from __future__ import annotations

from dataclasses import dataclass

from gibil.classes.predictors.usage_sequence_dataset import (
    UsageSequenceDatasetBuilder,
    UsageSequenceScaleConfig,
)


@dataclass(frozen=True)
class UsageHybridModelShape:
    """Describes the fixed-plus-token sequence model input contract."""

    past_scales: tuple[UsageSequenceScaleConfig, ...]
    past_fixed_features: tuple[str, ...]
    future_fixed_features: tuple[str, ...]
    future_steps: int
    quantiles: tuple[float, ...] = (0.10, 0.50, 0.90)

    @classmethod
    def from_dataset_builder(
        cls,
        builder: UsageSequenceDatasetBuilder,
    ) -> "UsageHybridModelShape":
        return cls(
            past_scales=builder.config.past_scales,
            past_fixed_features=tuple(builder.past_feature_names),
            future_fixed_features=tuple(builder.future_feature_names),
            future_steps=builder.future_steps,
        )

    @property
    def output_width(self) -> int:
        return self.future_steps * len(self.quantiles)