using System.Collections.Generic;
using System.Diagnostics;
using PKHeX.Core.Searching;
using static PKHeX.Core.CheckIdentifier;

namespace PKHeX.Core.Bulk;

public sealed class StandardCloneChecker : IBulkAnalyzer
{
    public void Analyze(BulkAnalysis input) => CheckClones(input);

    private static void CheckClones(BulkAnalysis input)
    {
        var dict = new Dictionary<string, SlotCache>();
        for (int i = 0; i < input.AllData.Count; i++)
        {
            var cs = input.AllData[i];
            var ca = input.AllAnalysis[i];
            Debug.Assert(cs.Entity.Format == input.Trainer.Generation);

            // Check the upload tracker to see if there's any duplication.
            if (cs.Entity is IHomeTrack home)
                CheckClonedTrackerHOME(input, home, cs, ca);

            // Hash Details like EC/IV to see if there's any duplication.
            var identity = SearchUtil.HashByDetails(cs.Entity);
            if (!dict.TryGetValue(identity, out var ps))
            {
                dict.Add(identity, cs);
                continue;
            }

            input.SetIsClone(i, true);
            input.AddLine(ps, cs, "Clone detected (Details).", Encounter);
        }
    }

    private const ulong DefaultUnsetTrackerHOME = 0ul;

    private static void CheckClonedTrackerHOME(BulkAnalysis input, IHomeTrack home, SlotCache cs, LegalityAnalysis ca)
    {
        var tracker = home.Tracker;
        if (tracker == DefaultUnsetTrackerHOME)
            CheckTrackerMissing(input, cs, ca);
        else
            CheckTrackerPresent(input, cs, tracker);
    }

    private static void CheckTrackerMissing(BulkAnalysis input, SlotCache cs, LegalityAnalysis ca)
    {
        if (ca.Info.Generation is (< 8 and not 0))
            input.AddLine(cs, "Missing tracker.", Encounter);
    }

    private static void CheckTrackerPresent(BulkAnalysis input, SlotCache cs, ulong tracker)
    {
        if (input.Trackers.TryGetValue(tracker, out var clone))
            input.AddLine(cs, clone, "Clone detected (Duplicate Tracker).", Encounter);
        else
            input.Trackers.Add(tracker, cs);
    }
}