# Copyright (C) 2013 Google Inc. All rights reserved.
#
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# modification, are permitted provided that the following conditions are
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#
#     * Redistributions of source code must retain the above copyright
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# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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"""Functions shared by various parts of the code generator.

Design doc: http://www.chromium.org/developers/design-documents/idl-compiler
"""

import re

from idl_types import IdlTypeBase
import idl_types
from idl_definitions import Exposure, IdlInterface, IdlAttribute
from v8_globals import includes

ACRONYMS = [
    'CSSOM',  # must come *before* CSS to match full acronym
    'CSS',
    'HTML',
    'IME',
    'JS',
    'SVG',
    'URL',
    'WOFF',
    'XML',
    'XSLT',
]


################################################################################
# Extended attribute parsing
################################################################################

def extended_attribute_value_contains(extended_attribute_value, key):
    return (extended_attribute_value == key or
            (isinstance(extended_attribute_value, list) and
             key in extended_attribute_value))


def has_extended_attribute(definition_or_member, extended_attribute_list):
    return any(extended_attribute in definition_or_member.extended_attributes
               for extended_attribute in extended_attribute_list)


def has_extended_attribute_value(definition_or_member, name, value):
    extended_attributes = definition_or_member.extended_attributes
    return (name in extended_attributes and
            extended_attribute_value_contains(extended_attributes[name], value))


def extended_attribute_value_as_list(definition_or_member, name):
    extended_attributes = definition_or_member.extended_attributes
    if name not in extended_attributes:
        return None
    value = extended_attributes[name]
    if isinstance(value, list):
        return value
    return [value]


################################################################################
# String handling
################################################################################

def capitalize(name):
    """Capitalize first letter or initial acronym (used in setter names)."""
    for acronym in ACRONYMS:
        if name.startswith(acronym.lower()):
            return name.replace(acronym.lower(), acronym)
    return name[0].upper() + name[1:]


def strip_suffix(string, suffix):
    if not suffix or not string.endswith(suffix):
        return string
    return string[:-len(suffix)]


def uncapitalize(name):
    """Uncapitalizes first letter or initial acronym (used in method names).

    E.g., 'SetURL' becomes 'setURL', but 'URLFoo' becomes 'urlFoo'.
    """
    for acronym in ACRONYMS:
        if name.startswith(acronym):
            return name.replace(acronym, acronym.lower())
    return name[0].lower() + name[1:]


def unique_by(dict_list, key):
    """Returns elements from a list of dictionaries with unique values for the named key."""
    keys_seen = set()
    filtered_list = []
    for item in dict_list:
        if item.get(key) not in keys_seen:
            filtered_list.append(item)
            keys_seen.add(item.get(key))
    return filtered_list


def for_origin_trial_feature(items, feature_name):
    """Filters the list of attributes or constants, and returns those defined for the named origin trial feature."""
    return [item for item in items if
            item['origin_trial_feature_name'] == feature_name and
            not item.get('exposed_test')]


################################################################################
# C++
################################################################################

def scoped_name(interface, definition, base_name):
    if 'ImplementedInPrivateScript' in definition.extended_attributes:
        return '%s::PrivateScript::%s' % (v8_class_name(interface), base_name)
    # partial interfaces are implemented as separate classes, with their members
    # implemented as static member functions
    partial_interface_implemented_as = definition.extended_attributes.get('PartialInterfaceImplementedAs')
    if partial_interface_implemented_as:
        return '%s::%s' % (partial_interface_implemented_as, base_name)
    if (definition.is_static or
            definition.name in ('Constructor', 'NamedConstructor')):
        return '%s::%s' % (cpp_name(interface), base_name)
    return 'impl->%s' % base_name


def v8_class_name(interface):
    return 'V8' + interface.name


def v8_class_name_or_partial(interface):
    class_name = v8_class_name(interface)
    if interface.is_partial:
        return ''.join([class_name, 'Partial'])
    return class_name


################################################################################
# Specific extended attributes
################################################################################

# [ActivityLogging]
def activity_logging_world_list(member, access_type=''):
    """Returns a set of world suffixes for which a definition member has activity logging, for specified access type.

    access_type can be 'Getter' or 'Setter' if only checking getting or setting.
    """
    extended_attributes = member.extended_attributes
    if 'LogActivity' not in extended_attributes:
        return set()
    log_activity = extended_attributes['LogActivity']
    if log_activity and not log_activity.startswith(access_type):
        return set()

    includes.add('bindings/core/v8/V8DOMActivityLogger.h')
    if 'LogAllWorlds' in extended_attributes:
        return set(['', 'ForMainWorld'])
    return set([''])  # At minimum, include isolated worlds.


