using System;
using System.Collections.Generic;
using System.Text;
using System.ComponentModel;
using System.Drawing;

using Menees.DiffUtils;
using System.Diagnostics;

namespace sharpcomparer
{
    public class ColumnComparison : Comparison<Column>
    {
        public ColumnComparison(Column leftItem, Column rightItem, ComparisonDifference difference)
            : base(leftItem, rightItem, difference)
        {
        }

        public static List<ColumnComparison> Compare(List<Column> left, List<Column> right)
        {
            int i = 0;

            left.Sort(delegate(Column p1, Column p2)
            {
                return p1.OrdinalPosition.CompareTo(p2.OrdinalPosition);
            });
            right.Sort(delegate(Column p1, Column p2)
            {
                return p1.OrdinalPosition.CompareTo(p2.OrdinalPosition);
            });

            List<ColumnComparison> c1 = new List<ColumnComparison>();
            List<ColumnComparison> c2 = new List<ColumnComparison>();
            foreach (Column c in left)
            {
                c1.Add(new ColumnComparison(c, null, Comparison<Column>.ComparisonDifference.None));
            }
            foreach (Column c in right)
            {
                c2.Add(new ColumnComparison(null, c, Comparison<Column>.ComparisonDifference.None));
            }

            if (left.Count > 0 && left[0].TableName == "ATTIVITA")
            {
                Debug.Write("Break");
            }



            int offset1 = 0;
            int offset2 = 0;

            MyersDiff<Column> comparer = new MyersDiff<Column>(left.ToArray(), right.ToArray(), true);
            EditScript script = comparer.Execute();
            List<ColumnComparison> ColumnsA;
            List<ColumnComparison> ColumnsB;

            if (script.Count > 0)
            {
                foreach (Edit edit in script)
                {
                    switch (edit.Type)
                    {
                        case EditType.Insert:

                            ColumnsB = c2.GetRange(edit.StartB + offset2, edit.Length);
                            ColumnsA = new List<ColumnComparison>();
                            foreach (ColumnComparison b in ColumnsB)
                            {
                                ColumnComparison a = new ColumnComparison(null, b.RightItem, Comparison<Column>.ComparisonDifference.RightOnly);
                                ColumnsA.Add(a);
                            }
                            c1.InsertRange(edit.StartA + offset1, ColumnsA);
                            offset1 += edit.Length;

                            break;

                        case EditType.Change:

                            for (i = 0; i < edit.Length; i++)
                            {
                                c1[edit.StartA + offset1 + i].Difference = Comparison<Column>.ComparisonDifference.Different;
                                c2[edit.StartA + offset1 + i].Difference = Comparison<Column>.ComparisonDifference.Different;

                                c1[edit.StartA + offset1 + i].RightItem = right[edit.StartB];
                            }

                            break;

                        case EditType.Delete:

                            ColumnsA = c1.GetRange(edit.StartA + offset1, edit.Length);
                            ColumnsB = new List<ColumnComparison>();
                            foreach (ColumnComparison a in ColumnsA)
                            {
                                ColumnComparison b = new ColumnComparison(a.LeftItem, null, Comparison<Column>.ComparisonDifference.LeftOnly);
                                ColumnsB.Add(b);
                                a.Difference = Comparison<Column>.ComparisonDifference.LeftOnly;
                            }
                            c2.InsertRange(edit.StartB + offset2, ColumnsB);
                            offset2 += edit.Length;

                            break;

                        case EditType.None:

                            // NOOP

                            break;
                    }
                }
            }

            for (i = 0; i < c1.Count; i++)
            {
                ColumnComparison cc1 = c1[i];
                ColumnComparison cc2 = c2[i];

                if ((cc1.Difference == Comparison<Column>.ComparisonDifference.None || cc1.Difference == Comparison<Column>.ComparisonDifference.Different) &&
                    cc1.RightItem == null)
                {
                    cc1.RightItem = cc2.RightItem;
                    if (cc1.LeftItem != null && cc1.LeftItem.TableName == "ATTIVITA" && cc2.RightItem == null)
                    {
                        int a = 0;
                    }
                }
            }

            for (i = 0; i < c1.Count; i++)
            {
                ColumnComparison cc1 = c1[i];
                if (
                    (cc1.Difference == Comparison<Column>.ComparisonDifference.Different && cc1.RightItem == null) ||
                    (cc1.Difference == Comparison<Column>.ComparisonDifference.None && cc1.RightItem == null)
                    )
                {
                    Debug.Assert(false, "null RightItem on Different comparison");
                }
            }

            return c1;
        }
    }
}