from collections.abc import Mapping
from datetime import date
from typing import Optional

from sqlalchemy import text

from app.dao import BaseDAO
from app.db_compat import inserted_primary_key


class ChildDAO(BaseDAO):
    def _create_relation(self, user_id: int, child_id: int) -> None:
        self.db.execute(
            text(
                """
                INSERT INTO parent_child_relations (user_id, child_id, relation_type, is_primary, status)
                VALUES (:user_id, :child_id, 9, 0, 1)
                """
            ),
            {"user_id": user_id, "child_id": child_id},
        )

    def create(
        self,
        user_id: int,
        child_name: str,
        child_gender: int = 2,
        child_birthday: Optional[date] = None,
    ) -> int:
        result = self.db.execute(
            text(
                """
                INSERT INTO children (child_name, child_gender, child_birthday, status)
                VALUES (:child_name, :child_gender, :child_birthday, 1)
                """
            ),
            {"child_name": child_name, "child_gender": child_gender, "child_birthday": child_birthday},
        )
        child_id = inserted_primary_key(result)
        self._create_relation(user_id, child_id)
        self.commit()
        return child_id

    def get_by_id(self, child_id: int) -> Optional[Mapping]:
        return (
            self.db.execute(
                text("SELECT * FROM children WHERE child_id = :child_id"),
                {"child_id": child_id},
            )
            .mappings()
            .first()
        )

    def list_by_parent(self, user_id: int, limit: int = 20, cursor: int = None) -> list[Mapping]:
        params = {"user_id": user_id, "limit": limit + 1}
        where = "pcr.user_id = :user_id AND pcr.status = 1 AND c.status = 1"
        if cursor is not None:
            where += " AND c.child_id < :cursor"
            params["cursor"] = cursor

        rows = (
            self.db.execute(
                text(
                    f"""
                    SELECT c.*
                    FROM children AS c
                    JOIN parent_child_relations AS pcr
                      ON pcr.child_id = c.child_id
                    WHERE {where}
                    ORDER BY c.child_id DESC
                    LIMIT :limit
                    """
                ),
                params,
            )
            .mappings()
            .all()
        )
        return rows

    def update(
        self,
        child_id: int,
        child_name: Optional[str] = None,
        child_gender: Optional[int] = None,
        child_birthday: Optional[date] = None,
    ) -> None:
        self.db.execute(
            text(
                """
                UPDATE children
                SET child_name = COALESCE(:child_name, child_name),
                    child_gender = COALESCE(:child_gender, child_gender),
                    child_birthday = COALESCE(:child_birthday, child_birthday)
                WHERE child_id = :child_id
                """
            ),
            {"child_id": child_id, "child_name": child_name, "child_gender": child_gender, "child_birthday": child_birthday},
        )
        self.commit()

    def has_access(self, child_id: int, user_id: int) -> bool:
        return (
            self.db.execute(
                text(
                    """
                    SELECT 1
                    FROM children AS c
                    JOIN parent_child_relations AS pcr
                      ON pcr.child_id = c.child_id
                    WHERE c.child_id = :child_id
                      AND pcr.user_id = :user_id
                      AND c.status = 1
                      AND pcr.status = 1
                    """
                ),
                {"child_id": child_id, "user_id": user_id},
            ).scalar_one_or_none()
            is not None
        )