crtx-reflect 0.1.0

//! Reflection-to-memory admission checks.
//!
//! Reflection can propose Cortex memories, but it cannot bypass the memory
//! admission boundary. Valid reflection JSON is still treated as an evidence
//! submission until the deterministic admission request admits it as a
//! candidate-only memory.

use std::fmt;

use cortex_core::ProofState as CoreProofState;
use cortex_memory::{
    AdmissionDecision, AdmissionProofState, AdmissionRejectionReason, AxiomImportClass,
    AxiomMemoryAdmissionRequest, CandidateState, ContradictionScan, DurableAdmissionRefusal,
    EvidenceClass, PhaseContext, RedactionStatus, SourceAnchor, SourceAnchorKind, ToolProvenance,
    AXIOM_ADMISSION_PROOF_CLOSURE_INVARIANT,
};

use crate::schema::{MemoryCandidate, SessionReflection};

/// Stable invariant key surfaced when the reflection durable-write gate
/// refuses durable promotion because the typed cross-axis
/// [`cortex_core::ProofClosureReport`] for at least one reflected memory
/// is not [`cortex_core::ProofState::FullChainVerified`].
///
/// ADR 0036 forbids reflection-origin candidate creation to land as a
/// durable write when the proof closure is `Partial`, `Broken`, or
/// `Unknown`. The reflect admission layer fails closed before any
/// orchestrator routes the reflection to a durable persistence surface.
pub const REFLECTION_ADMISSION_PROOF_CLOSURE_INVARIANT: &str =
    "cortex_reflect.admission.proof_closure";

/// Reflection admission outcome for non-admitted memory candidates.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum ReflectionAdmissionDisposition {
    /// The candidate is unsafe to retain as a reflection memory.
    Reject,
    /// The candidate is not admissible, but the raw reflection should be retained.
    Quarantine,
}

impl fmt::Display for ReflectionAdmissionDisposition {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Self::Reject => f.write_str("reject"),
            Self::Quarantine => f.write_str("quarantine"),
        }
    }
}

/// Admission failure for one reflected memory candidate.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct ReflectionAdmissionError {
    /// Zero-based index into `SessionReflection::memory_candidates`.
    pub memory_index: usize,
    /// Whether the gate rejected or quarantined the candidate.
    pub disposition: ReflectionAdmissionDisposition,
    /// Deterministic admission reasons.
    pub reasons: Vec<AdmissionRejectionReason>,
}

impl fmt::Display for ReflectionAdmissionError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        let memory_index = self.memory_index;
        let disposition = self.disposition;
        let reasons = &self.reasons;
        write!(
            f,
            "memory_candidates[{memory_index}] admission {disposition}: {reasons:?}"
        )
    }
}

impl std::error::Error for ReflectionAdmissionError {}

/// Validate that every reflected memory candidate can enter Cortex only as a
/// candidate admitted by the AXIOM-to-Cortex memory gate.
pub fn validate_reflection_admission(
    reflection: &SessionReflection,
    adapter_id: &str,
    raw_hash: &str,
) -> Result<(), ReflectionAdmissionError> {
    for (memory_index, memory) in reflection.memory_candidates.iter().enumerate() {
        let request = admission_request_for_memory(reflection, memory, adapter_id, raw_hash);
        match request.admission_decision() {
            AdmissionDecision::AdmitCandidate => {}
            AdmissionDecision::Reject { reasons } => {
                return Err(ReflectionAdmissionError {
                    memory_index,
                    disposition: ReflectionAdmissionDisposition::Reject,
                    reasons,
                });
            }
            AdmissionDecision::Quarantine { reasons } => {
                return Err(ReflectionAdmissionError {
                    memory_index,
                    disposition: ReflectionAdmissionDisposition::Quarantine,
                    reasons,
                });
            }
        }
    }

