#! /usr/bin/env python
"""Registry for loading Khronos API definitions from XML files"""
from lxml import etree as ET
import os, sys, json, logging
from OpenGL._bytes import as_8_bit, unicode, as_str

log = logging.getLogger(__name__)
HERE = os.path.dirname(__file__)

LENGTH_OVERRIDES = {
    'glGetPolygonStipple': {
        'mask': str(32 * 32 / 8),  # 32x32 bits
    },
    'glGetUniformfv': {
        'params': None,
    },
    'glGetUniformiv': {
        'params': None,
    },
    #    'glShaderSourceARB': {
    #        'string': None,
    #    },
    #    'glShaderSource': {
    #        'string': None,
    #    },
}


class Registry(object):
    def __init__(self):
        self.type_set = {}
        self.enum_namespaces = {}
        self.enum_groups = {}
        self.enumeration_set = {}
        self.command_set = {}
        self.apis = {}
        self.feature_set = {}
        self.extension_set = {}
        self.output_mapping = json.loads(
            open(os.path.join(HERE, 'gl_out_parameters.json')).read()
        )
        self.output_enum_groups = {}

    def load(self, tree):
        """Load an lxml.etree structure into our internal descriptions"""
        self.dispatch(tree, None)

    def dispatch(self, tree, context=None):
        """Dispatch for all children of the element"""
        for element in tree:
            if isinstance(element.tag, (str, unicode)):
                method = getattr(self, element.tag, None)
                if method:
                    method(element, context)
                else:
                    print('Expand', element.tag)
                    self.dispatch(element, context)

    def type(self, element, context=None):
        name = element.get('name')
        if not name:
            name = element.find('name').text
        self.type_set[as_str(name)] = element

    def debug_types(self):
        for name, type in self.types.items():
            print(name, type)

    def enums(self, element, context=None):
        name = as_str(element.get('namespace'))
        if name not in self.enum_namespaces:
            namespace = EnumNamespace(name)
            self.enum_namespaces[name] = namespace
        else:
            namespace = self.enum_namespaces[name]
        self.dispatch(element, namespace)

    def enum(self, element, context=None):
        if isinstance(context, EnumNamespace):
            name, value = as_str(element.get('name')), element.get('value')
            enum = Enum(name, value)
            context.append(enum)
            self.enumeration_set[name] = enum
        elif isinstance(context, (Require, Remove)):
            context.append(self.enumeration_set[element.get('name')])
        elif isinstance(context, EnumGroup):
            name = element.get('name')
            assert name, 'No name on %s' % ET.tostring(element)
            context.append(as_str(name))

    def debug_enums(self):
        for name, namespace in self.enum_namespaces.items():
            print('Namespace', namespace.namespace)
            for enum in namespace:
                print('  ', enum)

    def command(self, element, context=None):
        """Parse command definition into structured format"""
        proto = element.find('proto')
        if proto is not None:
            name = as_str(proto.find('name').text)
            assert name, 'No name in command: %s' % (ET.tostring(element))
            return_type = self._type_decl(proto)
            assert return_type, 'No return type in command: %s' % (ET.tostring(element))
            arg_names = []
            arg_types = []
            lengths = {}
            groups = {}
            for param in [x for x in element if x.tag == 'param']:
                pname = as_str(param.find('name').text)
                arg_names.append(pname)
                arg_types.append(self._type_decl(param))
                if param.get('len'):
                    length = param.get('len')
                    while length.endswith('*1'):
                        length = length[:-2]
                    length = LENGTH_OVERRIDES.get(name, {}).get(pname, length)
                    lengths[pname] = length
                if param.get('group'):
                    groups[pname] = param.get('group')
            aliases = []
            for alias in [x for x in element if x.tag == 'alias']:
                aliases.append(alias.get('name'))
            # Process lengths to look for output parameters
            outputs = self.output_mapping.get(name)
            command = Command(
                name,
                return_type,
                arg_names,
                arg_types,
                aliases,
                lengths,
                groups,
                outputs=outputs,
            )
            self.command_set[name] = command
        elif isinstance(context, (Require, Remove)):
            context.append(self.command_set[element.get('name')])

