effect.py

import settings
import os
import json
import template_handler


def get_effect_instance(effect_names):
    if len(effect_names) == 1:
        return Effect(effect_names[0])
    else:
        return CompositeEffect(effect_names)


class Effect(object):
    def __init__(self, name):
        self.template_dir = settings.EFFECT_DIRECTORY
        if name != 'new_layer':
            metadata_file_path = os.path.join(
                settings.EFFECT_DIRECTORY,
                '{}.json'.format(name)
            )
            try:
                with open(metadata_file_path) as data_file:
                    try:
                        metadata = json.load(data_file)
                    except ValueError:
                        raise Exception(
                            'Could not parse JSON file "{}".'
                            ' Please check that the JSON format/syntax is correct.'.format(
                                metadata_file_path
                            )
                        )
                    self.parameters = metadata['parameters']
            except IOError:
                raise Exception(
                    'Could not load {}. It doesn\'t exist. See effects/readme.txt for more info'.format(
                        metadata_file_path
                    )
                )

            self.num_parameters = len(self.parameters)
            self.parameter_names = [p['name'] for p in self.parameters]
        self.name = name

    def get_template_handler(self, live=False):
        return template_handler.TemplateHandler(
            template_dir=self.template_dir,
            template_string=self.generate_template_string(live)
        )

    def generate_template_string(self, live=False):
        return '''
        {{% extends "{0}" %}}
        {{% block globals %}}
          {{% include "{1}.globals.jinja2" ignore missing %}}
        {{% endblock %}}
        {{% block effect %}}
          {{% include "{1}.effect.jinja2" %}}
        {{% endblock %}}
        '''.format(
            'base_template_live.csd.jinja2' if live else 'base_template.csd.jinja2',
            self.name
        )

    def get_serialized_representation(self):
        return {
            'num_parameters': self.num_parameters,
            'parameter_names': self.parameter_names
        }


class CompositeEffect(object):
    def __init__(self, effect_names):
        if effect_names[-1] != 'new_layer':
            effect_names.append('new_layer')
        if len(effect_names) <= 1:
            raise Exception('At least one effect must be specified')

        self.layer_indexes = {}
        effect_indexes = []
        for i, effect_name in enumerate(effect_names):
            if effect_name == 'new_layer':
                self.layer_indexes[i] = effect_indexes
                effect_indexes = []
            else:
                effect_indexes.append(i)

        self.template_dir = settings.EFFECT_DIRECTORY
        self.effect_names = effect_names
        self.effects = [Effect(name) for name in effect_names]

        self.parameter_names = []
        self.parameters = []
        i = 0
        for effect in self.effects:
            if effect.name != 'new_layer':
                softmax_post_gain_parameter = {
                    "name": "softmax_post_gain_{}_{}".format(effect.name, i),
                    "mapping": {
                        "min_value": -10.0,
                        "max_value": 10.0,
                        "skew_factor": 1.0
                    }
                }
                effect.parameters.append(softmax_post_gain_parameter)
                effect.parameter_names.append(softmax_post_gain_parameter['name'])
                effect.num_parameters += 1

                self.parameters += effect.parameters
                self.parameter_names += effect.parameter_names
                effect.parameter_indexes = range(i, i + effect.num_parameters)
                i += effect.num_parameters

        self.num_parameters = i

        self.name = 'composite'

    def get_template_handler(self, live=False):
        return template_handler.TemplateHandler(
            template_dir=self.template_dir,
            template_string=self.generate_template_string(live)
        )

    def generate_template_string(self, live=False):
        template_template_file_path = os.path.join(settings.EFFECT_DIRECTORY, 'composite.jinja2')
        with open(template_template_file_path, 'r') as template_file:
            template_template_string = template_file.read()

        that_template_handler = template_handler.TemplateHandler(
            template_dir=self.template_dir,
            template_string=template_template_string
        )

        base_template = 'base_template_live.csd.jinja2' if live else 'base_template.csd.jinja2'
        return that_template_handler.compile(
            base_template=base_template,
            effects=self.effects,
            layer_indexes=self.layer_indexes,
            parameter_names=self.parameter_names
        )

    def get_serialized_representation(self):
        return {
            'num_parameters': self.num_parameters,
            'parameter_names': self.parameter_names
        }