public int complete()

in shell/console/src/main/java/org/apache/karaf/shell/compat/ArgumentCompleter.java [296:424]
101 lines of code
44 McCabe index (conditional complexity)

    public int complete(final Session session, final CommandLine list, final List<String> candidates) {
        int argpos = list.getArgumentPosition();
        int argIndex = list.getCursorArgumentIndex();

        //Store the argument list so that it can be used by completers.
        CommandSession commandSession = CommandSessionHolder.getSession();
        if(commandSession != null) {
            commandSession.put(ARGUMENTS_LIST,list);
        }

        Completer comp = null;
        String[] args = list.getArguments();
        int index = 0;
        // First argument is command name
        if (index < argIndex) {
            // Verify scope
            if (!Session.SCOPE_GLOBAL.equals(scope) && !session.resolveCommand(args[index]).equals(scope + ":" + name)) {
                return -1;
            }
            // Verify command name
            if (!verifyCompleter(commandCompleter, args[index])) {
                return -1;
            }
            index++;
        } else {
            comp = commandCompleter;
        }
        // Now, check options
        if (comp == null) {
            while (index < argIndex && args[index].startsWith("-")) {
                if (!verifyCompleter(optionsCompleter, args[index])) {
                    return -1;
                }
                Option option = options.get(args[index]);
                if (option == null) {
                    return -1;
                }
                Field field = fields.get(option);
                if (field != null && field.getType() != boolean.class && field.getType() != Boolean.class) {
                    if (++index == argIndex) {
                        comp = NullCompleter.INSTANCE;
                    }
                }
                index++;
            }
            if (comp == null && index >= argIndex && index < args.length && args[index].startsWith("-")) {
                comp = optionsCompleter;
            }
        }
        //Now check for if last Option has a completer
        int lastAgurmentIndex = argIndex - 1;
        if (lastAgurmentIndex >= 1) {
            Option lastOption = options.get(args[lastAgurmentIndex]);
            if (lastOption != null) {

                Field lastField = fields.get(lastOption);
                if (lastField != null && lastField.getType() != boolean.class && lastField.getType() != Boolean.class) {
                    Option option = lastField.getAnnotation(Option.class);
                    if (option != null) {
                        Completer optionValueCompleter = null;
                        String name = option.name();
                        if (optionalCompleters != null && name != null) {
                            optionValueCompleter = optionalCompleters.get(name);
                            if (optionValueCompleter == null) {
                                String[] aliases = option.aliases();
                                if (aliases.length > 0) {
                                    for (int i = 0; i < aliases.length && optionValueCompleter == null; i++) {
                                        optionValueCompleter = optionalCompleters.get(option.aliases()[i]);
                                    }
                                }
                            }
                        }
                        if(optionValueCompleter != null) {
                            comp = optionValueCompleter;
                        }
                    }
                }
            }
        }

        // Check arguments
        if (comp == null) {
            int indexArg = 0;
            while (index < argIndex) {
                Completer sub = argsCompleters.get(indexArg >= argsCompleters.size() ? argsCompleters.size() - 1 : indexArg);
                if (!verifyCompleter(sub, args[index])) {
                    return -1;
                }
                index++;
                indexArg++;
            }
            comp = argsCompleters.get(indexArg >= argsCompleters.size() ? argsCompleters.size() - 1 : indexArg);
        }

        int ret = comp.complete(list.getCursorArgument(), argpos, candidates);

        if (ret == -1) {
            return -1;
        }

        int pos = ret + (list.getBufferPosition() - argpos);

        /**
         * Special case: when completing in the middle of a line, and the
         * area under the cursor is a delimiter, then trim any delimiters
         * from the candidates, since we do not need to have an extra
         * delimiter.
         *
         * E.g., if we have a completion for "foo", and we
         * enter "f bar" into the buffer, and move to after the "f"
         * and hit TAB, we want "foo bar" instead of "foo  bar".
         */
        String buffer = list.getBuffer();
        int cursor = list.getBufferPosition();
        if ((buffer != null) && (cursor != buffer.length()) && isDelimiter(buffer, cursor)) {
            for (int i = 0; i < candidates.size(); i++) {
                String val = candidates.get(i);

                while ((val.length() > 0)
                        && isDelimiter(val, val.length() - 1)) {
                    val = val.substring(0, val.length() - 1);
                }

                candidates.set(i, val);
            }
        }

        return pos;
    }