provider-core 0.1.1

// SPDX-License-Identifier: AGPL-3.0-or-later

//! Provider-native catalog normalization and immutable last-known-good state.

use router_protocol::CatalogSourceKind;
use serde::{Deserialize, Serialize};
use sha2::{Digest, Sha256};
use std::collections::{BTreeSet, HashSet};
use thiserror::Error;

pub const CATALOG_SCHEMA_VERSION: &str = "1.0.0";
pub const PROMOTION_AUTHORITY_SCHEMA_VERSION: &str = "1.0.0";
pub const REFRESH_BUCKET_SECONDS: u64 = 6 * 60 * 60;
pub const STALE_WARNING_SECONDS: u64 = 18 * 60 * 60;
pub const SNAPSHOT_EXPIRY_SECONDS: u64 = 24 * 60 * 60;
const MAX_CATALOG_MODELS: usize = 512;
const MAX_MODEL_MODALITIES: usize = 8;
const MAX_REASONING_MODES: usize = 8;
const MAX_ROLE_ALIASES: usize = 8;

/// Provider adapters normalize their native discovery response through this
/// interface. It has no transport or inference capability.
pub trait ProviderCatalogDiscovery {
    type NativeResponse;

    fn source(&self) -> CatalogSourceKind;
    fn normalize(
        &self,
        response: &Self::NativeResponse,
        observed_at_epoch_seconds: u64,
    ) -> Result<Vec<NormalizedModelSpec>, CatalogError>;
}

#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
#[serde(deny_unknown_fields)]
pub struct NormalizedModelSpec {
    pub provider_model_id: String,
    pub context_tokens: u64,
    pub modalities: Vec<String>,
    pub tool_support: bool,
    pub reasoning_modes: Vec<String>,
    pub pricing_provenance: String,
    pub availability: String,
    pub observed_at_epoch_seconds: u64,
}

impl NormalizedModelSpec {
    pub fn fingerprint(&self) -> Result<String, CatalogError> {
        validate_spec(self)?;
        serde_json::to_vec(self)
            .map(|bytes| sha256_hex(&bytes))
            .map_err(|_| CatalogError::Malformed)
    }
}

#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
#[serde(deny_unknown_fields)]
pub struct CatalogSnapshot {
    schema_version: String,
    snapshot_id: String,
    provider_id: String,
    catalog_version: String,
    source: CatalogSourceKind,
    source_receipt: String,
    created_at_epoch_seconds: u64,
    expires_at_epoch_seconds: u64,
    content_sha256: String,
    models: Vec<NormalizedModelSpec>,
}

#[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize)]
#[serde(rename_all = "snake_case")]
pub enum CatalogFreshness {
    Fresh,
    Warning,
    Expired,
    InvalidClock,
}

impl CatalogSnapshot {
    #[allow(clippy::too_many_arguments)]
    pub fn accept(
        snapshot_id: impl Into<String>,
        provider_id: impl Into<String>,
        catalog_version: impl Into<String>,
        source: CatalogSourceKind,
        source_receipt: impl Into<String>,
        created_at_epoch_seconds: u64,
        mut models: Vec<NormalizedModelSpec>,
    ) -> Result<Self, CatalogError> {
        let snapshot_id = snapshot_id.into();
        let provider_id = provider_id.into();
        let catalog_version = catalog_version.into();
        let source_receipt = source_receipt.into();
        if !valid_id(&snapshot_id)
            || !valid_id(&provider_id)
            || !valid_id(&catalog_version)
            || !valid_typed_digest_ref(&source_receipt, &["receipt", "manifest"])
            || models.is_empty()
            || models.len() > MAX_CATALOG_MODELS
        {
            return Err(CatalogError::Malformed);
        }
        let mut ids = HashSet::new();
        for model in &models {
            validate_spec(model)?;
            if model.observed_at_epoch_seconds > created_at_epoch_seconds
                || !ids.insert(model.provider_model_id.as_str())
            {
                return Err(CatalogError::Contradictory);
            }
        }
        models.sort_by(|left, right| left.provider_model_id.cmp(&right.provider_model_id));
        let canonical = serde_json::to_vec(&models).map_err(|_| CatalogError::Malformed)?;
        Ok(Self {
            schema_version: CATALOG_SCHEMA_VERSION.to_owned(),
            snapshot_id,
            provider_id,
            catalog_version,
            source,
            source_receipt,
            created_at_epoch_seconds,
            expires_at_epoch_seconds: created_at_epoch_seconds
                .saturating_add(SNAPSHOT_EXPIRY_SECONDS),
            content_sha256: sha256_hex(&canonical),
            models,
        })
    }

    pub fn freshness(&self, now_epoch_seconds: u64) -> CatalogFreshness {
        if self.validate_integrity().is_err() {
            return CatalogFreshness::Expired;
        }
        if now_epoch_seconds < self.created_at_epoch_seconds {
            return CatalogFreshness::InvalidClock;
        }
        let age = now_epoch_seconds - self.created_at_epoch_seconds;
        if age >= SNAPSHOT_EXPIRY_SECONDS {
            CatalogFreshness::Expired
        } else if age >= STALE_WARNING_SECONDS {
            CatalogFreshness::Warning
        } else {
            CatalogFreshness::Fresh
        }
    }

