"""Service layer for exercise, warmup, and workout day data access.

All exercise-related database operations go through this service.
"""

from typing import Optional

import structlog
from sqlmodel import Session, select

from app.models.exercise import Exercise
from app.models.warmup import Warmup
from app.models.workout_day import WorkoutDay

logger = structlog.get_logger(__name__)


class ExerciseService:
    """Handles read operations for exercises, warmups, and workout days.

    Args:
        session: An active SQLModel Session.
    """

    def __init__(self, session: Session) -> None:
        self._session = session

    def list_exercises(
        self,
        workout_day: Optional[str] = None,
        muscle_group: Optional[str] = None,
    ) -> list[Exercise]:
        """List exercises with optional filtering.

        Args:
            workout_day: Filter by workout day name (e.g., "Push").
            muscle_group: Filter by muscle group (e.g., "Chest").

        Returns:
            List of matching Exercise records.
        """
        statement = select(Exercise)
        if workout_day:
            statement = statement.where(Exercise.workout_day == workout_day)
        if muscle_group:
            statement = statement.where(Exercise.muscle_group == muscle_group)
        return list(self._session.exec(statement).all())

    def get_exercise_by_id(self, exercise_id: int) -> Optional[Exercise]:
        """Retrieve an exercise by primary key.

        Args:
            exercise_id: The exercise ID.

        Returns:
            The Exercise record, or None if not found.
        """
        return self._session.get(Exercise, exercise_id)

    def get_exercise_by_name(self, name: str) -> Optional[Exercise]:
        """Retrieve an exercise by exact name match.

        Args:
            name: The exercise name to look up.

        Returns:
            The Exercise record, or None if not found.
        """
        statement = select(Exercise).where(Exercise.name == name)
        return self._session.exec(statement).first()

    def list_warmups(self) -> list[Warmup]:
        """List all warmups in display order.

        Returns:
            List of Warmup records sorted by sort_order.
        """
        statement = select(Warmup).order_by(Warmup.sort_order)
        return list(self._session.exec(statement).all())

    def list_workout_days(self) -> list[WorkoutDay]:
        """List all workout days in order.

        Returns:
            List of WorkoutDay records sorted by day_number.
        """
        statement = select(WorkoutDay).order_by(WorkoutDay.day_number)
        return list(self._session.exec(statement).all())