одиночная передача от банка клиенту с расчётом сдачи работает

pom.xml

@@ -90,6 +90,13 @@
             <version>2.0.0</version>
         </dependency>
 
+        <!-- https://mvnrepository.com/artifact/commons-codec/commons-codec -->
+        <dependency>
+            <groupId>commons-codec</groupId>
+            <artifactId>commons-codec</artifactId>
+            <version>1.14</version>
+        </dependency>
+
     </dependencies>
 
     <build>

src/main/java/in/ocsf/bee/freigeld/core/model/Emitter.java

@@ -1,5 +1,7 @@
 package in.ocsf.bee.freigeld.core.model;
 
+import org.jetbrains.annotations.NotNull;
+
 import java.util.Collection;
 import java.util.UUID;
 import java.util.concurrent.CompletableFuture;
@@ -15,7 +17,7 @@ public interface Emitter {
 
     UUID emitOne(Coin coin);
 
-    default void free(Collection<Coin> coins) {
+    default void free(@NotNull Collection<Coin> coins) {
         coins.forEach(this::free);
     }
 

src/main/java/in/ocsf/bee/freigeld/core/model/EmitterStopRecalculationEvent.java

@@ -1,4 +1,25 @@
 package in.ocsf.bee.freigeld.core.model;
 
+import java.util.HashSet;
+import java.util.Set;
+import java.util.UUID;
+
 public class EmitterStopRecalculationEvent implements EmitterEvent {
+
+    private Set<UUID> nullCoins = new HashSet<>();
+
+    public EmitterStopRecalculationEvent() {
+    }
+
+    public EmitterStopRecalculationEvent(Set<UUID> nullCoins) {
+        this.nullCoins = nullCoins;
+    }
+
+    public Set<UUID> getNullCoins() {
+        return nullCoins;
+    }
+
+    public void setNullCoins(Set<UUID> nullCoins) {
+        this.nullCoins = nullCoins;
+    }
 }

src/main/java/in/ocsf/bee/freigeld/utils/ZBase32Utils.java

@@ -0,0 +1,13 @@
+package in.ocsf.bee.freigeld.utils;
+
+import org.apache.commons.codec.binary.ZBase32;
+
+import java.nio.charset.StandardCharsets;
+
+public class ZBase32Utils {
+    private static final ZBase32 codec = new ZBase32();
+
+    public static String encode(String str) {
+        return codec.encodeAsString(str.getBytes(StandardCharsets.UTF_8));
+    }
+}

