using System;
using static System.Buffers.Binary.BinaryPrimitives;

namespace PKHeX.Core;

public sealed class SuperTrainBlock : SaveBlock<SAV6>
{
    public SuperTrainBlock(SAV6XY sav, int offset) : base(sav) => Offset = offset;
    public SuperTrainBlock(SAV6AO sav, int offset) : base(sav) => Offset = offset;

    // Structure:
    // 6 bytes stage unlock flags
    // 1 byte distribution stage unlock flags
    // 1 byte counter (max value = 10)
    // float[48] recordScore1; // 0x08, 4byte/entry
    // float[48] recordScore2; // 0xC8, 4byte/entry
    // SS-F-G[48] recordHolder1; // 0x188, 4byte/entry
    // SS-F-G[48] recordHolder2; // 0x248, 4byte/entry
    // byte[12] bags // 0x308
    // u32 tutorial tracker (max value = 6) // 0x314

    // 0x318 total size

    // SS-F-G = u16 species, u8 form, u8 gender

    private const int MAX = 48;
    private const int MAX_RELEASED = 32;
    private const int MAX_DIST = 6;
    private const int MAX_BAG = 12;

    /// <summary>
    /// Checks if a Regimen is unlocked.
    /// </summary>
    /// <param name="index">Index of regimen.</param>
    /// <returns>Is Unlocked</returns>
    public bool GetIsRegimenUnlocked(int index)
    {
        if ((uint)index >= MAX)
            throw new ArgumentOutOfRangeException(nameof(index));
        return SAV.GetFlag(Offset, index);
    }

    /// <summary>
    /// Sets a Regimen to the desired unlocked state.
    /// </summary>
    /// <param name="index">Index of regimen.</param>
    /// <param name="value">Is Unlocked</param>
    public void SetIsRegimenUnlocked(int index, bool value)
    {
        if ((uint)index >= MAX)
            throw new ArgumentOutOfRangeException(nameof(index));
        SAV.SetFlag(Offset, index, value);
    }

    /// <summary>
    /// Checks if a Distribution Regimen is unlocked.
    /// </summary>
    /// <param name="index">Index of regimen.</param>
    /// <returns>Is Unlocked</returns>
    public bool GetIsDistributionUnlocked(int index)
    {
        if ((uint)index >= MAX_DIST)
            throw new ArgumentOutOfRangeException(nameof(index));
        return SAV.GetFlag(Offset + 6, index);
    }

    /// <summary>
    /// Sets a Distribution Regimen to the desired unlocked state.
    /// </summary>
    /// <param name="index">Index of regimen.</param>
    /// <param name="value">Is Unlocked</param>
    public void SetIsDistributionUnlocked(int index, bool value)
    {
        if ((uint)index >= MAX_DIST)
            throw new ArgumentOutOfRangeException(nameof(index));
        SAV.SetFlag(Offset + 6, index, value);
    }

    /// <summary>
    /// Counts something up to 10 (overall stages unlocked?)
    /// </summary>
    public byte Counter
    {
        get => Data[Offset + 7];
        set => Data[Offset + 7] = Math.Min((byte)10, value);
    }

    /// <summary>
    /// Gets the record time.
    /// </summary>
    /// <param name="index">Index of the record.</param>
    public float GetTime1(int index)
    {
        if ((uint) index >= MAX)
            throw new ArgumentOutOfRangeException(nameof(index));

        return ReadSingleLittleEndian(Data.AsSpan(Offset + 0x08 + (4 * index)));
    }

    /// <summary>
    /// Sets the record time.
    /// </summary>
    /// <param name="index">Index of the record.</param>
    /// <param name="value">Value to set.</param>
    public void SetTime1(int index, float value = 0)
    {
        if ((uint)index >= MAX)
            throw new ArgumentOutOfRangeException(nameof(index));

        WriteSingleLittleEndian(Data.AsSpan(Offset + 0x08 + (4 * index)), value);
    }

    /// <summary>
    /// Gets the record time.
    /// </summary>
    /// <param name="index">Index of the record.</param>
    public float GetTime2(int index)
    {
        if ((uint)index >= MAX)
            throw new ArgumentOutOfRangeException(nameof(index));

        return ReadSingleLittleEndian(Data.AsSpan(Offset + 0xC8 + (4 * index)));
    }

    /// <summary>
    /// Sets the record time.
    /// </summary>
    /// <param name="index">Index of the record.</param>
    /// <param name="value">Value to set.</param>
    public void SetTime2(int index, float value = 0)
    {
        if ((uint)index >= MAX)
            throw new ArgumentOutOfRangeException(nameof(index));

        WriteSingleLittleEndian(Data.AsSpan(Offset + 0xC8 + (4 * index)), value);
    }

    /// <summary>
    /// Returns an object which will edit the record directly from data.
    /// </summary>
    /// <param name="index">Index of the record.</param>
    /// <returns>Object that will edit the record data if modified.</returns>
    public SuperTrainingSpeciesRecord GetHolder1(int index)
    {
        if ((uint)index >= MAX)
            throw new ArgumentOutOfRangeException(nameof(index));

        return new SuperTrainingSpeciesRecord(Data, Offset + 0x188 + (4 * index));
    }

    /// <summary>
    /// Returns an object which will edit the record directly from data.
    /// </summary>
    /// <param name="index">Index of the record.</param>
    /// <returns>Object that will edit the record data if modified.</returns>
    public SuperTrainingSpeciesRecord GetHolder2(int index)
    {
        if ((uint)index >= MAX)
            throw new ArgumentOutOfRangeException(nameof(index));

        return new SuperTrainingSpeciesRecord(Data, Offset + 0x248 + (4 * index));
    }

    /// <summary>
    /// Gets the bag from the desired <see cref="index"/>.
    /// </summary>
    /// <param name="index">Bag index</param>
    public byte GetBag(int index)
    {
        if ((uint)index >= MAX_BAG)
            throw new ArgumentOutOfRangeException(nameof(index));
        return Data[Offset + 0x308 + index];
    }

