1 files changed, 186 insertions, 0 deletions
diff --git a/dicore3/command/src/main/java/io/dico/dicore/command/chat/HelpCache.java b/dicore3/command/src/main/java/io/dico/dicore/command/chat/HelpCache.java
new file mode 100644
index 0000000..ed91d69
--- /dev/null
+++ b/dicore3/command/src/main/java/io/dico/dicore/command/chat/HelpCache.java
@@ -0,0 +1,186 @@
+package io.dico.dicore.command.chat;
+
+import io.dico.dicore.command.Command;
+import io.dico.dicore.command.EMessageType;
+import io.dico.dicore.command.ICommandAddress;
+import io.dico.dicore.command.parameter.Parameter;
+import io.dico.dicore.command.parameter.ParameterList;
+
+import java.util.*;
+import java.util.stream.Collectors;
+
+public class HelpCache {
+    private static Map<ICommandAddress, HelpCache> caches = new IdentityHashMap<>();
+    private ICommandAddress address;
+    private String shortSyntax;
+    private String[] lines;
+    private int[] pageStarts;
+
+    public static HelpCache getHelpCache(ICommandAddress address) {
+        return caches.computeIfAbsent(address, HelpCache::new);
+    }
+
+    private HelpCache(ICommandAddress address) {
+        this.address = address;
+    }
+
+    private void loadHelp() {
+        List<String> lines = new ArrayList<>();
+        List<Integer> potentialPageStarts = new ArrayList<>();
+        int curLineIdx = 0;
+        potentialPageStarts.add(curLineIdx);
+
+        String curLine = address.getChatController().getMessagePrefixForType(EMessageType.INSTRUCTION);
+        curLine += address.getChatController().getChatFormatForType(EMessageType.INSTRUCTION);
+        curLine += getSyntax();
+        lines.add(curLine);
+        curLineIdx++;
+
+        if (address.hasCommand()) {
+            Command command = address.getCommand();
+            String[] description = command.getDescription();
+            if (description != null && description.length > 0) {
+                for (String line : description) {
+                    curLine = address.getChatController().getChatFormatForType(EMessageType.INFORMATIVE).toString();
+                    curLine += line;
+                    lines.add(curLine);
+                    curLineIdx++;
+                }
+            }
+        }
+
+        List<ICommandAddress> children = address.getChildren().values().stream()
+                .distinct()
+                .sorted(Comparator.comparing(ICommandAddress::getMainKey))
+                .collect(Collectors.toList());
+
+        for (ICommandAddress address : children) {
+            potentialPageStarts.add(curLineIdx);
+
+            curLine = this.address.getChatController().getChatFormatForType(EMessageType.INSTRUCTION) + "/";
+            if (address.isDepthLargerThan(2)) {
+                curLine += "... ";
+            }
+            curLine += address.getMainKey();
+            curLine += getHelpCache(address).getShortSyntax();
+            lines.add(curLine);
+            curLineIdx++;
+
+            if (address.hasCommand()) {
+                String shortDescription = address.getCommand().getShortDescription();
+                if (shortDescription != null) {
+                    curLine = this.address.getChatController().getChatFormatForType(EMessageType.INFORMATIVE).toString();
+                    curLine += shortDescription;
+                    lines.add(curLine);
+                    curLineIdx++;
+                }
+            }
+        }
+
+        this.lines = lines.toArray(new String[lines.size()]);
+
+        // compute where the pages start with a maximum page size of 10
+        List<Integer> pageStarts = new ArrayList<>();
+        pageStarts.add(0);
+        int maxLength = 10;
+        int curPageEndTarget = maxLength;
+        for (int i = 1, n = potentialPageStarts.size(); i < n; i++) {
+            int index = potentialPageStarts.get(i);
+            if (index == curPageEndTarget) {
+                pageStarts.add(curPageEndTarget);
+                curPageEndTarget += maxLength;
+            } else if (index > curPageEndTarget) {
+                curPageEndTarget = potentialPageStarts.get(i - 1);
+                pageStarts.add(curPageEndTarget);
+                curPageEndTarget += maxLength;
+            }
+        }
+
+        int[] pageStartsArray = new int[pageStarts.size()];
+        for (int i = 0, n = pageStartsArray.length; i < n; i++) {
+            pageStartsArray[i] = pageStarts.get(i);
+        }
+        this.pageStarts = pageStartsArray;
+    }
+
+    /**
+     * Get a help page
+     *
+     * @param page the 0-bound page number (first page is page 0)
+     * @return the help page
+     */
+    public String getHelpPage(int page) {
+        if (lines == null) {
+            loadHelp();
+        }
+
+        //System.out.println(Arrays.toString(lines));
+
+        if (page >= pageStarts.length) {
+            //System.out.println("page >= pageStarts.length: " + Arrays.toString(pageStarts));
+            return "";
+        } else if (page < 0) {
+            throw new IllegalArgumentException("Page number is negative");
+        }
+
+        int start = pageStarts[page];
+        int end = page + 1 == pageStarts.length ? lines.length : pageStarts[page + 1];
+        //System.out.println("start = " + start);
+        //System.out.println("end = " + end);
+        return String.join("\n", Arrays.copyOfRange(lines, start, end));
+    }
+
+    public int getTotalPageCount() {
+        return pageStarts.length;
+    }
+
+    /**
+     * The latter syntax of the command, prefixed by a space.
+     *
+     * @return The latter part of the syntax for this command. That is, without the actual command name.
+     */
+    public String getShortSyntax() {
+        if (shortSyntax != null) {
+            return shortSyntax;
+        }
+
+        StringBuilder syntax = new StringBuilder();
+        if (address.hasCommand()) {
+            Command command = address.getCommand();
+            ParameterList list = command.getParameterList();
+            Parameter<?, ?> repeated = list.getRepeatedParameter();
+
+            int requiredCount = list.getRequiredCount();
+            List<Parameter<?, ?>> indexedParameters = list.getIndexedParameters();
+            for (int i = 0, n = indexedParameters.size(); i < n; i++) {
+                syntax.append(i < requiredCount ? " <" : " [");
+                Parameter<?, ?> param = indexedParameters.get(i);
+                syntax.append(param.getName());
+                if (param == repeated) {
+                    syntax.append("...");
+                }
+                syntax.append(i < requiredCount ? '>' : ']');
+            }
+
+            Map<String, Parameter<?, ?>> parametersByName = list.getParametersByName();
+            for (Parameter<?, ?> param : parametersByName.values()) {
+                if (param.isFlag()) {
+                    syntax.append(" [").append(param.getName());
+                    if (param.expectsInput()) {
+                        syntax.append(" <>");
+                    }
+                    syntax.append(']');
+                }
+            }
+        } else {
+            syntax.append(' ');
+        }
+        this.shortSyntax = syntax.toString();
+        return this.shortSyntax;
+    }
+
+    public String getSyntax() {
+        return '/' + address.getAddress() + getShortSyntax();
+    }
+
+}