# [ActivityLogging]
def activity_logging_world_check(member):
    """Returns if an isolated world check is required when generating activity
    logging code.

    The check is required when there is no per-world binding code and logging is
    required only for isolated world.
    """
    extended_attributes = member.extended_attributes
    if 'LogActivity' not in extended_attributes:
        return False
    if ('PerWorldBindings' not in extended_attributes and
            'LogAllWorlds' not in extended_attributes):
        return True
    return False


# [CallWith]
CALL_WITH_ARGUMENTS = {
    'ScriptState': 'scriptState',
    'ExecutionContext': 'executionContext',
    'ScriptArguments': 'scriptArguments',
    'CurrentWindow': 'currentDOMWindow(info.GetIsolate())',
    'EnteredWindow': 'enteredDOMWindow(info.GetIsolate())',
    'Document': 'document',
    'ThisValue': 'ScriptValue(scriptState, info.Holder())',
}
# List because key order matters, as we want arguments in deterministic order
CALL_WITH_VALUES = [
    'ScriptState',
    'ExecutionContext',
    'ScriptArguments',
    'CurrentWindow',
    'EnteredWindow',
    'Document',
    'ThisValue',
]


def call_with_arguments(call_with_values):
    if not call_with_values:
        return []
    return [CALL_WITH_ARGUMENTS[value]
            for value in CALL_WITH_VALUES
            if extended_attribute_value_contains(call_with_values, value)]


# [Constructor], [NamedConstructor]
def is_constructor_attribute(member):
    # TODO(yukishiino): replace this with [Constructor] and [NamedConstructor] extended attribute
    return (type(member) == IdlAttribute and
            member.idl_type.name.endswith('Constructor'))


# [DeprecateAs]
def deprecate_as(member):
    extended_attributes = member.extended_attributes
    if 'DeprecateAs' not in extended_attributes:
        return None
    includes.add('core/frame/Deprecation.h')
    return extended_attributes['DeprecateAs']


# [Exposed]
EXPOSED_EXECUTION_CONTEXT_METHOD = {
    'AnimationWorklet': 'isAnimationWorkletGlobalScope',
    'CompositorWorker': 'isCompositorWorkerGlobalScope',
    'DedicatedWorker': 'isDedicatedWorkerGlobalScope',
    'PaintWorklet': 'isPaintWorkletGlobalScope',
    'ServiceWorker': 'isServiceWorkerGlobalScope',
    'SharedWorker': 'isSharedWorkerGlobalScope',
    'Window': 'isDocument',
    'Worker': 'isWorkerGlobalScope',
    'Worklet': 'isWorkletGlobalScope',
}


EXPOSED_WORKERS = set([
    'CompositorWorker',
    'DedicatedWorker',
    'SharedWorker',
    'ServiceWorker',
])


class ExposureSet:
    """An ExposureSet is a collection of Exposure instructions."""
    def __init__(self, exposures=None):
        self.exposures = set(exposures) if exposures else set()

    def issubset(self, other):
        """Returns true if |self|'s exposure set is a subset of
        |other|'s exposure set. This function doesn't care about
        RuntimeEnabled."""
        self_set = self._extended(set(e.exposed for e in self.exposures))
        other_set = self._extended(set(e.exposed for e in other.exposures))
        return self_set.issubset(other_set)

    @staticmethod
    def _extended(target):
        if EXPOSED_WORKERS.issubset(target):
            return target | set(['Worker'])
        elif 'Worker' in target:
            return target | EXPOSED_WORKERS
        return target

    def add(self, exposure):
        self.exposures.add(exposure)

    def __len__(self):
        return len(self.exposures)

    def __iter__(self):
        return self.exposures.__iter__()

