path: root/src/com/sneed/pkrandom/SettingsUpdater.java

package com.sneed.pkrandom;

/*----------------------------------------------------------------------------*/
/*--  SettingsUpdater.java - handles the process of updating a Settings file--*/
/*--                         from an old randomizer version to use the      --*/
/*--                         correct binary format so it can be loaded by   --*/
/*--                         the current version.                           --*/
/*--                                                                        --*/
/*--  Part of "Universal Pokemon Randomizer ZX" by the UPR-ZX team          --*/
/*--  Originally part of "Universal Pokemon Randomizer" by sneed        --*/
/*--  Pokemon and any associated names and the like are                     --*/
/*--  trademark and (C) Nintendo 1996-2020.                                 --*/
/*--                                                                        --*/
/*--  The custom code written here is licensed under the terms of the GPL:  --*/
/*--                                                                        --*/
/*--  This program is free software: you can redistribute it and/or modify  --*/
/*--  it under the terms of the GNU General Public License as published by  --*/
/*--  the Free Software Foundation, either version 3 of the License, or     --*/
/*--  (at your option) any later version.                                   --*/
/*--                                                                        --*/
/*--  This program is distributed in the hope that it will be useful,       --*/
/*--  but WITHOUT ANY WARRANTY; without even the implied warranty of        --*/
/*--  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the          --*/
/*--  GNU General Public License for more details.                          --*/
/*--                                                                        --*/
/*--  You should have received a copy of the GNU General Public License     --*/
/*--  along with this program. If not, see <http://www.gnu.org/licenses/>.  --*/
/*----------------------------------------------------------------------------*/

import java.nio.ByteBuffer;
import java.util.Base64;
import java.util.zip.CRC32;

public class SettingsUpdater {

    private byte[] dataBlock;
    private int actualDataLength;

    /**
     * Given a quicksettings config string from an old randomizer version,
     * update it to be compatible with the currently running randomizer version.
     * 
     * @param oldVersion
     *            The PRESET_FILE_VERSION used to generate the given string
     * @param configString
     *            The outdated config string
     * @return The updated config string to be applied
     */
    public String update(int oldVersion, String configString) {
        byte[] data = Base64.getDecoder().decode(configString);
        this.dataBlock = new byte[200];
        this.actualDataLength = data.length;
        System.arraycopy(data, 0, this.dataBlock, 0, this.actualDataLength);

        // new field values here are written as bitwise ORs
        // this is slightly slower in execution, but it makes it clearer
        // just what values we actually want to set
        // bit fields 1 2 3 4 5 6 7 8
        // are values 0x01 0x02 0x04 0x08 0x10 0x20 0x40 0x80

        // versions prior to 120 didn't have quick settings file,
        // they're just included here for completeness' sake

        // versions < 102: add abilities set to unchanged
        if (oldVersion < 102) {
            dataBlock[1] |= 0x10;
        }

        // versions < 110: add move tutor byte (set both to unchanged)
        if (oldVersion < 110) {
            insertExtraByte(15, (byte) (0x04 | 0x10));
        }

        // version 110-111 no change (only added trainer names/classes to preset
        // files, and some checkboxes which it is safe to leave as off)

        // 111-112 no change (another checkbox we leave as off)

        // 112-120 no change (only another checkbox)

        // 120-150 new features
        if (oldVersion < 150) {
            // trades and field items: both unchanged
            insertExtraByte(16, (byte) (0x40));
            insertExtraByte(17, (byte) (0x04));
            // add a fake checksum for nicknames at the very end of the data,
            // we can leave it at 0
            actualDataLength += 4;
        }

        // 150-160 lots of re-org etc
        if (oldVersion < 160) {
            // byte 0:
            // copy "update moves" to "update legacy moves"
            // move the other 3 fields after it up one
            int firstByte = dataBlock[0] & 0xFF;
            int updateMoves = firstByte & 0x08;
            int laterFields = firstByte & (0x10 | 0x20 | 0x40);
            dataBlock[0] = (byte) ((firstByte & (0x01 | 0x02 | 0x04 | 0x08)) | (updateMoves << 1) | (laterFields << 1));

            // byte 1:
            // leave as is (don't turn on exp standardization)

            // byte 2:
            // retrieve values of bw exp patch & held items
            // code tweaks keeps the same value as bw exp patch had
            // but turn held items off (it got replaced by pokelimit)
            int hasBWPatch = (dataBlock[2] & 0x08) >> 3;
            int hasHeldItems = (dataBlock[2] & 0x80) >> 7;
            dataBlock[2] &= (0x01 | 0x02 | 0x04 | 0x08 | 0x10 | 0x20 | 0x40);

            // byte 3:
            // turn on starter held items if held items checkbox was on
            if (hasHeldItems > 0) {
                dataBlock[3] |= 0x10;
            }

            // byte 4-9 are starters
            // byte 10 adds "4 moves" but we leave it off

