package konogonka.Tools.PFS0;

import konogonka.RainbowHexDump;

import java.io.File;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.nio.charset.StandardCharsets;
import java.util.Arrays;

import static konogonka.LoperConverter.*;

public class PFS0Provider {
    private long pfs0offsetPosition;
    private long rawFileDataStart;

    private String magic;
    private int filesCount;
    private int stringTableSize;
    private byte[] padding;
    private PFS0subFile[] pfs0subFiles;

    public PFS0Provider(File fileWithPfs0) throws Exception{ this(fileWithPfs0, 0); }

    public PFS0Provider(File fileWithPfs0, long pfs0offsetPosition) throws Exception{
        this.pfs0offsetPosition = pfs0offsetPosition;

        try {
            RandomAccessFile raf = new RandomAccessFile(fileWithPfs0, "r");

            raf.seek(pfs0offsetPosition);
            byte[] fileStartingBytes = new byte[0x10];
            // Read PFS0Provider, files count, header, padding (4 zero bytes)
            if (raf.read(fileStartingBytes) != 0x10){
                raf.close();
                throw new Exception("PFS0Provider: Unable to read starting bytes");
            }
            // Check PFS0Provider
            magic = new String(fileStartingBytes, 0x0, 0x4, StandardCharsets.US_ASCII);
            if (! magic.equals("PFS0")){
                raf.close();
                throw new Exception("PFS0Provider: Bad magic");
            }
            // Get files count
            filesCount = getLEint(fileStartingBytes, 0x4);
            if (filesCount <= 0 ) {
                raf.close();
                throw new Exception("PFS0Provider: Files count is too small");
            }
            // Get string table
            stringTableSize = getLEint(fileStartingBytes, 0x8);
            if (stringTableSize <= 0 ){
                raf.close();
                throw new Exception("PFS0Provider: String table is too small");
            }
            padding = Arrays.copyOfRange(fileStartingBytes, 0xc, 0x10);
            //---------------------------------------------------------------------------------------------------------
            pfs0subFiles = new PFS0subFile[filesCount];

            long[] offsetsSubFiles = new long[filesCount];
            long[] sizesSubFiles = new long[filesCount];
            int[] strTableOffsets = new int[filesCount];
            byte[][] zeroBytes = new byte[filesCount][];

            byte[] fileEntryTable = new byte[0x18];
            for (int i=0; i<filesCount; i++){
                if (raf.read(fileEntryTable) != 0x18)
                    throw new Exception("PFS0Provider: String table is too small");
                offsetsSubFiles[i] = getLElong(fileEntryTable, 0);
                sizesSubFiles[i] = getLElong(fileEntryTable, 0x8);
                strTableOffsets[i] = getLEint(fileEntryTable, 0x10);
                zeroBytes[i] = Arrays.copyOfRange(fileEntryTable, 0x14, 0x18);
            }
            //**********************************************************************************************************
            // In here pointer in front of String table
            String[] subFileNames = new String[filesCount];
            byte[] stringTbl = new byte[stringTableSize];
            if (raf.read(stringTbl) != stringTableSize){
                throw new Exception("Read PFS0Provider String table failure. Can't read requested string table size ("+stringTableSize+")");
            }

            for (int i=0; i < filesCount; i++){
                int j = 0;
                while (stringTbl[strTableOffsets[i]+j] != (byte)0x00)
                    j++;
                subFileNames[i] = new String(stringTbl, strTableOffsets[i], j, StandardCharsets.UTF_8);
            }
            for (int i = 0; i < filesCount; i++){
                pfs0subFiles[i] = new PFS0subFile(
                        subFileNames[i],
                        offsetsSubFiles[i],
                        sizesSubFiles[i],
                        zeroBytes[i]
                );
            }
            rawFileDataStart = raf.getFilePointer();
            raf.close();
        }
        catch (IOException ioe){
            throw new IOException("PFS0Provider: "+ioe.getMessage());
        }
    }

    public long getPfs0offsetPosition() { return pfs0offsetPosition; }
    public String getMagic() { return magic; }
    public int getFilesCount() { return filesCount; }
    public int getStringTableSize() { return stringTableSize; }
    public byte[] getPadding() { return padding; }

    public long getRawFileDataStart() { return rawFileDataStart; }
    public PFS0subFile[] getPfs0subFiles() { return pfs0subFiles; }
}