    /// <summary>
    /// Sets a bag to the desired <see cref="index"/>.
    /// </summary>
    /// <param name="index">Bag index</param>
    /// <param name="value">Bag ID</param>
    public void SetBag(int index, byte value)
    {
        if ((uint)index >= MAX_BAG)
            throw new ArgumentOutOfRangeException(nameof(index));
        Data[Offset + 0x308 + index] = value;
    }

    /// <summary>
    /// Gets the next open bag index.
    /// </summary>
    /// <returns>Bag index that is empty</returns>
    public int GetOpenBagIndex()
    {
        for (int i = 0; i < MAX_BAG; i++)
        {
            if (GetBag(i) != 0)
                return i;
        }

        return -1;
    }

    /// <summary>
    /// Adds a bag to the list of bags.
    /// </summary>
    /// <param name="bag">Bag type</param>
    /// <returns>Bag was added or not</returns>
    public bool AddBag(byte bag)
    {
        int index = GetOpenBagIndex();
        if (index < 0)
            return false;
        SetBag(index, bag);
        return true;
    }

    /// <summary>
    /// Removes a bag from the list of bags.
    /// </summary>
    /// <param name="index">Bag index</param>
    public void RemoveBag(int index)
    {
        if ((uint)index >= MAX_BAG)
            throw new ArgumentOutOfRangeException(nameof(index));
        for (int i = index; i < MAX_BAG - 1; i++)
        {
            var next = GetBag(i + 1);
            SetBag(i, next);
        }
        SetBag(MAX_BAG - 1, 0);
    }

    public uint TutorialIndex
    {
        get => ReadUInt32LittleEndian(Data.AsSpan(Offset + 0x314));
        set => WriteUInt32LittleEndian(Data.AsSpan(Offset + 0x314), value);
    }

    /// <summary>
    /// Clears all data for the record.
    /// </summary>
    /// <param name="index">Index of the record.</param>
    public void ClearRecord1(int index)
    {
        if ((uint)index >= MAX)
            throw new ArgumentOutOfRangeException(nameof(index));

        SetTime1(index, 0f);
        GetHolder1(index).Clear();
    }

    /// <summary>
    /// Clears all data for the record.
    /// </summary>
    /// <param name="index">Index of the record.</param>
    public void ClearRecord2(int index)
    {
        if ((uint)index >= MAX)
            throw new ArgumentOutOfRangeException(nameof(index));

        SetTime2(index, 0f);
        GetHolder2(index).Clear();
    }

    /// <summary>
    /// Unlocks all stages.
    /// </summary>
    /// <param name="dist">Unlock all Distribution stages too.</param>
    public void UnlockAllStages(bool dist)
    {
        for (int i = 0; i < MAX_RELEASED; i++)
            SetIsRegimenUnlocked(i, true);

        if (!dist)
            return;

        for (int i = 0; i < MAX_DIST; i++)
            SetIsDistributionUnlocked(i, true);
    }

    /// <summary>
    /// Clears all data in the block.
    /// </summary>
    public void ClearBlock() => Array.Clear(Data, Offset, 0x318);
}

public sealed class SuperTrainingSpeciesRecord : ISpeciesForm
{
    private readonly byte[] Data;
    private readonly int Offset;

    public SuperTrainingSpeciesRecord(byte[] data, int offset)
    {
        Data = data;
        Offset = offset;
    }

    /// <summary>
    /// <see cref="PKM.Species"/> of the Record Holder.
    /// </summary>
    public int Species
    {
        get => ReadUInt16LittleEndian(Data.AsSpan(Offset + 0));
        set => WriteUInt16LittleEndian(Data.AsSpan(Offset + 0), (ushort)value);
    }

    /// <summary>
    /// <see cref="PKM.Form"/> of the Record Holder.
    /// </summary>
    public int Form
    {
        get => Data[Offset + 2];
        set => Data[Offset + 2] = (byte)value;
    }

    /// <summary>
    /// <see cref="PKM.Gender"/> of the Record Holder.
    /// </summary>
    /// <seealso cref="Core.Gender"/>
    public int Gender
    {
        get => Data[Offset + 3];
        set => Data[Offset + 3] = (byte)value;
    }

    /// <summary>
    /// Wipes the record holder's pk-related data.
    /// </summary>
    public void Clear() => Species = Form = Gender = 0;

    /// <summary>
    /// Sets the data to match what is in the provided reference.
    /// </summary>
    /// <param name="pk">Reference to load from.</param>
    public void LoadFrom(PKM pk)
    {
        Species = pk.Species;
        Form = pk.Form;
        Gender = pk.Gender;
    }
}