    pub fn content_sha256(&self) -> &str {
        &self.content_sha256
    }

    pub fn catalog_version(&self) -> &str {
        &self.catalog_version
    }

    pub fn provider_id(&self) -> &str {
        &self.provider_id
    }

    pub fn model(&self, provider_model_id: &str) -> Option<&NormalizedModelSpec> {
        self.models
            .iter()
            .find(|model| model.provider_model_id == provider_model_id)
    }

    pub fn models(&self) -> &[NormalizedModelSpec] {
        &self.models
    }

    /// Builds a deterministic promotion artifact containing only the exact
    /// configured models that completed qualification. The observed catalog
    /// remains unchanged in the LKG; this derived snapshot is a bounded,
    /// integrity-checked authority input with the same source/version/time.
    pub fn promotion_subset(&self, provider_model_ids: &[String]) -> Result<Self, CatalogError> {
        self.validate_integrity()?;
        if provider_model_ids.is_empty() || provider_model_ids.len() > MAX_CATALOG_MODELS {
            return Err(CatalogError::Malformed);
        }
        let wanted = provider_model_ids.iter().collect::<HashSet<_>>();
        if wanted.len() != provider_model_ids.len() {
            return Err(CatalogError::Contradictory);
        }
        let models = self
            .models
            .iter()
            .filter(|model| wanted.contains(&model.provider_model_id))
            .cloned()
            .collect::<Vec<_>>();
        if models.len() != wanted.len() {
            return Err(CatalogError::Contradictory);
        }
        Self::accept(
            format!("{}.qualified", self.snapshot_id),
            self.provider_id.clone(),
            self.catalog_version.clone(),
            self.source,
            self.source_receipt.clone(),
            self.created_at_epoch_seconds,
            models,
        )
    }

    pub fn validate_integrity(&self) -> Result<(), CatalogError> {
        if self.schema_version != CATALOG_SCHEMA_VERSION
            || !valid_id(&self.snapshot_id)
            || !valid_id(&self.provider_id)
            || !valid_id(&self.catalog_version)
            || !valid_typed_digest_ref(&self.source_receipt, &["receipt", "manifest"])
            || self.models.is_empty()
            || self.models.len() > MAX_CATALOG_MODELS
            || self.expires_at_epoch_seconds
                != self
                    .created_at_epoch_seconds
                    .saturating_add(SNAPSHOT_EXPIRY_SECONDS)
        {
            return Err(CatalogError::Malformed);
        }
        let mut ids = HashSet::with_capacity(self.models.len());
        for model in &self.models {
            validate_spec(model)?;
            if model.observed_at_epoch_seconds > self.created_at_epoch_seconds
                || !ids.insert(model.provider_model_id.as_str())
            {
                return Err(CatalogError::Contradictory);
            }
        }
        let mut canonical = self.models.clone();
        canonical.sort_by(|left, right| left.provider_model_id.cmp(&right.provider_model_id));
        let encoded = serde_json::to_vec(&canonical).map_err(|_| CatalogError::Malformed)?;
        if self.content_sha256 != sha256_hex(&encoded) {
            return Err(CatalogError::Contradictory);
        }
        Ok(())
    }
}

#[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize)]
#[serde(rename_all = "snake_case")]
pub enum QualificationState {
    Discovered,
    Quarantined,
    Qualifying,
    Qualified,
    Rejected,
    Retired,
}

#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
#[serde(deny_unknown_fields)]
pub struct QualificationEvidence {
    pub evidence_ref: String,
    pub model_sha256: String,
    pub catalog_version: String,
    pub catalog_sha256: String,
    pub policy_version: String,
    pub policy_sha256: String,
    pub conformance_sha256: String,
    pub operator_promotion_receipt: String,
    pub role_aliases: Vec<String>,
    pub fixture_only: bool,
}

#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
#[serde(deny_unknown_fields)]
pub struct ModelQualification {
    pub provider_model_id: String,
    pub model_fingerprint: String,
    pub catalog_version: String,
    pub state: QualificationState,
    pub evidence: Option<QualificationEvidence>,
}

#[derive(Clone, Debug, PartialEq, Eq)]
pub struct EligibilityBinding<'a> {
    pub policy_version: &'a str,
    pub policy_sha256: &'a str,
    pub conformance_sha256: &'a str,
    pub operator_promotion_receipt: &'a str,
}

