#!/usr/bin/env python
#
# License: BSD
#   https://raw.githubusercontent.com/splintered-reality/py_trees/devel/LICENSE
#
##############################################################################
# Documentation
##############################################################################

"""
.. argparse::
   :module: py_trees.demos.logging
   :func: command_line_argument_parser
   :prog: py-trees-demo-logging

.. graphviz:: dot/demo-logging.dot

.. image:: images/logging.gif
"""

##############################################################################
# Imports
##############################################################################

import argparse
import functools
import json
import py_trees
import sys
import time

import py_trees.console as console

##############################################################################
# Classes
##############################################################################


def description(root):
    content = "A demonstration of logging with trees.\n\n"
    content += "This demo utilises a SnapshotVisitor to trigger\n"
    content += "a post-tick handler to dump a serialisation of the\n"
    content += "tree to a json log file.\n"
    content += "\n"
    content += "This coupling of visitor and post-tick handler can be\n"
    content += "used for any kind of event handling - the visitor is the\n"
    content += "trigger and the post-tick handler the action. Aside from\n"
    content += "logging, the most common use case is to serialise the tree\n"
    content += "for messaging to a graphical, runtime monitor.\n"
    content += "\n"
    if py_trees.console.has_colours:
        banner_line = console.green + "*" * 79 + "\n" + console.reset
        s = "\n"
        s += banner_line
        s += console.bold_white + "Logging".center(79) + "\n" + console.reset
        s += banner_line
        s += "\n"
        s += content
        s += "\n"
        s += banner_line
    else:
        s = content
    return s


def epilog():
    if py_trees.console.has_colours:
        return console.cyan + "And his noodly appendage reached forth to tickle the blessed...\n" + console.reset
    else:
        return None


def command_line_argument_parser():
    parser = argparse.ArgumentParser(description=description(create_tree()),
                                     epilog=epilog(),
                                     formatter_class=argparse.RawDescriptionHelpFormatter,
                                     )
    group = parser.add_mutually_exclusive_group()
    group.add_argument('-r', '--render', action='store_true', help='render dot tree to file')
    group.add_argument('-i', '--interactive', action='store_true', help='pause and wait for keypress at each tick')
    return parser


def logger(snapshot_visitor, behaviour_tree):
    """
    A post-tick handler that logs the tree (relevant parts thereof) to a yaml file.
    """
    if snapshot_visitor.changed:
        print(console.cyan + "Logging.......................yes\n" + console.reset)
        tree_serialisation = {
            'tick': behaviour_tree.count,
            'nodes': []
        }
        for node in behaviour_tree.root.iterate():
            node_type_str = "Behaviour"
            for behaviour_type in [py_trees.composites.Sequence,
                                   py_trees.composites.Selector,
                                   py_trees.composites.Parallel,
                                   py_trees.decorators.Decorator]:
                if isinstance(node, behaviour_type):
                    node_type_str = behaviour_type.__name__
            node_snapshot = {
                'name': node.name,
                'id': str(node.id),
                'parent_id': str(node.parent.id) if node.parent else "none",
                'child_ids': [str(child.id) for child in node.children],
                'tip_id': str(node.tip().id) if node.tip() else 'none',
                'class_name': str(node.__module__) + '.' + str(type(node).__name__),
                'type': node_type_str,
                'status': node.status.value,
                'message': node.feedback_message,
                'is_active': True if node.id in snapshot_visitor.visited else False
                }
            tree_serialisation['nodes'].append(node_snapshot)
        if behaviour_tree.count == 0:
            with open('dump.json', 'w+') as outfile:
                json.dump(tree_serialisation, outfile, indent=4)
        else:
            with open('dump.json', 'a') as outfile:
                json.dump(tree_serialisation, outfile, indent=4)
    else:
        print(console.yellow + "Logging.......................no\n" + console.reset)


def create_tree():
    every_n_success = py_trees.behaviours.SuccessEveryN("EveryN", 5)
    sequence = py_trees.composites.Sequence(name="Sequence")
    guard = py_trees.behaviours.Success("Guard")
    periodic_success = py_trees.behaviours.Periodic("Periodic", 3)
    finisher = py_trees.behaviours.Success("Finisher")
    sequence.add_child(guard)
    sequence.add_child(periodic_success)
    sequence.add_child(finisher)
    sequence.blackbox_level = py_trees.common.BlackBoxLevel.COMPONENT
    idle = py_trees.behaviours.Success("Idle")
    root = py_trees.composites.Selector(name="Logging")
    root.add_child(every_n_success)
    root.add_child(sequence)
    root.add_child(idle)
    return root


##############################################################################
# Main
##############################################################################

def main():
    """
    Entry point for the demo script.
    """
    args = command_line_argument_parser().parse_args()
    py_trees.logging.level = py_trees.logging.Level.DEBUG
    tree = create_tree()
    print(description(tree))

    ####################
    # Rendering
    ####################
    if args.render:
        py_trees.display.render_dot_tree(tree)
        sys.exit()

    ####################
    # Tree Stewardship
    ####################
    behaviour_tree = py_trees.trees.BehaviourTree(tree)

    debug_visitor = py_trees.visitors.DebugVisitor()
    snapshot_visitor = py_trees.visitors.DisplaySnapshotVisitor()

    behaviour_tree.visitors.append(debug_visitor)
    behaviour_tree.visitors.append(snapshot_visitor)

    behaviour_tree.add_post_tick_handler(functools.partial(logger, snapshot_visitor))

    behaviour_tree.setup(timeout=15)

    ####################
    # Tick Tock
    ####################
    if args.interactive:
        py_trees.console.read_single_keypress()
    while True:
        try:
            behaviour_tree.tick()
            if args.interactive:
                py_trees.console.read_single_keypress()
            else:
                time.sleep(0.5)
        except KeyboardInterrupt:
            break
    print("\n")