"""Exercise model for the exercise library catalog.

Each exercise belongs to a workout day and includes form cues.
"""

from datetime import datetime
from typing import Optional

from sqlmodel import Field, SQLModel


class Exercise(SQLModel, table=True):
    """An exercise in the workout library.

    Attributes:
        id: Primary key, auto-incremented.
        name: Exercise name (e.g., "DB Chest Press (Floor)").
        muscle_group: Target muscle group (e.g., "Chest", "Shoulders").
        workout_day: Which day this exercise belongs to (Push/Pull/Lower/Full Body).
        sets: Default number of sets.
        tempo: Tempo notation (e.g., "3-1-2" = 3s eccentric, 1s pause, 2s concentric).
        form_cues: Detailed form instructions.
        created_at: Timestamp when the record was created.
    """

    __tablename__ = "exercises"

    id: Optional[int] = Field(default=None, primary_key=True)
    name: str = Field(index=True)
    muscle_group: str = Field(default="")
    workout_day: str = Field(index=True)
    sets: int = Field(default=3)
    tempo: str = Field(default="")
    form_cues: str = Field(default="")
    created_at: datetime = Field(default_factory=datetime.utcnow)