit!");
            }

            return false;
        }

        private BitmapImage QualificationImage(CoreRow arg)
        {
            BitmapImage result = null;

            CheckEmployeeQualifications();
            CheckJobQualifications();

            var empid = arg != null ? arg.Get<JobEmployee, Guid>(x => x.EmployeeLink.ID) : Guid.Empty;
            var erows = EmployeeQualifications.Rows.Where(r => r.Get<EmployeeQualification, Guid>(c => c.Employee.ID).Equals(empid));

            var CheckedQualifications = new List<Guid>();

            // Check Job Requirements
            var jrows = JobQualifications.Rows.Where(r => r.Get<JobQualification, bool>(x => x.Required).Equals(true));
            foreach (var jrow in jrows)
            {
                var qualificationid = jrow.Get<JobQualification, Guid>(x => x.Qualification.ID);
                var erow = erows.FirstOrDefault(r =>
                    r.Get<EmployeeQualification, Guid>(c => c.Employee.ID).Equals(empid) &&
                    r.Get<EmployeeQualification, Guid>(c => c.Qualification.ID).Equals(qualificationid));
                if (erow == null)
                {
                    Warn(empid,
                        string.Format("{0} is missing",
                            jrow.Get<JobQualification, string>(c => c.Qualification.Description)
                        ),
                        ""
                    );
                    result = PRSDesktop.Resources.disabled.AsBitmapImage();
                }
                else
                {
                    var expiry = erow.Get<EmployeeQualification, DateTime>(c => c.Expiry);
                    var permanent = erow.Get<EmployeeQualification, QualificationRenewal>(c => c.Qualification.Renewal) == QualificationRenewal.Permanent;
                    if (!permanent && expiry < DateTime.Today)
                    {
                        Warn(empid,
                            string.Format("{0} expired on {1: dd MMM yy}",
                                jrow.Get<JobQualification, string>(c => c.Qualification.Description),
                                expiry
                            ),
                            ""
                        );
                        result = PRSDesktop.Resources.disabled.AsBitmapImage();
                    }
                    else if (!permanent && expiry < DateTime.MaxValue.Date)
                    {
                        Warn(empid,
                            string.Format("{0} is valid until {1:dd MMM yy}",
                                jrow.Get<JobQualification, string>(c => c.Qualification.Description),
                                erow.Get<EmployeeQualification, DateTime>(c => c.Expiry)
                            ),
                            ""
                        );
                    }
                    else
                    {
                        Warn(empid,
                            string.Format("{0} is valid",
                                jrow.Get<JobQualification, string>(c => c.Qualification.Description)
                            ),
                            ""
                        );
                    }
                }

                CheckedQualifications.Add(erow.Get<EmployeeQualification, Guid>(x => x.ID));
            }

            // Check Qualification Expiry
            foreach (var erow in erows)
                if (!CheckedQualifications.Contains(erow.Get<EmployeeQualification, Guid>(x => x.ID)))
                {
                    var expiry = erow.Get<EmployeeQualification, DateTime>(x => x.Expiry);
                    var permanent = erow.Get<EmployeeQualification, QualificationRenewal>(c => c.Qualification.Renewal) == QualificationRenewal.Permanent;
                    if (!permanent && expiry < DateTime.Today)
                    {
                        Warn(empid,
                            "",
                            string.Format("{0} has expired",
                                erow.Get<EmployeeQualification, string>(c => c.Qualification.Description)
                            )
                        );
                        if (result == null)
                            result = PRSDesktop.Resources.warning.AsBitmapImage();
                    }
                    else if (!permanent && expiry < DateTime.MaxValue.Date)
                    {
                        Warn(empid,
                            "",
                            string.Format("{0} is valid until {1:dd MMM yy}",
                                erow.Get<JobQualification, string>(c => c.Qualification.Description),
                                expiry
                            )
                        );
                    }
                    else
                    {
                        Warn(empid,
                            "",
                            string.Format("{0} is valid",
                                erow.Get<JobQualification, string>(c => c.Qualification.Description)
                            )
                        );
                    }
                }

