from dataclasses import dataclass
from typing import Tuple

from serato_doctor.models.reference import TrackReference
from serato_doctor.models.track import DiskTrack


@dataclass(frozen=True)
class MatchEvidence:
    """One explainable scoring decision for a candidate track."""

    field: str
    matched: bool
    points: int
    max_points: int
    explanation: str


@dataclass(frozen=True)
class TrackMatch:
    """A ranked candidate backed by explicit, inspectable evidence."""

    reference: TrackReference
    track: DiskTrack
    evidence: Tuple[MatchEvidence, ...]

    @property
    def score(self) -> int:
        return sum(item.points for item in self.evidence)

    @property
    def max_score(self) -> int:
        return sum(item.max_points for item in self.evidence)

    @property
    def score_percent(self) -> float:
        if not self.max_score:
            return 0.0
        return round(self.score / self.max_score * 100, 1)