
# Copyright 2017-present Open Networking Foundation
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.


import pdb
import re
from inflect import engine as inflect_engine_class

inflect_engine = inflect_engine_class()

class FieldNotFound(Exception):
    def __init__(self, message):
        super(FieldNotFound, self).__init__(message)

def xproto_debug(**kwargs):
    print kwargs
    pdb.set_trace()

def xproto_unquote(s):
    return unquote(s)

def unquote(s):
    if (s.startswith('"') and s.endswith('"')):
        return s[1:-1]
    else:
        return s

def xproto_singularize(field):
    try:
        # The user has set a singular, as an exception that cannot be handled automatically
        singular = field['options']['singular']
        singular = unquote(singular)
    except KeyError:
        singular = inflect_engine.singular_noun(field['name'])
        if singular is False:
            # singular_noun returns False on a noun it can't singularize
            singular = field["name"]

    return singular

def xproto_singularize_pluralize(field):
    try:
        # The user has set a plural, as an exception that cannot be handled automatically
        plural = field['options']['plural']
        plural = unquote(plural)
    except KeyError:
        singular = inflect_engine.singular_noun(field['name'])
        if singular is False:
            # singular_noun returns False on a noun it can't singularize
            singular = field["name"]

        plural = inflect_engine.plural_noun(singular)

    return plural

def xproto_pluralize(field):
    try:
        # The user has set a plural, as an exception that cannot be handled automatically
        plural = field['options']['plural']
        plural = unquote(plural)
    except KeyError:
        plural = inflect_engine.plural_noun(field['name'])

    return plural

def xproto_base_def(model_name, base, suffix='', suffix_list=[]):
    if (model_name=='XOSBase'):
        return '(models.Model, PlModelMixIn)'
    elif (not base):
        return ''
    else:
        int_base = [i['name']+suffix for i in base if i['name'] in suffix_list]
        ext_base = [i['name'] for i in base if i['name'] not in suffix_list]
        return '(' + ','.join(int_base + ext_base) + ')'

def xproto_first_non_empty(lst):
    for l in lst:
        if l: return l

def xproto_api_type(field):
    try:
        if (unquote(field['options']['content_type'])=='date'):
            return 'double'
    except KeyError:
        pass

    return field['type']


def xproto_base_name(n):
    # Hack - Refactor NetworkParameter* to make this go away
    if (n.startswith('NetworkParameter')):
        return '_'

    expr = r'^[A-Z]+[a-z]*'

    try:
        match = re.findall(expr, n)[0]
    except:
        return '_'

    return match

def xproto_base_fields(m, table):
    fields = []

    for b in m['bases']:
        option1 = b['fqn']
        try:
            option2 = m['package'] + '.' + b['name']
        except TypeError:
            option2 = option1

        accessor = None
        if option1 in table: accessor = option1
        elif option2 in table: accessor = option2

        if accessor:
            base_fields = xproto_base_fields(table[accessor], table)

            model_fields = [x.copy() for x in table[accessor]['fields']]
            for field in model_fields:
                field["accessor"] = accessor

            fields.extend(base_fields)
            fields.extend(model_fields)

    if 'no_sync' in m['options'] and m['options']['no_sync']:
        fields = [f for f in fields if f['name'] != 'backend_status' and f['name'] != 'backend_code']

    if 'no_policy' in m['options'] and m['options']['no_policy']:
        fields = [f for f in fields if f['name'] != 'policy_status' and f['name'] != 'policy_code']

    return fields

def xproto_fields(m, table):
    """ Generate the full list of models for the xproto message `m` including fields from the classes it inherits.

        Inserts the special field "id" at the very beginning.

        Each time we descend a new level of inheritance, increment the offset field numbers by 100. The base
        class's fields will be numbered from 1-99, the first descendant will be number 100-199, the second
        descdendant numbered from 200-299, and so on. This assumes any particular model as at most 100
        fields.
    """

    model_fields = [x.copy() for x in m["fields"]]
    for field in model_fields:
        field["accessor"] = m["fqn"]

    fields = xproto_base_fields(m, table) + model_fields

    # The "id" field is a special field. Every model has one. Put it up front and pretend it's part of the

    if not fields:
        raise Exception("Model %s has no fields. Check for missing base class." % m["name"])

    id_field = {'type': 'int32', 'name': 'id', 'options': {}, "id": "1", "accessor": fields[0]["accessor"]}

    fields = [id_field] + fields

    # Walk through the list of fields. They will be in depth-first search order from the base model forward. Each time
    # the model changes, offset the protobuf field numbers by 100.
    offset = 0
    last_accessor = fields[0]["accessor"]
    for field in fields:
        if (field["accessor"] != last_accessor):
            last_accessor = field["accessor"]
            offset += 100
        field_id = int(field["id"])
        if (field_id < 1) or (field_id >= 100):
            raise Exception("Only field numbers from 1 to 99 are permitted, field %s in model %s" % (field["name"], field["accessor"]))
        field["id"] = int(field["id"]) + offset

    # Check for duplicates
    fields_by_number = {}
    for field in fields:
        id = field["id"]
        dup = fields_by_number.get(id)
        if dup:
            raise Exception("Field %s has duplicate number %d with field %s in model %s" % (field["name"], id, dup["name"], field["accessor"]))
        fields_by_number[id] = field

    return fields

def xproto_base_rlinks(m, table):
    links = []

    for base in m['bases']:
        b = base['name']
        if b in table:
            base_rlinks = xproto_base_rlinks(table[b], table)

            model_rlinks = [x.copy() for x in table[b]['rlinks']]
            for link in model_rlinks:
                link["accessor"] = b

            links.extend(base_rlinks)
            links.extend(model_rlinks)

    return links

def xproto_rlinks(m, table):
    """ Return the reverse links for the xproto message `m`.