src/main/java/org/apache/commons/codec/binary/ZBase32.java

@@ -0,0 +1,401 @@
+package org.apache.commons.codec.binary;
+
+public class ZBase32 extends BaseNCodec {
+
+    /**
+     * BASE32 characters are 5 bits in length.
+     * They are formed by taking a block of five octets to form a 40-bit string,
+     * which is converted into eight BASE32 characters.
+     */
+    private static final int BITS_PER_ENCODED_BYTE = 5;
+    private static final int BYTES_PER_ENCODED_BLOCK = 8;
+    private static final int BYTES_PER_UNENCODED_BLOCK = 5;
+
+    /**
+     * Chunk separator per RFC 2045 section 2.1.
+     *
+     * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045 section 2.1</a>
+     */
+    private static final byte[] CHUNK_SEPARATOR = {'\r', '\n'};
+
+    /**
+     * compute from scala code:
+     * <pre>{@code
+     * def fill(decodeTable: Array[Byte], encodeTable: String) = {
+     *   encodeTable.zipWithIndex.foreach {
+     *     case (c, i) => decodeTable(c) = i.toByte
+     *   }
+     * }
+     * def toDecodeTable(encodeTable: String): Array[Byte] = {
+     *   val t = Array.fill[Byte](128)(-1)
+     *   fill(t, encodeTable.toLowerCase)
+     *   fill(t, encodeTable.toUpperCase)
+     *   t.reverse.dropWhile(_ == -1).reverse
+     * }
+     * def fmt[T](v: T): String = {
+     *   var s = s"$v,"
+     *   while(s.length < 4) s = " " + s
+     *   s
+     * }
+     * def pretty[T](t: Array[T]) = t.zipWithIndex.foreach {
+     *   case (v, i) =>
+     *     print(fmt(v))
+     *     if (i % 16 == 15) println()
+     * }
+     * val tbl = "ybndrfg8ejkmcpqxot1uwisza345h769"
+     * pretty(toDecodeTable(tbl))
+     * pretty(tbl.map(c => s"'$c'").toArray)
+     * }</pre>
+     */
+    private static final byte[] decodeTable = {
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+            -1, 18, -1, 25, 26, 27, 30, 29, 7, 31, -1, -1, -1, -1, -1, -1,
+            -1, 24, 1, 12, 3, 8, 5, 6, 28, 21, 9, 10, -1, 11, 2, 16,
+            13, 14, 4, 22, 17, 19, -1, 20, 15, 0, 23, -1, -1, -1, -1, -1,
+            -1, 24, 1, 12, 3, 8, 5, 6, 28, 21, 9, 10, -1, 11, 2, 16,
+            13, 14, 4, 22, 17, 19, -1, 20, 15, 0, 23,
+    };
+    private static final byte[] encodeTable = {
+            'y', 'b', 'n', 'd', 'r', 'f', 'g', '8', 'e', 'j', 'k', 'm', 'c', 'p', 'q', 'x',
+            'o', 't', '1', 'u', 'w', 'i', 's', 'z', 'a', '3', '4', '5', 'h', '7', '6', '9',
+    };
+
+    /**
+     * Mask used to extract 5 bits, used when encoding Base32 bytes
+     */
+    private static final int MASK_5BITS = 0x1f;
+
+    // The static final fields above are used for the original static byte[] methods on Base32.
+    // The private member fields below are used with the new streaming approach, which requires
+    // some state be preserved between calls of encode() and decode().
+
+    /**
+     * Place holder for the bytes we're dealing with for our based logic.
+     * Bitwise operations store and extract the encoding or decoding from this variable.
+     */
+
+    /**
+     * Convenience variable to help us determine when our buffer is going to run out of room and needs resizing.
+     * <code>decodeSize = {@link #BYTES_PER_ENCODED_BLOCK} - 1 + lineSeparator.length;</code>
+     */
+    private final int decodeSize;
+
+    /**
+     * Convenience variable to help us determine when our buffer is going to run out of room and needs resizing.
+     * <code>encodeSize = {@link #BYTES_PER_ENCODED_BLOCK} + lineSeparator.length;</code>
+     */
+    private final int encodeSize;
+
+    /**
+     * Line separator for encoding. Not used when decoding. Only used if lineLength &gt; 0.
+     */
+    private final byte[] lineSeparator;
+
+    /**
+     * Creates a Base32 codec used for decoding and encoding.
+     * <p>
+     * When encoding the line length is 0 (no chunking).
+     * </p>
+     */
+    public ZBase32() {
+        this(0, null, PAD_DEFAULT);
+    }
+
+    /**
+     * Creates a Base32 codec used for decoding and encoding.
+     * <p>
+     * When encoding the line length is given in the constructor, the line separator is CRLF.
+     * </p>
+     *
+     * @param lineLength Each line of encoded data will be at most of the given length (rounded down to nearest multiple of
+     *                   8). If lineLength &lt;= 0, then the output will not be divided into lines (chunks). Ignored when
+     *                   decoding.
+     */
+    public ZBase32(final int lineLength) {
+        this(lineLength, CHUNK_SEPARATOR, PAD_DEFAULT);
+    }
+
+    /**
+     * Creates a Base32 / Base32 Hex codec used for decoding and encoding.
+     * <p>
+     * When encoding the line length and line separator are given in the constructor.
+     * </p>
+     * <p>
+     * Line lengths that aren't multiples of 8 will still essentially end up being multiples of 8 in the encoded data.
+     * </p>
+     *
+     * @param lineLength    Each line of encoded data will be at most of the given length (rounded down to nearest multiple of
+     *                      8). If lineLength &lt;= 0, then the output will not be divided into lines (chunks). Ignored when
+     *                      decoding.
