"""
Hurdle Step rubric scorer — pure function, no model calls.

FMS Hurdle Step Criteria (bilateral — score each side, report lower):
- Score 3: hips/knees/ankles aligned, minimal trunk movement, dowel/posture stable,
           no contact with hurdle.
- Score 2: movement completed with compensation (trunk lean, loss of alignment).
- Score 1: contact with hurdle, loss of balance, or inability to maintain alignment.
- Score 0: PAIN — never auto-scored.
"""
from __future__ import annotations

from formscout.types import BiomechFeatures, ScoreResult


def score_hurdle_step(features: BiomechFeatures) -> ScoreResult:
    """Pure rubric scorer for hurdle step."""
    angles = features.angles
    alignments = features.alignments

    has_hip_flex = "step_hip_flexion_deg" in angles
    if not has_hip_flex:
        return ScoreResult(
            score=1, rationale="Insufficient data: hip flexion not measurable",
            confidence=0.3, notes="missing key measurements",
        )

    trunk_stable = alignments.get("trunk_stable", False)
    stance_extended = alignments.get("stance_knee_extended", False)
    hip_flex = angles.get("step_hip_flexion_deg", 0)

    rationale_parts = []

    # Score 3: good hip flexion, trunk stable, stance solid
    if hip_flex > 90 and trunk_stable and stance_extended:
        score = 3
        rationale_parts.append("Hip flexion adequate, trunk stable, stance knee extended")
    elif hip_flex > 70 or (trunk_stable and stance_extended):
        score = 2
        if not trunk_stable:
            rationale_parts.append("trunk lean detected")
        if not stance_extended:
            rationale_parts.append("stance knee flexion")
        if hip_flex <= 90:
            rationale_parts.append(f"hip flexion {hip_flex:.0f}° (borderline)")
        rationale_parts.insert(0, "Movement completed with compensation")
    else:
        score = 1
        rationale_parts.append("Unable to maintain alignment")
        if not trunk_stable:
            rationale_parts.append("significant trunk lean")
        if not stance_extended:
            rationale_parts.append("stance knee collapse")

    confidence = features.confidence * 0.85

    return ScoreResult(
        score=score, rationale="; ".join(rationale_parts),
        confidence=confidence, notes="",
    )