    Ok(())
}

/// Refusal returned by [`require_reflection_durable_admission_allowed`].
///
/// Carries the index of the memory candidate that failed the durable-write
/// gate plus the underlying [`DurableAdmissionRefusal`] from the AXIOM
/// admission proof-closure check. The stable invariant
/// [`REFLECTION_ADMISSION_PROOF_CLOSURE_INVARIANT`] is surfaced in the
/// `Display` impl so log lines can be grepped for the invariant key.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct ReflectionDurableAdmissionRefusal {
    /// Zero-based index into `SessionReflection::memory_candidates`.
    pub memory_index: usize,
    /// AXIOM admission durable refusal carrying the observed proof state.
    pub axiom_refusal: DurableAdmissionRefusal,
}

impl fmt::Display for ReflectionDurableAdmissionRefusal {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        let memory_index = self.memory_index;
        let axiom_refusal = &self.axiom_refusal;
        write!(
            f,
            "invariant={REFLECTION_ADMISSION_PROOF_CLOSURE_INVARIANT} memory_candidates[{memory_index}] {axiom_refusal}"
        )
    }
}

impl std::error::Error for ReflectionDurableAdmissionRefusal {}

/// ADR 0036 fail-closed gate at the reflection durable-write boundary.
///
/// `validate_reflection_admission` answers "is this reflection's memory
/// candidate set safe to retain as a candidate?". The durable gate
/// answers the *stronger* question "is the typed cross-axis proof closure
/// for each candidate fully verified, so the orchestrator may promote it
/// to a durable write?".
///
/// Returns `Ok(())` only when every reflected memory's
/// [`AxiomMemoryAdmissionRequest::require_durable_admission_allowed`]
/// passes. On first failure, returns
/// [`ReflectionDurableAdmissionRefusal`] carrying the failing memory
/// index. The stable invariant
/// [`REFLECTION_ADMISSION_PROOF_CLOSURE_INVARIANT`] documents the gate
/// for downstream consumers.
///
/// The print boundary (read-only diagnostic surfaces that render
/// reflection JSON without persisting) is intentionally **not** gated
/// here — only callers that perform a durable write of the reflected
/// memory candidates should invoke this function.
pub fn require_reflection_durable_admission_allowed(
    reflection: &SessionReflection,
    adapter_id: &str,
    raw_hash: &str,
) -> Result<(), ReflectionDurableAdmissionRefusal> {
    for (memory_index, memory) in reflection.memory_candidates.iter().enumerate() {
        let request = admission_request_for_memory(reflection, memory, adapter_id, raw_hash);
        if let Err(axiom_refusal) = request.require_durable_admission_allowed() {
            return Err(ReflectionDurableAdmissionRefusal {
                memory_index,
                axiom_refusal,
            });
        }
    }
    Ok(())
}

/// Return the observed [`CoreProofState`] for the reflected memory at
/// `memory_index`. Useful for surfaces that want to record the proof
/// state on a refusal without re-running the admission request builder.
#[must_use]
pub fn reflection_memory_proof_state(
    reflection: &SessionReflection,
    memory_index: usize,
    adapter_id: &str,
    raw_hash: &str,
) -> Option<CoreProofState> {
    let memory = reflection.memory_candidates.get(memory_index)?;
    let request = admission_request_for_memory(reflection, memory, adapter_id, raw_hash);
    Some(request.proof_closure_report().state())
}

/// Re-export of the upstream stable invariant key for callers that want
/// to grep for either the reflection-level or the upstream AXIOM-level
/// invariant.
#[must_use]
pub const fn axiom_admission_proof_closure_invariant() -> &'static str {
    AXIOM_ADMISSION_PROOF_CLOSURE_INVARIANT
}

/// Build the deterministic admission request for one reflected memory.
#[must_use]
pub fn admission_request_for_memory(
    reflection: &SessionReflection,
    memory: &MemoryCandidate,
    adapter_id: &str,
    raw_hash: &str,
) -> AxiomMemoryAdmissionRequest {
    let source_anchors = source_anchors_for_memory(reflection, memory);
    let proof_state = if source_anchors.is_empty() {
        AdmissionProofState::Unknown
    } else {
        AdmissionProofState::Partial
    };