+     * @param lineSeparator Each line of encoded data will end with this sequence of bytes.
+     * @throws IllegalArgumentException The provided lineSeparator included some Base32 characters. That's not going to work! Or the
+     *                                  lineLength &gt; 0 and lineSeparator is null.
+     */
+    public ZBase32(final int lineLength, final byte[] lineSeparator) {
+        this(lineLength, lineSeparator, PAD_DEFAULT);
+    }
+
+    /**
+     * Creates a Base32 / Base32 Hex codec used for decoding and encoding.
+     * <p>
+     * When encoding the line length and line separator are given in the constructor.
+     * </p>
+     * <p>
+     * Line lengths that aren't multiples of 8 will still essentially end up being multiples of 8 in the encoded data.
+     * </p>
+     *
+     * @param lineLength    Each line of encoded data will be at most of the given length (rounded down to nearest multiple of
+     *                      8). If lineLength &lt;= 0, then the output will not be divided into lines (chunks). Ignored when
+     *                      decoding.
+     * @param lineSeparator Each line of encoded data will end with this sequence of bytes.
+     * @param pad           byte used as padding byte.
+     * @throws IllegalArgumentException The provided lineSeparator included some Base32 characters. That's not going to work! Or the
+     *                                  lineLength &gt; 0 and lineSeparator is null.
+     */
+    public ZBase32(final int lineLength, final byte[] lineSeparator, final byte pad) {
+        super(BYTES_PER_UNENCODED_BLOCK, BYTES_PER_ENCODED_BLOCK, lineLength,
+                lineSeparator == null ? 0 : lineSeparator.length, pad);
+        if (lineLength > 0) {
+            if (lineSeparator == null) {
+                throw new IllegalArgumentException("lineLength " + lineLength + " > 0, but lineSeparator is null");
+            }
+            // Must be done after initializing the tables
+            if (containsAlphabetOrPad(lineSeparator)) {
+                final String sep = StringUtils.newStringUtf8(lineSeparator);
+                throw new IllegalArgumentException("lineSeparator must not contain Base32 characters: [" + sep + "]");
+            }
+            this.encodeSize = BYTES_PER_ENCODED_BLOCK + lineSeparator.length;
+            this.lineSeparator = new byte[lineSeparator.length];
+            System.arraycopy(lineSeparator, 0, this.lineSeparator, 0, lineSeparator.length);
+        } else {
+            this.encodeSize = BYTES_PER_ENCODED_BLOCK;
+            this.lineSeparator = null;
+        }
+        this.decodeSize = this.encodeSize - 1;
+
+        if (isInAlphabet(pad) || isWhiteSpace(pad)) {
+            throw new IllegalArgumentException("pad must not be in alphabet or whitespace");
+        }
+    }
+
+    /**
+     * <p>
+     * Decodes all of the provided data, starting at inPos, for inAvail bytes. Should be called at least twice: once
+     * with the data to decode, and once with inAvail set to "-1" to alert decoder that EOF has been reached. The "-1"
+     * call is not necessary when decoding, but it doesn't hurt, either.
+     * </p>
+     * <p>
+     * Ignores all non-Base32 characters. This is how chunked (e.g. 76 character) data is handled, since CR and LF are
+     * silently ignored, but has implications for other bytes, too. This method subscribes to the garbage-in,
+     * garbage-out philosophy: it will not check the provided data for validity.
+     * </p>
+     *
+     * @param in      byte[] array of ascii data to Base32 decode.
+     * @param inPos   Position to start reading data from.
+     * @param inAvail Amount of bytes available from input for encoding.
+     * @param context the context to be used
+     *                <p>
+     *                Output is written to {@link Context#buffer} as 8-bit octets, using {@link Context#pos} as the buffer position
+     */
+    @Override
+    void decode(final byte[] in, int inPos, final int inAvail, final Context context) {
+        // package protected for access from I/O streams
+
+        if (context.eof) {
+            return;
+        }
+        if (inAvail < 0) {
+            context.eof = true;
+        }
+        for (int i = 0; i < inAvail; i++) {
+            final byte b = in[inPos++];
+            if (b == pad) {
+                // We're done.
+                context.eof = true;
+                break;
+            }
+            final byte[] buffer = ensureBufferSize(decodeSize, context);
+            if (b >= 0 && b < decodeTable.length) {
+                final int result = decodeTable[b];
+                if (result >= 0) {
+                    context.modulus = (context.modulus + 1) % BYTES_PER_ENCODED_BLOCK;
+                    // collect decoded bytes
+                    context.lbitWorkArea = (context.lbitWorkArea << BITS_PER_ENCODED_BYTE) + result;
+                    if (context.modulus == 0) { // we can output the 5 bytes
+                        buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 32) & MASK_8BITS);
+                        buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 24) & MASK_8BITS);