            if (result == null && erows.Any())
                result = PRSDesktop.Resources.tick.AsBitmapImage();
            return result;
        }

        private void CheckJobQualifications()
        {
            if (JobQualifications == null)
            {
                if (ParentID != Guid.Empty)
                {
                    JobQualifications = new Client<JobQualification>().Query(new Filter<JobQualification>(x => x.Job.ID).IsEqualTo(ParentID));
                }
                else
                {
                    JobQualifications = new CoreTable();
                    JobQualifications.LoadColumns(typeof(JobQualification));
                }
            }
        }

        private void CheckEmployeeQualifications()
        {
            if (EmployeeQualifications == null)
            {
                var emps = new List<Guid>();
                foreach (var row in Data.Rows)
                {
                    var emp = row.Get<JobEmployee, Guid>(x => x.EmployeeLink.ID);
                    if (!emps.Contains(emp))
                        emps.Add(emp);
                }

                if (emps.Any())
                {
                    EmployeeQualifications =
                        new Client<EmployeeQualification>().Query(new Filter<EmployeeQualification>(x => x.Employee.ID).InList(emps.ToArray()));
                }
                else
                {
                    EmployeeQualifications = new CoreTable();
                    EmployeeQualifications.LoadColumns(typeof(EmployeeQualification));
                }
            }
        }

        private bool QualificationsCheck(CoreRow arg)
        {
            var empid = arg != null ? arg.Get<JobEmployee, Guid>(x => x.EmployeeLink.ID) : Guid.Empty;
            if (warnings.ContainsKey(empid))
            {
                var summary = new List<string>();

                if (warnings[empid].Item1.Any())
                {
                    summary.Add("Required Qualifications:");
                    foreach (var warning in warnings[empid].Item1)
                        summary.Add("- " + warning);
                    summary.Add("");
                }

                if (warnings[empid].Item2.Any())
                {
                    summary.Add("Other Qualifications:");
                    foreach (var warning in warnings[empid].Item2)
                        summary.Add("- " + warning);
                }

                if (summary.Any())
                    MessageBox.Show(string.Join("\n", summary));
                else
                    MessageBox.Show("No job-specific qualifications found for " + arg.Get<JobEmployee, string>(x => x.EmployeeLink.Name));
            }
            else
            {
                MessageBox.Show("No job-specific qualifications found for " + arg.Get<JobEmployee, string>(x => x.EmployeeLink.Name));
            }

            return false;
        }

        private void Warn(Guid empid, string required, string optional)
        {
            if (!warnings.ContainsKey(empid))
                warnings[empid] = new Tuple<List<string>, List<string>>(new List<string>(), new List<string>());
            if (!string.IsNullOrWhiteSpace(required))
                warnings[empid].Item1.Add(required);
            if (!string.IsNullOrWhiteSpace(optional))
                warnings[empid].Item2.Add(optional);
        }

        protected override void Reload(Filters<JobEmployee> criteria, Columns<JobEmployee> columns, ref SortOrder<JobEmployee> sort,
            Action<CoreTable, Exception> action)
        {
            EmployeeQualifications = null;
            JobQualifications = null;
            warnings.Clear();

            criteria.Add(new Filter<JobEmployee>(x => x.JobLink.ID).IsEqualTo(ParentID));
            criteria.Add(new Filter<JobEmployee>(x => x.EmployeeLink.StartDate).IsEqualTo(DateTime.MinValue).Or(x => x.EmployeeLink.StartDate)
                .IsLessThanOrEqualTo(DateTime.Today));
            criteria.Add(new Filter<JobEmployee>(x => x.EmployeeLink.FinishDate).IsEqualTo(DateTime.MinValue).Or(x => x.EmployeeLink.FinishDate)
                .IsGreaterThanOrEqualTo(DateTime.Today));
            base.Reload(criteria, columns, ref sort, action);
        }
    }
}