Better handling of commands.

src/service.cr

@@ -13,17 +13,6 @@ args = [] of String
 
 parser = OptionParser.parse do |parser|
 	parser.banner = "usage: service <command> [options]\n" +
-		"\n" +
-		"commands:\n" +
-		"    start                     Starts a stopped or dead service.\n" +
-		"    stop                      Stops a running service.\n" +
-		"    status                    Shows the current state of a service.\n" +
-		"    show                      Describe a service in detail.\n" +
-		"    add                       Add a service to an environment.\n" +
-		"    del                       Remove a service from an environment.\n" +
-		"    add-environment           Creates a new, empty environment.\n" +
-		"    list-environments         Lists registered environments.\n" +
-		"\n" +
 		"options:\n"
 
 	parser.on "-h", "--help", "Prints this help message." do
@@ -35,25 +24,38 @@ parser = OptionParser.parse do |parser|
 	end
 end
 
-command = args[0]?
-if command.nil?
-	STDERR << parser << "\n"
-	exit 1
+alias Command = Proc(Array(String), Nil)
+alias CommandTuple = Tuple(String, String, Command)
+class CommandsList
+	def initialize
+		@commands = Array(CommandTuple).new
 	end
 
-ServiceDefinition.load SERVICES_DIRECTORY
-Environment.load ENVIRONMENTS_DIRECTORY
-Service.load RC_DIRECTORY
+	def push(name : String, description : String, &proc : Command)
+		@commands << Tuple.new(name, description, proc)
+	end
 
-begin
-	if args[0] == "help"
-		puts parser
-	elsif args[0] == "add"
+	def find(&block : Proc(CommandTuple, Bool))
+		@commands.find do |tuple|
+			if block.call tuple
+				next true
+			end
+		end
+	end
+
+	def to_s
+		"commands:\n\n"+ @commands.map do |tuple|
+			"    %-32s %s" % [tuple[0], tuple[1]]
+		end.join "\n"
+	end
+end
+commands = CommandsList.new
+
+commands.push "add", "Adds a service to an environment." do |args|
 	providers = Hash(String, String).new
 
-		environment, service = Service.parse_id args[1]
+	environment, service = Service.parse_id args[0]
 
-		args.shift
 	args.each_with_index do |arg, i|
 		next if i == 0
 
@@ -85,10 +87,14 @@ begin
 		end
 		pp! service.providers
 	end.write RC_DIRECTORY
-	elsif args[0] == "del"
-		Service.new(args[1], args[2]?).remove RC_DIRECTORY
-	elsif args[0] == "start"
-		services = args[1..args.size].map do |arg|
+end
+
+commands.push "del", "Removes a service from an environment." do |args|
+	Service.new(args[0], args[1]?).remove RC_DIRECTORY
+end
+
+commands.push "start", "Starts a service." do
+	services = args.map do |arg|
 		service = Service.get_by_id(arg)
 
 		unless service
@@ -106,8 +112,10 @@ begin
 			service.start PID_DIRECTORY, LOG_DIRECTORY
 		end
 	end
-	elsif args[0] == "stop"
-		services = args[1..args.size].map do |arg|
+end
+
+commands.push "stop", "Stops a running service." do |args|
+	services = args.map do |arg|
 		service = Service.get_by_id(arg)
 
 		unless service
@@ -129,8 +137,9 @@ begin
 			service.stop PID_DIRECTORY
 		end
 	end
-	elsif args[0] == "status"
-		args.shift
+end
+
+commands.push "status", "Prints the status of services." do |args|
 	child = Process.run "#{OWN_LIBEXEC_DIR}/status", args,
 		output: Process::Redirect::Inherit,
 		error: Process::Redirect::Inherit
@@ -142,13 +151,15 @@ begin
 	end
 
 	exit return_value
-	elsif args[0] == "show"
+end
+
+commands.push "show", "Shows a service's configuration and state." do |args|
 	service = Service.all.find do |service|
-			unless service.name == args[1]
+		unless service.name == args[0]
 			next false
 		end
 
-			env = args[2]? || "root"
+		env = args[1]? || "root"
 		if service.environment.name != env
 			next false
 		end
@@ -161,16 +172,39 @@ begin
 		STDERR << "No such service is registered.\n"
 		exit 2
 	end
-	elsif args[0] == "add-environment"
-		Environment.new(args[1]).write ENVIRONMENTS_DIRECTORY
-	elsif args[0] == "list-environments"
+end
+
+commands.push "add-environment", "Creates a new (empty) environment." do |arg|
+	Environment.new(args[9]).write ENVIRONMENTS_DIRECTORY
+end
+
+commands.push "list-environments", "Lists all currently defined environments.s", do |arg|
 	Environment.all.map do |env|
 		puts env.to_s
 	end
-	else
+end
+
+commands.push "help", "Prints this help message." do
+	puts parser
+	puts
+	puts commands.to_s
+end
+
+command = commands.find &.[0].==(args[0]?)
+if command.nil?
 	STDERR << parser << "\n"
+	STDERR << "\n"
+	STDERR << commands.to_s << "\n"
 	exit 1
 end
+
+ServiceDefinition.load SERVICES_DIRECTORY
+Environment.load ENVIRONMENTS_DIRECTORY
+Service.load RC_DIRECTORY
+
+begin
+	args.shift
+	command.[2].call(args)
 rescue e : Service::Exception
 	STDERR << e.message << "\n"
 	exit 2