cli: describing plugin actions along with arguments and options

cli/lrcli.js

@@ -43,6 +43,44 @@ Options:
     console.log(usage)
 }
 
+
+let printPluginActionUsage = (action, action_name) => {
+    
+    let options = ""
+    for (const opt in action.arguments) {
+        if (opt == '_') {
+            continue
+        }
+        options += `\n        --${opt}`
+        if ("default" in action.arguments[opt]) {
+            options += ` (default: ${action.arguments[opt].default})`
+        }
+        options += `\n            ${action.arguments[opt].description}`
+        options += `\n`
+    }
+    
+    let positional = ''
+    let positional_desc = ''
+    if ('_' in action.arguments) {
+        if ('name' in action.arguments._) {
+            positional = ` <${action.arguments._.name}...>`
+        } else {
+            positional = ' <item...>'
+        }
+        positional_desc = `
+
+        ${positional}
+            ${action.arguments._.description}`
+    }
+    
+    let usage = `    ${action_name}${ (options != "") ? " [options...]" : "" }${positional}
+        ${action.description}${positional_desc}
+${options}`
+
+    console.log(usage)
+}
+
+
 let printpluginUsage = (plugin) => {
     let usage = `
 CLI plugin:
@@ -64,6 +102,10 @@ Actions and Action Options:
 `
 
     console.log(usage)
+    
+    for (const action in plugin.actions) {
+        printPluginActionUsage(plugin.actions[action], action)
+    }
 }
 
 //console.log(parsed_args)
@@ -156,20 +198,25 @@ if (parsed_args._.length == 1) {
    
 let action = parsed_args._[1]
 if ( ! (action in plugin.actions) ) {
-    var exit_code = 4
+    var exit_code = 0
     if (!['--help', '-h'].includes(action)) {
         console.log(`\n*** Action not supported: ${action} ***`)
-        exit_code = 0
+        exit_code = 4
     }
     printpluginUsage(plugin)
     Deno.exit(exit_code)
 }
 
+if (['--help', '-h'].includes(parsed_args._[2])) {
+    printpluginUsage(plugin)
+    Deno.exit(0)
+}
+
 var parsed_plugin_args = parsePluginActionArgs(
                             // removing the plugin name and the method name
                             parsed_args._.slice(2),
                             plugin.actions[action].arguments
-                            )
+                        )
 
 //console.log(parsed_plugin_args)