+                        buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 16) & MASK_8BITS);
+                        buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 8) & MASK_8BITS);
+                        buffer[context.pos++] = (byte) (context.lbitWorkArea & MASK_8BITS);
+                    }
+                }
+            }
+        }
+
+        // Two forms of EOF as far as Base32 decoder is concerned: actual
+        // EOF (-1) and first time '=' character is encountered in stream.
+        // This approach makes the '=' padding characters completely optional.
+        if (context.eof && context.modulus >= 2) { // if modulus < 2, nothing to do
+            final byte[] buffer = ensureBufferSize(decodeSize, context);
+
+            //  we ignore partial bytes, i.e. only multiples of 8 count
+            switch (context.modulus) {
+                case 2: // 10 bits, drop 2 and output one byte
+                    buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 2) & MASK_8BITS);
+                    break;
+                case 3: // 15 bits, drop 7 and output 1 byte
+                    buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 7) & MASK_8BITS);
+                    break;
+                case 4: // 20 bits = 2*8 + 4
+                    context.lbitWorkArea = context.lbitWorkArea >> 4; // drop 4 bits
+                    buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 8) & MASK_8BITS);
+                    buffer[context.pos++] = (byte) ((context.lbitWorkArea) & MASK_8BITS);
+                    break;
+                case 5: // 25bits = 3*8 + 1
+                    context.lbitWorkArea = context.lbitWorkArea >> 1;
+                    buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 16) & MASK_8BITS);
+                    buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 8) & MASK_8BITS);
+                    buffer[context.pos++] = (byte) ((context.lbitWorkArea) & MASK_8BITS);
+                    break;
+                case 6: // 30bits = 3*8 + 6
+                    context.lbitWorkArea = context.lbitWorkArea >> 6;
+                    buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 16) & MASK_8BITS);
+                    buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 8) & MASK_8BITS);
+                    buffer[context.pos++] = (byte) ((context.lbitWorkArea) & MASK_8BITS);
+                    break;
+                case 7: // 35 = 4*8 +3
+                    context.lbitWorkArea = context.lbitWorkArea >> 3;
+                    buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 24) & MASK_8BITS);
+                    buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 16) & MASK_8BITS);
+                    buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 8) & MASK_8BITS);
+                    buffer[context.pos++] = (byte) ((context.lbitWorkArea) & MASK_8BITS);
+                    break;
+                default:
+                    // modulus can be 0-7, and we excluded 0,1 already
+                    throw new IllegalStateException("Impossible modulus " + context.modulus);
+            }
+        }
+    }
+
+    /**
+     * <p>
+     * Encodes all of the provided data, starting at inPos, for inAvail bytes. Must be called at least twice: once with
+     * the data to encode, and once with inAvail set to "-1" to alert encoder that EOF has been reached, so flush last
+     * remaining bytes (if not multiple of 5).
+     * </p>
+     *
+     * @param in      byte[] array of binary data to Base32 encode.
+     * @param inPos   Position to start reading data from.
+     * @param inAvail Amount of bytes available from input for encoding.
+     * @param context the context to be used
+     */
+    @Override
+    void encode(final byte[] in, int inPos, final int inAvail, final Context context) {
+        // package protected for access from I/O streams
+
+        if (context.eof) {
+            return;
+        }
+        // inAvail < 0 is how we're informed of EOF in the underlying data we're
+        // encoding.
+        if (inAvail < 0) {
+            context.eof = true;
+            if (0 == context.modulus && lineLength == 0) {
+                return; // no leftovers to process and not using chunking
+            }
+            final byte[] buffer = ensureBufferSize(encodeSize, context);
+            final int savedPos = context.pos;
+            switch (context.modulus) { // % 5
+                case 0:
+                    break;
+                case 1: // Only 1 octet; take top 5 bits then remainder
+                    buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 3) & MASK_5BITS]; // 8-1*5 = 3
+                    buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea << 2) & MASK_5BITS]; // 5-3=2
+                    buffer[context.pos++] = pad;
+                    buffer[context.pos++] = pad;
+                    buffer[context.pos++] = pad;
+                    buffer[context.pos++] = pad;
+                    buffer[context.pos++] = pad;
+                    buffer[context.pos++] = pad;
+                    break;
