using System;
using System.Collections.Generic;
using System.Linq.Expressions;
using InABox.Core;

namespace Comal.Classes
{
    public class KanbanDocumentCount : CoreAggregate<Kanban, KanbanDocument, Guid>
    {
        public override Expression<Func<KanbanDocument, Guid>> Aggregate => x => x.ID;

        public override AggregateCalculation Calculation => AggregateCalculation.Count;

        public override Dictionary<Expression<Func<KanbanDocument, object>>, Expression<Func<Kanban, object>>> Links =>
            new Dictionary<Expression<Func<KanbanDocument, object>>, Expression<Func<Kanban, object>>> ()
            {
                { KanbanDocument => KanbanDocument.EntityLink.ID, Kanban => Kanban.ID }
            };
    }

    public class KanbaAssignmentDuration : CoreAggregate<Kanban, Assignment, TimeSpan>
    {
        public override Expression<Func<Assignment, TimeSpan>> Aggregate => x => x.Actual.Duration;

        public override AggregateCalculation Calculation => AggregateCalculation.Sum;

        public override Dictionary<Expression<Func<Assignment, object>>, Expression<Func<Kanban, object>>> Links =>
            new Dictionary<Expression<Func<Assignment, object>>, Expression<Func<Kanban, object>>>()
            {
                { Assignment => Assignment.Task.ID, Kanban => Kanban.ID }
            };
    }

    public enum KanbanStatus
    {
        Open,
        InProgress,
        Waiting,
        Complete
    }

    [UserTracking("Task Management")]
    [Caption("Tasks")]
    public class Kanban : Entity, IPersistent, IRemotable, IKanban, IScheduleAction, IOneToMany<Schedule>, INumericAutoIncrement<Kanban>,
        IOneToMany<Equipment>, ILicense<TaskManagementLicense>, IExportable, IImportable, IJobScopedItem
    {
        private bool bChanging;

        [NullEditor]
        public DeliveryLink Delivery { get; set; }

        [IntegerEditor(Editable = Editable.Disabled)]
        [EditorSequence(-1)]
        public int Number { get; set; }

        [TextBoxEditor]
        [EditorSequence(0)]
        public string Title { get; set; }

        [EditorSequence(1)]
        public JobLink JobLink { get; set; }

        private class JobScopeLookup : LookupDefinitionGenerator<JobScope, Kanban>
        {
            public override Filter<JobScope> DefineFilter(Kanban[] items)
            {
                var item = items?.Length == 1 ? items[0] : null;
                if (item != null)
                    return new Filter<JobScope>(x => x.Job.ID).IsEqualTo(item.JobLink.ID).And(x => x.Status.Approved).IsEqualTo(true);
                return new Filter<JobScope>(x => x.ID).None();
            }

            public override Columns<Kanban> DefineFilterColumns()
                => new Columns<Kanban>(x => x.JobLink.ID);
        }
        [LookupDefinition(typeof(JobScopeLookup))]
        [EditorSequence(2)]
        public JobScopeLink JobScope { get; set; }

        [RichTextEditor]
        [EditorSequence(3)]
        public string Description { get; set; }

        [NotesEditor]
        [EditorSequence(4)]
        public string[] Notes { get; set; } = Array.Empty<string>();

        [MemoEditor(Visible = Visible.Optional, Editable = Editable.Hidden)]
        [EditorSequence(5)]
        public string Summary { get; set; }

        [EditorSequence(6)]
        [Caption("Task Type")]
        public KanbanTypeLink Type { get; set; }

        [DateEditor]
        [EditorSequence(7)]
        public DateTime DueDate { get; set; } = DateTime.Today;

        // Same lookup right now used for manager and employee.
        private class EmployeeLookup : LookupDefinitionGenerator<Employee, Kanban>
        {
            public override Filter<Employee> DefineFilter(Kanban[] items)
            {
                var result = LookupFactory.DefineFilter<Employee>();
                result.Ands.Add(new Filter<Employee>(x => x.CanAllocateTasks).IsEqualTo(true));
                return result;
            }

            public override Columns<Kanban> DefineFilterColumns()
                => new Columns<Kanban>();
        }
        [LookupDefinition(typeof(EmployeeLookup))]
        [EditorSequence(8)]
        [Caption("Assigned To")]
        public EmployeeLink EmployeeLink { get; set; }

        [EditorSequence(9)]
        [Caption("Allocated By")]
        [LookupDefinition(typeof(EmployeeLookup))]
        public EmployeeLink ManagerLink { get; set; }

        [DateTimeEditor(Editable = Editable.Hidden)]
        [EditorSequence(10)]
        public DateTime Completed { get; set; } = DateTime.MinValue;

        [EditorSequence("Other", 1)]
        [Caption("Equipment Item")]
        public EquipmentLink Equipment { get; set; }

        [DateEditor]
        [EditorSequence("Other", 2)]
        public DateTime StartDate { get; set; } = DateTime.Today;

        [DurationEditor]
        [EditorSequence("Other", 3)]
        public TimeSpan EstimatedTime { get; set; } = TimeSpan.FromHours(1);

        [Aggregate(typeof(KanbaAssignmentDuration))]
        [EditorSequence("Other", 4)]
        public TimeSpan ActualTime { get; set; }

        [CheckBoxEditor]
        [EditorSequence("Other", 5)]
        public bool Private { get; set; }

        [EditorSequence("Other", 6)]
        [CheckBoxEditor]
        public bool Locked { get; set; }

        [EditorSequence("Other", 7)]
        [LoggableProperty]
        [EnumLookupEditor(typeof(KanbanStatus))]
        public KanbanStatus Status { get; set; }

        [SecondaryIndex]
        [NullEditor]
        public DateTime Closed { get; set; } = DateTime.MinValue;

        [NullEditor]
        [Aggregate(typeof(KanbanDocumentCount))]
        public int Attachments { get; set; }

        [NullEditor]
        [Obsolete("Replaced with Status",true)]
        public string Category { get; set; }
        
        public Expression<Func<Kanban, int>> AutoIncrementField()
        {
            return x => x.Number;
        }

        public Filter<Kanban>? AutoIncrementFilter()
        {
            return null;
        }

        [NullEditor]
        public ScheduleLink ScheduleLink { get; set; }

        private bool IsCompleted(object? value)
        {
            if (value == null)
                return false;
            if (value is DateTime dateTime)
                return !dateTime.IsEmpty();
            if (value is KanbanStatus category)
                return category == KanbanStatus.Complete;
            return false;
        }

        protected override void DoPropertyChanged(string name, object? before, object? after)
        {
            base.DoPropertyChanged(name, before, after);

            if (bChanging)
                return;
            bChanging = true;
            if (name.Equals(nameof(Completed))) // set the completed date
            {
                Status = IsCompleted(after) ? KanbanStatus.Complete : IsCompleted(Status) ? KanbanStatus.InProgress : Status;
            }
            else if (name.Equals(nameof(Status))) // set the completed date
            {
                Completed = IsCompleted(after) ? IsCompleted(Completed) ? Completed : DateTime.Now : DateTime.MinValue;
            }
            else if (name.Equals(nameof(Description)))
            {
                var summary = after as string;
                Summary = CoreUtils.StripHTML(summary);
            }

            bChanging = false;
        }

        static Kanban()
        {
            Classes.JobScope.LinkScopeProperties<Kanban>();
        }
    }
}