package com.sigmatauproductions.sc2k;

import java.io.IOException;
import java.util.List;
import java.util.ArrayList;

public class IFFChunk {

    private String chunkType = null;
    private int size = 0;
    private byte[] contents = null;

    public IFFChunk(String type, int size, byte[] contents) throws IOException {
        chunkType = type;
        this.size = size;
        this.contents = contents;
    }

    public String getType() {
        return chunkType;
    }

    public int getSize() {
        return size;
    }

    public byte[] getContents() {
        return contents;
    }

    public void decompress() {
        List<Byte> buffer = new ArrayList<Byte>();

        int counter = 0; // debug purposes
        System.out.println(contents.length + " bytes at start of decompression operation");

        // Begin debug block
        System.out.println("Creating dump of original active block");
        int bytesRemaining = contents.length;
        System.out.print("0: ");
        while (bytesRemaining > 0) {
            int startingIndex = contents.length-bytesRemaining;
            byte firstByte = contents[startingIndex];
            int firstByteAsInt;
            if (firstByte < 0) {
                firstByteAsInt = (255+firstByte);
            } else {
                firstByteAsInt = firstByte;
            }
            System.out.print(firstByteAsInt + "   ");
            if (firstByteAsInt < 9) { System.out.print(" "); }
            if (firstByteAsInt < 99) { System.out.print(" "); }
            if (counter % 16 == 0 && counter != 0) { System.out.print("\n"+(counter+1)+": "); }
            bytesRemaining--;
            counter++; // debug purposes
        }
        System.out.println("End of dump.");
        // End debug block

        bytesRemaining = contents.length;
        while (bytesRemaining > 0) {
            int startingIndex = contents.length-bytesRemaining;
            byte firstByte = contents[startingIndex];
            byte[] extracted = null;

            // SimCity stores its values as unsigned shorts.
            // Java doesn't have unsigned integers, so we have to account for
            // that.  Yay for Java being shit as usual!  I need uint8 :(
            int firstUnsigned;
            if (firstByte < 0) {
                firstUnsigned = (255+firstByte);
            } else {
                firstUnsigned = firstByte;
            }

            System.out.println("Starting index is " + startingIndex); // debug
            if (firstUnsigned <= 127) {
                System.out.print("Detected normal subblock " + firstUnsigned
                    + " bytes in size at position "+startingIndex+"\n{ "); // debug
                extracted = GenericIFF.extractSegment(contents, startingIndex+1, startingIndex+(firstUnsigned));

                for (byte b : extracted) {
                    buffer.add(b);
                    System.out.print(b + " "); // debug
                }

                System.out.println("}"); //debug

                bytesRemaining -= (extracted.length+1);
            } else {
                int repetitions = firstUnsigned-127;
                System.out.println("Detected compressed subblock of " + repetitions
                    + " repetitions."); // debug
                byte source = contents[startingIndex+1];
                extracted = expandData(repetitions, source);



                System.out.print("{ ");
                for (byte b : extracted) {
                    buffer.add(b);
                    System.out.print(b + " ");
                }
                System.out.println("}"); // debug

                bytesRemaining -= 2;
            }

            System.out.println(buffer.size() + " bytes total in result");
            System.out.println(bytesRemaining + " bytes remain in source");
            System.out.println("-------");

            counter++; // debug purposes
        }



        System.out.println();
        System.out.println();
        System.out.println(buffer.size() + " bytes at end of decompression operation");
    }

    protected byte[] expandData(int repetitions, byte data) {
        if (repetitions <= 0) { return null; }
        byte[] repeated = new byte[repetitions];
        for (int i = 0; i < repeated.length; i++) {
            repeated[i] = data;
        }
        return repeated;
    }
}