/// Canonical authority input for one exact catalog-promotion mutation.
///
/// This type deliberately does not choose a signature/MAC algorithm or trust-
/// anchor representation. Those remain an explicit product/Security decision.
/// A future verifier must authenticate these exact canonical bytes before an
/// apply path may consume the resulting private proof token.
#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
#[serde(deny_unknown_fields)]
pub struct PromotionMutationBinding {
    pub schema_version: String,
    pub promotion_id: String,
    pub provider_id: String,
    pub phase_id: String,
    pub account_ref: String,
    pub catalog_ref: String,
    pub provider_model_id: String,
    pub model_sha256: String,
    pub catalog_version: String,
    pub catalog_sha256: String,
    pub policy_version: String,
    pub policy_sha256: String,
    pub conformance_sha256: String,
    pub configuration_authority_id: String,
    pub configuration_authority_sha256: String,
    pub expected_state_generation: u64,
    pub state_preimage_sha256: String,
    pub state_postimage_sha256: String,
    pub rollback_snapshot_sha256: String,
    pub authorization_nonce: String,
    pub authorized_at_epoch_seconds: u64,
    pub rollback_not_after_epoch_seconds: u64,
}

impl PromotionMutationBinding {
    /// Hashes the strict, field-ordered Serde representation used as the future
    /// verifier input. Any generation, preimage, postimage, authority, catalog,
    /// model, policy, conformance, nonce, or rollback substitution changes it.
    pub fn binding_sha256(&self) -> Result<String, PromotionAuthorityError> {
        self.validate()?;
        serde_json::to_vec(self)
            .map(|canonical| sha256_hex(&canonical))
            .map_err(|_| PromotionAuthorityError::MalformedBinding)
    }

    fn validate(&self) -> Result<(), PromotionAuthorityError> {
        if self.schema_version != PROMOTION_AUTHORITY_SCHEMA_VERSION
            || !valid_id(&self.promotion_id)
            || !valid_id(&self.provider_id)
            || !valid_id(&self.phase_id)
            || !valid_id(&self.account_ref)
            || !valid_id(&self.catalog_ref)
            || !valid_model_id(&self.provider_model_id)
            || !valid_sha256(&self.model_sha256)
            || !valid_id(&self.catalog_version)
            || !valid_sha256(&self.catalog_sha256)
            || !valid_id(&self.policy_version)
            || !valid_sha256(&self.policy_sha256)
            || !valid_sha256(&self.conformance_sha256)
            || !valid_id(&self.configuration_authority_id)
            || !valid_sha256(&self.configuration_authority_sha256)
            || !valid_sha256(&self.state_preimage_sha256)
            || !valid_sha256(&self.state_postimage_sha256)
            || !valid_sha256(&self.rollback_snapshot_sha256)
            || self.state_preimage_sha256 == self.state_postimage_sha256
            || self.rollback_snapshot_sha256 != self.state_preimage_sha256
            || !valid_id(&self.authorization_nonce)
            || self.rollback_not_after_epoch_seconds <= self.authorized_at_epoch_seconds
        {
            return Err(PromotionAuthorityError::MalformedBinding);
        }
        Ok(())
    }
}

/// Algorithm-neutral inputs for the separately decided promotion verifier.
/// Evidence bytes are intentionally opaque and are never formatted or logged.
pub struct PromotionAuthorityRequest {
    pub binding: PromotionMutationBinding,
    pub operator_authority_id: String,
    pub conformance_authority_id: String,
    pub operator_evidence: Vec<u8>,
    pub conformance_evidence: Vec<u8>,
    pub fixture_only: bool,
}

impl PromotionAuthorityRequest {
    fn validate(&self) -> Result<(), PromotionAuthorityError> {
        const MAX_AUTHORITY_EVIDENCE_BYTES: usize = 64 * 1024;
        self.binding.validate()?;
        if !valid_id(&self.operator_authority_id)
            || !valid_id(&self.conformance_authority_id)
            || self.operator_evidence.is_empty()
            || self.operator_evidence.len() > MAX_AUTHORITY_EVIDENCE_BYTES
            || self.conformance_evidence.is_empty()
            || self.conformance_evidence.len() > MAX_AUTHORITY_EVIDENCE_BYTES
        {
            return Err(PromotionAuthorityError::MalformedEvidence);
        }
        Ok(())
    }
}

mod promotion_verifier_sealed {
    pub trait Sealed {}
}

/// Sealed until the product owner and Security choose the production
/// algorithm, trust-anchor format/lifecycle, and replay-store contract.
pub trait PromotionAuthorityVerifier: promotion_verifier_sealed::Sealed {
    fn verify(
        &self,
        request: &PromotionAuthorityRequest,
    ) -> Result<AuthenticatedPromotionAuthority, PromotionAuthorityError>;
}

/// The only production verifier available while M-01's trust-root decision is
/// open. It makes accidental apply fail closed rather than treating a digest
/// reference or caller boolean as authentication.
#[derive(Clone, Copy, Debug, Default)]
pub struct UnconfiguredPromotionAuthorityVerifier;

impl promotion_verifier_sealed::Sealed for UnconfiguredPromotionAuthorityVerifier {}

impl PromotionAuthorityVerifier for UnconfiguredPromotionAuthorityVerifier {
    fn verify(
        &self,
        _request: &PromotionAuthorityRequest,
    ) -> Result<AuthenticatedPromotionAuthority, PromotionAuthorityError> {
        Err(PromotionAuthorityError::TrustRootDecisionUnavailable)
    }
}

/// Non-cloneable proof that both configured authorities authenticated one exact
/// mutation binding. Only verifier implementations in this module can mint it.
#[derive(Debug, PartialEq, Eq)]
#[must_use]
pub struct AuthenticatedPromotionAuthority {
    binding_sha256: String,
    operator_authority_id: String,
    conformance_authority_id: String,
}

impl AuthenticatedPromotionAuthority {
    pub fn binding_sha256(&self) -> &str {
        &self.binding_sha256
    }

    pub fn operator_authority_id(&self) -> &str {
        &self.operator_authority_id
    }

    pub fn conformance_authority_id(&self) -> &str {
        &self.conformance_authority_id
    }