    def _type_decl(self, proto):
        """Get the string type declaration for parent (proto/param)"""
        return_type = []
        if proto.text:
            return_type.append(proto.text)
        for item in proto:
            if item.tag == 'name':
                break
            else:
                if item.text:
                    return_type.append(item.text.strip())
                if item.tail:
                    return_type.append(item.tail.strip())
        return ' '.join([x for x in return_type if x]) or 'void'

    def debug_commands(self):
        for name, command in sorted(self.command_set.items()):
            print(command)

    def feature(self, element, context=None):
        api, name, number = [element.get(x) for x in ('api', 'name', 'number')]
        feature = Feature(api, name, number)
        self.feature_set[name] = feature
        self.dispatch(element, feature)

    def extension(self, element, context=None):
        name, apis, require = [element.get(x) for x in ['name', 'supported', 'protect']]
        extension = Extension(name, apis.split('|'), require)
        self.extension_set[name] = extension
        self.dispatch(element, extension)

    def unused(self, element, context=None):
        pass

    def group(self, element, context=None):
        name = element.get('name')
        current = self.enum_groups.get(name)
        if current is None:
            current = self.enum_groups[name] = EnumGroup(name)
        self.dispatch(element, current)

    def require(self, element, context):
        if isinstance(context, (Feature, Extension)):
            profile, comment = element.get('profile'), element.get('comment')
            require = Require(profile, comment)
            context.append(require)
            self.dispatch(element, require)

    def remove(self, element, context):
        if isinstance(context, Feature):
            profile, comment = element.get('profile'), element.get('comment')
            remove = Remove(profile, comment)
            context.append(remove)
            self.dispatch(element, remove)

    def debug_apis(self):
        print([x.api for x in self.feature_set.values()])


class EnumNamespace(list):
    def __init__(self, namespace, *args):
        self.namespace = namespace
        super(EnumNamespace, self).__init__(*args)


class EnumGroup(list):
    def __init__(self, name, *args):
        self.name = name
        super(EnumGroup, self).__init__(*args)


class Enum(object):
    def __init__(self, name, value):
        self.name = name
        self.value = value

    def __repr__(self):
        return '%s = %s' % (self.name, self.value)


class Command(object):
    def __init__(
        self,
        name,
        returnType,
        argNames,
        argTypes,
        aliases=None,
        lengths=None,
        groups=None,
        outputs=None,
    ):
        self.name = name
        self.returnType = returnType
        self.argNames = argNames
        self.argTypes = argTypes
        self.aliases = aliases or []
        self.lengths = lengths or {}
        self.groups = groups or {}
        self.outputs = outputs or {}
        self.output_groups = {}
        self.size_dependencies = self.calculate_sizes()

    def __repr__(self):
        return '%s %s( %s )' % (
            self.returnType,
            self.name,
            ', '.join(
                [
                    '%s %s' % (typ, name)
                    for (typ, name) in zip(self.argTypes, self.argNames)
                ]
            ),
        )

    def calculate_sizes(self):
        result = []
        other_lengths = self.lengths.copy()
        for target in self.outputs.keys():
            definition = self.lengths.get(target)
            if definition is None:
                if target not in self.argNames:
                    # may be a discrepency between .spec and xml registry file...
                    if target == 'params' and 'data' in self.argNames:
                        target = 'data'
                        definition = self.lengths.get('data')
            if target in other_lengths:
                del other_lengths[target]

            if definition is None:
                result.append((target, Output()))
            elif definition.startswith('COMPSIZE'):
                variables = definition[8:].strip('()').split(',')
                output_groups = {}
                if len(variables) == 1:
                    # for now we only support automated single-dependency wrapping...
                    for var in variables:
                        if var in self.groups:
                            output_groups.setdefault(self.groups[var], []).append(
                                target
                            )
                    self.output_groups.update(output_groups)
                result.append((target, Compsize(variables, output_groups)))
            elif definition.isdigit():
                result.append((target, Staticsize(int(definition, 10))))
            elif '*' in definition:
                var, multiple = definition.split('*')
                result.append((target, Multiple(var, int(multiple, 10))))
            else:
                result.append((target, Dynamicsize(definition)))
        for target, length in other_lengths.items():
            if length is None:
                # length/array-conversion suppressed
                continue
            if length.isdigit():
                result.append((target, StaticInput(int(length, 10))))
            elif length.startswith('COMPSIZE'):
                result.append((target, Input(length[9:-1])))
            elif length in self.argNames:
                result.append((target, DynamicInput(length)))
            elif '*' in length:
                params = [x.strip() for x in length.split('*')]
                in_set = [x for x in params if x in self.argNames]
                result.append((target, MultiplyInput(params)))
            elif '/' in length:
                params = [x.strip() for x in length.split('/')]
                in_set = [x for x in params if x in self.argNames]
                result.append((target, DivideInput(params)))
            else:
                raise RuntimeError((target, length))
        return dict(result)


