using System;
using System.Collections.Generic;
using static PKHeX.Core.EReaderBerryMatch;

namespace PKHeX.Core;

/// <summary>
/// Stores details about the Gen3 e-Reader Berry values.
/// </summary>
public static class EReaderBerrySettings
{
    /// <summary> e-Reader Berry is Enigma or special berry (from e-Reader data)</summary>
    public static bool IsEnigma { get; set; } = true;

    /// <summary> e-Reader Berry Name </summary>
    private static string Name { get; set; } = string.Empty;

    /// <summary> e-Reader Berry Name formatted in Title Case </summary>
    public static string DisplayName => string.Format(LegalityCheckStrings.L_XEnigmaBerry_0, Util.ToTitleCase(Name.AsSpan()));

    private static int Language { get; set; }

    /// <summary>
    /// Checks if the most recently loaded Generation 3 Save File has a proper Enigma Berry that matches known distributions.
    /// </summary>
    public static EReaderBerryMatch GetStatus()
    {
        if (IsEnigma) // no e-Reader Berry data provided, can't hold berry.
            return NoData;

        var name = Name;
        if (EReaderBerriesNames_USA.Contains(name))
        {
            return Language switch
            {
                <= 0 => ValidAny,
                not 1 => ValidUSA,
                _ => InvalidUSA,
            };
        }
        if (EReaderBerriesNames_JP.Contains(name))
        {
            return Language switch
            {
                <= 0 => ValidAny,
                1 => ValidJPN,
                _ => InvalidJPN,
            };
        }
        return NoMatch;
    }

    private static readonly HashSet<string> EReaderBerriesNames_USA = new()
    {
        // USA Series 1
        "PUMKIN",
        "DRASH",
        "EGGANT",
        "STRIB",
        "CHILAN",
        "NUTPEA",
    };

    private static readonly HashSet<string> EReaderBerriesNames_JP = new()
    {
        // JP Series 1
        "カチャ", // PUMKIN
        "ブ－カ", // DRASH
        "ビスナ", // EGGANT
        "エドマ", // STRIB
        "ホズ", // CHILAN
        "ラッカ", // NUTPEA
        "クオ", // KU
        // JP Series 2
        "ギネマ", // GINEMA
        "クオ", // KUO
        "ヤゴ", // YAGO
        "トウガ", // TOUGA
        "ニニク", // NINIKU
        "トポ", // TOPO
    };

    public static void LoadFrom(SAV3 sav3)
    {
        Language = sav3.Japanese ? (int)LanguageID.Japanese : (int)LanguageID.English;
        if (sav3.IsEBerryEngima)
        {
            IsEnigma = true;
            Name = string.Empty;
        }
        else
        {
            IsEnigma = false;
            Name = sav3.EBerryName;
        }
    }
}

/// <summary>
/// For use in validating the current e-Reader Berry settings.
/// </summary>
public enum EReaderBerryMatch : byte
{
    /// <summary> Invalid: Doesn't match either language </summary>
    NoMatch,
    /// <summary> Invalid: No data provided from a save file </summary>
    NoData,
    /// <summary> Invalid: USA berry name on JPN save file </summary>
    InvalidUSA,
    /// <summary> Invalid: JPN berry name on USA save file</summary>
    InvalidJPN,

    /// <summary> Valid: Berry name matches either USA/JPN (Ambiguous Save File Language) </summary>
    ValidAny,
    /// <summary> Valid: Berry name matches a USA berry name </summary>
    ValidUSA,
    /// <summary> Valid: Berry name matches a JPN berry name </summary>
    ValidJPN,
}