+                case 2: // 2 octets = 16 bits to use
+                    buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 11) & MASK_5BITS]; // 16-1*5 = 11
+                    buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 6) & MASK_5BITS]; // 16-2*5 = 6
+                    buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 1) & MASK_5BITS]; // 16-3*5 = 1
+                    buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea << 4) & MASK_5BITS]; // 5-1 = 4
+                    buffer[context.pos++] = pad;
+                    buffer[context.pos++] = pad;
+                    buffer[context.pos++] = pad;
+                    buffer[context.pos++] = pad;
+                    break;
+                case 3: // 3 octets = 24 bits to use
+                    buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 19) & MASK_5BITS]; // 24-1*5 = 19
+                    buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 14) & MASK_5BITS]; // 24-2*5 = 14
+                    buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 9) & MASK_5BITS]; // 24-3*5 = 9
+                    buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 4) & MASK_5BITS]; // 24-4*5 = 4
+                    buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea << 1) & MASK_5BITS]; // 5-4 = 1
+                    buffer[context.pos++] = pad;
+                    buffer[context.pos++] = pad;
+                    buffer[context.pos++] = pad;
+                    break;
+                case 4: // 4 octets = 32 bits to use
+                    buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 27) & MASK_5BITS]; // 32-1*5 = 27
+                    buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 22) & MASK_5BITS]; // 32-2*5 = 22
+                    buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 17) & MASK_5BITS]; // 32-3*5 = 17
+                    buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 12) & MASK_5BITS]; // 32-4*5 = 12
+                    buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 7) & MASK_5BITS]; // 32-5*5 =  7
+                    buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 2) & MASK_5BITS]; // 32-6*5 =  2
+                    buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea << 3) & MASK_5BITS]; // 5-2 = 3
+                    buffer[context.pos++] = pad;
+                    break;
+                default:
+                    throw new IllegalStateException("Impossible modulus " + context.modulus);
+            }
+            context.currentLinePos += context.pos - savedPos; // keep track of current line position
+            // if currentPos == 0 we are at the start of a line, so don't add CRLF
+            if (lineLength > 0 && context.currentLinePos > 0) { // add chunk separator if required
+                System.arraycopy(lineSeparator, 0, buffer, context.pos, lineSeparator.length);
+                context.pos += lineSeparator.length;
+            }
+        } else {
+            for (int i = 0; i < inAvail; i++) {
+                final byte[] buffer = ensureBufferSize(encodeSize, context);
+                context.modulus = (context.modulus + 1) % BYTES_PER_UNENCODED_BLOCK;
+                int b = in[inPos++];
+                if (b < 0) {
+                    b += 256;
+                }
+                context.lbitWorkArea = (context.lbitWorkArea << 8) + b; // BITS_PER_BYTE
+                if (0 == context.modulus) { // we have enough bytes to create our output
+                    buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 35) & MASK_5BITS];
+                    buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 30) & MASK_5BITS];
+                    buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 25) & MASK_5BITS];
+                    buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 20) & MASK_5BITS];
+                    buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 15) & MASK_5BITS];
+                    buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 10) & MASK_5BITS];
+                    buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 5) & MASK_5BITS];
+                    buffer[context.pos++] = encodeTable[(int) context.lbitWorkArea & MASK_5BITS];
+                    context.currentLinePos += BYTES_PER_ENCODED_BLOCK;
+                    if (lineLength > 0 && lineLength <= context.currentLinePos) {
+                        System.arraycopy(lineSeparator, 0, buffer, context.pos, lineSeparator.length);
+                        context.pos += lineSeparator.length;
+                        context.currentLinePos = 0;
+                    }
+                }
+            }
+        }
+    }
+
+    /**
+     * Returns whether or not the {@code octet} is in the Base32 alphabet.
+     *
+     * @param octet The value to test
+     * @return {@code true} if the value is defined in the the Base32 alphabet {@code false} otherwise.
+     */
+    @Override
+    public boolean isInAlphabet(final byte octet) {
+        return octet >= 0 && octet < decodeTable.length && decodeTable[octet] != -1;
+    }
+}

