--- a/roundup/scripts/roundup_demo.py	Sun May 14 01:23:36 2023 -0400
+++ b/roundup/scripts/roundup_demo.py	Sun May 14 09:43:53 2023 -0400
@@ -3,13 +3,9 @@
 # Copyright 2004 Richard Jones (richard@mechanicalcat.net)
 #
 
-DEFAULT_HOME = './demo'
-DEFAULT_TEMPLATE = 'classic'
-
-
+import argparse
 import sys
 
-
 # --- patch sys.path to make sure 'import roundup' finds correct version
 import os.path as osp
 
@@ -21,48 +17,171 @@
     sys.path.insert(0, rootdir)
 # --/
 
+# import also verifies python version as side effect
+from roundup import version_check                         # noqa: F401 E402
+from roundup import admin, configuration, demo, instance  # noqa: E402
+from roundup import __version__ as roundup_version        # noqa: E402
+from roundup.anypy.my_input import my_input               # noqa: E402
+from roundup.backends import list_backends                # noqa: E402
+from roundup.i18n import _                                # noqa: E402
 
-from roundup import admin, configuration, demo, instance
-from roundup.i18n import _
-from roundup.anypy.my_input import my_input
-from roundup import version_check
+
+DEFAULT_HOME = './demo'
+DEFAULT_TEMPLATE = 'classic'
+DEFAULT_BACKEND = 'sqlite'
+DEFAULT_PORT = 8917
+
+
+def usage(home, cli, msg=''):
+
+    # massage the help. I want [directory [backend]] but there is no way to
+    # specify that in argparse, so replace the three positional args with
+    # the proper syntax.
+    usage = cli.format_help() % dict(locals())
+    usage = usage.replace('[directory] [backend] [nuke]',
+                          '[[directory] [backend]] [nuke]')
+
+    print("%s\n" % usage)
+
+    if msg:
+        print(msg)
 
