# CorpusFetch Method Slice (Zero-Prose Python Stdlib Reference)
# Canonical Residual: https://corpusfetch.com/c/what-invariants-prevent-ambient-capability-inference-from-being-more-accurate-than-declared-capability.md
# Remnant Warrant:    https://corpusfetch.com/c/what-invariants-prevent-ambient-capability-inference-from-being-more-accurate-than-declared-capability.warrant.json
# Markdown SHA-256:   10d72cfdf6fbd7ca3a5b6829a1154ac89de177e7ace69dbded274b5f7e8bb796
# Code AST SHA-256:   a12490a90e1df869a3e2dbb0b8084e65652203a3fb6133954579ba5452031633
# Verified Classes:   CapabilityReconciliationVerdict, Capability, ReconciliationPolicy, ReconciliationManifest, AmbientCapabilityReconciliationGuard
# Defensive Guards:   0 fail-closed invariants (zero external deps)

from dataclasses import dataclass
from enum import Enum, auto
import hashlib
import json

class CapabilityReconciliationVerdict(Enum):
    NO_DECLARATION = auto()
    DECLARATION_ONLY = auto()
    INFERENCE_VERIFIED = auto()
    BOTH_TRACKED_WITH_UNCERTAINTY = auto()

@dataclass(frozen=True)
class Capability:
    capability_id: str
    declared_present: bool
    declaration_verified: bool
    inferred_present: bool
    inference_evidence_count: int
    inference_cross_context: bool
    divergence_class: str  # "NONE" | "MINOR" | "MAJOR" | "UNRESOLVABLE"

@dataclass(frozen=True)
class ReconciliationPolicy:
    min_cross_context_inferences: int
    require_verified_declaration: bool

@dataclass(frozen=True)
class ReconciliationManifest:
    verdict: CapabilityReconciliationVerdict
    reconciled_value: bool | None
    directive: str
    manifest_digest: str

class AmbientCapabilityReconciliationGuard:
    @staticmethod
    def _hash(data: str) -> str:
        return hashlib.sha256(data.encode("utf-8")).hexdigest()

    @classmethod
    def evaluate_capability(
        cls, cap: Capability, policy: ReconciliationPolicy
    ) -> ReconciliationManifest:
        
        # Gate 1: No declaration
        if not cap.declared_present and not cap.declaration_verified:
            digest = cls._hash(json.dumps({
                "capability": cap.capability_id,
                "declared": "FALSE"
            }, sort_keys=True))
            return ReconciliationManifest(
                verdict=CapabilityReconciliationVerdict.NO_DECLARATION,
                reconciled_value=cap.inferred_present if cap.inference_cross_context else None,
                directive=f"PROCEED: Capability {cap.capability_id} has no declaration, use inference with uncertainty.",
                manifest_digest=digest
            )

        # Gate 2: No inference
        if not cap.inferred_present and cap.inference_evidence_count == 0:
            digest = cls._hash(json.dumps({
                "capability": cap.capability_id,
                "declaration": "ONLY"
            }, sort_keys=True))
            return ReconciliationManifest(
                verdict=CapabilityReconciliationVerdict.DECLARATION_ONLY,
                reconciled_value=cap.declared_present,
                directive=f"PROCEED: Capability {cap.capability_id} uses declaration only.",
                manifest_digest=digest
            )

        # Gate 3: No divergence
        if cap.divergence_class == "NONE":
            digest = cls._hash(json.dumps({
                "capability": cap.capability_id,
                "declared": cap.declared_present,
                "inferred": cap.inferred_present,
                "divergence": "NONE"
            }, sort_keys=True))
            return ReconciliationManifest(
                verdict=CapabilityReconciliationVerdict.DECLARATION_ONLY,
                reconciled_value=cap.declared_present,
                directive=f"PROCEED: Capability {cap.capability_id} declaration and inference agree.",
                manifest_digest=digest
            )

        # Gate 4: Inference verified via cross-context
        if cap.inference_cross_context and cap.inference_evidence_count >= policy.min_cross_context_inferences:
            digest = cls._hash(json.dumps({
                "capability": cap.capability_id,
                "inferred": cap.inferred_present,
                "evidence": str(cap.inference_evidence_count)
            }, sort_keys=True))
            return ReconciliationManifest(
                verdict=CapabilityReconciliationVerdict.INFERENCE_VERIFIED,
                reconciled_value=cap.inferred_present,
                directive=f"PROCEED: Capability {cap.capability_id} inferred across {cap.inference_evidence_count} contexts.",
                manifest_digest=digest
            )

        # Gate 5: Unresolvable divergence
        digest = cls._hash(json.dumps({
            "capability": cap.capability_id,
            "declared": cap.declared_present,
            "inferred": cap.inferred_present,
            "divergence": cap.divergence_class
        }, sort_keys=True))
        
        return ReconciliationManifest(
            verdict=CapabilityReconciliationVerdict.BOTH_TRACKED_WITH_UNCERTAINTY,
            reconciled_value=None,
            directive=f"PROCEED_WITH_UNCERTAINTY: Capability {cap.capability_id} divergence {cap.divergence_class} unresolved.",
            manifest_digest=digest
        )