1 package org.argeo.cli;
2
3 import java.io.PrintWriter;
4 import java.io.StringWriter;
5 import java.util.List;
6 import java.util.function.Function;
7
8 import org.apache.commons.cli.HelpFormatter;
9 import org.apache.commons.cli.Options;
10
11
12 public class HelpCommand implements DescribedCommand<String> {
13 private CommandsCli commandsCli;
14 private CommandsCli parentCommandsCli;
15
16
17 private static int helpWidth = 80;
18 private static int helpLeftPad = 4;
19 private static int helpDescPad = 20;
20
21 public HelpCommand(CommandsCli parentCommandsCli, CommandsCli commandsCli) {
22 super();
23 this.parentCommandsCli = parentCommandsCli;
24 this.commandsCli = commandsCli;
25 }
26
27 @Override
28 public String apply(List<String> args) {
29 StringWriter out = new StringWriter();
30
31 if (args.size() == 0) {
32 printHelp(commandsCli, out);
33 } else {
34 String cmd = args.get(0);
35 Function<List<String>, ?> function = commandsCli.getCommand(cmd);
36 if (function == null)
37 return "Command " + cmd + " not found.";
38 Options options;
39 String examples;
40 DescribedCommand<?> command = null;
41 if (function instanceof DescribedCommand) {
42 command = (DescribedCommand<?>) function;
43 options = command.getOptions();
44 examples = command.getExamples();
45 } else {
46 options = new Options();
47 examples = null;
48 }
49 String description = getShortDescription(function);
50 String commandCall = getCommandUsage(cmd, command);
51 HelpFormatter formatter = new HelpFormatter();
52 formatter.printHelp(new PrintWriter(out), helpWidth, commandCall, description, options, helpLeftPad,
53 helpDescPad, examples, false);
54 }
55 return out.toString();
56 }
57
58 private static String getShortDescription(Function<List<String>, ?> function) {
59 if (function instanceof DescribedCommand) {
60 return ((DescribedCommand<?>) function).getDescription();
61 } else {
62 return function.toString();
63 }
64 }
65
66 public String getCommandUsage(String cmd, DescribedCommand<?> command) {
67 String commandCall = getCommandCall(commandsCli) + " " + cmd;
68 assert command != null;
69 if (command != null && command.getUsage() != null) {
70 commandCall = commandCall + " " + command.getUsage();
71 }
72 return commandCall;
73 }
74
75 @Override
76 public String getDescription() {
77 return "Shows this help or describes a command";
78 }
79
80 @Override
81 public String getUsage() {
82 return "[command]";
83 }
84
85 public CommandsCli getParentCommandsCli() {
86 return parentCommandsCli;
87 }
88
89 protected String getCommandCall(CommandsCli commandsCli) {
90 HelpCommand hc = commandsCli.getHelpCommand();
91 if (hc.getParentCommandsCli() != null) {
92 return getCommandCall(hc.getParentCommandsCli()) + " " + commandsCli.getCommandName();
93 } else {
94 return commandsCli.getCommandName();
95 }
96 }
97
98 public static void printHelp(DescribedCommand<?> command, StringWriter out) {
99 String usage = "java " + command.getClass().getName()
100 + (command.getUsage() != null ? " " + command.getUsage() : "");
101 HelpFormatter formatter = new HelpFormatter();
102 formatter.printHelp(new PrintWriter(out), helpWidth, usage, command.getDescription(), command.getOptions(),
103 helpLeftPad, helpDescPad, command.getExamples(), false);
104
105 }
106
107 public static void printHelp(CommandsCli commandsCli, String commandName, StringWriter out) {
108 DescribedCommand<?> command = (DescribedCommand<?>) commandsCli.getCommand(commandName);
109 String usage = commandsCli.getHelpCommand().getCommandUsage(commandName, command);
110 HelpFormatter formatter = new HelpFormatter();
111 formatter.printHelp(new PrintWriter(out), helpWidth, usage, command.getDescription(), command.getOptions(),
112 helpLeftPad, helpDescPad, command.getExamples(), false);
113
114 }
115
116 public static void printHelp(CommandsCli commandsCli, StringWriter out) {
117 out.append(commandsCli.getDescription()).append('\n');
118 String leftPad = spaces(helpLeftPad);
119 for (String cmd : commandsCli.getSubCommands()) {
120 Function<List<String>, ?> function = commandsCli.getCommand(cmd);
121 assert function != null;
122 out.append(leftPad);
123 out.append(cmd);
124
125 out.append(spaces(helpDescPad - cmd.length()));
126 out.append(getShortDescription(function));
127 out.append('\n');
128 }
129 }
130
131 private static String spaces(int count) {
132
133
134 if (count <= 0)
135 return "";
136 else {
137 StringBuilder sb = new StringBuilder(count);
138 for (int i = 0; i < count; i++)
139 sb.append(' ');
140 return sb.toString();
141 }
142 }
143 }