"""
Deep Squat rubric scorer — pure function, no model calls.

FMS Deep Squat Criteria:
- Score 3: femur below horizontal, torso parallel to tibia, knees tracking
           over feet, dowel over feet, heels flat.
- Score 2: criteria met only with heels elevated.
- Score 1: criteria unmet even with heels elevated.
- Score 0: PAIN — never auto-scored by this function.

Input:  BiomechFeatures for deep_squat
Output: ScoreResult(score, rationale, confidence, needs_human)
"""
from __future__ import annotations

import math

from formscout.types import BiomechFeatures, ScoreResult
from formscout import config


def score_deep_squat(features: BiomechFeatures) -> ScoreResult:
    """
    Pure rubric scorer for deep squat.
    Returns ScoreResult with score 1-3 based on biomechanical measurements.
    Never assigns score 0 (pain) — that requires needs_human=True from JudgeAgent.
    """
    angles = features.angles
    alignments = features.alignments

    # Check if we have enough data to score
    has_femur = any(
        k in angles for k in ("left_femur_from_horizontal_deg", "right_femur_from_horizontal_deg")
    )
    has_torso_tibia = "torso_tibia_angle_deg" in angles

    if not has_femur:
        return ScoreResult(
            score=1,
            rationale="Insufficient data: femur angle not measurable",
            confidence=0.3,
            needs_human=False,
            notes="missing femur measurements — defaulting to lowest passing score",
        )

    # Evaluate criteria
    # Femur below horizontal: femur angle from horizontal > 90° means above horizontal
    # In our measurement: angle is from horizontal, so < 90 means below horizontal
    femur_angles = []
    if "left_femur_from_horizontal_deg" in angles:
        femur_angles.append(angles["left_femur_from_horizontal_deg"])
    if "right_femur_from_horizontal_deg" in angles:
        femur_angles.append(angles["right_femur_from_horizontal_deg"])

    # Femur below horizontal means the thigh slopes down steeply (angle > ~60° from horizontal in image coords)
    femur_below_horizontal = any(a > 60.0 for a in femur_angles) if femur_angles else False

    # Torso parallel to tibia
    torso_parallel_tibia = (
        angles.get("torso_tibia_angle_deg", 999) <= config.DEEP_SQUAT_TORSO_TIBIA_MAX_DEG
    )

    # Knee tracking
    knees_tracking = alignments.get("knees_tracking_over_feet", False)

    # Dowel alignment
    dowel_over_feet = alignments.get("dowel_over_feet", False)

    # Heels
    heels_elevated = alignments.get("heels_elevated", False)

    # Scoring logic
    all_criteria = femur_below_horizontal and torso_parallel_tibia and knees_tracking and dowel_over_feet

    rationale_parts: list[str] = []

    if all_criteria and not heels_elevated:
        score = 3
        rationale_parts.append("All criteria met with heels flat")
    elif all_criteria and heels_elevated:
        score = 2
        rationale_parts.append("Criteria met only with heels elevated")
    else:
        # Check what failed
        if not femur_below_horizontal:
            rationale_parts.append("femur not below horizontal")
        if not torso_parallel_tibia:
            rationale_parts.append(
                f"torso-tibia angle {angles.get('torso_tibia_angle_deg', '?')}° "
                f"exceeds {config.DEEP_SQUAT_TORSO_TIBIA_MAX_DEG}° threshold"
            )
        if not knees_tracking:
            rationale_parts.append("knees not tracking over feet")
        if not dowel_over_feet:
            rationale_parts.append("dowel not aligned over feet")

        if heels_elevated:
            score = 1
            rationale_parts.append("criteria unmet even with heels elevated")
        else:
            # They might score 2 with heel elevation — but without it, still 1
            score = 1
            rationale_parts.append("criteria unmet with heels flat")

    confidence = features.confidence * (0.9 if has_torso_tibia else 0.6)

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