src/main/kotlin/in/ocsf/bee/freigeld/core/demo/DemoInMem.kt

@@ -1,6 +1,7 @@
 package `in`.ocsf.bee.freigeld.core.demo
 
 import `in`.ocsf.bee.freigeld.core.model.*
+import `in`.ocsf.bee.freigeld.utils.ZBase32Utils
 import com.oblac.nomen.Nomen
 import kotlinx.coroutines.CompletableDeferred
 import kotlinx.coroutines.GlobalScope
@@ -149,7 +150,7 @@ class GlobalBank : Bank {
                     }
                     if (ok) {
                         e.to.accept(coinsExact)
-                        emitter.free(coinsExact)
+                        if (e.to.id != selfAccount.id) emitter.free(coinsExact)
                         globalQueue.offerLast(ExchangeSuccessEvent(UUID.randomUUID(), e))
                     } else {
                         e.from.accept(coinsExact)
@@ -197,6 +198,15 @@ class GlobalBank : Bank {
     fun start() {
         emitter.listen { e ->
             log.info("emitter event ${e.javaClass.name}")
+            when (e) {
+                is EmitterStopRecalculationEvent -> {
+                    accountMap.values.map { it to it.internalCoins.keys.intersect(e.nullCoins) }.filter { it.second.isNotEmpty() }.forEach { ap ->
+                        ap.first._overall = null
+                        val nullCoins = ap.second.map { ap.first.extractOne(it) }
+                        emitter.accept(nullCoins)
+                    }
+                }
+            }
         }
     }
 
@@ -261,8 +271,10 @@ class DemoInMemEmitter : GlobalEmitter {
         (0 until count).forEach { coinMap.computeIfAbsent(UUID.randomUUID()) { id -> DemoCoin(id, value) } }
     }
 
-    override fun accept(coins: MutableCollection<Coin>?) {
-        TODO("not implemented")
+    override fun accept(nullCoins: MutableCollection<Coin>) {
+        val nullIds = nullCoins.map { it.id }
+        coinFreeSet.removeAll(nullIds)
+        coinExtractedSet.removeAll(nullIds)
     }
 
     override fun getId(): UUID {
@@ -299,8 +311,8 @@ class DemoInMemEmitter : GlobalEmitter {
         }
     }
 
-    private suspend fun calcLater() {
-        coinFreeSet.map { coinMap[it] }.filterNotNull().map { it as DemoCoin }.forEach { it._era = min(maxEraValue, it._era + 1) }
+    private suspend fun calcLater(): Set<UUID> {
+        return coinFreeSet.mapNotNull { coinMap[it] }.map { it as DemoCoin }.onEach { it._era = min(maxEraValue, it._era + 1) }.filter { it.era == maxEraValue }.map { it.id }.toSet()
     }
 
     override fun calc(): CompletableFuture<Any> {
@@ -310,9 +322,9 @@ class DemoInMemEmitter : GlobalEmitter {
         deferred!!.invokeOnCompletion { t: Throwable? -> if (t == null) ret.complete(null) else ret.completeExceptionally(t) }
         GlobalScope.launch {
             try {
-                calcLater()
+                val nullCoins = calcLater()
                 deferred!!.complete(true)
-                listeners.forEach { it.accept(EmitterStopRecalculationEvent()) }
+                listeners.forEach { it.accept(EmitterStopRecalculationEvent(nullCoins)) }
             } catch (t: Throwable) {
                 deferred!!.completeExceptionally(t)
             }
@@ -335,12 +347,6 @@ class DemoCoin(val coinId: UUID, val initialValue: CoinValue, var _era: Int = 0)
 
     override fun getValue(): CoinValue = initialValue
 
-    /*
-    override fun getCurrent(): Long {
-        return initialValue.amount - ((_era - 1) * initialValue.delta)
-    }
-    */
-
     override fun getEra(): Int {
         return _era
     }
@@ -420,6 +426,8 @@ open class DemoAccount(val accountId: UUID, personId: UUID) : BankAccount {
     val internalCoins = mutableMapOf<UUID, Coin>()
     var _overall: Long? = null
 