        If the link includes a reverse_id, then it will be used for the protobuf field id. Each level of inheritance
        will add an offset of 100 to the supplied reverse_id.

        If there is no reverse_id, then one will automatically be allocated started at id 1900. It is encouraged that
        all links include reverse_ids, so that field identifiers are deterministic across all protobuf messages.
    """

    model_rlinks = [x.copy() for x in m["rlinks"]]
    for link in model_rlinks:
        link["accessor"] = m["fqn"]

    links = xproto_base_rlinks(m, table) + model_rlinks

    links = [x for x in links if ("+" not in x["src_port"]) and ("+" not in x["dst_port"])]

    if links:
        last_accessor = links[0]["accessor"]
        offset = 0
        index = 1900
        for link in links:
            if (link["accessor"] != last_accessor):
                last_accessor = link["accessor"]
                offset += 100

            if link["reverse_id"]:
                # Statically numbered reverse links. Use the id that the developer supplied, adding the offset based on
                # inheritance depth.
                link["id"] = int(link["reverse_id"]) + offset
            else:
                # Automatically numbered reverse links. These will eventually go away.
                link["id"] = index
                index += 1

        # check for duplicates
        links_by_number={}
        for link in links:
            id = link["id"]
            dup=links_by_number.get(id)
            if dup:
                raise Exception("Field %s has duplicate number %d in model %s with reverse field %s" %
                                (link["src_port"], id, m["name"], dup["src_port"]))
            links_by_number[id] = link

    return links


def xproto_base_links(m, table):
    links = []

    for base in m['bases']:
        b = base['name']
        if b in table:
            base_links = xproto_base_links(table[b], table)

            model_links = table[b]['links']
            links.extend(base_links)
            links.extend(model_links)
    return links

def xproto_string_type(xptags):
    try:
        max_length = eval(xptags['max_length'])
    except:
        max_length = 1024

    if ('varchar' not in xptags):
        return 'string'
    else:
        return 'text'

def xproto_tuplify(nested_list_or_set):
    if not isinstance(nested_list_or_set, list) and not isinstance(nested_list_or_set, set):
        return nested_list_or_set
    else:
        return tuple([xproto_tuplify(i) for i in nested_list_or_set])

def xproto_field_graph_components(fields, model, tag='unique_with'):
    def find_components(graph):
        pending = set(graph.keys())
        components = []

        while pending:
            front = { pending.pop() }
            component = set()

            while front:
                node = front.pop()
                neighbours = graph[node]
                neighbours -= component  # These we have already visited
                front |= neighbours

                pending -= neighbours
                component |= neighbours
            
            components.append(component)

        return components

    field_graph = {}
    field_names = {f['name'] for f in fields}

    for f in fields:
        try:
            tagged_str = unquote(f['options'][tag])
            tagged_fields = tagged_str.split(',')

            for uf in tagged_fields:
                if uf not in field_names:
                    raise FieldNotFound('Field "%s" not found in model "%s", referenced from field "%s" by option "%s"' % (uf, model['name'], f['name'], tag))

                field_graph.setdefault(f['name'], set()).add(uf)
                field_graph.setdefault(uf, set()).add(f['name'])
        except KeyError:
            pass

    return find_components(field_graph)

def xproto_api_opts(field):
    options = []
    if 'max_length' in field['options'] and field['type']=='string':
        options.append('(val).maxLength = %s'%field['options']['max_length'])

    try:
        if field['options']['null'] == 'False':
            options.append('(val).nonNull = true')
    except KeyError:
        pass

    if 'link' in field and 'model' in field['options']:
        options.append('(foreignKey).modelName = "%s"'%field['options']['model'])
        if ("options" in field) and ("port" in field["options"]):
            options.append('(foreignKey).reverseFieldName = "%s"' % field['options']['port'])

    if options:
        options_str = '[' + ', '.join(options) + ']'
    else:
        options_str = ''

    return options_str

def xproto_type_to_swagger_type(f):
    try:
        content_type = f['options']['content_type']
        content_type = eval(content_type)
    except:
        content_type = None
        pass

    if 'choices' in f['options']:
        return 'string'
    elif content_type == 'date':
        return 'string'
    elif f['type'] == 'bool':
        return 'boolean'
    elif f['type'] == 'string':
        return 'string'
    elif f['type'] in ['int','uint32','int32'] or 'link' in f:
        return 'integer'
    elif f['type'] in ['double','float']:
        return 'string'

def xproto_field_to_swagger_enum(f):
    if 'choices' in f['options']:
        list = []

        for c in eval(xproto_unquote(f['options']['choices'])):
            list.append(c[0])

        return list
    else:
        return False

def xproto_is_true(x):
    # TODO: Audit xproto and make specification of trueness more uniform
    if (x==True) or (x=="True") or (x=='"True"'):
        return True
    return False