    @staticmethod
    def _code(exposure):
        exposed = ('executionContext->%s()' %
                   EXPOSED_EXECUTION_CONTEXT_METHOD[exposure.exposed])
        if exposure.runtime_enabled is not None:
            runtime_enabled = ('RuntimeEnabledFeatures::%sEnabled()' %
                               uncapitalize(exposure.runtime_enabled))
            return '({0} && {1})'.format(exposed, runtime_enabled)
        return exposed

    def code(self):
        if len(self.exposures) == 0:
            return None
        # We use sorted here to deflake output.
        return ' || '.join(sorted(self._code(e) for e in self.exposures))


def exposed(member, interface):
    """Returns a C++ code that checks if a method/attribute/etc is exposed.

    When the Exposed attribute contains RuntimeEnabledFeatures (i.e.
    Exposed(Arguments) form is given), the code contains check for them as
    well.

    EXAMPLE: [Exposed=Window, RuntimeEnabledFeature=Feature1]
      => context->isDocument()

    EXAMPLE: [Exposed(Window Feature1, Window Feature2)]
      => context->isDocument() && RuntimeEnabledFeatures::feature1Enabled() ||
         context->isDocument() && RuntimeEnabledFeatures::feature2Enabled()
    """
    exposure_set = ExposureSet(
        extended_attribute_value_as_list(member, 'Exposed'))
    interface_exposure_set = ExposureSet(
        extended_attribute_value_as_list(interface, 'Exposed'))
    for e in exposure_set:
        if e.exposed not in EXPOSED_EXECUTION_CONTEXT_METHOD:
            raise ValueError('Invalid execution context: %s' % e.exposed)

    # Methods must not be exposed to a broader scope than their interface.
    if not exposure_set.issubset(interface_exposure_set):
        raise ValueError('Interface members\' exposure sets must be a subset of the interface\'s.')

    return exposure_set.code()


# [SecureContext]
def secure_context(member, interface):
    """Returns C++ code that checks whether an interface/method/attribute/etc. is exposed
    to the current context."""
    if 'SecureContext' in member.extended_attributes or 'SecureContext' in interface.extended_attributes:
        return "executionContext->isSecureContext()"
    return None


# [ImplementedAs]
def cpp_name(definition_or_member):
    extended_attributes = definition_or_member.extended_attributes
    if 'ImplementedAs' not in extended_attributes:
        return definition_or_member.name
    return extended_attributes['ImplementedAs']


def cpp_name_from_interfaces_info(name, interfaces_info):
    return interfaces_info.get(name, {}).get('implemented_as') or name


def cpp_name_or_partial(interface):
    cpp_class_name = cpp_name(interface)
    if interface.is_partial:
        return ''.join([cpp_class_name, 'Partial'])
    return cpp_class_name


# [MeasureAs]
def measure_as(definition_or_member, interface):
    extended_attributes = definition_or_member.extended_attributes
    if 'MeasureAs' in extended_attributes:
        includes.add('core/frame/UseCounter.h')
        return lambda suffix: extended_attributes['MeasureAs']
    if 'Measure' in extended_attributes:
        includes.add('core/frame/UseCounter.h')
        measure_as_name = capitalize(definition_or_member.name)
        if interface is not None:
            measure_as_name = '%s_%s' % (capitalize(interface.name), measure_as_name)
        return lambda suffix: 'V8%s_%s' % (measure_as_name, suffix)
    return None


# [OriginTrialEnabled]
def origin_trial_enabled_function_name(definition_or_member):
    """Returns the name of the OriginTrials enabled function.

    An exception is raised if both the OriginTrialEnabled and RuntimeEnabled
    extended attributes are applied to the same IDL member. Only one of the
    two attributes can be applied to any member - they are mutually exclusive.

