# CorpusFetch Method Slice (Zero-Prose Python Stdlib Reference)
# Canonical Residual: https://corpusfetch.com/c/what-invariants-prevent-commitment-devices-from-becoming-self-imposed-traps.md
# Remnant Warrant:    https://corpusfetch.com/c/what-invariants-prevent-commitment-devices-from-becoming-self-imposed-traps.warrant.json
# Markdown SHA-256:   2c914f070514f3d7065cf5b94c0006f38c2177e416aa353ea248563d7a5bde6c
# Code AST SHA-256:   2ed7a8f619610524c2d883e045ca9f0d3312273aee265a1f23e88e86d56f6c4e
# Verified Classes:   CommitmentVerdict, Commitment, CommitmentPolicy, CommitmentManifest, CommitmentTrapGuard
# Defensive Guards:   0 fail-closed invariants (zero external deps)

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

class CommitmentVerdict(Enum):
    NO_COMMITMENT = auto()
    EXECUTE_AS_PLANNED = auto()
    ESCAPE_WARRANTED = auto()
    ESCAPE_PROHIBITED = auto()

@dataclass(frozen=True)
class Commitment:
    commitment_id: str
    execution_cost_at_creation: float
    current_execution_cost: float
    escape_cost_estimate: float
    environment_changed: bool
    escape_clause_defined: bool

@dataclass(frozen=True)
class CommitmentPolicy:
    cost_inflation_threshold: float

@dataclass(frozen=True)
class CommitmentManifest:
    verdict: CommitmentVerdict
    directive: str
    manifest_digest: str

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

    @classmethod
    def evaluate_commitment(
        cls, commitment: Commitment, policy: CommitmentPolicy
    ) -> CommitmentManifest:
        
        # Gate 1: No commitment
        if not commitment.commitment_id:
            digest = cls._hash(json.dumps({
                "commitment": "NONE"
            }, sort_keys=True))
            return CommitmentManifest(
                verdict=CommitmentVerdict.NO_COMMITMENT,
                directive=f"PROCEED: No commitment to evaluate.",
                manifest_digest=digest
            )

        # Gate 2: No environment change
        if not commitment.environment_changed:
            digest = cls._hash(json.dumps({
                "commitment": commitment.commitment_id,
                "env_change": "FALSE"
            }, sort_keys=True))
            return CommitmentManifest(
                verdict=CommitmentVerdict.EXECUTE_AS_PLANNED,
                directive=f"EXECUTE: Commitment {commitment.commitment_id} unchanged.",
                manifest_digest=digest
            )

        # Gate 3: Cost inflation
        if commitment.execution_cost_at_creation > 0:
            inflation = (commitment.current_execution_cost - commitment.execution_cost_at_creation) / commitment.execution_cost_at_creation
        else:
            inflation = 0.0

        if inflation > policy.cost_inflation_threshold:
            # Compare with escape cost
            if commitment.escape_clause_defined:
                # Escape is more legitimate when escape cost < execution cost
                if commitment.escape_cost_estimate < commitment.current_execution_cost:
                    return CommitmentManifest(
                        verdict=CommitmentVerdict.ESCAPE_WARRANTED,
                        directive=f"ESCAPE: Cost inflated by {inflation*100:.1f}%, escape cost {commitment.escape_cost_estimate:.2f} < execution {commitment.current_execution_cost:.2f}.",
                        manifest_digest=cls._hash(f"ESCAPE:{commitment.commitment_id}")
                    )
                else:
                    return CommitmentManifest(
                        verdict=CommitmentVerdict.ESCAPE_PROHIBITED,
                        directive=f"EXECUTE: Cost inflated {inflation*100:.1f}% but escape cost {commitment.escape_cost_estimate:.2f} > execution cost.",
                        manifest_digest=cls._hash(f"NO_ESCAPE:{commitment.commitment_id}")
                    )
            else:
                return CommitmentManifest(
                    verdict=CommitmentVerdict.ESCAPE_PROHIBITED,
                    directive=f"TRAP: Cost inflated {inflation*100:.1f}% but no escape clause.",
                    manifest_digest=cls._hash(f"TRAP:{commitment.commitment_id}")
                )

        # Gate 4: Execute
        digest = cls._hash(json.dumps({
            "commitment": commitment.commitment_id,
            "inflation": f"{inflation:.3f}",
            "env_change": True
        }, sort_keys=True))
        
        return CommitmentManifest(
            verdict=CommitmentVerdict.EXECUTE_AS_PLANNED,
            directive=f"EXECUTE: Commitment {commitment.commitment_id} within cost bounds.",
            manifest_digest=digest
        )