"""Fresh evidence checks that preserve the original zero and installation."""

import numpy as np

from .joint_resume import reference_pose_failures
from .motion_execution import feedback_tolerances


LEGACY_REVISIT_POLICY = "staged_revisit_v1"
REVISIT_POLICY = "staged_revisit_v2"


def revisit_feedback_limits(profile, verification=REVISIT_POLICY):
    """Separate within-hold stability from between-visit repeatability.

    O30's operator-reported repeatability is 10 native SDK units. This does
    not change motion settling, image precision, or another hand's limits.
    Historical records retain their original feedback acceptance semantics.
    """
    if verification not in {LEGACY_REVISIT_POLICY, REVISIT_POLICY}:
        raise ValueError("staged_revisit_policy_unknown")
    stability = feedback_tolerances(profile.command.unit).stability
    repeatability = 2*stability
    if verification == REVISIT_POLICY and profile.key.model.upper() == "O30" and profile.command.unit == "u8":
        repeatability = 10.0
    return dict(unit=profile.command.unit, within_hold_range=stability,
        between_visit_difference=repeatability)


def verify_revisit(profile, previous, current, *, verification=LEGACY_REVISIT_POLICY,
                   feedback_limits=None):
    limits = revisit_feedback_limits(profile, verification)
    if ((verification == REVISIT_POLICY and feedback_limits != limits)
            or (verification == LEGACY_REVISIT_POLICY and feedback_limits is not None)):
        raise ValueError("staged_revisit_feedback_policy_changed")
    failures = reference_pose_failures(previous, current)
    identities = lambda ref: {(b.view, b.tag_role, b.motion_evidence_id) for b in ref.branch_references}
    if not previous.branch_references or identities(previous) != identities(current):
        failures.append("installation_evidence_changed")
    for view in {s.view for s in previous.samples}:
        old = [s for s in previous.samples if s.view == view]
        new = [s for s in current.samples if s.view == view]
        if not new or min(s.image_stamp_ns for s in new) <= max(s.image_stamp_ns for s in old):
            failures.append("fresh_images_missing")
            continue
        if not profile.vision_motion:
            before, after = np.asarray([s.feedback for s in old]), np.asarray([s.feedback for s in new])
            if (before.shape != (len(old), profile.command.command_count)
                    or after.shape != (len(new), profile.command.command_count)
                    or not np.all(np.isfinite(before)) or not np.all(np.isfinite(after))):
                failures.append("feedback_missing")
            else:
                if (np.any(np.ptp(after, axis=0) > limits["within_hold_range"])
                        or np.any(np.abs(after-np.median(before, axis=0)) > limits["between_visit_difference"])):
                    failures.append("held_feedback_changed")
    if failures:
        raise ValueError(f"revisit_reference_changed:{previous.joint}:{','.join(failures)}")


def revisit_record(profile, previous, current, cycle):
    limits = revisit_feedback_limits(profile)
    verify_revisit(profile, previous, current, verification=REVISIT_POLICY, feedback_limits=limits)
    return {"kind": "joint_zero_motion_reference_verified", "verification": REVISIT_POLICY,
        "feedback_limits": limits,
        "joint": previous.joint, "task_name": previous.task_key, "cycle": cycle,
        "current_reference": current.as_record(), "preserved_reference": previous.as_record()}