 def run():
-    home = DEFAULT_HOME
-    template = DEFAULT_TEMPLATE
-    nuke = sys.argv[-1] == 'nuke'
+    templates = admin.AdminTool().listTemplates().keys()
+    backends = list_backends()
+
+    cli = argparse.ArgumentParser(
+        description= """
+Instant gratification demo - Roundup Issue Tracker
+
+  Run a demo server. Config and database files are created in
+  'directory' (current setting/default '%(home)s') which should
+  not exist or should exist and already be a tracker home
+  directory (usually used with nuke).
+
+  'nuke' will re-initialize the tracker instance, deleting the old data.
+
+  The tracker that is created will have email notifications turned off.
+""" % {"home": DEFAULT_HOME},
+        epilog=("\nIf items marked with (*) are missing, they will be "
+                "asked for interactively when setting up the tracker."),
+        formatter_class=argparse.RawTextHelpFormatter,
+        add_help=True)
+
+    cli.add_argument('-B', '--bind_address',
+                     default="127.0.0.1",
+                     help=( "Choose address for server to listen at.\n"
+                            "Use 0.0.0.0 to bind to all addreses.\n"
+                            "Default: %(default)s.\n\n"))
+    cli.add_argument('-b', '--backend_db',
+                     choices=backends,
+                     help=( "Choose backend database. Default: %s.\n\n" %
+                            DEFAULT_BACKEND))
+    cli.add_argument('-t', '--template',
+                     choices=templates,
+                     help="Use specified template. (*)\n\n")
+    cli.add_argument('-p', '--port',
+                     type=int,
+                     help=( "Listen at this port. Default: search for\n"
+                            "open port starting at %s\n\n" % DEFAULT_PORT))
+    cli.add_argument('-P', '--urlport',
+                     type=int,
+                     help=( "Set docker external port. If using\n"
+                            "   docker ... -p 9090:8917 ..."
+                            "this should be set to 9090. "
+                            "Default: as selected by --port\n\n"))
+    cli.add_argument('-V', '--version', action='version',
+                     version='Roundup version %s'%roundup_version,
+                     help=(
+                         "Show program's version number: %s and exit\n" %
+                         roundup_version))
+
+    cli.add_argument('directory', nargs='?',
+                     help="Create home for tracker in directory. (*)\n")
+
+    # add 'nuke' to choices so backend will accept nuke if only 2 args.
+    choices = backends + ['nuke']
+    cli.add_argument('backend', nargs='?', metavar='backend', choices=choices,
+                     help=( "Choose backend database. "
+                            "Depricated, use -b instead.\n"
+           "If it is used, you *must* specify directory.\n\n"))
+
+    cli.add_argument('nuke', nargs='?', metavar='nuke', choices=['nuke'],
+                     help=( "The word 'nuke' will delete tracker and reset.\n"
+                            "E.G. %(prog)s -b sqlite -t classic ./mytracker nuke\n") % {"prog": sys.argv[0]})
+
+    cli_args = cli.parse_args()
+
+    # collect all positional args in order in array to parse
+    # strip all None.
+    cli_args.cmd = [ x for x in [cli_args.directory, cli_args.backend, cli_args.nuke] if x != None ]
+
+    try:
+        nuke = cli_args.cmd[-1] == 'nuke'
+        if nuke:
+            _ignore = cli_args.cmd.pop()  # remove nuke
+    except IndexError:
+        nuke = False
+
+    try:
+        tracker_home = cli_args.cmd[0]
+    except IndexError:
+        tracker_home = None
+
+    # invoked as demo tracker_dir sqlite [nuke]
+    try:
+        cli_backend = cli_args.cmd[1]
+    except IndexError:
+        cli_backend = None
+
+    home = tracker_home or DEFAULT_HOME
+    template = cli_args.template or DEFAULT_TEMPLATE
+    backend = cli_args.backend_db or cli_backend or DEFAULT_BACKEND
+
     # if there is no tracker in home, force nuke
     try:
         instance.open(home)
+        valid_home = True
     except configuration.NoConfigError:
-        nuke = 1
-    # if we are to create the tracker, prompt for home
+        nuke = True
+        valid_home = False
+
+    # if we are to create the tracker, prompt for settings
     if nuke:
-        if len(sys.argv) > 2:
-            backend = sys.argv[-2]
-        else:
-            backend = 'anydbm'
         # FIXME: i'd like to have an option to abort the tracker creation
         #   say, by entering a single dot.  but i cannot think of
         #   appropriate prompt for that.
-        home = my_input(
-            _('Enter directory path to create demo tracker [%s]: ') % home)
-        if not home:
-            home = DEFAULT_HOME
-        templates = admin.AdminTool().listTemplates().keys()
-        template = my_input(
-            _('Enter tracker template to use (one of (%(template_list)s)) [%(d\
-efault_template)s]: ') %
+        if not tracker_home:
+            home = my_input(
+                _('Enter directory path to create demo tracker [%s]: ') % home)
+            if not home:
+                home = DEFAULT_HOME
+
+        if not cli_args.template in templates:
+            template = my_input(
+            _('Enter tracker template to use (one of (%(template_list)s)) [%(default_template)s]: ') %
             { 'template_list': ','.join(templates),
               'default_template': template})
-        if not template:
-            template = DEFAULT_TEMPLATE
+            if not template:
+                template = DEFAULT_TEMPLATE
+            elif template not in templates:
+                print("Unknown template: %s. Exiting." % template)
+                exit(1)
         # install
         demo.install_demo(home, backend,
-                          admin.AdminTool().listTemplates()[template]['path'])
+                          admin.AdminTool().listTemplates()[template]['path'],
+                          use_port=cli_args.urlport or DEFAULT_PORT)
+    else:
+        # make sure that no options are specified that are only useful on initialization.
+        if ( cli_args.backend or cli_args.template or
+             cli_args.backend_db ):
+            usage(home, cli, msg=(
+                "Specifying backend or template is only allowed when\n"
+                "creating a tracker or with nuke.\n"))
+            exit(1)
     # run
-    demo.run_demo(home)
-
+    demo.run_demo(home, bind_addr=cli_args.bind_address,
+                  bind_port=cli_args.port)
 
 if __name__ == '__main__':
     run()