    #[cfg(test)]
    fn from_verified(request: &PromotionAuthorityRequest) -> Result<Self, PromotionAuthorityError> {
        Ok(Self {
            binding_sha256: request.binding.binding_sha256()?,
            operator_authority_id: request.operator_authority_id.clone(),
            conformance_authority_id: request.conformance_authority_id.clone(),
        })
    }
}

pub fn authenticate_promotion(
    verifier: &impl PromotionAuthorityVerifier,
    request: &PromotionAuthorityRequest,
) -> Result<AuthenticatedPromotionAuthority, PromotionAuthorityError> {
    request.validate()?;
    if request.fixture_only {
        return Err(PromotionAuthorityError::FixtureEvidenceForbidden);
    }
    let expected_binding = request.binding.binding_sha256()?;
    let authenticated = verifier.verify(request)?;
    if authenticated.binding_sha256 != expected_binding
        || authenticated.operator_authority_id != request.operator_authority_id
        || authenticated.conformance_authority_id != request.conformance_authority_id
    {
        return Err(PromotionAuthorityError::BindingMismatch);
    }
    Ok(authenticated)
}

#[derive(Clone, Copy, Debug, PartialEq, Eq, Error)]
pub enum PromotionAuthorityError {
    #[error("promotion authority binding is malformed")]
    MalformedBinding,
    #[error("promotion authority evidence is malformed")]
    MalformedEvidence,
    #[error("fixture evidence cannot authorize promotion")]
    FixtureEvidenceForbidden,
    #[error("promotion trust-root decision is unavailable")]
    TrustRootDecisionUnavailable,
    #[error("promotion authority authentication failed")]
    AuthenticationFailed,
    #[error("authenticated promotion binding changed")]
    BindingMismatch,
}

impl ModelQualification {
    pub fn discovered(
        provider_model_id: impl Into<String>,
        model_fingerprint: impl Into<String>,
        catalog_version: impl Into<String>,
    ) -> Result<Self, CatalogError> {
        let value = Self {
            provider_model_id: provider_model_id.into(),
            model_fingerprint: model_fingerprint.into(),
            catalog_version: catalog_version.into(),
            state: QualificationState::Discovered,
            evidence: None,
        };
        if !valid_model_id(&value.provider_model_id)
            || !valid_sha256(&value.model_fingerprint)
            || !valid_id(&value.catalog_version)
        {
            return Err(CatalogError::Malformed);
        }
        Ok(value)
    }

    pub fn quarantine(mut self) -> Result<Self, CatalogError> {
        self.transition(
            QualificationState::Discovered,
            QualificationState::Quarantined,
        )?;
        Ok(self)
    }

    pub fn begin_qualification(mut self) -> Result<Self, CatalogError> {
        self.transition(
            QualificationState::Quarantined,
            QualificationState::Qualifying,
        )?;
        Ok(self)
    }

    pub fn qualify(mut self, evidence: QualificationEvidence) -> Result<Self, CatalogError> {
        if self.state != QualificationState::Qualifying
            || evidence.model_sha256 != self.model_fingerprint
            || evidence.catalog_version != self.catalog_version
            || !valid_qualification_evidence(&evidence)
        {
            return Err(CatalogError::InvalidTransition);
        }
        self.state = QualificationState::Qualified;
        self.evidence = Some(evidence);
        Ok(self)
    }

    pub fn reject(mut self) -> Result<Self, CatalogError> {
        if !matches!(
            self.state,
            QualificationState::Quarantined | QualificationState::Qualifying
        ) {
            return Err(CatalogError::InvalidTransition);
        }
        self.state = QualificationState::Rejected;
        Ok(self)
    }

    pub fn retire(mut self) -> Result<Self, CatalogError> {
        if self.state != QualificationState::Qualified {
            return Err(CatalogError::InvalidTransition);
        }
        self.state = QualificationState::Retired;
        Ok(self)
    }

    pub fn automatic_eligible(
        &self,
        snapshot: &CatalogSnapshot,
        now_epoch_seconds: u64,
        binding: &EligibilityBinding<'_>,
        operator_approved: bool,
    ) -> bool {
        snapshot.validate_integrity().is_ok()
            && valid_typed_digest_ref(binding.operator_promotion_receipt, &["approval", "receipt"])
            && valid_model_id(&self.provider_model_id)
            && valid_sha256(&self.model_fingerprint)
            && valid_id(&self.catalog_version)
            && self.state == QualificationState::Qualified
            && operator_approved
            && matches!(
                snapshot.freshness(now_epoch_seconds),
                CatalogFreshness::Fresh | CatalogFreshness::Warning
            )
            && snapshot.catalog_version() == self.catalog_version
            && self.evidence.as_ref().is_some_and(|evidence| {
                valid_qualification_evidence(evidence)
                    && !evidence.fixture_only
                    && evidence.model_sha256 == self.model_fingerprint
                    && evidence.catalog_version == self.catalog_version
                    && evidence.catalog_sha256 == snapshot.content_sha256()
                    && evidence.policy_version == binding.policy_version
                    && evidence.policy_sha256 == binding.policy_sha256
                    && evidence.conformance_sha256 == binding.conformance_sha256
                    && evidence.operator_promotion_receipt == binding.operator_promotion_receipt
            })
            && snapshot
                .model(&self.provider_model_id)
                .is_some_and(|model| {
                    model.fingerprint().ok().as_deref() == Some(self.model_fingerprint.as_str())
                })
    }

