namespace PKHeX.Core
{
    /// <summary>
    /// Game Version ID enum shared between actual Version IDs and lumped version groupings.
    /// </summary>
    public enum GameVersion
    {
        // Indicators
        Invalid = -2,
        Any = -1,
        Unknown = 0,

        // Version IDs, also stored in PKM structure
        /*Gen3*/ S = 1, R = 2, E = 3, FR = 4, LG = 5, CXD = 15,
        /*Gen4*/ D = 10, P = 11, Pt = 12, HG = 7, SS = 8,
        /*Gen5*/ W = 20, B = 21, W2 = 22, B2 = 23,
        /*Gen6*/ X = 24, Y = 25, AS = 26, OR = 27,
        /*Gen7*/ SN = 30, MN = 31, US = 32, UM = 33,
        /* GO */ GO = 34,
        /* VC1*/ RD = 35, GN = 36, BU = 37, YW = 38, // GN = Blue for international release
        /* VC2*/ GD = 39, SV = 40, C = 41, // Crystal is unused

        // Not actually stored values, but assigned as properties.

        // Game Groupings (SaveFile type)
        /*SAV1*/ RB, RBY,
        /*SAV2*/ GS, GSC,
        /*SAV3*/ RS, RSE, FRLG, RSBOX, COLO, XD,
        /*SAV4*/ DP, DPPt, HGSS, BATREV,
        /*SAV5*/ BW, B2W2,
        /*SAV6*/ XY, ORASDEMO, ORAS,
        /*SAV7*/ SM, USUM,

        // Extra Game Groupings (Generation)
        Gen1, Gen2, Gen3, Gen4, Gen5, Gen6, Gen7,
        GBCartEraOnly,
        Stadium,
        Stadium2,
        EventsGBGen1,
        EventsGBGen2,
        VCEvents
    }

    public static partial class Extensions
    {
        public static int GetGeneration(this GameVersion g)
        {
            if (GameVersion.Gen1.Contains(g)) return 1;
            if (GameVersion.Gen2.Contains(g)) return 2;
            if (GameVersion.Gen3.Contains(g)) return 3;
            if (GameVersion.Gen4.Contains(g)) return 4;
            if (GameVersion.Gen5.Contains(g)) return 5;
            if (GameVersion.Gen6.Contains(g)) return 6;
            if (GameVersion.Gen7.Contains(g)) return 7;
            return -1;
        }
        public static bool Contains(this GameVersion g1, GameVersion g2)
        {
            if (g1 == g2 || g1 == GameVersion.Any)
                return true;

            switch (g1)
            {
                case GameVersion.RB:
                    return g2 == GameVersion.RD || g2 == GameVersion.BU || g2 == GameVersion.GN;
                case GameVersion.RBY:
                    return GameVersion.RB.Contains(g2) || g2 == GameVersion.YW;
                case GameVersion.Gen1:
                    return GameVersion.RBY.Contains(g2) || g2 == GameVersion.Stadium || g2 == GameVersion.EventsGBGen1 || g2 == GameVersion.VCEvents;
                case GameVersion.Stadium:
                case GameVersion.EventsGBGen1:
                case GameVersion.VCEvents:
                    goto case GameVersion.RBY;

                case GameVersion.GS: return g2 == GameVersion.GD || g2 == GameVersion.SV;
                case GameVersion.GSC:
                    return GameVersion.GS.Contains(g2) || g2 == GameVersion.C;
                case GameVersion.Gen2:
                    return GameVersion.GSC.Contains(g2) || g2 == GameVersion.Stadium2 || g2 == GameVersion.EventsGBGen2;
                case GameVersion.Stadium2:
                case GameVersion.EventsGBGen2:
                    goto case GameVersion.GSC;
                case GameVersion.GBCartEraOnly:
                    return g2 == GameVersion.Stadium || g2 == GameVersion.Stadium2 || g2 == GameVersion.EventsGBGen1 || g2 == GameVersion.EventsGBGen2;

                case GameVersion.RS: return g2 == GameVersion.R || g2 == GameVersion.S;
                case GameVersion.RSE:
                    return GameVersion.RS.Contains(g2) || g2 == GameVersion.E;
                case GameVersion.FRLG: return g2 == GameVersion.FR || g2 == GameVersion.LG;
                case GameVersion.COLO:
                case GameVersion.XD: return g2 == GameVersion.CXD;
                case GameVersion.CXD: return g2 == GameVersion.COLO || g2 == GameVersion.XD;
                case GameVersion.RSBOX: return GameVersion.RS.Contains(g2) || g2 == GameVersion.E || GameVersion.FRLG.Contains(g2);
                case GameVersion.Gen3:
                    return GameVersion.RSE.Contains(g2) || GameVersion.FRLG.Contains(g2) || GameVersion.CXD.Contains(g2) || g2 == GameVersion.RSBOX;

                case GameVersion.DP: return g2 == GameVersion.D || g2 == GameVersion.P;
                case GameVersion.HGSS: return g2 == GameVersion.HG || g2 == GameVersion.SS;
                case GameVersion.DPPt:
                    return GameVersion.DP.Contains(g2) || g2 == GameVersion.Pt;
                case GameVersion.BATREV: return GameVersion.DP.Contains(g2) || g2 == GameVersion.Pt || GameVersion.HGSS.Contains(g2);
                case GameVersion.Gen4:
                    return GameVersion.DPPt.Contains(g2) || GameVersion.HGSS.Contains(g2) || g2 == GameVersion.BATREV;

                case GameVersion.BW: return g2 == GameVersion.B || g2 == GameVersion.W;
                case GameVersion.B2W2: return g2 == GameVersion.B2 || g2 == GameVersion.W2;
                case GameVersion.Gen5:
                    return GameVersion.BW.Contains(g2) || GameVersion.B2W2.Contains(g2);

                case GameVersion.XY: return g2 == GameVersion.X || g2 == GameVersion.Y;
                case GameVersion.ORAS: return g2 == GameVersion.OR || g2 == GameVersion.AS;
                case GameVersion.Gen6:
                    return GameVersion.XY.Contains(g2) || GameVersion.ORAS.Contains(g2);

                case GameVersion.SM:
                    return g2 == GameVersion.SN || g2 == GameVersion.MN;
                case GameVersion.USUM:
                    return g2 == GameVersion.US || g2 == GameVersion.UM;
                case GameVersion.Gen7:
                    return GameVersion.SM.Contains(g2) || GameVersion.USUM.Contains(g2);

                default: return false;
            }
        }
        public static bool IsValid(this GameVersion g) => 0 < g && g <= GameVersion.RB;
    }
}