using MU3.Data;
using MU3.DataStudio;
using MU3.User;
using MU3.Util;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;

namespace MU3.Mod;

public static class CustomRating {
    // Adapted from MU3.User.UserRating.calcBest()
    private static RatingList calcNaive() {
        RatingList ratingList = [];

        var usMgr = Singleton<UserManager>.instance;
        var musicDict = usMgr.userMusic;

        foreach(KeyValuePair<int, UserMusic> item in musicDict) {
            var musicData = SingletonStateMachine<DataManager, DataManager.EState>
                .instance.getMusicData(item.Key);

            if(musicData == null || item.Key == 1 || musicData.isBonusTrack) {
                continue;
            }
            for(int i = 0; i < 5; i++) {
                var fumenDifficulty = (FumenDifficulty)i;
                var userFumen = usMgr.getUserFumen(item.Key, fumenDifficulty, create: false);
                if(userFumen == null) {
                    continue;
                }
                Rating rating = new(musicData.id, fumenDifficulty, userFumen.TechScoreMax);
                if(rating.level100 == 0) {
                    continue;
                }
                ratingList.Add(rating);
            }
        }

        ratingList.Sort();
        return ratingList;
    }
    public static int GetNaive() {
        int res = 0;
        foreach(Rating best in calcNaive().Take(45)) {
            res += best.rate100;
        }
        return res / 45;
    }

    public static int GetReachable() {
        FieldInfo piOld = typeof(UserRating).GetField("_bestOldList", BindingFlags.Instance | BindingFlags.NonPublic);
        FieldInfo piNew = typeof(UserRating).GetField("_bestNewList", BindingFlags.Instance | BindingFlags.NonPublic);

        var ur = Singleton<UserManager>.instance.userRating;

        int res = 0;
        int top = 0;
        foreach(Rating best in ((RatingList)piOld.GetValue(ur))) {
            res += best.rate100;
            if(best.musicID < 7000) {
                top = Math.Max(top, best.rate100);
            }
        }
        foreach(Rating best in ((RatingList)piNew.GetValue(ur))) {
            res += best.rate100;
            if(best.musicID < 7000) {
                top = Math.Max(top, best.rate100);
            }
        }

        res += top * 10;

        return res / 55;
    }

    private static bool isNaiveEnabled() {
        return Singleton<UserManager>.instance.userOption.customSet.Rating == (UserOption.eRating)patch_UserOption.eRating.Naive;
    }
    private static bool isReachableEnabled() {
        return Singleton<UserManager>.instance.userOption.customSet.Rating == (UserOption.eRating)patch_UserOption.eRating.Reachable;
    }
    public static bool IsEnabled() {
        return isNaiveEnabled() || isReachableEnabled();
    }

    public static int Get() {
        if(isNaiveEnabled()) {
            return GetNaive();
        } else if(isReachableEnabled()) {
            return GetReachable();
        } else {
            return 0;
        }
    }

    public static byte GetSuffix() {
        if(isNaiveEnabled()) {
            return MU3CounterBase.FigurePlus;
        } else if(isReachableEnabled()) {
            return MU3CounterBase.FigureMinus;
        } else {
            return 0;
        }
    }
}