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# to you 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
#
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# software distributed under the License is distributed on an
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# KIND, either express or implied.  See the License for the
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"""a collection of model-related helper classes and functions"""
import json
import logging
import re
from datetime import datetime, timedelta
from json.decoder import JSONDecodeError
from typing import Any, Dict, List, Optional, Set, Union

import humanize
import pandas as pd
import pytz
import sqlalchemy as sa
import yaml
from flask import escape, g, Markup
from flask_appbuilder.models.decorators import renders
from flask_appbuilder.models.mixins import AuditMixin
from flask_appbuilder.security.sqla.models import User
from sqlalchemy import and_, or_, UniqueConstraint
from sqlalchemy.ext.declarative import declared_attr
from sqlalchemy.orm import Mapper, Session
from sqlalchemy.orm.exc import MultipleResultsFound

from superset.utils.core import QueryStatus

logger = logging.getLogger(__name__)


def json_to_dict(json_str: str) -> Dict[Any, Any]:
    if json_str:
        val = re.sub(",[ \t\r\n]+}", "}", json_str)
        val = re.sub(",[ \t\r\n]+\\]", "]", val)
        return json.loads(val)

    return {}


class ImportMixin:
    export_parent: Optional[str] = None
    # The name of the attribute
    # with the SQL Alchemy back reference

    export_children: List[str] = []
    # List of (str) names of attributes
    # with the SQL Alchemy forward references

    export_fields: List[str] = []
    # The names of the attributes
    # that are available for import and export

    __mapper__: Mapper

    @classmethod
    def _parent_foreign_key_mappings(cls) -> Dict[str, str]:
        """Get a mapping of foreign name to the local name of foreign keys"""
        parent_rel = cls.__mapper__.relationships.get(cls.export_parent)
        if parent_rel:
            return {l.name: r.name for (l, r) in parent_rel.local_remote_pairs}
        return {}

    @classmethod
    def _unique_constrains(cls) -> List[Set[str]]:
        """Get all (single column and multi column) unique constraints"""
        unique = [
            {c.name for c in u.columns}
            for u in cls.__table_args__  # type: ignore
            if isinstance(u, UniqueConstraint)
        ]
        unique.extend(
            {c.name} for c in cls.__table__.columns if c.unique  # type: ignore
        )
        return unique

    @classmethod
    def parent_foreign_key_mappings(cls) -> Dict[str, str]:
        """Get a mapping of foreign name to the local name of foreign keys"""
        parent_rel = cls.__mapper__.relationships.get(cls.export_parent)
        if parent_rel:
            return {l.name: r.name for (l, r) in parent_rel.local_remote_pairs}
        return {}

    @classmethod
    def export_schema(
        cls, recursive: bool = True, include_parent_ref: bool = False
    ) -> Dict[str, Any]:
        """Export schema as a dictionary"""
        parent_excludes = set()
        if not include_parent_ref:
            parent_ref = cls.__mapper__.relationships.get(cls.export_parent)
            if parent_ref:
                parent_excludes = {column.name for column in parent_ref.local_columns}

        def formatter(column: sa.Column) -> str:
            return (
                "{0} Default ({1})".format(str(column.type), column.default.arg)
                if column.default
                else str(column.type)
            )

        schema: Dict[str, Any] = {
            column.name: formatter(column)
            for column in cls.__table__.columns  # type: ignore
            if (column.name in cls.export_fields and column.name not in parent_excludes)
        }
        if recursive:
            for column in cls.export_children:
                child_class = cls.__mapper__.relationships[column].argument.class_
                schema[column] = [
                    child_class.export_schema(
                        recursive=recursive, include_parent_ref=include_parent_ref
                    )
                ]
        return schema

    @classmethod
    def import_from_dict(
        # pylint: disable=too-many-arguments,too-many-branches,too-many-locals
        cls,
        session: Session,
        dict_rep: Dict[Any, Any],
        parent: Optional[Any] = None,
        recursive: bool = True,
        sync: Optional[List[str]] = None,
    ) -> Any:
        """Import obj from a dictionary"""
        if sync is None:
            sync = []
        parent_refs = cls.parent_foreign_key_mappings()
        export_fields = set(cls.export_fields) | set(parent_refs.keys())
        new_children = {c: dict_rep[c] for c in cls.export_children if c in dict_rep}
        unique_constrains = cls._unique_constrains()

        filters = []  # Using these filters to check if obj already exists

        # Remove fields that should not get imported
        for k in list(dict_rep):
            if k not in export_fields:
                del dict_rep[k]

        if not parent:
            if cls.export_parent:
                for prnt in parent_refs.keys():
                    if prnt not in dict_rep:
                        raise RuntimeError(
                            "{0}: Missing field {1}".format(cls.__name__, prnt)
                        )
        else:
            # Set foreign keys to parent obj
            for k, v in parent_refs.items():
                dict_rep[k] = getattr(parent, v)