    fn transition(
        &mut self,
        expected: QualificationState,
        next: QualificationState,
    ) -> Result<(), CatalogError> {
        if self.state != expected {
            return Err(CatalogError::InvalidTransition);
        }
        self.state = next;
        Ok(())
    }
}

#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum RefreshReason {
    StartupCatchUp,
    UtcBucket,
}

#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum RefreshDirective {
    Due { bucket: u64, reason: RefreshReason },
    Wait { until_epoch_seconds: u64 },
}

#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub struct RefreshScheduler {
    jitter_seconds: u64,
}

impl RefreshScheduler {
    pub fn new(jitter_seconds: u64) -> Result<Self, CatalogError> {
        if jitter_seconds >= REFRESH_BUCKET_SECONDS {
            return Err(CatalogError::InvalidSchedule);
        }
        Ok(Self { jitter_seconds })
    }

    pub fn directive(
        self,
        now_epoch_seconds: u64,
        last_success_epoch_seconds: Option<u64>,
    ) -> RefreshDirective {
        let bucket = now_epoch_seconds / REFRESH_BUCKET_SECONDS;
        let scheduled = bucket
            .saturating_mul(REFRESH_BUCKET_SECONDS)
            .saturating_add(self.jitter_seconds);
        let Some(last_success) = last_success_epoch_seconds else {
            return RefreshDirective::Due {
                bucket,
                reason: RefreshReason::StartupCatchUp,
            };
        };
        if last_success / REFRESH_BUCKET_SECONDS < bucket && now_epoch_seconds >= scheduled {
            RefreshDirective::Due {
                bucket,
                reason: RefreshReason::UtcBucket,
            }
        } else {
            RefreshDirective::Wait {
                until_epoch_seconds: if now_epoch_seconds < scheduled {
                    scheduled
                } else {
                    bucket
                        .saturating_add(1)
                        .saturating_mul(REFRESH_BUCKET_SECONDS)
                        .saturating_add(self.jitter_seconds)
                },
            }
        }
    }
}

#[derive(Clone, Copy, Debug, PartialEq, Eq, Error)]
pub enum CatalogError {
    #[error("catalog record is malformed")]
    Malformed,
    #[error("catalog contains contradictory records")]
    Contradictory,
    #[error("qualification transition is invalid")]
    InvalidTransition,
    #[error("refresh schedule is invalid")]
    InvalidSchedule,
}

fn validate_spec(spec: &NormalizedModelSpec) -> Result<(), CatalogError> {
    if !valid_model_id(&spec.provider_model_id)
        || spec.context_tokens == 0
        || spec.modalities.is_empty()
        || spec.modalities.len() > MAX_MODEL_MODALITIES
        || spec.modalities.iter().any(|item| !valid_id(item))
        || spec.modalities.iter().collect::<BTreeSet<_>>().len() != spec.modalities.len()
        || spec.reasoning_modes.len() > MAX_REASONING_MODES
        || spec.reasoning_modes.iter().any(|item| !valid_id(item))
        || spec.reasoning_modes.iter().collect::<BTreeSet<_>>().len() != spec.reasoning_modes.len()
        || !valid_id(&spec.pricing_provenance)
        || !valid_id(&spec.availability)
    {
        return Err(CatalogError::Malformed);
    }
    Ok(())
}

fn valid_qualification_evidence(evidence: &QualificationEvidence) -> bool {
    valid_sha256(&evidence.model_sha256)
        && valid_id(&evidence.catalog_version)
        && valid_sha256(&evidence.catalog_sha256)
        && valid_id(&evidence.policy_version)
        && valid_sha256(&evidence.policy_sha256)
        && valid_sha256(&evidence.conformance_sha256)
        && valid_typed_digest_ref(
            &evidence.operator_promotion_receipt,
            &["approval", "receipt"],
        )
        && valid_typed_digest_ref(
            &evidence.evidence_ref,
            &["evaluation", "manifest", "receipt"],
        )
        && !evidence.role_aliases.is_empty()
        && evidence.role_aliases.len() <= MAX_ROLE_ALIASES
        && evidence.role_aliases.iter().all(|role| valid_id(role))
        && evidence.role_aliases.iter().collect::<BTreeSet<_>>().len()
            == evidence.role_aliases.len()
}

fn valid_id(value: &str) -> bool {
    !value.is_empty()
        && value.len() <= 128
        && value
            .bytes()
            .all(|byte| byte.is_ascii_alphanumeric() || matches!(byte, b'-' | b'_' | b'.' | b':'))
}