    The returned function checks if the IDL member should be enabled.
    Given extended attribute OriginTrialEnabled=FeatureName, return:
        OriginTrials::{featureName}Enabled

    If the OriginTrialEnabled extended attribute is found, the includes are
    also updated as a side-effect.
    """
    extended_attributes = definition_or_member.extended_attributes
    is_origin_trial_enabled = 'OriginTrialEnabled' in extended_attributes

    if is_origin_trial_enabled and 'RuntimeEnabled' in extended_attributes:
        raise Exception('[OriginTrialEnabled] and [RuntimeEnabled] must '
                        'not be specified on the same definition: '
                        '%s.%s' % (definition_or_member.idl_name, definition_or_member.name))

    if is_origin_trial_enabled:
        trial_name = extended_attributes['OriginTrialEnabled']
        return 'OriginTrials::%sEnabled' % uncapitalize(trial_name)

    is_feature_policy_enabled = 'FeaturePolicy' in extended_attributes

    if is_feature_policy_enabled and 'RuntimeEnabled' in extended_attributes:
        raise Exception('[FeaturePolicy] and [RuntimeEnabled] must '
                        'not be specified on the same definition: '
                        '%s.%s' % (definition_or_member.idl_name, definition_or_member.name))

    if is_feature_policy_enabled:
        includes.add('bindings/core/v8/ScriptState.h')
        includes.add('platform/feature_policy/FeaturePolicy.h')

        trial_name = extended_attributes['FeaturePolicy']
        return 'FeaturePolicy::%sEnabled' % uncapitalize(trial_name)

    return None


def origin_trial_feature_name(definition_or_member):
    extended_attributes = definition_or_member.extended_attributes
    return extended_attributes.get('OriginTrialEnabled') or extended_attributes.get('FeaturePolicy')


def runtime_feature_name(definition_or_member):
    extended_attributes = definition_or_member.extended_attributes
    if 'RuntimeEnabled' not in extended_attributes:
        return None
    return extended_attributes['RuntimeEnabled']


# [RuntimeEnabled]
def runtime_enabled_function_name(definition_or_member):
    """Returns the name of the RuntimeEnabledFeatures function.

    The returned function checks if a method/attribute is enabled.
    Given extended attribute RuntimeEnabled=FeatureName, return:
        RuntimeEnabledFeatures::{featureName}Enabled

    If the RuntimeEnabled extended attribute is found, the includes
    are also updated as a side-effect.
    """
    feature_name = runtime_feature_name(definition_or_member)

    if not feature_name:
        return

    includes.add('platform/RuntimeEnabledFeatures.h')
    return 'RuntimeEnabledFeatures::%sEnabled' % uncapitalize(feature_name)


# [Unforgeable]
def is_unforgeable(interface, member):
    return (('Unforgeable' in interface.extended_attributes or
             'Unforgeable' in member.extended_attributes) and
            not member.is_static)


# [LegacyInterfaceTypeChecking]
def is_legacy_interface_type_checking(interface, member):
    return ('LegacyInterfaceTypeChecking' in interface.extended_attributes or
            'LegacyInterfaceTypeChecking' in member.extended_attributes)


# [Unforgeable], [Global], [PrimaryGlobal]
def on_instance(interface, member):
    """Returns True if the interface's member needs to be defined on every
    instance object.

    The following members must be defiend on an instance object.
    - [Unforgeable] members
    - regular members of [Global] or [PrimaryGlobal] interfaces
    """
    if member.is_static:
        return False

    # TODO(yukishiino): Remove a hack for toString once we support
    # Symbol.toStringTag.
    if (interface.name == 'Window' and member.name == 'toString'):
        return False

    # TODO(yukishiino): Implement "interface object" and its [[Call]] method
    # in a better way.  Then we can get rid of this hack.
    if is_constructor_attribute(member):
        return True

    if ('PrimaryGlobal' in interface.extended_attributes or
            'Global' in interface.extended_attributes or
            'Unforgeable' in member.extended_attributes or
            'Unforgeable' in interface.extended_attributes):
        return True
    return False


def on_prototype(interface, member):
    """Returns True if the interface's member needs to be defined on the
    prototype object.