        # Add filter for parent obj
        filters.extend([getattr(cls, k) == dict_rep.get(k) for k in parent_refs.keys()])

        # Add filter for unique constraints
        ucs = [
            and_(
                *[
                    getattr(cls, k) == dict_rep.get(k)
                    for k in cs
                    if dict_rep.get(k) is not None
                ]
            )
            for cs in unique_constrains
        ]
        filters.append(or_(*ucs))

        # Check if object already exists in DB, break if more than one is found
        try:
            obj_query = session.query(cls).filter(and_(*filters))
            obj = obj_query.one_or_none()
        except MultipleResultsFound as ex:
            logger.error(
                "Error importing %s \n %s \n %s",
                cls.__name__,
                str(obj_query),
                yaml.safe_dump(dict_rep),
            )
            raise ex

        if not obj:
            is_new_obj = True
            # Create new DB object
            obj = cls(**dict_rep)  # type: ignore
            logger.info("Importing new %s %s", obj.__tablename__, str(obj))
            if cls.export_parent and parent:
                setattr(obj, cls.export_parent, parent)
            session.add(obj)
        else:
            is_new_obj = False
            logger.info("Updating %s %s", obj.__tablename__, str(obj))
            # Update columns
            for k, v in dict_rep.items():
                setattr(obj, k, v)

        # Recursively create children
        if recursive:
            for child in cls.export_children:
                child_class = cls.__mapper__.relationships[child].argument.class_
                added = []
                for c_obj in new_children.get(child, []):
                    added.append(
                        child_class.import_from_dict(
                            session=session, dict_rep=c_obj, parent=obj, sync=sync
                        )
                    )
                # If children should get synced, delete the ones that did not
                # get updated.
                if child in sync and not is_new_obj:
                    back_refs = child_class.parent_foreign_key_mappings()
                    delete_filters = [
                        getattr(child_class, k) == getattr(obj, back_refs.get(k))
                        for k in back_refs.keys()
                    ]
                    to_delete = set(
                        session.query(child_class).filter(and_(*delete_filters))
                    ).difference(set(added))
                    for o in to_delete:
                        logger.info("Deleting %s %s", child, str(obj))
                        session.delete(o)

        return obj

    def export_to_dict(
        self,
        recursive: bool = True,
        include_parent_ref: bool = False,
        include_defaults: bool = False,
    ) -> Dict[Any, Any]:
        """Export obj to dictionary"""
        cls = self.__class__
        parent_excludes = set()
        if recursive and not include_parent_ref:
            parent_ref = cls.__mapper__.relationships.get(cls.export_parent)
            if parent_ref:
                parent_excludes = {c.name for c in parent_ref.local_columns}
        dict_rep = {
            c.name: getattr(self, c.name)
            for c in cls.__table__.columns  # type: ignore
            if (
                c.name in self.export_fields
                and c.name not in parent_excludes
                and (
                    include_defaults
                    or (
                        getattr(self, c.name) is not None
                        and (not c.default or getattr(self, c.name) != c.default.arg)
                    )
                )
            )
        }
        if recursive:
            for cld in self.export_children:
                # sorting to make lists of children stable
                dict_rep[cld] = sorted(
                    [
                        child.export_to_dict(
                            recursive=recursive,
                            include_parent_ref=include_parent_ref,
                            include_defaults=include_defaults,
                        )
                        for child in getattr(self, cld)
                    ],
                    key=lambda k: sorted(str(k.items())),
                )

        return dict_rep

    def override(self, obj: Any) -> None:
        """Overrides the plain fields of the dashboard."""
        for field in obj.__class__.export_fields:
            setattr(self, field, getattr(obj, field))

    def copy(self) -> Any:
        """Creates a copy of the dashboard without relationships."""
        new_obj = self.__class__()
        new_obj.override(self)
        return new_obj