fn valid_model_id(value: &str) -> bool {
    !value.is_empty()
        && value.len() <= 256
        && !value.starts_with('/')
        && !value.ends_with('/')
        && !value.contains("..")
        && !value.contains("//")
        && value.bytes().all(|byte| {
            byte.is_ascii_alphanumeric() || matches!(byte, b'-' | b'_' | b'.' | b':' | b'/')
        })
}

fn valid_sha256(value: &str) -> bool {
    value.len() == 64
        && value
            .bytes()
            .all(|byte| byte.is_ascii_digit() || (b'a'..=b'f').contains(&byte))
}

fn valid_typed_digest_ref(value: &str, allowed_kinds: &[&str]) -> bool {
    let mut parts = value.split(':');
    let kind = parts.next();
    let algorithm = parts.next();
    let digest = parts.next();
    parts.next().is_none()
        && kind.is_some_and(|kind| allowed_kinds.contains(&kind))
        && algorithm == Some("sha256")
        && digest.is_some_and(valid_sha256)
}

fn sha256_hex(bytes: &[u8]) -> String {
    let digest = Sha256::digest(bytes);
    digest.iter().map(|byte| format!("{byte:02x}")).collect()
}

#[cfg(test)]
mod tests {
    use super::*;

    struct DeterministicTestVerifier;

    impl promotion_verifier_sealed::Sealed for DeterministicTestVerifier {}

    impl DeterministicTestVerifier {
        fn evidence(label: &[u8], binding_sha256: &str) -> Vec<u8> {
            let mut hasher = Sha256::new();
            hasher.update(label);
            hasher.update(binding_sha256.as_bytes());
            hasher.finalize().to_vec()
        }

        fn request(&self, binding: PromotionMutationBinding) -> PromotionAuthorityRequest {
            let binding_sha256 = binding.binding_sha256().expect("fixture binding");
            PromotionAuthorityRequest {
                binding,
                operator_authority_id: "operator.test-anchor".to_owned(),
                conformance_authority_id: "conformance.test-anchor".to_owned(),
                operator_evidence: Self::evidence(b"operator-test-anchor", &binding_sha256),
                conformance_evidence: Self::evidence(b"conformance-test-anchor", &binding_sha256),
                fixture_only: false,
            }
        }
    }

    impl PromotionAuthorityVerifier for DeterministicTestVerifier {
        fn verify(
            &self,
            request: &PromotionAuthorityRequest,
        ) -> Result<AuthenticatedPromotionAuthority, PromotionAuthorityError> {
            let binding_sha256 = request.binding.binding_sha256()?;
            let operator = Self::evidence(b"operator-test-anchor", &binding_sha256);
            let conformance = Self::evidence(b"conformance-test-anchor", &binding_sha256);
            if request.operator_evidence != operator
                || request.conformance_evidence != conformance
                || request.operator_authority_id != "operator.test-anchor"
                || request.conformance_authority_id != "conformance.test-anchor"
            {
                return Err(PromotionAuthorityError::AuthenticationFailed);
            }
            AuthenticatedPromotionAuthority::from_verified(request)
        }
    }

    fn digest_ref(kind: &str, digit: char) -> String {
        format!("{kind}:sha256:{}", digit.to_string().repeat(64))
    }

    fn model(id: &str, observed: u64) -> NormalizedModelSpec {
        NormalizedModelSpec {
            provider_model_id: id.to_owned(),
            context_tokens: 32_768,
            modalities: vec!["text".to_owned()],
            tool_support: true,
            reasoning_modes: vec!["medium".to_owned()],
            pricing_provenance: "fixture".to_owned(),
            availability: "available".to_owned(),
            observed_at_epoch_seconds: observed,
        }
    }

    #[test]
    fn snapshot_is_versioned_hashed_and_expires_at_exact_boundaries() {
        let snapshot = CatalogSnapshot::accept(
            "snapshot.fixture.1",
            "openai",
            "catalog.1",
            CatalogSourceKind::OpenaiHarnessCatalog,
            digest_ref("receipt", '1'),
            100,
            vec![model("gpt-5.6-terra", 100)],
        )
        .expect("valid snapshot");
        assert!(valid_sha256(snapshot.content_sha256()));
        assert_eq!(
            snapshot.freshness(100 + STALE_WARNING_SECONDS - 1),
            CatalogFreshness::Fresh
        );
        assert_eq!(
            snapshot.freshness(100 + STALE_WARNING_SECONDS),
            CatalogFreshness::Warning
        );
        assert_eq!(
            snapshot.freshness(100 + SNAPSHOT_EXPIRY_SECONDS),
            CatalogFreshness::Expired
        );
        assert_eq!(snapshot.freshness(99), CatalogFreshness::InvalidClock);
    }

