using GameBuilder;
using GameBuilder.Cue;
using GameBuilder.Psp;
using Li.Utilities;
using PspCrypto;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;

namespace GameBuilder.Pops
{
    public abstract class PopsImg : NpDrmPsar
    {
        
        public PopsImg(NpDrmInfo versionKey) : base(versionKey)
        {
            simple = new MemoryStream();
            simpleUtil = new StreamUtil(simple);

            this.StartDat = NpDrmPsar.CreateStartDat(Resources.STARTDATPOPS);
            this.createSimpleDat();
            this.SimplePgd = CreatePgd(simple.ToArray());

            this.EbootElf = Resources.DATAPSPSD;
            this.ConfigBin = Resources.DATAPSPSDCFG;
            this.PatchEboot = true;
        }
        internal void createSimpleDat()
        {
            simpleUtil.WriteStr("SIMPLE  ");
            simpleUtil.WriteInt32(100);
            simpleUtil.WriteInt32(16);
            simpleUtil.WriteInt32(Resources.SIMPLE.Length);
            simpleUtil.WriteInt32(0);
            simpleUtil.WriteInt32(0);

            simpleUtil.WriteBytes(Resources.SIMPLE);
        }
        public byte[] CreatePgd(byte[] buffer)
        {

            int bufferSz = DNASHelper.CalculateSize(buffer.Length, 0x400);
            byte[] bufferEnc = new byte[bufferSz];

            // get pgd
            int sz = DNASHelper.Encrypt(bufferEnc, buffer, DrmInfo.VersionKey, buffer.Length, DrmInfo.KeyIndex, 1, blockSize: 0x400);
            byte[] pgd = bufferEnc.ToArray();
            Array.Resize(ref pgd, sz);

            return pgd;
        }


        public override byte[] GenerateDataPsp()
        {
            Span<byte> loaderEnc = new byte[0x9B13];
            
            //byte[] dataPspElf = Resources.DATAPSPSD;

            if (this.PatchEboot)
            {
                // calculate size low and high part ..
                uint szLow = Convert.ToUInt32(Psar.Length) >> 16;
                uint szHigh = Convert.ToUInt32(Psar.Length) & 0xFFFF;

                // convert to big endain bytes
                byte[] lowBits = BitConverter.GetBytes(Convert.ToUInt16(szLow)).ToArray();
                byte[] highBits = BitConverter.GetBytes(Convert.ToUInt16(szHigh)).ToArray();

                // overwrite data.psar size check ..
                Array.ConstrainedCopy(lowBits, 0, this.EbootElf, 0x68C, 0x2);
                Array.ConstrainedCopy(highBits, 0, this.EbootElf, 0x694, 0x2);
            }

            SceMesgLed.Encrypt(
                loaderEnc,
                this.EbootElf,
                0x0DAA06F0,
                SceExecFileDecryptMode.DECRYPT_MODE_POPS_EXEC,
                DrmInfo.VersionKey,
                DrmInfo.ContentId, 
                this.ConfigBin);
            return loaderEnc.ToArray();
        }

        private MemoryStream simple;
        private StreamUtil simpleUtil;

        public byte[] EbootElf;
        public byte[] ConfigBin;
        public bool PatchEboot;

        public byte[] StartDat;
        public byte[] SimplePgd;

    }
}