            // byte 11:
            // pull out value of WP no legendaries
            // replace it with TP no early shedinja
            // also get WP catch rate value
            int wpNoLegendaries = (dataBlock[11] & 0x80) >> 7;
            int tpNoEarlyShedinja = (dataBlock[13] & 0x10) >> 4;
            int wpCatchRate = (dataBlock[13] & 0x08) >> 3;
            dataBlock[11] = (byte) ((dataBlock[11] & (0x01 | 0x02 | 0x04 | 0x08 | 0x10 | 0x20 | 0x40)) | (tpNoEarlyShedinja << 7));

            // byte 12 unchanged

            // insert a new byte for "extra" WP stuff
            // include no legendaries & catch rate
            // also include WP held items if overall held items box was on
            // leave similar strength off, there's a bugfix a little later on...
            insertExtraByte(13, (byte) ((wpCatchRate) | (wpNoLegendaries << 1) | (hasHeldItems << 3)));

            // new byte 14 (was 13 in 150):
            // switch off bits 4 and 5 (were for catch rate & no early shedinja)
            dataBlock[14] &= 0x07;

            // the rest of the config bytes are unchanged
            // but we need to add the fields for pokemon limit & code tweaks

            // no pokemon limit
            insertIntField(19, 0);

            // only possible code tweak = bw exp
            insertIntField(23, hasBWPatch);
        }

        // 160 to 161: no change
        // the only changes were in implementation, which broke presets, but
        // leaves settings files the same

        // 161 to 162:
        // some added fields to tm/move tutors that we can leave blank
        // more crucially: a new general options byte @ offset 3
        // set it to all off by default
        if (oldVersion < 162) {
            insertExtraByte(3, (byte) 0);
        }

        // no significant changes from 162 to 163

        if (oldVersion < 170) {
            // 163 to 170: add move data/evolution randoms and 2nd TM byte
            insertExtraByte(17, (byte) 0);
            insertExtraByte(21, (byte) 0);
            insertExtraByte(22, (byte) 1);

            // Move some bits from general options to misc tweaks
            int oldTweaks = FileFunctions.readFullIntBigEndian(dataBlock, 27);
            if ((dataBlock[0] & 1) != 0) {
                oldTweaks |= MiscTweak.LOWER_CASE_POKEMON_NAMES.getValue();
            }
            if ((dataBlock[0] & (1 << 1)) != 0) {
                oldTweaks |= MiscTweak.NATIONAL_DEX_AT_START.getValue();
            }
            if ((dataBlock[0] & (1 << 5)) != 0) {
                oldTweaks |= MiscTweak.UPDATE_TYPE_EFFECTIVENESS.getValue();
            }
            if ((dataBlock[2] & (1 << 5)) != 0) {
                oldTweaks |= MiscTweak.FORCE_CHALLENGE_MODE.getValue();
            }
            FileFunctions.writeFullIntBigEndian(dataBlock, 27, oldTweaks);

            // Now remap the affected bytes
            dataBlock[0] = getRemappedByte(dataBlock[0], new int[] { 2, 3, 4, 6, 7 });
            dataBlock[2] = getRemappedByte(dataBlock[2], new int[] { 0, 1, 2, 4, 6, 7 });
        }

        if (oldVersion < 171) {
            // 170 to 171: base stats follow evolutions is now a checkbox
            // so if it's set in the settings file (byte 1 bit 0), turn on the
            // "random" radiobox (byte 1 bit 1)
            if ((dataBlock[1] & 1) != 0) {
                dataBlock[1] |= (1 << 1);
            }

            // shift around stuff to give abilities their own byte.

            // move byte 3 bit 0 to byte 0 bit 5
            // (byte 0 got cleared out by things becoming Tweaks in 170)
            if ((dataBlock[3] & 1) != 0) {
                dataBlock[0] |= (1 << 5);
            }

            // move bits 4-6 from byte 1 to byte 3
            dataBlock[3] = (byte) ((dataBlock[1] & 0x70) >> 4);

            // clean up byte 1 (keep bits 0-3, move bit 7 to 4, clear 5-7)
            dataBlock[1] = (byte) ((dataBlock[1] & 0x0F) | ((dataBlock[1] & 0x80) >> 3));

            // empty byte for fully evolved trainer mon setting
            insertExtraByte(13, (byte) 30);

            // bytes for "good damaging moves" settings
            insertExtraByte(12, (byte) 0);
            insertExtraByte(20, (byte) 0);
            insertExtraByte(22, (byte) 0);
        }
        
        if(oldVersion < 172) {
            // 171 to 172: removed separate names files in favor of one unified file
            // so two of the trailing checksums are gone
            actualDataLength -= 8;
            
            // fix wild legendaries
            dataBlock[16] = (byte) (dataBlock[16] ^ (1 << 1));
            
            // add space for the trainer level modifier
            insertExtraByte(35, (byte) 50); // 50 in the settings file = +0% after adjustment
        }

        if (oldVersion < 300) {
            // wild level modifier
            insertExtraByte(38, (byte) 50);

            // exp curve modifier
            insertExtraByte(39, (byte) 1);
        }

        if (oldVersion < 311) {
            // double battle mode + boss/important extra pokemon
            insertExtraByte(40, (byte) 0);