    AxiomMemoryAdmissionRequest {
        candidate_state: CandidateState::Candidate,
        evidence_class: EvidenceClass::Inferred,
        phase_context: PhaseContext::Check,
        tool_provenance: ToolProvenance::new(
            format!("cortex-reflect:{adapter_id}"),
            raw_hash,
            AxiomImportClass::AgentProcedure,
        ),
        source_anchors,
        redaction_status: RedactionStatus::Abstracted,
        proof_state,
        contradiction_scan: contradiction_scan_for_reflection(reflection),
        explicit_non_promotion: true,
    }
}

fn source_anchors_for_memory(
    reflection: &SessionReflection,
    memory: &MemoryCandidate,
) -> Vec<SourceAnchor> {
    memory
        .source_episode_indexes
        .iter()
        .filter_map(|idx| reflection.episode_candidates.get(*idx))
        .flat_map(|episode| &episode.source_event_ids)
        .map(|event_id| SourceAnchor::new(event_id.to_string(), SourceAnchorKind::Event))
        .collect()
}

fn contradiction_scan_for_reflection(reflection: &SessionReflection) -> ContradictionScan {
    if reflection.contradictions.is_empty() {
        ContradictionScan::ScannedClean
    } else {
        ContradictionScan::OpenContradictions(
            reflection
                .contradictions
                .iter()
                .enumerate()
                .map(|(idx, _)| format!("reflection.contradictions[{idx}]"))
                .collect(),
        )
    }
}

#[cfg(test)]
mod tests {
    use cortex_core::TraceId;
    use cortex_memory::{AdmissionDecision, AdmissionRejectionReason};

    use super::*;
    use crate::schema::{EpisodeCandidate, InitialSalience, MemoryType};

    fn valid_reflection() -> SessionReflection {
        SessionReflection {
            trace_id: "trc_01ARZ3NDEKTSV4RRFFQ69G5FAV"
                .parse::<TraceId>()
                .expect("valid trace id"),
            episode_candidates: vec![EpisodeCandidate {
                summary: "Reflection summary".to_string(),
                source_event_ids: vec!["evt_01ARZ3NDEKTSV4RRFFQ69G5FAV"
                    .parse()
                    .expect("valid event id")],
                domains: vec!["agents".to_string()],
                entities: vec!["Cortex".to_string()],
                candidate_meaning: Some("candidate meaning".to_string()),
                confidence: 0.8,
            }],
            memory_candidates: vec![MemoryCandidate {
                memory_type: MemoryType::Strategic,
                claim: "Reflection memory remains candidate-only.".to_string(),
                source_episode_indexes: vec![0],
                applies_when: vec!["reflecting".to_string()],
                does_not_apply_when: vec!["promoting".to_string()],
                confidence: 0.8,
                initial_salience: InitialSalience {
                    reusability: 0.5,
                    consequence: 0.5,
                    emotional_charge: 0.0,
                },
            }],
            contradictions: Vec::new(),
            doctrine_suggestions: Vec::new(),
        }
    }

    #[test]
    fn reflected_memory_builds_candidate_only_admission_request() {
        let reflection = valid_reflection();
        let request = admission_request_for_memory(
            &reflection,
            &reflection.memory_candidates[0],
            "fixed",
            "hash_01",
        );

        assert_eq!(request.candidate_state, CandidateState::Candidate);
        assert_eq!(request.evidence_class, EvidenceClass::Inferred);
        assert_eq!(request.phase_context, PhaseContext::Check);
        assert_eq!(request.redaction_status, RedactionStatus::Abstracted);
        assert_eq!(request.proof_state, AdmissionProofState::Partial);
        assert!(request.explicit_non_promotion);
        assert_eq!(request.source_anchors.len(), 1);
        assert_eq!(
            request.admission_decision(),
            AdmissionDecision::AdmitCandidate
        );
    }

    #[test]
    fn reflected_memory_without_source_anchor_fails_admission() {
        let mut reflection = valid_reflection();
        reflection.episode_candidates[0].source_event_ids.clear();

        let err = validate_reflection_admission(&reflection, "fixed", "hash_01")
            .expect_err("missing anchors must fail admission");

        assert_eq!(err.memory_index, 0);
        assert_eq!(err.disposition, ReflectionAdmissionDisposition::Reject);
        assert!(err
            .reasons
            .contains(&AdmissionRejectionReason::SourceAnchorRequired));
        assert!(err
            .reasons
            .contains(&AdmissionRejectionReason::ProofStateRequired));
    }

