ic-backup 0.64.1

//! Common exact identity and explicit new-candidate checks for inventory settlements.

use crate::model::inventory_settlement::{IcInventoryAttribution, IcInventorySettlement};

use super::ic_observation::IcObservationResponseView;

use super::{
    settlement_identity::{SettlementIdentity, SettlementIdentityMismatch},
    snapshot_inventory_delta::{SnapshotInventoryDeltaError, compare_inventories},
};
use crate::model::{
    artifacts::ArtifactChecksumRecord,
    attempt_journal::ObservationOutcomeRecord,
    ic_snapshot_reply::{IcSnapshotInfo, IcSnapshotReply},
};

fn compare_identity(
    claimed: &IcInventorySettlement,
    operation: &SettlementIdentity<'_>,
    baseline: &ArtifactChecksumRecord,
    inventory: &ArtifactChecksumRecord,
    observation_evidence: &ArtifactChecksumRecord,
) -> Result<(), InventorySettlementMismatch> {
    SettlementIdentity::from(&claimed.context).compare(operation)?;
    if &claimed.baseline != baseline {
        return Err(InventorySettlementMismatch::Baseline);
    }
    if &claimed.inventory != inventory {
        return Err(InventorySettlementMismatch::Inventory);
    }
    if &claimed.context.observation_evidence != observation_evidence {
        return Err(InventorySettlementMismatch::ObservationEvidence);
    }
    Ok(())
}

/// Passive settlement claims differ from their independently qualified original evidence.
#[derive(Debug, thiserror::Error, Eq, PartialEq)]
pub enum InventorySettlementMismatch {
    /// Full original operation authority differs.
    #[error("inventory settlement authority differs")]
    Authority,
    /// Original mutation or observation attempt differs.
    #[error("inventory settlement attempts differ")]
    Attempt,
    /// Caller-owned qualification challenge differs.
    #[error("inventory settlement challenge differs")]
    Challenge,
    /// Exact retained baseline request and raw evidence differ.
    #[error("inventory settlement baseline differs")]
    Baseline,
    /// Exact current inventory request and raw evidence differ.
    #[error("inventory settlement inventory differs")]
    Inventory,
    /// Retained opaque observation evidence differs.
    #[error("inventory settlement observation evidence differs")]
    ObservationEvidence,
}

impl From<SettlementIdentityMismatch> for InventorySettlementMismatch {
    fn from(value: SettlementIdentityMismatch) -> Self {
        match value {
            SettlementIdentityMismatch::Authority => Self::Authority,
            SettlementIdentityMismatch::Attempt => Self::Attempt,
            SettlementIdentityMismatch::Challenge => Self::Challenge,
        }
    }
}

pub(crate) fn validate_pair<'a, E>(
    target: &str,
    baseline: &IcSnapshotReply<'_>,
    inventory: &'a IcSnapshotReply<'_>,
    claimed: &IcInventorySettlement,
    operation: &SettlementIdentity<'_>,
    observation_evidence: &ArtifactChecksumRecord,
) -> Result<Vec<&'a IcSnapshotInfo>, E>
where
    E: From<SnapshotInventoryDeltaError> + From<InventorySettlementMismatch>,
{
    let candidates = compare_inventories(target, baseline, inventory)?;
    compare_identity(
        claimed,
        operation,
        &baseline.digest(),
        &inventory.digest(),
        observation_evidence,
    )?;
    Ok(candidates)
}

// Retain only the selected index; the borrowed attribution owns the outcome.
pub(crate) fn admitted_snapshot_index(
    inventory: &IcSnapshotReply<'_>,
    candidates: &[&IcSnapshotInfo],
    attribution: &IcInventoryAttribution,
) -> Result<Option<usize>, ()> {
    match attribution {
        IcInventoryAttribution::Applied { snapshot_id, .. } => {
            new_candidate_index(inventory, candidates, snapshot_id)
                .map(Some)
                .ok_or(())
        }
        IcInventoryAttribution::NotApplied { .. } | IcInventoryAttribution::Unresolved { .. } => {
            Ok(None)
        }
    }
}

pub(crate) fn new_candidate_index(
    inventory: &IcSnapshotReply<'_>,
    candidates: &[&IcSnapshotInfo],
    snapshot_id: &[u8],
) -> Option<usize> {
    if !candidates
        .iter()
        .any(|snapshot| snapshot.id() == snapshot_id)
    {
        return None;
    }
    inventory
        .snapshots()
        .binary_search_by(|snapshot| snapshot.id().cmp(snapshot_id))
        .ok()
}

/// Matched passive inventory claim and exact inventories; never an authenticated receipt.
#[derive(Debug)]
pub struct IcInventorySettlementView<'a> {
    pub(crate) observation: IcObservationResponseView<'a>,
    pub(crate) baseline: &'a IcSnapshotReply<'a>,
    pub(crate) settlement: &'a IcInventorySettlement,
    pub(crate) snapshot_index: Option<usize>,
}
impl<'a> IcInventorySettlementView<'a> {
    /// Read the independent claim; integration qualification precedes explicit recording.
    #[must_use]
    pub const fn outcome(&self) -> ObservationOutcomeRecord {
        match &self.settlement.attribution {
            IcInventoryAttribution::Applied { .. } => ObservationOutcomeRecord::Applied,
            IcInventoryAttribution::NotApplied { .. } => ObservationOutcomeRecord::NotApplied,
            IcInventoryAttribution::Unresolved { .. } => ObservationOutcomeRecord::Uncertain,
        }
    }
    /// Read the original independently retained full baseline.
    #[must_use]
    pub const fn baseline(&self) -> &'a IcSnapshotReply<'a> {
        self.baseline
    }
    /// Read the exact current reserved list association.
    #[must_use]
    pub const fn observation(&self) -> &IcObservationResponseView<'a> {
        &self.observation
    }
    /// Read the complete retained integration claims.
    #[must_use]
    pub const fn settlement(&self) -> &'a IcInventorySettlement {
        self.settlement
    }
    /// Read only the explicitly attributed new descriptor, without singleton inference.
    #[must_use]
    pub fn snapshot(&self) -> Option<&IcSnapshotInfo> {
        self.observation.inventory_snapshot(self.snapshot_index?)
    }
}

#[cfg(test)]
mod tests;