class IsInput(object):
    pass


class Input(IsInput, object):
    """Unsized Input Parameter"""

    def __init__(self, value=None):
        self.value = value

    def __repr__(self):
        return repr(self.value)


class StaticInput(IsInput, int):
    """Statically sized input parameter"""


class DynamicInput(IsInput, str):
    """Dynamically sized based on other parameter"""


class MultiplyInput(IsInput, list):
    """Size depends on multiple elements being multiplied"""

    def __str__(self):
        return '*'.join(self)


class DivideInput(IsInput, list):
    """Size depends on multiple elements being multiplied"""

    def __str__(self):
        return '/'.join(self)


class Output(object):
    """Unsized output parameter"""


class Compsize(list):
    """Compute size based on other variables"""

    def __init__(self, iterable, groups=None):
        super(Compsize, self).__init__(iterable)
        self.groups = groups


class Staticsize(int):
    """Static output array size"""


class Dynamicsize(str):
    """Sized by the value in dynamic variable"""


class Multiple(list):
    """Variable * static size for array"""


# The order-dependent set of require/remove holding features/extensions
class Module(list):
    """Base class for Features and Extensions"""

    feature = False

    def __init__(self, name):
        self.name = name

    def members(self, of_type=None):
        members = []
        for req in self:
            if req.require:
                for item in req:
                    if of_type is not None:
                        if isinstance(item, of_type):
                            members.append(item)
                    else:
                        members.append(item)
        return members

    def enums(self):
        return self.members(Enum)

    def commands(self):
        return self.members(Command)


class Feature(Module):
    feature = True
    NORMALIZERS = {
        'GL_VERSION_ES_CM_1_0': 'GLES_VERSION_1_0',
        'GL_ES_VERSION_2_0': 'GLES_VERSION_2_0',
        'GL_ES_VERSION_3_0': 'GLES_VERSION_3_0',
    }

    def __init__(self, api, name, number):
        super(Feature, self).__init__(self.NORMALIZERS.get(name, name))
        self.api = api
        if name == 'GL_ES_VERSION_3_0':
            self.api = 'gles3'
        self.number = number

    _profiles = None

    @property
    def profiles(self):
        """Create set of profiles with subsets of our functionality"""
        if self._profiles is None:
            profiles = {}
            for req in self:
                # Logic isn't right here, there's a base and then
                # a set of profiles which customize the base...
                profile = req.profile or ''
                set = profiles.get(profile)
                if set is None:
                    set = Module(profile or '')
                    set.feature = True
                    profiles[profile] = set
                if req.require:

                    set.extend(req)
                else:
                    for item in req:
                        while item in set:
                            set.remove(item)
            self._profiles = sorted(profiles.values(), key=lambda x: x.name)
        return self._profiles


class Extension(Module):
    def __init__(self, name, apis, require=None):
        super(Extension, self).__init__(name)
        self.apis = apis  # only available for these APIs
        self.require = require

    @property
    def profiles(self):
        module = Module('default')
        module.extend(self)
        return module


class Require(list):
    require = True
    remove = False

    def __init__(self, profile=None, comment=None):
        self.profile = profile
        self.comment = comment
        super(Require, self).__init__()


class Remove(list):
    require = False
    remove = True

    def __init__(self, profile=None, comment=None):
        self.profile = profile
        self.comment = comment
        super(Remove, self).__init__()


def parse(xmlfile):
    registry = Registry()
    registry.load(ET.fromstring(open(xmlfile, 'rb').read()))
    return registry


if __name__ == "__main__":
    if sys.argv[1:]:
        for file in sys.argv[1:]:
            print(file)
            registry = parse(file)

    # registry.debug_types()
    # registry.debug_enums()
    # registry.debug_commands()
    # registry.debug_apis()