+    private val log = LoggerFactory.getLogger(javaClass)
+
     override fun getId(): UUID {
         return accountId
     }
@@ -427,6 +435,7 @@ open class DemoAccount(val accountId: UUID, personId: UUID) : BankAccount {
     override fun extractOne(coinId: UUID): Coin {
         return if (internalCoins.containsKey(coinId)) {
             val coin = internalCoins.remove(coinId)!!
+            log.info("${this} credit coin ${coin.current}")
             coin
         } else {
             throw IllegalArgumentException("no such coin")
@@ -467,6 +476,7 @@ open class DemoAccount(val accountId: UUID, personId: UUID) : BankAccount {
                 throw IllegalArgumentException("same coin is not acceptable")
             }
         }
+        log.info("${this} debit coins ${CoinUtils.sum(coins)}")
     }
 
     override fun extractMoreOrExact(amount: Long): MutableCollection<Coin> {
@@ -476,9 +486,13 @@ open class DemoAccount(val accountId: UUID, personId: UUID) : BankAccount {
             internalCoins.remove(it.id)
             decOverall(it.current)
         }
+        log.info("${this} credit coins ${CoinUtils.sum(coins)}")
         return coins
     }
 
+    override fun toString(): String {
+        return ZBase32Utils.encode(accountId.toString())
+    }
 }
 
 class CoinUtils {
@@ -537,39 +551,10 @@ class CoinUtils {
             if (fakeAmount != amount) {
                 TODO()
             }
-            /* val sortedCoins = coins.sortedBy { it.current }
-             val position = sortedCoins.binarySearch { it.current.compareTo(amount) }
-             val ret = mutableListOf<Coin>()
-             if (position == 0) {
-                 TODO()
-             } else if (position > 0) {
-                 val coinL = sortedCoins.get(position)
-                 val coinR = sortedCoins.get(position - 1)
-                 if (coinL.current == amount) {
-                     ret.add(coinL)
-                 } else if (coinR.current == amount) {
-                     ret.add(coinR)
-                 } else {
-                     TODO()
-                 }
-             } else if (position < 0) {
-                 val actualPosition = -(position + 1)
-                 if (actualPosition == 0) {
-                     TODO()
-                 } else if (actualPosition < sortedCoins.size) {
-                     TODO()
-                 } else {
-                     var idx = sortedCoins.size - 1
-                     do {
-                         val coin = sortedCoins.get(idx)
-                         totalAmount = totalAmount + coin.current
-                         ret.add(coin)
-                         idx--
-                     } while (totalAmount < amount)
-                 }
-             } */
             return ret
         }
+
+        fun sum(coins: Iterable<Coin>): Long = coins.map { it.current }.sum()
     }
 }
 

src/test/kotlin/`in`/ocsf/bee/freigeld/core/demo/CoinUtilsTest.kt

@@ -1,8 +1,27 @@
 package `in`.ocsf.bee.freigeld.core.demo
 
+import `in`.ocsf.bee.freigeld.core.model.CoinValue
 import org.junit.jupiter.api.Test
+import java.util.*
+import kotlin.test.assertEquals
 
-@Test
-fun `test coin amount`() {
+class CoinUtilsTest {
+
+    val fromId = UUID.randomUUID()
+
+    val fromAccount = DemoAccount(fromId, fromId)
+
+    val toId = UUID.randomUUID()
+
+    val toAccount = DemoAccount(toId, toId)
+
+    init {
+        fromAccount.accept(mutableListOf(DemoCoin(UUID.randomUUID(), CoinValue.one)))
+    }
+
+    @Test
+    fun `test coin amount`() {
+        assertEquals(fromAccount.overall, CoinValue.one.amount)
+    }
 
 }