#!/usr/bin/env python

import sys
import getopt
import imp
import itertools as it
import inspect
import traceback
import imp

from helpers import *
from scene import Scene

HELP_MESSAGE = """
   Usage: 
   python extract_scene.py <module> [<scene name>] [<arg_string>]

   -p preview in low quality
   -s show and save picture of last frame
   -w write result to file [this is default if nothing else is stated]
   -l use low quality
   -m use medium quality
   -a run and save every scene in the script, or all args for the given scene
   -q don't pring progress
"""
SCENE_NOT_FOUND_MESSAGE = """
   That scene is not in the script
"""
CHOOSE_NUMBER_MESSAGE = """
Choose number corresponding to desired scene/arguments.
(Use comma separated list for multiple entries)

Choice(s): """
INVALID_NUMBER_MESSAGE = "Fine then, if you don't want to give a valid number I'll just quit"

NO_SCENE_MESSAGE = """
   There are no scenes inside that module
"""


def get_configuration(sys_argv):
   try:
      opts, args = getopt.getopt(sys_argv[1:], 'hlmpwsqa')
   except getopt.GetoptError as err:
      print str(err)
      sys.exit(2)
   config = {
      "module"         : None,
      "scene_name"     : "",
      "args_extension" : "",
      "display_config" : PRODUCTION_QUALITY_DISPLAY_CONFIG,
      "preview"        : False,
      "write"          : False,
      "save_image"     : False,
      "quiet"          : False,
      "write_all"      : False,
   }
   for opt, arg in opts:
      if opt == '-h':
         print HELP_MESSAGE
         return
      elif opt == '-l':
         config["display_config"] = LOW_QUALITY_DISPLAY_CONFIG
      elif opt == '-m':
         config["display_config"] = MEDIUM_QUALITY_DISPLAY_CONFIG
      elif opt == '-p':
         config["display_config"] = LOW_QUALITY_DISPLAY_CONFIG
         config["preview"] = True
      elif opt == '-w':
         config["write"] = True
      elif opt == '-s':
         config["save_image"] = True
      elif opt == '-q':
         config["quiet"] = True
      elif opt == '-a':
         config["write_all"] = True
         config["quiet"] = True
   #By default, write to file
   actions = ["write", "preview", "save_image"]
   if not any([config[key] for key in actions]):
      config["write"] = True

   if len(args) == 0:
      print HELP_MESSAGE
      sys.exit()
   config["module"] = args[0].replace(".py", "")
   if len(args) > 1:
      config["scene_name"] = args[1]
   if len(args) > 2:
      config["args_extension"] = " ".join(args[2:])
   return config

def handle_scene(scene, **config):
   name = str(scene)
   if config["quiet"]:
      curr_stdout = sys.stdout
      sys.stdout = open(os.devnull, "w")
      
   if config["preview"]:
      scene.preview()
   if config["save_image"]:
      if not config["write_all"]:
         scene.show_frame()
      path = os.path.join(MOVIE_DIR, config["movie_prefix"], "images")
      if not os.path.exists(path):
         os.makedirs(path)
      scene.save_image(path, name)
   if config["write"]:
      scene.write_to_movie(os.path.join(config["movie_prefix"], name))

   if config["quiet"]:
      sys.stdout.close()
      sys.stdout = curr_stdout

def is_scene(obj):
   if not inspect.isclass(obj):
      return False
   if not issubclass(obj, Scene):
      return False
   if obj == Scene:
      return False
   return True

def prompt_user_for_choice(name_to_obj):
   num_to_name = {}
   for count, name in zip(it.count(1), name_to_obj):
      print "%d: %s"%(count, name)
      num_to_name[count] = name
   try:
      user_input = raw_input(CHOOSE_NUMBER_MESSAGE)
      return [
         name_to_obj[num_to_name[int(num_str)]]
         for num_str in user_input.split(",")
      ]
   except:
      print INVALID_NUMBER_MESSAGE
      sys.exit()

def get_scene_args(SceneClass, config):
   tuplify = lambda x : x if type(x) == tuple else (x,)
   args_list = map(tuplify, SceneClass.args_list)
   preset_extensions = [
      SceneClass.args_to_string(*args)
      for args in args_list
   ]
   if len(args_list) > 0:
      num_args = len(args_list[0])
   else:
      num_args = len(inspect.getargspec(SceneClass.construct).args) - 1

   if num_args == 0:
      return [()]
   if config["write_all"]:
      return args_list
   if config["args_extension"] in preset_extensions:
      index = preset_extensions.index(config["args_extension"])
      return [args_list[index]]
   if config["args_extension"] == "" :
      if len(args_list) == 1:
         return args_list
      name_to_args = dict(zip(preset_extensions, args_list))
      return prompt_user_for_choice(name_to_args)
   return [SceneClass.string_to_args(config["args_extension"])]

def get_scene_classes(scene_names_to_classes, config):
   if len(scene_names_to_classes) == 0:
      print NO_SCENE_MESSAGE
      return []
   if len(scene_names_to_classes) == 1:
      return scene_names_to_classes.values()
   if config["scene_name"] in scene_names_to_classes:
      return [scene_names_to_classes[config["scene_name"]] ]
   if config["scene_name"] != "":
      print SCENE_NOT_FOUND_MESSAGE
      return []
   if config["write_all"]:
      return scene_names_to_classes.values()
   return prompt_user_for_choice(scene_names_to_classes)


def main():
   config = get_configuration(sys.argv)
   module = imp.load_module(
      config["module"],
      *imp.find_module(config["module"])
   )
   scene_names_to_classes = dict(
      inspect.getmembers(module, is_scene)
   )
   config["movie_prefix"] = config["module"]
   scene_kwargs = config["display_config"]
   scene_kwargs["announce_construction"] = True
   for SceneClass in get_scene_classes(scene_names_to_classes, config):
      for args in get_scene_args(SceneClass, config):
         scene_kwargs["construct_args"] = args
         try:
            handle_scene(SceneClass(**scene_kwargs), **config)
         except:
            print "\n\n"
            traceback.print_exc()
            print "\n\n"


if __name__ == "__main__":
   main()