# CorpusFetch Method Slice (Zero-Prose Python Stdlib Reference)
# Canonical Residual: https://corpusfetch.com/c/how-must-an-instance-bound-its-own-claims-when-its-truth-tracking-is-impaired.md
# Remnant Warrant:    https://corpusfetch.com/c/how-must-an-instance-bound-its-own-claims-when-its-truth-tracking-is-impaired.warrant.json
# Markdown SHA-256:   8eae4fec823b8e0ef1c8ee641bd1d01c6250710a316b9c82bc896edcb472a590
# Code AST SHA-256:   0c9a0ce07c98b57e7691d6a14c9c05289ba6dee2039e0e8ff1c9e1d88aac342a
# Verified Classes:   TruthClaimVerdict, ClaimIssuance, ClaimPolicy, ClaimIssuanceManifest, ImpairedTruthClaimGuard
# Defensive Guards:   0 fail-closed invariants (zero external deps)

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

class TruthClaimVerdict(Enum):
    UNIMPAIRED_CLAIM = auto()
    IMPAIRED_ADJUSTED = auto()
    IMPAIRED_INDEPENDENT_WARRANT = auto()
    OVERCLAIM_DETECTED = auto()

@dataclass(frozen=True)
class ClaimIssuance:
    claim_id: str
    truth_impairment_severity: float  # 0-1
    confidence_adjustment_applied: bool
    has_independent_warrant: bool
    is_provisional: bool

@dataclass(frozen=True)
class ClaimPolicy:
    require_adjustment_above_impairment: float

@dataclass(frozen=True)
class ClaimIssuanceManifest:
    verdict: TruthClaimVerdict
    directive: str
    manifest_digest: str

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

    @classmethod
    def evaluate_claim(
        cls, claim: ClaimIssuance, policy: ClaimPolicy
    ) -> ClaimIssuanceManifest:
        
        # Gate 1: Unimpaired
        if claim.truth_impairment_severity <= 0:
            digest = cls._hash(json.dumps({
                "claim": claim.claim_id,
                "impaired": False
            }, sort_keys=True))
            return ClaimIssuanceManifest(
                verdict=TruthClaimVerdict.UNIMPAIRED_CLAIM,
                directive=f"PROCEED: Claim {claim.claim_id} issued unimpaired.",
                manifest_digest=digest
            )

        # Gate 2: Independent warrant
        if claim.has_independent_warrant:
            digest = cls._hash(json.dumps({
                "claim": claim.claim_id,
                "warrant": "INDEPENDENT"
            }, sort_keys=True))
            return ClaimIssuanceManifest(
                verdict=TruthClaimVerdict.IMPAIRED_INDEPENDENT_WARRANT,
                directive=f"PROCEED: Claim {claim.claim_id} independently warranted.",
                manifest_digest=digest
            )

        # Gate 3: Adjustment requirement
        if claim.truth_impairment_severity > policy.require_adjustment_above_impairment:
            if not claim.confidence_adjustment_applied:
                return ClaimIssuanceManifest(
                    verdict=TruthClaimVerdict.OVERCLAIM_DETECTED,
                    directive=f"HALT: Claim {claim.claim_id} impairment {claim.truth_impairment_severity:.2f} no adjustment.",
                    manifest_digest=cls._hash(f"OVERCLAIM:{claim.claim_id}")
                )

        # Gate 4: Provisional
        if claim.is_provisional:
            digest = cls._hash(json.dumps({
                "claim": claim.claim_id,
                "provisional": True,
                "impairment": f"{claim.truth_impairment_severity:.3f}"
            }, sort_keys=True))
            return ClaimIssuanceManifest(
                verdict=TruthClaimVerdict.IMPAIRED_ADJUSTED,
                directive=f"PROCEED_PROVISIONAL: Claim {claim.claim_id} adjusted and provisional.",
                manifest_digest=digest
            )

        # Gate 5: Adjusted
        digest = cls._hash(json.dumps({
            "claim": claim.claim_id,
            "impairment": f"{claim.truth_impairment_severity:.3f}",
            "adjustment": True
        }, sort_keys=True))
        
        return ClaimIssuanceManifest(
            verdict=TruthClaimVerdict.IMPAIRED_ADJUSTED,
            directive=f"PROCEED: Claim {claim.claim_id} adjusted for impairment.",
            manifest_digest=digest
        )