"""
RGD-PHYSICS :: COHERENCE LAW (CFT ENFORCER)
Ensures alignment with the Local Causal Vector Field u^mu(x).
Reference: Chronon Field Theory (2025).
"""
from ..core.interfaces import PhysicsLaw, Microsecond, PhysicsReport
from ..chronon.interfaces import ChrononProtocol
from ..core.exceptions import CausalityBreak

class Coherence(PhysicsLaw):
    """
    The Unitary Guardian.
    Checks probability conservation and vector alignment.
    """
    
    @property
    def name(self) -> str:
        return "coherence"

    def audit(self, t0: ChrononProtocol, t1: ChrononProtocol, dt: Microsecond) -> PhysicsReport:
        # 1. EXTRACT CAUSAL FIELD PHASE (The 'w' coordinate)
        # In RGD, 'w' represents the probability branch or phase.
        # A stable timeline implies continuity in w.
        w0 = t0.metric_coordinates[3]
        w1 = t1.metric_coordinates[3]
        
        # 2. CHECK CAUSAL FLOW DIRECTION
        # Simple check: Time (Anchor) must move forward.
        if t1.anchor < t0.anchor:
             raise CausalityBreak("TEMPORAL INVERSION: Cannot move backwards in Anchor Time.")

        # 3. UNITARY CHECK (Probability Conservation)
        # The sum of probabilities across the jump must be conserved.
        # If w changes drastically without a geometry bridge, we are leaking existence.
        phase_delta = abs(w1 - w0)
        
        # Threshold for unitary violation (Decoherence)
        DECOHERENCE_THRESHOLD = 0.5 
        
        if phase_delta > DECOHERENCE_THRESHOLD:
             return {
                 "status": "DECOHERENCE_WARNING",
                 "probability_leak": phase_delta,
                 "aligned": False
             }

        return {
            "status": "COHERENT",
            "field_alignment": 1.0, # Perfectly aligned
            "phase_delta": phase_delta
        }