    #[test]
    fn new_models_are_ineligible_until_exact_qualification_and_approval() {
        let spec = model("gpt-5.6-luna", 10);
        let fingerprint = spec.fingerprint().expect("fingerprint");
        let snapshot = CatalogSnapshot::accept(
            "snapshot.fixture.2",
            "openai",
            "catalog.2",
            CatalogSourceKind::OpenaiHarnessCatalog,
            digest_ref("receipt", '2'),
            10,
            vec![spec],
        )
        .expect("snapshot");
        let discovered =
            ModelQualification::discovered("gpt-5.6-luna", fingerprint.clone(), "catalog.2")
                .expect("discovered");
        let policy_sha256 = "1".repeat(64);
        let conformance_sha256 = "2".repeat(64);
        let operator_receipt = digest_ref("approval", '3');
        let binding = EligibilityBinding {
            policy_version: "policy.1",
            policy_sha256: &policy_sha256,
            conformance_sha256: &conformance_sha256,
            operator_promotion_receipt: &operator_receipt,
        };
        assert!(!discovered.automatic_eligible(&snapshot, 10, &binding, true));
        let qualified = discovered
            .quarantine()
            .expect("quarantine")
            .begin_qualification()
            .expect("qualification")
            .qualify(QualificationEvidence {
                evidence_ref: digest_ref("evaluation", '4'),
                model_sha256: fingerprint,
                catalog_version: "catalog.2".to_owned(),
                catalog_sha256: snapshot.content_sha256().to_owned(),
                policy_version: "policy.1".to_owned(),
                policy_sha256: "1".repeat(64),
                conformance_sha256: "2".repeat(64),
                operator_promotion_receipt: digest_ref("approval", '3'),
                role_aliases: vec!["routine".to_owned()],
                fixture_only: false,
            })
            .expect("qualified");
        assert!(!qualified.automatic_eligible(&snapshot, 10, &binding, false));
        assert!(qualified.automatic_eligible(&snapshot, 10, &binding, true));
        let mut fixture_qualification = qualified.clone();
        fixture_qualification
            .evidence
            .as_mut()
            .expect("evidence")
            .fixture_only = true;
        assert!(!fixture_qualification.automatic_eligible(&snapshot, 10, &binding, true));
        assert!(!qualified.automatic_eligible(
            &snapshot,
            10 + SNAPSHOT_EXPIRY_SECONDS,
            &binding,
            true
        ));
    }

    #[test]
    fn namespaced_model_ids_remain_eligible_after_exact_qualification() {
        let spec = model("vendor/gpt-role", 10);
        let fingerprint = spec.fingerprint().expect("fingerprint");
        let snapshot = CatalogSnapshot::accept(
            "snapshot.fixture.namespaced",
            "openrouter",
            "catalog.namespaced",
            CatalogSourceKind::OpenrouterCatalog,
            digest_ref("receipt", '5'),
            10,
            vec![spec],
        )
        .expect("namespaced snapshot");
        let policy_sha256 = "6".repeat(64);
        let conformance_sha256 = "7".repeat(64);
        let operator_receipt = digest_ref("approval", '8');
        let qualification = ModelQualification::discovered(
            "vendor/gpt-role",
            fingerprint.clone(),
            "catalog.namespaced",
        )
        .expect("discovered namespaced model")
        .quarantine()
        .expect("quarantined")
        .begin_qualification()
        .expect("qualifying")
        .qualify(QualificationEvidence {
            evidence_ref: digest_ref("evaluation", '9'),
            model_sha256: fingerprint,
            catalog_version: "catalog.namespaced".to_owned(),
            catalog_sha256: snapshot.content_sha256().to_owned(),
            policy_version: "policy.namespaced".to_owned(),
            policy_sha256: policy_sha256.clone(),
            conformance_sha256: conformance_sha256.clone(),
            operator_promotion_receipt: operator_receipt.clone(),
            role_aliases: vec!["standard".to_owned()],
            fixture_only: false,
        })
        .expect("qualified namespaced model");
        let binding = EligibilityBinding {
            policy_version: "policy.namespaced",
            policy_sha256: &policy_sha256,
            conformance_sha256: &conformance_sha256,
            operator_promotion_receipt: &operator_receipt,
        };

        assert!(qualification.automatic_eligible(&snapshot, 10, &binding, true));
    }

    #[test]
    fn contradictory_and_invalid_transitions_fail_closed() {
        assert_eq!(
            CatalogSnapshot::accept(
                "snapshot.fixture.3",
                "openai",
                "catalog.3",
                CatalogSourceKind::OpenaiHarnessCatalog,
                digest_ref("receipt", '3'),
                10,
                vec![model("duplicate", 10), model("duplicate", 10)],
            ),
            Err(CatalogError::Contradictory)
        );
        let discovered = ModelQualification::discovered("gpt-5.6-sol", "0".repeat(64), "catalog.3")
            .expect("discovered");
        assert_eq!(
            discovered.clone().begin_qualification(),
            Err(CatalogError::InvalidTransition)
        );
        assert_eq!(discovered.retire(), Err(CatalogError::InvalidTransition));
    }

    #[test]
    fn deserialized_catalog_tampering_and_unhashed_receipts_fail_closed() {
        assert_eq!(
            CatalogSnapshot::accept(
                "snapshot.fixture.4",
                "openai",
                "catalog.4",
                CatalogSourceKind::OpenaiHarnessCatalog,
                "receipt:raw-path/unsafe",
                10,
                vec![model("gpt-5.6-terra", 10)],
            ),
            Err(CatalogError::Malformed)
        );
        let mut snapshot = CatalogSnapshot::accept(
            "snapshot.fixture.4",
            "openai",
            "catalog.4",
            CatalogSourceKind::OpenaiHarnessCatalog,
            digest_ref("receipt", '4'),
            10,
            vec![model("gpt-5.6-terra", 10)],
        )
        .expect("snapshot");
        snapshot.models[0].context_tokens = 1;
        assert_eq!(
            snapshot.validate_integrity(),
            Err(CatalogError::Contradictory)
        );
        assert_eq!(snapshot.freshness(10), CatalogFreshness::Expired);
    }

