"""
Common database requests.
"""

import asyncio
import re
from datetime import timedelta, datetime, time
from typing import TypeVar

from fastapi import HTTPException
from pydantic import BaseModel

from app.api.common.schemas import SearchRequest
from app.core.config import settings

T = TypeVar("T", bound=BaseModel)

collection_map = {
    "JobModel": "jobs",
}


async def get_obj_by_id(
    model: T,
    obj_id: str | None,
    additional_filter: dict | None = None,
    projection: dict | None = None,
    exception: bool = True,
) -> T | None:
    """
    Get an object by ID.
    """
    filter_ = {"id": obj_id} if obj_id else {}
    if additional_filter:
        filter_.update(additional_filter)
    obj = await settings.DB_CLIENT[collection_map[model.__name__]].find_one(filter_, projection)
    if obj is None:
        if exception:
            raise HTTPException(status_code=404, detail="Object not found.")
        else:
            return None
    return model.from_mongo(obj)


async def get_all_objs(
    model: T,
    page_size: int,
    page_index: int,
    sort: tuple[str, int] = ("id", -1),
    additional_filter: dict | None = None,
) -> tuple[list[T], int]:
    """
    Get all objects.
    """
    filter_ = additional_filter if additional_filter else {}
    skip = page_index * page_size
    objs, total_count = await asyncio.gather(
        settings.DB_CLIENT[collection_map[model.__name__]]
        .find(filter_)
        .sort(*sort)
        .skip(skip)
        .limit(page_size)
        .to_list(page_size),
        settings.DB_CLIENT[collection_map[model.__name__]].count_documents(filter_),
    )
    return [model.from_mongo(obj) for obj in objs], total_count


async def delete_obj(model: T, obj_id: str) -> None:
    """
    Delete an object.
    """
    obj = await settings.DB_CLIENT[collection_map[model.__name__]].find_one({"id": obj_id})
    if obj is None:
        raise HTTPException(status_code=404, detail="Object not found.")
    await settings.DB_CLIENT[collection_map[model.__name__]].delete_one({"id": obj_id})


async def search_objs(
    model: T,
    data: SearchRequest,
    additional_filter: dict | None = None,
    projection: dict | None = None,
) -> tuple[list[T], int]:
    """
    Search for objects in a specified collection based on search filters.
    """
    filters = []
    date_filters = {}

    for search_filter in data.filter:
        if isinstance(search_filter.value, str):
            date_match = re.fullmatch(r"^(\d{4}-\d{2}-\d{2});([+-]\d{1,2})$", search_filter.value)

            if date_match:
                if search_filter.name not in date_filters:
                    date_filters[search_filter.name] = []

                date_filters[search_filter.name].append(
                    {
                        "date": datetime.strptime(date_match.group(1), "%Y-%m-%d"),
                        "timezone_offset": int(date_match.group(2)),
                    }
                )
            else:
                filters.append(
                    {
                        search_filter.name: {
                            "$regex": f"^{re.escape(search_filter.value)}",
                            "$options": "i",
                        }
                    }
                )
        else:
            filters.append({search_filter.name: search_filter.value})

    for field_name, dates in date_filters.items():
        if len(dates) == 1:
            date_info = dates[0]
            user_local_day_start = date_info["date"]
            user_local_day_end = user_local_day_start + timedelta(days=1)
            filters.append(
                {
                    field_name: {
                        "$gte": (
                            user_local_day_start - timedelta(hours=date_info["timezone_offset"])
                        ).isoformat(),
                        "$lt": (
                            user_local_day_end - timedelta(hours=date_info["timezone_offset"])
                        ).isoformat(),
                    }
                }
            )
        elif len(dates) == 2:
            start_date = min(dates, key=lambda x: x["date"])
            end_date = max(dates, key=lambda x: x["date"])

            start_datetime = start_date["date"] - timedelta(hours=start_date["timezone_offset"])
            end_datetime = (
                end_date["date"] + timedelta(days=1) - timedelta(hours=end_date["timezone_offset"])
            )

            filters.append(
                {
                    field_name: {
                        "$gte": start_datetime.isoformat(),
                        "$lt": end_datetime.isoformat(),
                    }
                }
            )
        elif len(dates) > 2:
            dates_sorted = sorted(dates, key=lambda x: x["date"])
            start_date = dates_sorted[0]
            end_date = dates_sorted[-1]

            start_datetime = start_date["date"] - timedelta(hours=start_date["timezone_offset"])
            end_datetime = (
                end_date["date"] + timedelta(days=1) - timedelta(hours=end_date["timezone_offset"])
            )

            filters.append(
                {
                    field_name: {
                        "$gte": start_datetime.isoformat(),
                        "$lt": end_datetime.isoformat(),
                    }
                }
            )

    if additional_filter:
        filters.append(additional_filter)
    regex_filter = {"$and": filters} if filters else {}
    objects, total_count = await asyncio.gather(
        settings.DB_CLIENT[collection_map[model.__name__]]
        .find(regex_filter, projection)
        .sort("id", -1)
        .skip(data.pageSize * data.pageIndex)
        .limit(data.pageSize)
        .to_list(length=data.pageSize),
        settings.DB_CLIENT[collection_map[model.__name__]].count_documents(regex_filter),
    )
    return [model.from_mongo(obj) for obj in objects], total_count