# Licensed to Elasticsearch B.V under one or more agreements.
# Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
# See the LICENSE file in the project root for more information

import warnings
from copy import deepcopy
from typing import Optional, Dict, List, Any

from eland.filter import BooleanFilter, NotNull, IsNull, IsIn


class Query:
    """
    Simple class to manage building Elasticsearch queries.
    """

    def __init__(self, query: Optional["Query"] = None):
        # type defs
        self._query: BooleanFilter
        self._aggs: Dict[str, Any]

        if query is None:
            self._query = BooleanFilter()
            self._aggs = {}
        else:
            # Deep copy the incoming query so we can change it
            self._query = deepcopy(query._query)
            self._aggs = deepcopy(query._aggs)

    def exists(self, field: str, must: bool = True) -> None:
        """
        Add exists query
        https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-exists-query.html
        """
        if must:
            if self._query.empty():
                self._query = NotNull(field)
            else:
                self._query = self._query & NotNull(field)
        else:
            if self._query.empty():
                self._query = IsNull(field)
            else:
                self._query = self._query & IsNull(field)

    def ids(self, items: List[Any], must: bool = True) -> None:
        """
        Add ids query
        https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-ids-query.html
        """
        if must:
            if self._query.empty():
                self._query = IsIn("ids", items)
            else:
                self._query = self._query & IsIn("ids", items)
        else:
            if self._query.empty():
                self._query = ~(IsIn("ids", items))
            else:
                self._query = self._query & ~(IsIn("ids", items))

    def terms(self, field: str, items: List[str], must: bool = True) -> None:
        """
        Add ids query
        https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-terms-query.html
        """
        if must:
            if self._query.empty():
                self._query = IsIn(field, items)
            else:
                self._query = self._query & IsIn(field, items)
        else:
            if self._query.empty():
                self._query = ~(IsIn(field, items))
            else:
                self._query = self._query & ~(IsIn(field, items))

    def terms_aggs(self, name: str, func: str, field: str, es_size: int) -> None:
        """
        Add terms agg e.g

        "aggs": {
            "name": {
                "terms": {
                    "field": "Airline",
                    "size": 10
                }
            }
        }
        """
        agg = {func: {"field": field, "size": es_size}}
        self._aggs[name] = agg

    def metric_aggs(self, name: str, func: str, field: str) -> None:
        """
        Add metric agg e.g

        "aggs": {
            "name": {
                "max": {
                    "field": "AvgTicketPrice"
                }
            }
        }
        """
        agg = {func: {"field": field}}
        self._aggs[name] = agg

    def hist_aggs(
        self, name: str, field: str, min_value: Any, max_value: Any, num_bins: int,
    ) -> None:
        """
        Add histogram agg e.g.
        "aggs": {
            "name": {
                "histogram": {
                    "field": "AvgTicketPrice"
                    "interval": (max_value - min_value)/bins
                    "offset": min_value
                }
            }
        }
        """

        interval = (max_value - min_value) / num_bins

        if interval != 0:
            agg = {
                "histogram": {"field": field, "interval": interval, "offset": min_value}
            }
            self._aggs[name] = agg

    def to_search_body(self) -> Dict[str, Any]:
        body = {}
        if self._aggs:
            body["aggs"] = self._aggs
        if not self._query.empty():
            body["query"] = self._query.build()
        return body

    def to_count_body(self) -> Optional[Dict[str, Any]]:
        if len(self._aggs) > 0:
            warnings.warn(f"Requesting count for agg query {self}")
        if self._query.empty():
            return None
        else:
            return {"query": self._query.build()}

    def update_boolean_filter(self, boolean_filter: BooleanFilter) -> None:
        if self._query.empty():
            self._query = boolean_filter
        else:
            self._query = self._query & boolean_filter

    def __repr__(self) -> str:
        return repr(self.to_search_body())