    #[test]
    fn scheduler_uses_six_hour_utc_buckets_jitter_and_startup_catchup() {
        let scheduler = RefreshScheduler::new(300).expect("schedule");
        assert_eq!(
            scheduler.directive(25, None),
            RefreshDirective::Due {
                bucket: 0,
                reason: RefreshReason::StartupCatchUp
            }
        );
        assert_eq!(
            scheduler.directive(REFRESH_BUCKET_SECONDS, Some(100)),
            RefreshDirective::Wait {
                until_epoch_seconds: REFRESH_BUCKET_SECONDS + 300
            }
        );
        assert_eq!(
            scheduler.directive(REFRESH_BUCKET_SECONDS + 300, Some(100)),
            RefreshDirective::Due {
                bucket: 1,
                reason: RefreshReason::UtcBucket
            }
        );
    }

    fn promotion_binding() -> PromotionMutationBinding {
        PromotionMutationBinding {
            schema_version: PROMOTION_AUTHORITY_SCHEMA_VERSION.to_owned(),
            promotion_id: "promotion.catalog.1".to_owned(),
            provider_id: "openai".to_owned(),
            phase_id: "openai_subscription".to_owned(),
            account_ref: "account:openai".to_owned(),
            catalog_ref: "catalog:v2:openai-subscription".to_owned(),
            provider_model_id: "gpt-5.6-terra".to_owned(),
            model_sha256: "1".repeat(64),
            catalog_version: "catalog.1".to_owned(),
            catalog_sha256: "2".repeat(64),
            policy_version: "policy.1".to_owned(),
            policy_sha256: "3".repeat(64),
            conformance_sha256: "4".repeat(64),
            configuration_authority_id: "config-authority.local".to_owned(),
            configuration_authority_sha256: "5".repeat(64),
            expected_state_generation: 9,
            state_preimage_sha256: "6".repeat(64),
            state_postimage_sha256: "7".repeat(64),
            rollback_snapshot_sha256: "6".repeat(64),
            authorization_nonce: "nonce.catalog.1".to_owned(),
            authorized_at_epoch_seconds: 100,
            rollback_not_after_epoch_seconds: 200,
        }
    }

    #[test]
    fn promotion_authority_binding_is_canonical_and_tamper_evident() {
        let binding = promotion_binding();
        let digest = binding.binding_sha256().expect("valid exact binding");
        assert!(valid_sha256(&digest));
        assert_eq!(
            digest,
            binding.binding_sha256().expect("deterministic digest")
        );

        let mut changed_generation = binding.clone();
        changed_generation.expected_state_generation += 1;
        assert_ne!(
            digest,
            changed_generation
                .binding_sha256()
                .expect("changed generation remains structurally valid")
        );
        let mut changed_postimage = binding.clone();
        changed_postimage.state_postimage_sha256 = "8".repeat(64);
        assert_ne!(
            digest,
            changed_postimage
                .binding_sha256()
                .expect("changed postimage remains structurally valid")
        );
    }

    #[test]
    fn promotion_authority_is_fail_closed_without_a_decided_trust_root() {
        let request = PromotionAuthorityRequest {
            binding: promotion_binding(),
            operator_authority_id: "operator.local".to_owned(),
            conformance_authority_id: "conformance.local".to_owned(),
            operator_evidence: b"opaque-operator-evidence".to_vec(),
            conformance_evidence: b"opaque-conformance-evidence".to_vec(),
            fixture_only: false,
        };
        assert_eq!(
            authenticate_promotion(&UnconfiguredPromotionAuthorityVerifier, &request),
            Err(PromotionAuthorityError::TrustRootDecisionUnavailable)
        );
    }

    #[test]
    fn deterministic_test_verifier_rejects_fixture_replay_and_binding_substitution() {
        let verifier = DeterministicTestVerifier;
        let mut request = verifier.request(promotion_binding());
        request.fixture_only = true;
        assert_eq!(
            authenticate_promotion(&verifier, &request),
            Err(PromotionAuthorityError::FixtureEvidenceForbidden)
        );

        request.fixture_only = false;
        let authenticated = authenticate_promotion(&verifier, &request)
            .expect("unit-only configured-anchor fixture authenticates exact binding");
        assert_eq!(
            authenticated.binding_sha256(),
            request.binding.binding_sha256().expect("binding digest")
        );

        let mut substituted = request;
        substituted.binding.state_preimage_sha256 = "9".repeat(64);
        substituted.binding.rollback_snapshot_sha256 = "9".repeat(64);
        assert_eq!(
            authenticate_promotion(&verifier, &substituted),
            Err(PromotionAuthorityError::AuthenticationFailed)
        );
    }
}