using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace WeldingCommon.Utils.Diff
{
    public static class CompareHelper
    {
        public sealed class FieldSpec<T>
        {
            public string Name { get; }
            public Func<T, object> Getter { get; }
            public Func<object, string> Formatter { get; }

            public FieldSpec(string name, Func<T, object> getter, Func<object, string> formatter = null)
            {
                Name = name;
                Getter = getter;
                Formatter = formatter;
            }
        }

        /// <summary>
        /// 지정한 항목만 비교해서, 달라진 것만 diffs에 쌓음
        /// </summary>
        public static void Fill<T>(T oldObj, T newObj, ObservableCollection<PropertyDiff> diffs, params FieldSpec<T>[] fields)
        {
            if (oldObj == null) throw new ArgumentNullException(nameof(oldObj));
            if (newObj == null) throw new ArgumentNullException(nameof(newObj));
            if (diffs == null) throw new ArgumentNullException(nameof(diffs));
            if (fields == null) throw new ArgumentNullException(nameof(fields));

            diffs.Clear();

            for (int i = 0; i < fields.Length; i++) {
                var f = fields[i];
                var oldVal = f.Getter(oldObj);
                var newVal = f.Getter(newObj);

                if (!Equals(oldVal, newVal))
                    diffs.Add(new PropertyDiff(f.Name, oldVal, newVal, f.Formatter));
            }
        }

        /*
         단위 테스트 자료
                //Compare 추가
                var diffs = new ObservableCollection<PropertyDiff>();
                CompareHelper.Fill(RecipeBeforeChangedStageA, RecipeStageA, diffs,
                    new CompareHelper.FieldSpec<MainRecipe>(nameof(MainRecipe.N2PressMFC), x => x.N2PressMFC),
                    new CompareHelper.FieldSpec<MainRecipe>(nameof(MainRecipe.AxisZPosition), x => x.AxisZPosition),
                    new CompareHelper.FieldSpec<MainRecipe>(nameof(MainRecipe.StraightParam.Velocity), x => x.StraightParam.Velocity),
                    new CompareHelper.FieldSpec<MainRecipe>(nameof(MainRecipe.CurveParam.Velocity), x => x.CurveParam.Velocity),
                    new CompareHelper.FieldSpec<MainRecipe>(nameof(MainRecipe.StraightParam.CorePowerW), x => x.StraightParam.CorePowerW),
                    new CompareHelper.FieldSpec<MainRecipe>(nameof(MainRecipe.StraightParam.RingPowerW), x => x.StraightParam.RingPowerW),
                    new CompareHelper.FieldSpec<MainRecipe>(nameof(MainRecipe.CurveParam.CorePowerW), x => x.CurveParam.CorePowerW),
                    new CompareHelper.FieldSpec<MainRecipe>(nameof(MainRecipe.RampingOnStartPower), x => x.RampingOnStartPower),
                    new CompareHelper.FieldSpec<MainRecipe>(nameof(MainRecipe.RampingOnOverlapDist), x => x.RampingOnOverlapDist),
                    new CompareHelper.FieldSpec<MainRecipe>(nameof(MainRecipe.RampingOffEndPower), x => x.RampingOffEndPower),
                    new CompareHelper.FieldSpec<MainRecipe>(nameof(MainRecipe.RampingOffOverlapDist), x => x.RampingOffOverlapDist)
                    );
                if(diffs.Count > 0) {
                    Log.FuncI("Recipe Parameter Changed");
                    foreach (var diff in diffs)
                        Log.V($"{diff.ToString()}");
                }
         */
    }
}