            // regular extra pokemon + aura mod
            insertExtraByte(41, (byte) 8);

            // Totem/Ally mod + totem items/alt formes
            insertExtraByte(42, (byte) 9);

            // totem level modifier
            insertExtraByte(43, (byte) 50);

            // base stat generation
            insertExtraByte(44, (byte) 0);

            // move generation
            insertExtraByte(45, (byte) 0);
        }

        if (oldVersion < 314) {
            // exp curve
            insertExtraByte(46, (byte) 0);

            // static level modifier
            insertExtraByte(47, (byte) 50);
        }

        if (oldVersion < 315) {
            // This tweak used to be "Randomize Hidden Hollows", which got moved to static Pokemon
            // randomization, so the misc tweak became unused in this version. It eventually *was*
            // used in a future version for something else, but don't get confused by the new name.
            int oldTweaks = FileFunctions.readFullIntBigEndian(dataBlock, 32);
            oldTweaks &= ~MiscTweak.FORCE_CHALLENGE_MODE.getValue();
            FileFunctions.writeFullIntBigEndian(dataBlock, 32, oldTweaks);

            // Trainer Pokemon held items
            insertExtraByte(48, (byte) 0);
        }

        if (oldVersion < 317) {
            // Pickup items
            insertExtraByte(49, (byte) 0);

            // Clear "assoc" state from GenRestrictions as it doesn't exist any longer
            int genRestrictions = FileFunctions.readFullIntBigEndian(dataBlock, 28);
            genRestrictions &= 127;
            FileFunctions.writeFullIntBigEndian(dataBlock, 28, genRestrictions);
        }

        if (oldVersion < 319) {
            // 5-10 custom starters, offset by 1 because of new "Random" option
            int starter1 = FileFunctions.read2ByteInt(dataBlock, 5);
            int starter2 = FileFunctions.read2ByteInt(dataBlock, 7);
            int starter3 = FileFunctions.read2ByteInt(dataBlock, 9);

            starter1 += 1;
            starter2 += 1;
            starter3 += 1;

            FileFunctions.write2ByteInt(dataBlock, 5, starter1);
            FileFunctions.write2ByteInt(dataBlock, 7, starter2);
            FileFunctions.write2ByteInt(dataBlock, 9, starter3);

            // 50 elite four unique pokemon (3 bits)
            insertExtraByte(50, (byte) 0);
        }

        if (oldVersion < 321) {
            // Minimum Catch Rate got moved around to give it more space for Guaranteed Catch.
            // Read the old one, clear it out, then write it to the new location.
            int oldMinimumCatchRate = ((dataBlock[16] & 0x60) >> 5) + 1;
            dataBlock[16] &= ~0x60;
            dataBlock[50] |= ((oldMinimumCatchRate - 1) << 3);
        }

        // fix checksum
        CRC32 checksum = new CRC32();
        checksum.update(dataBlock, 0, actualDataLength - 8);

        // convert crc32 to int bytes
        byte[] crcBuf = ByteBuffer.allocate(4).putInt((int) checksum.getValue()).array();
        System.arraycopy(crcBuf, 0, dataBlock, actualDataLength - 8, 4);

        // have to make a new byte array to convert to base64
        byte[] finalConfigString = new byte[actualDataLength];
        System.arraycopy(dataBlock, 0, finalConfigString, 0, actualDataLength);
        return Base64.getEncoder().encodeToString(finalConfigString);
    }

    private static byte getRemappedByte(byte old, int[] oldIndexes) {
        int newValue = 0;
        int oldValue = old & 0xFF;
        for (int i = 0; i < oldIndexes.length; i++) {
            if ((oldValue & (1 << oldIndexes[i])) != 0) {
                newValue |= (1 << i);
            }
        }
        return (byte) newValue;
    }

    /**
     * Insert a 4-byte int field in the data block at the given position. Shift
     * everything else up. Do nothing if there's no room left (should never
     * happen)
     * 
     * @param position
     *            The offset to add the field
     * @param value
     *            The value to give to the field
     */
    private void insertIntField(int position, int value) {
        if (actualDataLength + 4 > dataBlock.length) {
            // can't do
            return;
        }
        for (int j = actualDataLength; j > position + 3; j--) {
            dataBlock[j] = dataBlock[j - 4];
        }
        byte[] valueBuf = ByteBuffer.allocate(4).putInt(value).array();
        System.arraycopy(valueBuf, 0, dataBlock, position, 4);
        actualDataLength += 4;
    }

    /**
     * Insert a byte-field in the data block at the given position. Shift
     * everything else up. Do nothing if there's no room left (should never
     * happen)
     * 
     * @param position
     *            The offset to add the field
     * @param value
     *            The value to give to the field
     */
    private void insertExtraByte(int position, byte value) {
        if (actualDataLength == dataBlock.length) {
            // can't do
            return;
        }
        for (int j = actualDataLength; j > position; j--) {
            dataBlock[j] = dataBlock[j - 1];
        }
        dataBlock[position] = value;
        actualDataLength++;
    }

}