    Most members are defined on the prototype object.  Exceptions are as
    follows.
    - static members (optional)
    - [Unforgeable] members
    - members of [Global] or [PrimaryGlobal] interfaces
    - named properties of [Global] or [PrimaryGlobal] interfaces
    """
    if member.is_static:
        return False

    # TODO(yukishiino): Remove a hack for toString once we support
    # Symbol.toStringTag.
    if (interface.name == 'Window' and member.name == 'toString'):
        return True

    # TODO(yukishiino): Implement "interface object" and its [[Call]] method
    # in a better way.  Then we can get rid of this hack.
    if is_constructor_attribute(member):
        return False

    if ('PrimaryGlobal' in interface.extended_attributes or
            'Global' in interface.extended_attributes or
            'Unforgeable' in member.extended_attributes or
            'Unforgeable' in interface.extended_attributes):
        return False
    return True


# static, const
def on_interface(interface, member):
    """Returns True if the interface's member needs to be defined on the
    interface object.

    The following members must be defiend on an interface object.
    - static members
    """
    if member.is_static:
        return True
    return False


################################################################################
# Indexed properties
# http://heycam.github.io/webidl/#idl-indexed-properties
################################################################################

def indexed_property_getter(interface):
    try:
        # Find indexed property getter, if present; has form:
        # getter TYPE [OPTIONAL_IDENTIFIER](unsigned long ARG1)
        return next(
            method
            for method in interface.operations
            if ('getter' in method.specials and
                len(method.arguments) == 1 and
                str(method.arguments[0].idl_type) == 'unsigned long'))
    except StopIteration:
        return None


def indexed_property_setter(interface):
    try:
        # Find indexed property setter, if present; has form:
        # setter RETURN_TYPE [OPTIONAL_IDENTIFIER](unsigned long ARG1, ARG_TYPE ARG2)
        return next(
            method
            for method in interface.operations
            if ('setter' in method.specials and
                len(method.arguments) == 2 and
                str(method.arguments[0].idl_type) == 'unsigned long'))
    except StopIteration:
        return None


def indexed_property_deleter(interface):
    try:
        # Find indexed property deleter, if present; has form:
        # deleter TYPE [OPTIONAL_IDENTIFIER](unsigned long ARG)
        return next(
            method
            for method in interface.operations
            if ('deleter' in method.specials and
                len(method.arguments) == 1 and
                str(method.arguments[0].idl_type) == 'unsigned long'))
    except StopIteration:
        return None


################################################################################
# Named properties
# http://heycam.github.io/webidl/#idl-named-properties
################################################################################

def named_property_getter(interface):
    try:
        # Find named property getter, if present; has form:
        # getter TYPE [OPTIONAL_IDENTIFIER](DOMString ARG1)
        getter = next(
            method
            for method in interface.operations
            if ('getter' in method.specials and
                len(method.arguments) == 1 and
                str(method.arguments[0].idl_type) == 'DOMString'))
        getter.name = getter.name or 'anonymousNamedGetter'
        return getter
    except StopIteration:
        return None


def named_property_setter(interface):
    try:
        # Find named property setter, if present; has form:
        # setter RETURN_TYPE [OPTIONAL_IDENTIFIER](DOMString ARG1, ARG_TYPE ARG2)
        return next(
            method
            for method in interface.operations
            if ('setter' in method.specials and
                len(method.arguments) == 2 and
                str(method.arguments[0].idl_type) == 'DOMString'))
    except StopIteration:
        return None


def named_property_deleter(interface):
    try:
        # Find named property deleter, if present; has form:
        # deleter TYPE [OPTIONAL_IDENTIFIER](DOMString ARG)
        return next(
            method
            for method in interface.operations
            if ('deleter' in method.specials and
                len(method.arguments) == 1 and
                str(method.arguments[0].idl_type) == 'DOMString'))
    except StopIteration:
        return None


IdlInterface.indexed_property_getter = property(indexed_property_getter)
IdlInterface.indexed_property_setter = property(indexed_property_setter)
IdlInterface.indexed_property_deleter = property(indexed_property_deleter)
IdlInterface.named_property_getter = property(named_property_getter)
IdlInterface.named_property_setter = property(named_property_setter)
IdlInterface.named_property_deleter = property(named_property_deleter)