    def alter_params(self, **kwargs: Any) -> None:
        params = self.params_dict
        params.update(kwargs)
        self.params = json.dumps(params)

    def remove_params(self, param_to_remove: str) -> None:
        params = self.params_dict
        params.pop(param_to_remove, None)
        self.params = json.dumps(params)

    def reset_ownership(self) -> None:
        """ object will belong to the user the current user """
        # make sure the object doesn't have relations to a user
        # it will be filled by appbuilder on save
        self.created_by = None
        self.changed_by = None
        # flask global context might not exist (in cli or tests for example)
        self.owners = []
        if g and hasattr(g, "user"):
            self.owners = [g.user]

    @property
    def params_dict(self) -> Dict[Any, Any]:
        return json_to_dict(self.params)

    @property
    def template_params_dict(self) -> Dict[Any, Any]:
        return json_to_dict(self.template_params)  # type: ignore


def _user_link(user: User) -> Union[Markup, str]:
    if not user:
        return ""
    url = "/superset/profile/{}/".format(user.username)
    return Markup('<a href="{}">{}</a>'.format(url, escape(user) or ""))


class AuditMixinNullable(AuditMixin):
    """Altering the AuditMixin to use nullable fields

    Allows creating objects programmatically outside of CRUD
    """

    created_on = sa.Column(sa.DateTime, default=datetime.now, nullable=True)
    changed_on = sa.Column(
        sa.DateTime, default=datetime.now, onupdate=datetime.now, nullable=True
    )

    @declared_attr
    def created_by_fk(self) -> sa.Column:
        return sa.Column(
            sa.Integer,
            sa.ForeignKey("ab_user.id"),
            default=self.get_user_id,
            nullable=True,
        )

    @declared_attr
    def changed_by_fk(self) -> sa.Column:
        return sa.Column(
            sa.Integer,
            sa.ForeignKey("ab_user.id"),
            default=self.get_user_id,
            onupdate=self.get_user_id,
            nullable=True,
        )

    @property
    def changed_by_name(self) -> str:
        if self.changed_by:
            return escape("{}".format(self.changed_by))
        return ""

    @renders("created_by")
    def creator(self) -> Union[Markup, str]:
        return _user_link(self.created_by)

    @property
    def changed_by_(self) -> Union[Markup, str]:
        return _user_link(self.changed_by)

    @renders("changed_on")
    def changed_on_(self) -> Markup:
        return Markup(f'<span class="no-wrap">{self.changed_on}</span>')

    @renders("changed_on")
    def changed_on_delta_humanized(self) -> str:
        return self.changed_on_humanized

    @renders("changed_on")
    def changed_on_utc(self) -> str:
        # Convert naive datetime to UTC
        return self.changed_on.astimezone(pytz.utc).strftime("%Y-%m-%dT%H:%M:%S.%f%z")

    @property
    def changed_on_humanized(self) -> str:
        return humanize.naturaltime(datetime.now() - self.changed_on)

    @renders("changed_on")
    def modified(self) -> Markup:
        return Markup(f'<span class="no-wrap">{self.changed_on_humanized}</span>')


class QueryResult:  # pylint: disable=too-few-public-methods

    """Object returned by the query interface"""

    def __init__(  # pylint: disable=too-many-arguments
        self,
        df: pd.DataFrame,
        query: str,
        duration: timedelta,
        status: str = QueryStatus.SUCCESS,
        error_message: Optional[str] = None,
        errors: Optional[List[Dict[str, Any]]] = None,
    ) -> None:
        self.df = df
        self.query = query
        self.duration = duration
        self.status = status
        self.error_message = error_message
        self.errors = errors or []


class ExtraJSONMixin:
    """Mixin to add an `extra` column (JSON) and utility methods"""

    extra_json = sa.Column(sa.Text, default="{}")

    @property
    def extra(self) -> Dict[str, Any]:
        try:
            return json.loads(self.extra_json)
        except (TypeError, JSONDecodeError) as exc:
            logger.error(
                "Unable to load an extra json: %r. Leaving empty.", exc, exc_info=True
            )
            return {}

    def set_extra_json(self, extras: Dict[str, Any]) -> None:
        self.extra_json = json.dumps(extras)

    def set_extra_json_key(self, key: str, value: Any) -> None:
        extra = self.extra
        extra[key] = value
        self.extra_json = json.dumps(extra)