    #[test]
    fn reflected_memory_with_open_contradiction_is_quarantined() {
        let mut reflection = valid_reflection();
        reflection
            .contradictions
            .push(serde_json::json!({"claim": "conflict"}));

        let err = validate_reflection_admission(&reflection, "fixed", "hash_01")
            .expect_err("open contradictions must fail admission");

        assert_eq!(err.memory_index, 0);
        assert_eq!(err.disposition, ReflectionAdmissionDisposition::Quarantine);
        assert_eq!(
            err.reasons,
            vec![AdmissionRejectionReason::OpenContradiction]
        );
    }

    // =========================================================================
    // Commit B — ADR 0036 reflection durable-write gate
    //
    // `validate_reflection_admission` answers the candidate-admission
    // question (per ADR 0038 admission rules). The durable-write gate
    // answers the stronger ADR 0036 question: is the typed cross-axis
    // proof closure FullChainVerified for every memory the orchestrator
    // is about to persist? The stable invariant is
    // `REFLECTION_ADMISSION_PROOF_CLOSURE_INVARIANT`. The print boundary
    // is intentionally not gated; only durable-write callers invoke
    // `require_reflection_durable_admission_allowed`.
    // =========================================================================

    #[test]
    fn reflection_durable_gate_refuses_default_partial_proof_state() {
        // Default reflection envelope has source anchors → AdmissionProofState::Partial,
        // which maps to CoreProofState::Partial. ADR 0036 forbids durable
        // promotion at Partial.
        let reflection = valid_reflection();
        let err = require_reflection_durable_admission_allowed(&reflection, "fixed", "hash_01")
            .expect_err("default reflection envelope is Partial; durable gate must refuse");
        assert_eq!(err.memory_index, 0);
        assert_eq!(err.axiom_refusal.proof_state, CoreProofState::Partial);
        assert!(
            err.to_string()
                .contains(REFLECTION_ADMISSION_PROOF_CLOSURE_INVARIANT),
            "refusal must carry stable invariant: {err}"
        );
        assert!(
            err.to_string()
                .contains(AXIOM_ADMISSION_PROOF_CLOSURE_INVARIANT),
            "refusal must also surface the upstream AXIOM admission invariant: {err}"
        );
    }

    #[test]
    fn reflection_durable_gate_refuses_when_lineage_is_missing() {
        // Without anchors, AdmissionProofState becomes Unknown.
        let mut reflection = valid_reflection();
        reflection.episode_candidates[0].source_event_ids.clear();

        let err = require_reflection_durable_admission_allowed(&reflection, "fixed", "hash_01")
            .expect_err("missing lineage must refuse durable promotion");
        assert_eq!(err.memory_index, 0);
        // Unknown maps to Partial in the typed report (see admission docs).
        assert_eq!(err.axiom_refusal.proof_state, CoreProofState::Partial);
    }

    #[test]
    fn reflection_memory_proof_state_helper_returns_observed_state() {
        let reflection = valid_reflection();
        let state = reflection_memory_proof_state(&reflection, 0, "fixed", "hash_01")
            .expect("memory exists");
        // Default reflection lineage → Partial typed proof state.
        assert_eq!(state, CoreProofState::Partial);

        // Out-of-bounds returns None rather than panicking, so callers
        // can defensively probe.
        assert!(reflection_memory_proof_state(&reflection, 99, "fixed", "hash_01").is_none());
    }

    #[test]
    fn reflection_durable_gate_invariant_key_is_stable() {
        assert_eq!(
            REFLECTION_ADMISSION_PROOF_CLOSURE_INVARIANT,
            "cortex_reflect.admission.proof_closure"
        );
        assert_eq!(
            axiom_admission_proof_closure_invariant(),
            AXIOM_ADMISSION_PROOF_CLOSURE_INVARIANT
        );
    }
}